ARTICLE | doi:10.20944/preprints202211.0308.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Xenobiotic; Drug; Oral fibro epithelial polyps; Rothia mucilaginosa; Bacteriome
Online: 16 November 2022 (12:45:26 CET)
The proportion of human cells to the microbial cell is 1:1. These procaryotes use efflux pumps and enzymes to prevent cellular intoxication of ions and compounds respectively. There is promising evidence on the role of the gut microbiome and its enzymes in metabolizing xenobiotics. The genetic potential of oral bacteria in drug and xenobiotic metabolism is yet to be unveiled. This study aimed to characterize the bacteriome associated with oral fibroepithelial polyps (FEP) and to predict the genetic potential. A representative sub-sample of 22 clinically diagnosed oral FEP (the control group) was selected from a main case-control study. Amplification of nucleotides of extracted DNA from frozen tissues was performed for the V1 to V3 region and sequencing of the amplicon with Illumina’s 2 X 300–bp chemistry. Classification of high-quality nonchimeric merged reads was done to the species level with a prioritized BLASTN-based algorithm. Downstream compositional analysis was performed with QIIME (Quantitative Insights into Microbial Ecology). Functional prediction of bacteriome was obtained by PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States). Rothia mucilaginosa, Streptococcus mitis, Gamella haemolysans, Streptococcus sp. oral taxon 431, and Rothia dentocariosa accounted for the top five taxa among 810 bacterial species according to the percentage of average relative abundance. Rothia mucilaginosa was elevated statistically significantly (p< 0.05). The genetic potential of xenobiotics and drug metabolism catalyzed by the P450 enzymes was observed for the first time as an attribute of bacteriome associated with oral FEP tissues dominated by R. mucilaginosa. This finding needs further investigation.
ARTICLE | doi:10.20944/preprints202211.0141.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Regenerative dentistry; 3D printing; biomimetic; bioinspired materials; MSC; cell colonization; Tissue engineering; Regenerative medicine; Oral Bone; Tissue Regeneration; biocolonization; CDHA, MTT; LDH; SEM; FDM
Online: 8 November 2022 (03:03:17 CET)
This paper presents a proof-of-concept study on the biocolonization of 3D-printed hydroxyapatite scaffolds with mesenchymal stem cells (MSCs). Three-dimensional (3D) printed biomimetic bone structure made of Calcium Deficient HydroxyApatite (CDHA) intended as future bone graft was made from newly developed composite material for FDM printing. The biopolymer polyvinyl alcohol serves in this material as a thermoplastic binder for 3D molding of the printed object with a passive function and is completely removed during sintering. The study presents the material, the process of fused deposition modeling (FDM) of CDHA scaffolds and its post-processing at three temperatures (1200, 1300, 1400 °C), as well it evaluates the cytotoxicity and biocompatibility of scaffolds with MTT and LDH release assays after 14 days. The study also includes a morphological evaluation of the cellular colonization with scanning electron microscopy (SEM) in two different filament orientations (rectilinear and gyroid). The results of the MTT assay showed that the tested material was not toxic, and cells were preserved in both orientations, with most cells present on the material fired at 1300°C. Results of the LDH release assay showed a slight increase in LDH leakage from all samples. Visual evaluation of SEM confirmed the ideal post-processing temperature of the 3D-printed FDM framework for samples fired at 1300°C and 1400°C, with a porosity of 0.3 mm between filaments. In conclusion, the presented fabrication and colonization of CDHA scaffolds have great potential to be used in the tissue engineering of bones.
ARTICLE | doi:10.20944/preprints202210.0311.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Animal study; beagle dog; β-tricalcium phosphate (TCP); immunohistochemistry; micro computed tomography (CT); periodontal tissue engineering; periostin; recombinant human collagen peptide (RCP); scaffold material; 3-wall intrabony defect
Online: 20 October 2022 (12:24:49 CEST)
Recombinant human collagen peptide (RCP) is a recombinantly created xeno-free biomaterial enriched in RGD (arginine-glycine-aspartic acid) sequences, with good processability that is being investigated for regenerative medicine applications. Recently, the biocompatibility and osteogenic ability of β-TCP/RCP (RCP granules combined with β-tricalcium phosphate (TCP) submicron particles) were demonstrated. In the present study, β-TCP/RCP was implanted into experimental periodontal tissue defects (three-walled bone defect) created in beagle dogs to investigate tissue responses and subsequent regenerative effects. Micro computed tomography image analysis at 8 weeks postoperatively showed that the amount of new bone after β-TCP/RCP graft was significantly greater (2.2 fold, P<0.05) than that of the control (no graft) group. Histological findings showed that the transplanted β-TCP/RCP induced active bone-like tissue formation including TRAP-positive and OCN-positive cells as well as bioabsorbability. Ankylosis did not occur, and periostin-positive periodontal ligament-like tissue formation was observed. Histological measurements revealed that β-TCP/RCP implantation formed 1.7-fold more bone-like tissue and 2.1-fold more periodontal ligament-like tissue than the control, and significantly suppressed gingival recession and epithelial downgrowth (P<0.05). These results suggest that β-TCP/RCP is effective as a periodontal tissue regenerative material.
ARTICLE | doi:10.20944/preprints202210.0166.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: antibacterial photodynamic therapy; Oral hygiene; Periodontitis
Online: 12 October 2022 (08:59:58 CEST)
A single-site, randomized clinical trial was designed to determine the efficacy of regular home use of Lumoral® dual-light antibacterial aPDT in periodontitis patients. For the study, 200 patients are randomized to receive non-surgical periodontal treatment (NSPT), including standardized hygiene instructions and electric toothbrush, and scaling and root planing, or NSPT with adjunctive Lumoral® treatment. A complete clinical intraoral examination is conducted in the beginning, at three months, and at six months. This report presents the three-month results of the first 59 consecutive randomized subjects. At three months, bleeding on probing (BoP) was lower in the NSPT+Lumoral®-group than in the NSPT group (p=0.045), and more patients in the NSPT+Lumoral®-group had their BoP below 10% (52% vs. 29%, respectively, p=0.008). Patients in the NSPT+Lumoral®-group improved their oral hygiene by visible-plaque-index (p=0.0002), while the NSPT group showed no statistical improvement as compared to baseline. Both groups significantly reduced the number of deep periodontal pockets, but more patients with a reduction in their deep pocket number were found in the NSPT+Lumoral® group (92% vs. 63%, p=0.01). Patients whose number of deep pockets was reduced by 50% or more were also more frequent in the NSPT+Lumoral®-group (70% vs. 33%, p=0.01). Patients with initially less than ten deep pockets had fewer deep pockets at three-month follow-up in the Lumoral® group (p=0.02). In conclusion, adjunctive use of Lumoral® in NSPT results in improved treatment outcomes at three months post-therapy.
ARTICLE | doi:10.20944/preprints202210.0136.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Rural dental care; Preventive visits; Rural Vs Urban; community health centers; Hispanic Vs Non-Hispanics
Online: 11 October 2022 (04:07:45 CEST)
Abstract: Background: To determine the impact of a patient's ethnicity on the seeking preventive dental services at the Community Health Centers (CHCs) in South-Central Texas. Methods: Pri-mary electronic health records (HER) data were collected regarding each patient's medical and dental history, and comprehensive treatment planning. The researchers retrieved EHR from Jan-uary 2016 to 2022. Bivariate analysis was completed to test outcome with predicator and covariates using appropriate statistical tests. A multiple linear regression model was used to understand the association between the predictor and outcome variable while controlling for confounders. Results: The study findings revealed significantly higher dental visits (2.26 ± 2.88) for Hispanic patients. The results from the multiple regression model indicated that non-Hispanic patients had a 8% fewer chance of visiting the CHCs for preventive dental services compared to the Hispanic population (p-value<0.001) when all other variables are held constant. However, the study results were not significant as the effect size was small to conclude the effect of ethnicity on the patients visiting the dental clinic at the CHCs for preventive services. Conclusion: The study concluded that there is no difference in the preventive dental services completed by Hispanics and Non-Hispanics when all other variables are controlled.
BRIEF REPORT | doi:10.20944/preprints202209.0409.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: chlorhexidine; bioactive liquid; oral wound healing; pain index score; early wound healing score
Online: 27 September 2022 (03:37:27 CEST)
After surgery, oral cavity healing occurs in a hostile environment and requires proper oral care and hygiene to accelerate recovery. The aim of the current study is to investigate and compare the bioreactivity characteristics of chlorhexidine based (CHX) mouth rinse and a novel bone bioactive liquid (BBL) mouth rinse on oral healing within seven days application post-surgery. A randomized, double blind clinical trial conducted in 81 patients. The mouth rinses were applied twice a day for a period of 7 days. The visual analog scale (VAS) protocol was applied to measure pain index. Early wound healing score (EHI) was determined in evaluate the oral cavity healing progress. No adverse effects were observed using the mouth washes, but CHX resulted in teeth staining. CHX and BBL were sufficient to reduce pain over a period of 7 days. However, the BBL group demonstrated a statistically significant reduction in VAS stating day 4. Relative to CHX group, the EHI scores were significantly higher in the BBL group, independent from the tooth location. No gender differences were observed in both VAS and EHI scores. Relative to the commercially available CHX, BBL mouth rinse reduced pain and accelerated oral cavity healing. Suggesting an improvements of oral cavity microenvironment at the wound site that mediates soft tissue regeneration.
ARTICLE | doi:10.20944/preprints202209.0220.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: TrueDepth; CBCT; Orthodontics; Face scan; Smartphone; Facial diagnostics; Smartphone-based sensors; Facially driven orthodontics
Online: 15 September 2022 (05:45:29 CEST)
The current paradigm shift in orthodontic treatment planning is based on facially driven diagnostics. This requires an affordable, convenient, and non-invasive solution for face scanning. Therefore, utilization of smartphones` TrueDepth sensors is very tempting. TrueDepth refers to front-facing cameras with a dot projector in Apple devices that provide real-time depth data in addition to visual information. There are several applications that tout themselves as accurate solutions for 3D scanning of the face in dentistry. Their clinical accuracy has been uncertain. This study focuses on evaluating the accuracy of the Bellus3D Dental Pro app, which uses Apple's TrueDepth sensor. The app reconstructs a virtual, high-resolution version of the face, which is available for download as a 3D object. In this paper, sixty TrueDepth scans of the face were compared to sixty corresponding facial surfaces segmented from CBCT. Difference maps were created for each pair and evaluated in specific facial regions. The results confirmed statistically significant differences in some facial regions in amplitudes greater than 3 mm, suggesting that current technology has limited applicability for clinical use. The clinical utilization of facial scanning for orthodontic evaluation, which does not require accuracy in the lip region below 3 mm, can be considered.
ARTICLE | doi:10.20944/preprints202207.0454.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: orthodontics; airway; clear aligners; 3D diagnostics; sleep apnea; CBCT
Online: 29 July 2022 (09:37:56 CEST)
This retrospective study evaluated changes in the pharyngeal portion of the upper airway in pa-tients with constricted and normal airway treated with clear aligners (Invisalign, Align). Additionally, the paper has assessed the change of tongue position in the oral cavity from lateral view. Evaluation was performed with specialized software (Invivo 6.0, Anatomage) on pre-treatment and posttreatment pairs of cone beam computed tomography imaging (CBCT) data. The level of airway constriction, volume, cross-section minimal area, and tongue profile were evaluated. Patients with malocclusion, with pair or initial and finishing CBCT and without sig-nificant weight change between the scans, treated with Invisalign clear aligners were distributed in two groups. Group A consisted of fifty-five patients with orthodontic malocclusion and con-stricted upper airway. Control group B consisted of thirty-one patients with orthodontic malocclusions without any airway constriction. In the group with airway constriction, there was a statistically significant increase in volume during therapy (p<0.001). The surface of the most con-stricted cross-section of airway did not change significantly after treatment in any of the groups. The airway constriction was most frequently localized at the level of 2nd cervical vertebra. The final tongue position was different from initial in 62.2% of all clear aligner treatments.
CASE REPORT | doi:10.20944/preprints202207.0240.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: periodontitis; periodontal disease; necrotizing periodontitis; periodontal treatment; multiple sclerosis; relapsing-remitting multiple sclerosis
Online: 18 July 2022 (02:52:21 CEST)
Multiple sclerosis (MS) and necrotizing periodontitis (NP) are two diseases whose aetiology and pathophysiology do not seem to have a common link; however, the treatment of MS with monoclonal antibodies and the decrease in humoral immunity that this entails can be a trigger or an aggravation in patients who present NP. We present a clinical case of NP in which its clinical manifestations, treatment and evolution during therapy with ocrelizumab are reflected. During the evolution of the case, a rapid progression of NP was evidenced. During her evolution, the patient suffered bilateral pneumonia due to COVID requiring treatment with corticosteroids and antibiotics, which led to clinical relief of her NP. Given this important clinical finding, we consider of great interest the regulated dental monitoring of those patients with MS before, during and after the administration of monoclonal antibodies to prevent periodontal deterioration.
ARTICLE | doi:10.20944/preprints202206.0239.v1
Online: 16 June 2022 (10:54:10 CEST)
Objective: The purpose of the present study was to analyze the management of dental extractions in patients affected by coagulation disorders in order to prevent bleeding intraoperative and postoperative complications. Subjects and Methods: This study included 17 patients with a diagnosis of a coagulation disorder, who had been subjected to a single or multiple dental extraction. Recombinant activated Factor VII was administered in those patients who were affected by a deficit of factor VII ranged between 10,5% and 21%. The other patients were treated locally with tranexamic acid. Results: A total of 50 teeth were extracted, 7 by surgical extraction and 43 by simple extraction. Of the 17 patients included 9 of them suffering from factor VII deficiency, 5 from factor V deficiency, 1 from Glanzmann's thrombasthenia and 2 from Haemophilia A. Pretreatment with recombinant activated factor VII was performed on a total of 8 patients with factor VII deficiency; the remaining 9 patients underwent tranexamic acid treatment. 1 hemorragic postoperative complication was observed. Conclusions: Surgical and no surgical extractions appear to be a safe procedure for patients affected by coagulation disorders when appropriate prophylaxis is adopted.
CASE REPORT | doi:10.20944/preprints202206.0220.v1
Online: 15 June 2022 (09:56:44 CEST)
Periapical diseases are a frequent evolution of pulp necrosis. They appear without any painful episode. The incidence splits between 6% and 55%. Initially we can treat inflammatory periapical injury by conservative approach and studies reported 85% of success rate after endodontic disin-fection. Several techniques can be described in the nonsurgical management of peri-radicular le-sions: the root canal treatment, decompression procedure, decompression technique, calcium hydroxide, Apexum procedure. Unfortunately, periapical lesion recuperating is an unpredictable procedure. In some cases surgical approach is preffered to manage large periradicular wound including periapical cysts and abscess. periodic examination is primordial to evaluate efficacy of the therapy. In this report we describe an inflammatory radicular cyst of the anterior maxilla with which was successfully treated by conventional root canal retreatment and endodontic surgery
ARTICLE | doi:10.20944/preprints202206.0142.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Botulinum toxin type A; Myofascial pain; Temporomandibular disorders
Online: 9 June 2022 (10:59:51 CEST)
To demonstrate if botulinum toxin type A (BoNT-A) improves mandibular range of motion and muscle sensibility to palpation in refractory myofascial pain (MFP) patients. METHODS: Eighty consecutive female subjects with refractory MFP, were randomly divided into four equal groups (n=20): BoNT-A low (BoNTA-L/10 U in each temporalis and 30 U in each masseter), BoNT-A medium (BoNTA-M/20 U in each temporalis and 50 U in each masseter), BoNT-A high (BoNTA-H/25 U in each temporalis and 75 U in each masseter) and saline solution 0.9% (SS, placebo control group/0.4 mL in each temporalis and 0.6 mL in each masseter). Clinical measurements of the mandibular movements included: pain-free opening, maximum unassisted and assisted opening, and right and left lateral movements. Palpation tests were performed bilaterally in masseter and temporalis muscle. Results were expressed as median, minimum, maximum, and means ± standard deviation (SD). Chi-Square Test was used to compare differences among groups. A 5% probability level was considered significant in all tests RESULTS: Regardless of dose, all parameters of mandibular range of motion significantly improve after 180 days in BoNT- A groups, when compared to the control group. Pain to palpation on muscles, significantly reduced in all BoNT- A groups regardless of dose, when compared to the control group, after 28 and 180 days of treatment. CONCLUSIONS: Independent of doses, BoNT-A improved mandibular range of motion and muscle sensibility to palpation in refractory MFP patients when compared to SS injections.
ARTICLE | doi:10.20944/preprints202206.0140.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Undergraduate; Medical; Online; Distance Education; Perception
Online: 9 June 2022 (10:53:43 CEST)
In 2020, students of Pakistan had to adapt to the online environment for the very first time. This study aims to analyze the perceptions of medical, dental, and allied health students about online education in Pakistan. A descriptive, cross-sectional study was done to assess the level of acceptance of undergraduate students. A pre-validated questionnaire regarding demographics, past-experience of e-learning, advantages disadvantages of e-learning, and general perception of students towards e-learning was distributed. Descriptive statistics were computed for demographics, Mann-Witney-U test was used to compare the differences of perceptions between pre-clinical year and clinical years students. Kruskal-Wallis test was applied to compare the results of three specialties of students. Chi-square was used to compare overall category-wise positive and negative responses of students. 1200 students participated in the study. The major advantage identified by all students was the ‘comfortable environment’ in which they studied online. The major disadvantage selected by preclinical year students was ‘anxiety due to social isolation’ and that chosen by clinical year students was ‘lack of patient interaction’. Overall, 72% of students had a negative perception of e-learning. Student-teacher training, student counselling sessions, and innovative techniques need to be introduced to enhance student engagement and reduce pandemic stress.
ARTICLE | doi:10.20944/preprints202206.0107.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Access to Dental Care; COVID-19; Dental Public Health
Online: 7 June 2022 (11:22:41 CEST)
Background: The COVID-19 pandemic has changed the way dentistry has been practiced world over , this study sought to assess the impact of the COVID-19 pandemic on the patterns of attendance for dental treatment in a large hospital in Kuwait compare them to data from the year prior to the pandemic Methods: A total of 176,690 appointment records of 34,250 patients presenting to the AlJahra specialist hospital, Kuwait for dental treatment from April 2019 to March 2021 were analyzed. Types of procedures and the departments to which they presented were analyzed and the patterns of attendance before and during the pandemic were compared; Results: While there was a significant reduction in the number of orthodontic, endodontic and periodontal procedures there was no impact on oral surgery, restorative procedures or pediatric dentistry; Conclusions: There has been a return in the numbers of patients availing dental treatment, however, there has been a definite shift in the use of certain dental procedures .
ARTICLE | doi:10.20944/preprints202204.0181.v2
Subject: Medicine & Pharmacology, Dentistry Keywords: Scoring; Rubrics; Health; Personnel; Program Evaluation; Distance Education; Residency Education; Speciality
Online: 31 May 2022 (14:06:26 CEST)
Introduction: In the medical area, teaching is essential since it must offer the appropriate instruments to demonstrate that graduates have acquired the necessary skills. Objective: Evaluate the quality of research in residents of medical specialties after a standardized digital training program with rubrics. Methods: An observational, prospective research study in resident physicians of seven medical specialties first-year of an introductory program to methodology. It is integrated with the result variable through the quality of the final product and the quality variable will be measured with an ad hoc questionnaire validated by the Delphi method with a consistency level of 3-3. The data will be integrated into a base of the SPSS system and determined with the Chi-square test considering a minimum significance of 0.05. Results: 85 first-year medical residents (n=85) enrolled in the Research Seminar. The mean age was 31.34 years (± 3.96). About gender Male 38±31.13 Female 31.51±3.83. The global final grade was 80.61 (± 9.59) and the global sat-isfaction of the course was referred to as good by 62.2%. We observed a positive relationship between the scope of evaluation and the level of satisfaction. Conclusion: The research seminar implementation in a b-learning mode in response to the educational needs in medical residents for the field of health education showed a relationship between higher qualification, higher satisfaction, as well as determining that the comprehensive evaluation through the use of rubrics standardized allowed to delimit the deficiencies and strengths for timely feedback influencing the process of acquiring skills and the quality of the final product.
ARTICLE | doi:10.20944/preprints202205.0286.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: bioglass; ion release; hydroxyapatite deposition; bone tissue regeneration; macrophages; vascularization; copper doping; strontium doping; 45S5; ICIE16
Online: 23 May 2022 (05:24:12 CEST)
Bioglasses are highly adoptable bone substitute materials, which can be combined with so-called therapeutic ions. These ions have shown to influence underlying molecular processes of the bone regeneration cascade. Moreover, it is known that bone substitutes induce an immune reaction within their implantation area involving macrophages and their pro- and anti-inflammatory subtypes dependent on their chemical composition. However, only poor knowledge exists regarding the influence of therapeutic ions onto the immune reactions and the associated bone healing. Thus, the aim of this work was to investigate the influence of strontium- and copper-doped bioglasses on the induction of M1- and M2-macrophages as well as the implant bed vascularization. (2) Methods: For this study, two alkali glasses were produced on basis of ICIE-16 bioglass via the melt-quench route with the addition of 5 wt% copper or strontium (ICIE16-Cu and ICIE16-Sr). Pure ICIE16 and 45S5 bioglasses were used as control materials. The bioactivity (ion release), chemical composition and the surface pattern were investigated, as well as an in vivo experiment was performed using the subcutaneous implantation model in rats. (3) Results: SEM imaging showed different formations of hydroxyapatite on the surfaces of the bioglass systems after submersion in simulated body fluid. EDX analysis confirmed the doping process by showing the release kinetics. Copper-doped bioglass exhibited a higher ion release than strontium-doped bioglass. Copper induced both a low immune cell migration and triggered a low number of M1- and M2-macrophages but also of blood vessels. The strontium-containing bioactive glass induced higher numbers of M1-macrophages after 30 days. Both copper- and strontium-doped bioglasses induced comparable numbers of M2-macrophages as found in the control groups. (4) Conclusions: Bioglass doping with copper and strontium did not exhibit significant influence on the foreign body response or the implantation bed vascularization in vivo. However, the prepared bioglass systems seemed to be biocompatible.
ARTICLE | doi:10.20944/preprints202205.0241.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: carbon-footprint; dentistry; environment; management; sustainability
Online: 18 May 2022 (10:43:57 CEST)
Background There is increasing awareness of problems associated with global warming but a lack of a systematic approach on how to deliver more environmentally sustainable dental care. A sustainable world aims to ensure that basic needs and quality of life of everyone are met, now and for future generations. The carbon footprint is an indicator of environmental sustainability. Aim The aim is to suggest an environmental management change for the dental practice focusing on the objective of carbon footprint reduction. Environmental management change design The management change is based on the concept of “Plan-Do-Check-Act”, as recommended by the International Organisation for Standardisation (ISO) and described through the environmental aspects of the dental practice. The approach focuses on establishing and implementing environmental objectives, followed by monitoring results and taking actions to improve continually. The environmental aspects considered for the dental practice are activities causing an impact on the carbon footprint: energy use, travel, product purchasing, waste production, emission to air, water use, and contamination of land. Conclusions The “Plan-Do-Check-Act” ISO 14100-2015 model can be effectively integrated into the dental practice setting for its environmental management. A reduction of the carbon footprint of the dental practice is achieved by applying the environmental management change described for each activity.
ARTICLE | doi:10.20944/preprints202205.0078.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: furcation anatomy; furcation measurement; furcation evaluation
Online: 6 May 2022 (13:50:48 CEST)
Objectives: Few studies in literature evaluate the "mean measure" of root divergence. Most of them are linear measurements, they hardly describe the dental furcation conformation. It is left to the subjectivity of the operator deciding whether a furcation is convergent or divergent. The goal of this study is to create a visual evaluation method to overcome these problems giving a conformation of the entire interradicular space. Material and methods: A user-friendly software (Paint®, Windows10®) was used to measure endo-oral radiographs of upper and lower molars. Three kinds of measurements were taken. Three operators used the software to measure 20 radiographs, then the technique was repeated on 250 radiographic images to identify an average measurement. The ratio of these three measurements allowed to develop a new visual evaluation method of the interradicular space. Results: Intra and inter-operator reproducibility was statistically assessed on a sample of 20 anonymous endo-oral radiographs measured by 3 blind operators. Then, a sample of 250 anonymous endo-oral radiographs were measured by a blind operator and were statistically evaluated to identify an average value to define a main conformation of the interradicular space. Measurements made by the 3 operators on the 20 radiographic images showed that the technique is reproducible, and a mean value of the interradicular space was obtained. Conclusions: A new anatomical evaluation of the interradicular space in its entirety, which could help the clinicians in the therapy of furcated molars, can be obtained.
ARTICLE | doi:10.20944/preprints202204.0146.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Essential medicines; affordability; NCD prevention; oral healthcare; access
Online: 15 April 2022 (10:46:26 CEST)
Background: Fluoride toothpaste (FT) has recently been included in the World Health Organization’s (WHO) Model List of Essential Medicines. Whereas it is essential for preventing dental caries, its current affordability around the globe remains unclear. This study aimed to analyse the affordability of FT in as many as possible countries worldwide. Methods: A standardized protocol was developed to collect country-specific information about the characteristics of the cheapest FT at a common point of purchase. 82 members of the WHO Global Oral Health Network of Chief Dental Officers (CDOs), directors of WHO Collaborative Centres and other oral health experts collected data using mobile phone technology. The Fluoride Toothpaste Affordability Ratio (FTAR) was calculated as the price associated with the recommended annual consumption of FT, relative to the daily wage of the lowest-paid unskilled government worker (FTAR >1 = unaffordable spending on fluoride toothpaste). The daily expenditure per capita of the poorest 15% of the income distrubition was used as the main proxy of the daily wage, using World Bank data. Alternatively, we used the daily minimum wage as a proxy of the daily wage. Stratified descriptive statistics were undertaken with respect to different World Bank Income Groups and WHO Regions. Results: There are significant discrepancies in the affordability of FT across 78 countries. FT was strongly affordable in high-income countries, relatively affordable in upper middle-income countries, and strongly unaffordable in lower middle-income and low-income countries. The affordability of FT across WHO Regions was dependent upon the economic mix of WHO Regions’ member states. Conclusion: FT is still unaffordable for many people, particularly in low-resource settings. Health policy members should develop better strategies to address and improve the universal affordability of FTs, for the incidence of dental caries to be reduced at a global level.
ARTICLE | doi:10.20944/preprints202108.0413.v3
Subject: Medicine & Pharmacology, Dentistry Keywords: Dental Age Measurement; Dental Radiography; Orthopantomogram; Convolutional Neural Network; K-Nearest Neighbour; Health Data Analytics; Biomedical Machine Learning
Online: 12 April 2022 (10:12:48 CEST)
Age estimation in dental radiographs Orthopantomography (OPG) is a medical imaging technique that physicians and pathologists utilise for disease identification and legal matters. For example, for estimating post-mortem interval, detecting child abuse, drug trafficking, and identifying an unknown body. Recent development in automated image processing models improved the age estimation's limited precision to an approximate range of +/- one year. While this estimation is often accepted as accurate measurement, age estimation should be as precise as possible in most serious matters, such as homicide. Current age estimation techniques are highly dependent on manual and time-consuming image processing. Age estimation is often a time-sensitive matter in which the image processing time is vital. Recent development in Machine learning-based data processing methods has decreased the imaging time processing; however, the accuracy of these techniques remains to be further improved. We proposed an ensemble method of image classifiers and transfer learning techniques to enhance the accuracy of age estimation using OPGs from one year to a couple of months (1-3-6). This hybrid model is based on convolutional neural networks (CNN) and K nearest neighbours (KNN). The hybrid (HCNN-KNN) model was used to investigate 1,922 panoramic dental radiographs of patients aged 15 to 23. These OPGs were obtained from the various teaching institutes and private dental clinics in Malaysia. To minimise the chance of overfitting in our model, we used the principal component analysis (PCA) algorithm and eliminated the features with high correlation. To further enhance the performance of our hybrid model, we performed systematic image pre-processing. We applied a series of classifications to train our model. We have successfully demonstrated that combining these innovative approaches has improved the classification and segmentation and thus the age-estimation outcome of the model. Our findings suggest that our innovative model, for the first time, to the best of our knowledge, successfully estimated the age in classified studies of one year old, six months, three months and one-month-old cases with accuracies of 99.98, 99.96, 99.87, and 98.78 respectively.
ARTICLE | doi:10.20944/preprints202201.0315.v2
Subject: Medicine & Pharmacology, Dentistry Keywords: SARS-CoV-2; Omicron; biosafety protocol; dentistry; orthodontics; sustainability
Online: 8 April 2022 (03:58:00 CEST)
With arrival of highly transmissible Omicron variants in global pandemic, dentistry is facing another challenge to preserve biosafety of dental care. With a mission to protect both patients and healthcare workers, adaptability to the changing epidemiologic situation is required from dental professionals. This work presents a prospective sustainable biosafety setting for routine orthodontic care. The protocol is composed from combination of available technologies focused on the air-borne part of a virus pathway. Introduced biosafety protocol has been clinically evaluated after 18 months of application in the real clinical environment. The protocol has three fundamental pillars: (1) UVC air disinfection; (2) air saturation with certified virucidal oils through nebulizing diffusers; (3) complementary solutions. As a method of evaluation pseudonymous on-line smart form was used. Protocol operates with premise that everybody as a hypothetical asymptomatic carrier. Results from 115 patient feedbacks imply that with this protocol in place, there was no observed or reported translation of virus from patient to another patient or from patient to doctor or nurse and vice versa, albeit nine patients have retrospectively admitted visiting the clinic as probably infectious. Despite promising results, a larger clinical sample and exposition to current mutated strains is necessary for reliable conclusions about protocol virucidal efficiency.
ARTICLE | doi:10.20944/preprints202203.0408.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Type 2 Diabetes; Osteoporosis; Bisphosphonate; MRONJ; Osteoclast
Online: 31 March 2022 (13:44:57 CEST)
Osteoporosis is a common metabolic bone disease in patients with diabetes, which can develop simultane-ously with Type 2 diabetes (T2D) in postmenopausal women. Bisphosphonate (BP) is administered to pa-tients with both the conditions and may cause medication-related osteonecrosis of the jaws (MRONJ). It affects the differentiation and function of osteoclasts as well as thickness of cortical bone through bone mineralization. Therefore, this study aimed to investigate the effects of T2D on osteoclast differentiation and activity as well as cortical bone formation in postmenopausal patients with MRONJ. Tissue samples were collected from 10 patients diagnosed with T2D and Stage III MRONJ in the experimental group and from 10 patients without T2D in the control group. Histological examination was conducted, and expres-sion of dendritic cell-specific transmembrane protein (DC-STAMP) and tartrate resistant acid phosphatase (TRAP) was assessed. Cortical bone formation was analyzed using CBCT images. The number of TRAP-positive osteoclasts and DC-STAMP-positive mononuclear cells were significantly less in the experi-mental group (p < 0.05). Furthermore, the thickness and ratio of cortical bone were significantly greater in the experimental group (p < 0.05). In conclusion, T2D decreased the differentiation and function of osteo-clasts, and increased cortical bone formation in postmenopausal patients with MRONJ.
ARTICLE | doi:10.20944/preprints202203.0317.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: posterior edentulous maxilla; maxillary sinus; sinus floor elevation; tilted implants
Online: 23 March 2022 (12:49:55 CET)
The aim of this study was to evaluate implants survival rate, marginal bone loss, surgical and prosthetic complications of implants placed through sinus floor elevation and tilted implants en-gaged in basal bone in order to bypass maxillary sinus. 60 patients were enrolled for this study. According with residual bone height of posterior maxilla the sample was divided in three groups of 20 patients: Group A (lateral sinus floor elevation), Group B (transrectal sinus floor elevation) and Group C (tilted implants employed to bypass sinus floor). Follow-up visits were performed one week after surgery, at 3, 6 months and then once a year for next 4 years. The outcomes were implants survival rate, marginal bone loss and surgical and prosthetic complications. Although the Group A, B and C have demonstrated an implants survival rate of 83.3%, 86,7% and 98,3% respectively, the statistically analysis showed that there was no statistically significant difference between groups. Statistically significant differences between the groups were also not found con-cerning marginal bone loss, as recorded by intra-oral X-ray measurements during follow-up. About complications it wasn’t possible to perform a statistical analysis. To as to reduce potential surgical risks implants placement in basal bone should be preferred.
ARTICLE | doi:10.20944/preprints202203.0073.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: focus group; patient reported outcome measures; oral health; education; COVID-19; dental problem
Online: 4 March 2022 (07:08:57 CET)
This study reports results of focus groups with school nurses and teachers from elementary, middle, and high schools to explore their perceptions of child and adolescent oral health. Participants included 14 school nurses and 15 teachers (83% Female; 31% Hispanic, 21% White, 21% Asian, 14% African American, and 13% Others). Respondents were recruited from Los Angeles County schools and scheduled by school level for six one-hour focus groups, using Zoom. Audio recordings were transcribed, reviewed, and saved with anonymization of speaker identities. NVivo software was used to facilitate content analysis and identify key themes. The nurses’ rate of “Oral Health Education” comments statistically exceeded that of teachers, while teachers had higher rates for “Parental Involvement” and “Mutual Perception” “Need for Care” was perceived to be more prevalent in immigrants to the United States based on student behaviors and complaints. “Access to Care” was seen as primarily the nurse’s role. Strong relationships between community clinics and schools were viewed by some as integral to students achieving good oral health. The results suggest dimensions and questions important to item development for oral health surveys of children and parents to address screening, management, program assessment, and policy planning.
ARTICLE | doi:10.20944/preprints202203.0006.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Immunohistochemistry; CD31; D2-40; Tumor angiogenesis; OSSC.
Online: 1 March 2022 (06:55:40 CET)
(1) Background: The present study was carried out to provide new information about the relation between angiogenesis, tumor stage Oral squamous cell carcinoma (OSCC); (2) Materials and methods: Thirty formalin-fixed paraffin embedded blocks were used, 10 of them were previously diagnosed as well differentiated OSCC, 10 moderate differentiated OSCC and 10 poorly differentiated OSCC. To determine the expression of CD31 and D2-40 proteins, streptavidin-biotin immunoperoxidase staining technique was used. The areas with the most vascular density (hot spots) were determined. The stained vessels were counted independently in intratumoral and peritumoral stroma in five areas of hot spot at ×400 magnification; (3) Results: Immunohistochemical staining using CD 31 protein showed that CD31-positive vessels in the peritumoral and intratumoral stroma subjacent to the malignant invading nests which was recorded highest values in poor differentiated OSSC followed by moderate differentiated OSSC then well differentiated OSSC. D2-40 expression was positive in lymphatic vessel in the peritumoral and intratumoral stroma subjacent to the malignant invading nests. Poorly differentiated OSSC tissue sections recorded the highest vessels count followed by moderate differentiated OSSC then well differentiated OSSC. There was statistically significant difference found between the three studied groups regarding CD31 and D2-40 levels. Also there was statistically significant positive correlation found between CD31 level and D2-40 level and vice versa; (4) Conclusion: CD31 and D2-40 are related to stage of OSCC and are consistent with angiogenesis in tumor progression.
ARTICLE | doi:10.20944/preprints202201.0049.v2
Subject: Medicine & Pharmacology, Dentistry Keywords: dental pattern; forensic anthropology; forensic odontology; forensic dentistry; forensic radiolo-gy; forensic chemistry; forensic science; machine learning; identification; dental materials; acid solution; dissolution; sulfuric acid; dentition; teeth; acid degradation
Online: 24 February 2022 (03:41:16 CET)
(1) Teeth, represent in humans the most resilient tissues. However, exposure to concentrated acids might lead to their obliteration, thus making human identification difficult. Teeth often contain dental restorations from materials that are even more resilient to acid impact. This paper introduces novel method of 3D reconstruction of dental patterns as a crucial step for digital identification with dental records.; (2) With combination of modern methods of Micro-Computer Tomography, Cone Beam Computer Tomography, Attenuated Total Reflection in conjunction with Fourier-Transform Infrared Spectroscopy and Artificial Intelligence Convolutional Neural Network algorithms, the paper presents the way of 3D dental pattern reconstruction and human remains identification. Research studies morphology of teeth, bone, and dental materials (Amalgam, Composite, Glass-ionomer cement) under different periods of exposure to 75% sulfuric acid; (3) Results reveal significant volume loss in bone, enamel, dentine, and as well glass-ionomer cement. Results also reveal significant resistance of composite and amalgam dental materials to sulfuric acid impact, thus serving as strong parts in the dental pattern mosaic. Paper also introduces probably first successful artificial intelligence application in automated forensic CBCT segmentation.; (4) Interdisciplinary cooperation utilizing mentioned technologies can solve problem of human remains identification with 3D reconstruction of dental patterns and their 2D projections over existing ante-mortem records.
CASE REPORT | doi:10.20944/preprints202202.0291.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: granulomatous cheilitis; latent tuberculosis; IGRA; antibiotic treatment
Online: 23 February 2022 (12:08:19 CET)
The granulomatous cheilitis (GC) presents a heterogeneous group of disorders characterised by a granulomatous inflammation/reaction of the lips to various stimuli. Numerous etiologies have been proposed, including genetic, immunologic, allergic and infectious. Among the secondary causes of GC, a distant infection by Mycobacterium tuberculosis should be considered. The GC could be the clinical presentation of a tuberculide resulting from a hypersensitivity reaction to an underlying focus of active or latent tuberculosis infection (LTBI). This communication describes a woman diagnosed with GC related to LTBI, who responded well to antituberculosis treatment.
ARTICLE | doi:10.20944/preprints202201.0250.v2
Subject: Medicine & Pharmacology, Dentistry Keywords: follicular cyst; fracture; mandible; osteosynthesis; mini-plate; collagenic xenograft
Online: 8 February 2022 (12:41:39 CET)
The problem of filling the bone cavity remains relevant in maxillofacial and oral surgery. There is a large selection of osteotropic materials of various natures for filling of bone defects of different etiology. The aim of our research was to improve the result of surgical treatment in a patient with a complicated mandibular fracture with the use of collagenic xenograft during osteosynthesis. In this article, we introduce our experience in the treatment of a patient with a complicated mandibular angle fracture in a combination with the follicular cyst. The obligate steps of treatment included stabilization of the bony fragments, a decrease of risk in fracture line malposition along with titan mini- plates, and shortening in the time of bone regeneration due to a filling of bone defect with the osteotropic material. This approach allowed us to reduce the rehabilitation period and further prosthetic treatment after 4-5 months without additional bone grafting manipulations. Though, the use of collagen osteotropic material, possessing osteoconductive properties, can improve the treatment of patients with mandibular fractures.
ARTICLE | doi:10.20944/preprints202201.0307.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Docosahexaenoic acid; Chemoprevention; Bcl-2 family; Experimental Study; Hamster Buccal Pouch Carcinogenesis.
Online: 20 January 2022 (13:41:39 CET)
The purpose of the current study was directed to investigate the effectiveness of docosahexaenoic acid (DHA) as a chemopreventive agent on experimentally induced hamster buccal pouch (HBP) carcinogenesis; Material and methods: 40 Syrian male hamsters, five weeks old, were divided into 4 groups of 10 animals in each as follows, GI: Topical application of liquid paraffin alone (thrice a week for 14 weeks), GII: Topical application of 7, 12 dimethyl benz[a]anthracene (DMBA) alone (0.5 % in liquid paraffin, thrice a week for 14 weeks), GIII: Topical application of DMBA (0.5 % in liquid paraffin, thrice a week for 14 weeks) + Oral administration of DHA (125 mg/kg b.w. in 1 ml distilled water by oral gavage, thrice a week for 14 weeks on alternative days of DMBA application), GIV : Oral administration of DHA alone (125 mg/kg b.w. in 1 ml distilled water by oral gavage, thrice a week for 14 weeks); Results: Gross observations and histopathological findings revealed a-GI: normal stratified squamous epithelium b- GII: well and moderately differentiated squamous cell carcinoma (SCC) c-: GIII: showed variable results ranges from hyperkeratosis, hyperkeratosis and focal hyperplasia, mild dysplasia, and well differentiated SCC with superficial invasion of tumor cells not extended to deeper areas d: GIV: normal similar to GI. Immunohistochemical results revealed that oral DHA treatment to DMBA treated hamsters restored the normal expression of bcl-2; Conclusion: DHA has the potential to be a dietary chemopreventive agent due to its capacity to improve carcinogen detoxification and to block/suppress the initiation and promotion stages of experimentally produced HBP carcinogenesis.
ARTICLE | doi:10.20944/preprints202201.0167.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: rapid palatal expander; midpalatal suture; bone density; cone-beam computed tomography, facial patterns, skeletal growth pattern.
Online: 12 January 2022 (13:42:31 CET)
The aim of this paper was to evaluate the changes in the mean bone density values of the midpalatal suture in 392 young patients treated with the Rapid Palatal Expander appliance according to sex, gender, vertical and sagittal skeletal patterns. Materials and Methods. The evaluations were performed using the low-dose protocol cone-beam computed tomography scans at t0 (preoperatively) and t1 (1 year after the beginning of the therapy). The region of interest was used to calculate bone density in Hounsfield units (HU) in the area between the maxillary incisors. Results. CBCT scan data of 196 females and 196 males (mean age of 11,7 years) showed homogeneous and similar density values of the MPS at T0 (547.59 HU - 565.85 HU) and T1 (542.31 - 554.20 HU). Class III skeletal individuals showed a significant higher BD than the II class group at T0, but not at T1. Females showed significantly higher BD than males at t0 and t1. No significant differences were found between the other groups and between two-time points in terms of bone density values of the MPS. Conclusions. Females and III class groups showed significantly higher bone density values than males and II class, respectively. No statistically significant differences were found from T0 to T1 in any groups, suggesting that a similar rate of suture reorganization occurs after the use of the RPE, following reorganization and bone deposition along with the MPS.
ARTICLE | doi:10.20944/preprints202201.0157.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Proliferation; Angiogenesis; Biologic Behavior; Ameloblastoma; Ameloblastic Fibroma
Online: 12 January 2022 (08:20:26 CET)
Background: The present study was carried out to evaluate the roles of proliferation and angiogenesis in locally aggressive biologic behavior of ameloblastoma versus ameloblastic fibroma; Methods: 30 formalin-fixed paraffin embedded blocks (15 cases of ameloblastoma & 15 cases of ameloblastic fibroma) were used. To evaluate the proliferation, the tissue sections were stained with AgNORs stain. CD105 was used as immunohistochemical marker of angiogenesis. Quantitative evaluations of AgNORs were performed. The mean vascular density was evaluated as a measure for CD105 protein expression by using image analyzer computer system; Results: The mean number of AgNORs dots per nucleus was significantly higher in ameloblastoma as compared to ameloblastic fibroma. Also, the protein level of CD105 showed positive expression and wide distribution that the mean vascular density was significantly higher in ameloblastoma as compared to ameloblastic fibroma; Conclusion: Quantitative evaluation of AgNORs stain & the mean vascular density utilizing CD105 protein expression may reflect a higher proliferative activity and a more locally aggressive biologic behavior of ameloblastoma when compared to ameloblastic fibroma, that other factors may be involved in biologic behavior of ameloblastic fibroma.
ARTICLE | doi:10.20944/preprints202201.0150.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Oral Health; Adolescent; Knowledge, Practice, Behaviour
Online: 11 January 2022 (15:48:40 CET)
The aims of this study were to assess oral health knowledge, attitudes, and practices among orthodontic patients between the ages of 15 and 17 years old compared to adolescents without orthodontic treatment. This cross-sectional study included 392 adolescents drawn from various French teaching hospitals. A closed-ended questionnaire was used to collect data. Adolescents undergoing orthodontic treatment had a higher knowledge of oral health than adolescents without orthodontic treatment. The majority of adolescents for both groups (69%) claimed to brush their teeth twice a day. Regarding complimentary dental material, 81.9% of adolescents without orthodontic treatment never used an interdental brush and 78.8% never used dental floss. For those undergoing orthodontic treatment, 48.5% never used interdental brush. Only 4% of adolescents without and 3% of adolescents with orthodontic treatment never consumed fizzy drinks, 4.9% and 3% never consumed sweets, 4% and 8.4% never ate fast-food. Adolescents without treatment consumed more sodas (p=0.04) and more fast food (p=0.03). Adolescents had insufficient knowledge of oral health. Health education programmes should be implemented to improve adolescents' knowledge and individual oral prophylaxis with interdental brushes.
ARTICLE | doi:10.20944/preprints202201.0043.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Photobiomodulation; low level laser therapy; ectopic eye tooth; root resorption; treatment modalities.
Online: 5 January 2022 (13:15:17 CET)
The orthodontic treatment brings numerous benefits and, in most cases, the benefits outweigh the possible disadvantages. Root resorption (RR) is a common adverse phenomenon associated with orthodontic treatment. This study evaluates the role of low-level laser emission / Photobiomodu-lation (LE/P) in quantitative measurements of root resorption (QRR). The application of LE/P was done after each orthodontic activation with 4 types of treatment intervention (TI) on the RR after fixed orthodontic treatment (FOT) of the upper arch with ectopic eye tooth/teeth [EET]. 32 Orthodontic patients scheduled for FOT were selected and assigned to the 4 groups. These were LE/P+Self ligating bracket (SLB), LE/P+Conventional bracket (CB), Non-Photobiomodulation (non-LE/P)+SLB, and non-LE/P+CB. Standard management stages of FOT were followed in the maxilla. Each patient received a single application of LE/P labially/buccally and palatally, a total of 5 different points during each activation or appointment. The main outcome measure was QRR in maxillary anteriors before and after FOT assessed via cone-beam computed tomography (CBCT) using 3D OnDemand software. Insignificant QRR was found between before and after FOT in SLB, CLB, and LE/P, non-LE/P groups (p > 0.05). QRR in the SLB vs CB and LE/P vs non-LE/P group was significantly different in 11, 13, and 23 (p < 0.05). QRR in the LE/P+SLB group (p < 0.05) was significantly different in 11, 13, and 23 than that in the other groups. The most severe QRR was found on the 13 (0.88 ± 0.28mm and 0.87±0.27mm) and 23 (1.19 ± 0.14 mm and 1.16±0.13mm) in the CB and non-LE/P group (p < 0.001). LE/P+SLB showed highly significant superior outcome (p < 0.001) in relation to non-LE/P+CB, the QRR of 23 were 0.813± 0.114mm and 1.156± 0.166mm respectively. Significantly higher amount of QRR found in EET patients after FOT treated with the CB, non-LE/P, and non-LE/P+CB system and warrants further investigation to explore potential specific causes.
ARTICLE | doi:10.20944/preprints202112.0051.v1
Online: 3 December 2021 (11:00:57 CET)
Total edentulism is the loss of all teeth for any cause by a multifactorial process that involves biological and patient-related factors. Studies on edentulism and risk factors in Mexico are limited, and the epidemiological surveillance data is scarce and controversial since official governmental reports are not statistically representative of the country. We estimate the distribution for edentulism according to sociodemographic and socioeconomic variables in adults from a low-income state in 2003 and its progress in Mexico. We analyzed data from the National Performance Evaluation Survey in Oaxaca, Mexico, and the annual reports of the Epidemiological Surveillance System of Oral Pathologies in 2009-2019 using X2. Oaxacan patients older than 75 y.o (17.9%, p<0.05), those with lower schooling (11.2%), and diabetes (14.5%) presented the highest percentage of edentulism. We do not observe differences in edentulism between sex or residence (p>0.05). From 2009 to 2019, country data reports the lowest rate of edentulism in adults over 20 y.o (0.32%; 95% CI 0.18%-0.48%) and the most affected population over 79 y.o. (7.29%; 95% CI 5.2%-9.30%). As it is a cumulative phenomenon, it is necessary to establish better surveillance, prevention, and treatment programs to improve the oral health of older thus reducing edentulism.
ARTICLE | doi:10.20944/preprints202111.0547.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: biocompatible 3D printing; photopolymers; orthodontics; distalizer; CAD/CAM; personalized treatment; computer modeling
Online: 29 November 2021 (15:38:51 CET)
Aim of this research paper is to introduce a novel method of hybrid orthodontic tooth-borne distalizer treatment of class II malocclusion by using 3D printed biocompatible personalized distalizer. Explains 3D designing, printing and clinical application of individualized biocompatible medical device dedicated for orthodontic teeth distalization. Compares such distalizer manufactured from two different biocompatible photopolymers (white and transparent). Evaluates their clinical performance and also patients’ aesthetical perception. Clinical part includes comparison of treatment debonding on the set of 12 complete orthodontic treatments with uni-lateral class II malocclusion managed with hybrid approach (CAT-Invisalign with 3D printed distalizer). Paper offers an evaluation of the personalized distalizer functioning in regard to current publications and comparison to conventional prefabricated alternatives like Carriere® Distalizer™ appliance. Results showed no significance of material differences on clinical performance of such individualized distalizers. Research showed preference of patients towards transparent biocompatible photopolymer instead of white A2 shade.
REVIEW | doi:10.20944/preprints202111.0490.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: CAD/CAM; dental ceramics; dental technology; digital dentistry; dental education; dental innovation; disruptive technology
Online: 25 November 2021 (20:06:23 CET)
Digital dentistry, including CAD/CAM dentistry, is perhaps the most disruptive innovation in dentistry to date. The rapid development of digital dentistry technologies over the past several decades has enabled clinicians to improve patient care by significantly reducing the time necessary for the restorative phase of treatment. Advancements in intra-oral scanning and computer-aided design and manufacturing (CAD/CAM), in conjunction with new dental CAD/CAM ceramic materials, have simplified patient care and made same-day dentistry a reality. This review aims to present the most recent advancements described in current literature as well as to document the successful implementation of digital dentistry into a predoctoral program. The overall process of CAD/CAM same-day dentistry and the accompanying advancements in software and materials were presented and discussed. Implementation of technology and personnel requirements were reviewed. CAD/CAM dentistry has been influential in shaping and improving dental practice and education, and this influence will only continue with time.
ARTICLE | doi:10.20944/preprints202111.0455.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: child anxiety disorders; screening; SCARED-C; psychometrics; dental practice
Online: 24 November 2021 (12:48:07 CET)
SCARED-C instrument (the child version, 41 items) is used for screening anxiety in children between 8 to 18 years old and has been first introduced by Birmaher & collab. in 1995, with good psychometric data - internal consistency from α =.74 to .93 - and good discriminative validity indices in the original versions (1997, 1999). Since then, many countries have adopted the scale, for its utility in identifying five subsets of anxiety disorders (subscales): somatic/panic disorder, generalized anxiety, separation anxiety, social phobia, and school avoidance. The present study contains the first Romanian translated and adapted version of the SCARED-C instrument on a community sample of 477 children (8-18 years old) from Mureș county schools. The instrument showed moderate to good internal consistency (α Cronbach from to .63 to .91 for the total scale) and good test-retest reliability (.70) on a subset of 85 children sample. A confirmatory factorial analysis (CFA) was conducted to test the factor structure of the Romanian version of SCARED-C; results showed that SCARED-C has good psychometric properties to be used for screening anxiety in Romanian children and adolescents. The implications for using SCARED-C in dental practice are discussed. Future studies need to be conducted for exploring convergent and discriminative validity of the instrument and the sensitivity to current DSM-V criteria. Application on a dental pediatric sample is also required.
ARTICLE | doi:10.20944/preprints202111.0427.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: ethyl loflazepate; idiopathic taste disorder; psychogenic taste disorder
Online: 23 November 2021 (14:49:20 CET)
Ethyl loflazepate (EL) is a benzodiazepine derivative that has been reported to activate the gustatory cortex. Our department routinely uses EL as a first-line treatment for idiopathic and psychogenic taste disorders, although little has been reported in the literature with respect to patient outcomes, so we conducted a retrospective study examining its safety and efficacy. Between 2008 and 2020, 49 patients (14 males and 35 females; mean age, 62.1 years) were diagnosed with taste disorders and received EL as their only treatment for >14 days. Severity of taste disorder was evaluated using the paper disc method by Sakai et al , and treatment efficacy was evaluated using the Visual Analogue Scale, wherein patients gave subjective ratings for their symptoms (reductions by >50% after administration of EL for 4 weeks were defined as mprovements). Results showed that the improvement rates for patients with idiopathic and psychogenic taste disorders were 55% and 70%, respectively. Additionally, the majority (78%) improved within 2 weeks, and side effects were mild (seven cases of sleepiness and one case of dizziness). We conclude that EL is an appropriate first-line medication for patients with idiopathic and psychogenic taste disorders.
BRIEF REPORT | doi:10.20944/preprints202111.0392.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: oral leukoplakia; Bayesian Networks; malignant transformation
Online: 22 November 2021 (13:05:31 CET)
Oral squamous cell carcinoma often arises from an oral potentially malignant disorder called oral leukoplakia (OL). With this work we aimed to develop a novel data-driven predictive model based on gene expression profiles to distinguish OL patients who underwent malignant transformation from those who did not. We used the Tree Augmented Naïve (TAN) Bayes classifier to predict the posterior probability of having oral cancer given the data. 86 patients were included with a median follow-up of 7.11 years. Fifty-one patients (51/86; 59%) underwent malignant transformation. We found that 16 genes were predictors of oral cancer in patients with OL and these included SLC7A11, SPINK6, SERPINA12, VIT, ATP1B3, CST6, FLRT2, ELMOD1, AZGP1, RNASE13, DIO2, ECM1, CYP4F11, SYTL4, AKR1C1, and AKR1C3. In conclusion, we showed that Bayesian gene networks are a data-driven approach which could be used also in other predictor models in oncology.
BRIEF REPORT | doi:10.20944/preprints202110.0285.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: dental materials; finite element analysis; prosthodontics; biomechanics
Online: 20 October 2021 (10:00:45 CEST)
Evidence regarding the effect of the onlay preparation design for different CAD/CAM restorative materials considering the preservation of cusps is lacking. Molars were 3D modeled in four preparation designs for onlay restoration: traditional design with functional cusp coverage (TFC), non-retentive design with functional cusp coverage (NFC), traditional design with non-functional cusp coverage (TNFC), non-retentive design with non-functional cusp coverage (NNFC). Restorations were simulated with two CAD/CAM restorative materials: LD – lithium disilicate (IPS e.max CAD) and RC - resin composite (GrandioBloc). A 100 N axial load was applied to the occlusal surface simulating the centric contact point. Von Mises (VM) and maximum principal (Pmax) stresses were evaluated for restorations, cement layer and dental substrate. The non-retentive preparation design reduced the stress concentration in the tooth structure in comparison to the conventional retentive design. For LD onlays, the stress distribution on the restoration intaglio surface showed that the preparation design as well as the prepared cusp, influenced the stress magnitude. The non-retentive preparation design provided better load distribution in both restorative materials and more advantageous for tooth structure. The resin composite restoration on non-functional cusp is recommended when functional cusp is preserved, in order to associate conservative dentistry and low stress magnitude.
COMMUNICATION | doi:10.20944/preprints202110.0277.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: mouthguard; occlusal splint; trauma; finite element analysis; athletic injuries
Online: 19 October 2021 (13:33:35 CEST)
Orofacial injuries are common occurrences during contact sports activities; however, there is an absence of data regarding the performance of hybrid occlusal splint mouthguards, especially during compressive loading. To evaluate the total deformation and stress concentration, a skull model was selected and duplicated to receive two different designs of mouthguard devices: one model received a conventional custom-made mouthguard (MG) with 4-mm thickness and the other received a novel hybrid occlusal splint-mouthguard (HMG) with the same thickness. Both models were subdivided into finite elements. The frictionless contacts were used, and a nonlinear analysis was performed simulating the compressive loading in occlusion. The results were presented in von-Mises stress maps (MPa) and Total Deformation (mm). A higher stress concentration in teeth was observed for the model with the conventional MG, while the HMG design displayed a promising mechanical response with lower stress magnitude. The HMG de-sign displayed a higher magnitude of stress on its occlusal portion than the MG design. The hybrid mouthguard (HMG) reduced (1) jaw displacement during chewing and (2) the generated stresses in maxil-lary and mandibular teeth.
REVIEW | doi:10.20944/preprints202109.0464.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: aesthetics; gingiva; hyaluronic acid; injections; surgical procedures; minimally invasive
Online: 28 September 2021 (11:08:28 CEST)
The absence of interdental papillae leads to the appearance of black triangle. For most patients, the appearance of these triangles is an important reason for concern and affects their social relationships. Multiple reconstruction techniques have been developed with different degrees of success and predictability. The main aim of this study was to evaluate the efficiency of hyaluronic acid (HA) injected into interproximal papillae six months after injection and to perform a systematic review and meta-analysis. After a systematic review, five articles were selected: a clinical randomised controlled trial and four clinical trials. In total, eighty-five patients with a deficiency in upper papillae in the front of the maxilla and jaw were included in the study. The height variable was evaluated (mm) six months after HA injection. In total, one hundred and four interproximal papillae were studied. Three articles showed an important difference in favour of intervention. The total result regarding in the injection of AH was favourable with an approximate average filling of 0.7 mm in the height of the interdental papilla. The injection of HA for the reconstruction of deficient papillae in the region of the upper and lower maxilla was a possible option treatment strategy.
BRIEF REPORT | doi:10.20944/preprints202108.0462.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Dental Implants; fatigue; mechanical tests; torque
Online: 24 August 2021 (09:04:13 CEST)
The aim of this study was to compare the screw removal torque of mini conical prosthetic components and straight trunnion of indexed morse taper implants, after mechanical cycling. The sample consisted of 40 implants and 20 mini-conical prosthetic components (MC group) and 20 straight trunnion components (ST group). Each group consisted of 10 specimens, with 2 implants in each, and cobalt-chromium metallic crowns were screwed into each sample. The components of the MC group received a torque of 20 N.cm with a digital torque wrench and after 10 minutes were retightened with the same value as the initial torque. The components of the ST group received a torque of 30 N.cm, with a digital torque wrench and after 10 minutes, they were retightened with the same value. The screws of the respective crowns of the two groups received a torque of 10 N.cm and after 10 minutes were retightened with the same value. Each group was subjected to the fatigue test in a mechanical cycler at 2.000.000 cycles, with a load of 250 N and frequency of 4 Hz. At the end of the fatigue test, the loosening torque of each screw of the specimens was measured through a digital torque wrench. The data were analyzed by two-way ANOVA and Tukey test. In both groups, there were loss of torque. The results showed no statistic difference between MC and ST groups.
ARTICLE | doi:10.20944/preprints202108.0244.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Phentolamine Mesylate; dental implants; haemodynamic changes; adverse effects; satisfaction
Online: 11 August 2021 (08:59:37 CEST)
The clinical application of Phentolamine Mesylate (PM) as an anaesthetic reversal agent has been documented in paediatric patients and in conservative dentistry, but no studies have been found in implant surgery. A prospective randomised study was conducted in 60 patients eligible for mandibular implant treatment, randomly divided between the Control Group (CG) and Experimental Group (EG), who were administered PM. Haemodynamic changes, adverse effects and patient satisfaction were assessed. No statistically significant differences in haemodynamic changes and postoperative pain were found between CG and EG (p<0.05), except for Systolic Blood Pressure (SBP) which increased slightly in EG, without posing a risk to the patient. There were no differences in the presence of adverse effects between the two groups, except in the CG which presented greater difficulty in chewing and biting (p<0.05) and the EG with greater pain in the injection area (p=0.043). 83.3% of the EG patients would request PM again for future dental treatment. The use of PM offers an alternative in implant surgery, without increasing the risks and increasing the patient's quality of life.
ARTICLE | doi:10.20944/preprints202108.0177.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Antibacterial composites; Antiadhesive composites; Poly-Pore; Split-mouth; Clinical trial; Live/dead staining; Bacterial viability
Online: 9 August 2021 (07:53:57 CEST)
The purpose of the study was to investigate the bacterial viability of the initial biofilm on the surface of experimental modified dental resin composites. Twenty-five healthy individuals with good oral hygiene were included in this study. In a split-mouth design, they received acrylic splints with five experimental composite resin specimens. Four of them were modified with either a novel polymeric hollow beads delivery system or methacrylated polymerizable Irgasan (Antibacterial B), while one specimen served as unmodified control (ST). The delivery system based on Poly-Pore® was loaded with one of the active agents Tego® Protect 5000 (Antiadhesive A), Dimethicone (Antiadhesive B) or Irgasan (Antibacterial A). All study subjects refrained from toothbrushing during the study period. Specimens were detached from the splints after 8h and given a live/dead staining before fluorescence microscopy. Friedman test and post-hoc Nemenyi test were applied with significance level at p < 0.05. In summary all materials but Antibacterial B showed a significant antibacterial effect compared to ST. In conclusion dental resin composites with Poly-Pore loaded active agents show antibacterial effectiveness in situ.
ARTICLE | doi:10.20944/preprints202106.0569.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Sleep quality; Chronic pain; Temporomandibular disorder; Pittsburgh Sleep Quality Index; STOP-Bang; Epworth Sleepiness Scale
Online: 23 June 2021 (11:11:14 CEST)
Objectives: This study aimed to investigate and compare sleep quality between patients with chronic temporomandibular disorder and healthy controls, and to analyze the association of sleep quality with disease characteristics, obstructive sleep apnea risk factors, and excessive daytime sleepiness. Methods: Chronic temporomandibular disorder patients (n=503) and 180 age- and sex-matched healthy controls were included, who completed well-organized clinical report and answered questions on sleep quality (Pittsburgh Sleep Quality Index), sleep apnea risk factors (STOP-Bang questionnaire), and excessive daytime sleepiness (Epworth sleepiness scale). Results: Mean global Pittsburgh Sleep Quality Index scores were significantly higher in the patients (6.25±2.77) than in healthy controls (6.25±2.77) (p<0.001). Poor sleep was significantly more prevalent in the patient group (56.9%) than in healthy controls (22.2%) (p<0.001). Compared with healthy controls, chronic temporomandibular disorder patients had a higher likelihood of obstructive sleep apnea. (STOP-Bang total score ≥3; 7.2% vs. 16.1%; p<0.01) and higher excessive daytime sleepiness (Epworth sleepiness scale score ≥10; 12.8% vs. 19.7%; p<0.05). Age (odds ratio=2.551; p<0.001), female sex (odds ratio=1.885; p=0.007), total Epworth sleepiness scale score (odds ratio=1.839; p=0.014), and headache attributed to temporomandibular disorder (odds ratio=1.519; p=0.049) were the most powerful predictors of poor sleep (global Pittsburgh Sleep Quality Index score ≥5) in chronic temporomandibular disorder patients. Conclusion: Chronic temporomandibular disorder patients had sleep quality impairment. Various factors, including peripheral and central factors, affect the patient's sleep quality. Therefore, in addition to sleep quality and sleep-related problems, the underlying central mechanism for poor sleep quality should be assessed when treating chronic temporomandibular disorder patients.
COMMUNICATION | doi:10.20944/preprints202106.0407.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Dental Implants; biomechanical phenomena; dental prosthesis; finite element analysis.
Online: 15 June 2021 (14:20:23 CEST)
The effect of the different dental implants positioning region on the stress performance of the implant-supported prosthesis is not yet clear. This study evaluated the dental treatment with six dental implants in three different models and three different occlusal loading conditions, in terms of the biomechanical response of implants, prosthetic screw and maxilla, using three-dimensional finite element analysis. The finite element models were modelled containing external hexagon implants, as well as a Cobalt-Chromium superstructure. Three types of loads were applied: in the area of the central incisors, first premolar and in the second molars. For the finite element simulations, the von-Mises stress peaks in the implant and in the surrounding cortical bone were analyzed. All recorded results reported higher values for the implant-supported prosthesis in group C compared to the groups A and B. The highest stress values, regardless the evaluated model, was in the prosthesis in group C and in screws, the smallest were in group A.
REVIEW | doi:10.20944/preprints202102.0400.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Temporomandibular joint disorders; Temporomandibular Joint; Facial Pain; Craniomandibular Disorders
Online: 17 February 2021 (16:07:10 CET)
Temporomandibular disorders (TMD) is a group of orofacial pain conditions which is the most common non-dental pain complaint in the maxillofacial region. Due to the complexity of the etiology and often cyclical nature of the disease, the diagnosis and management of TMD remain a challenge where consensus is still lacking in many aspects. While clinical examination is considered the most important process in the diagnosis of TMD, imaging may serve as a valuable adjunct in selected cases. Depending on the type of TMD, many treatment modalities have been proposed, ranging from conservative options to open surgical procedures. In this review, the authors discuss the present thinking in the etiology and classification of TMD, followed by the diagnostic approach and the current trend and controversies in management.
ARTICLE | doi:10.20944/preprints202101.0571.v1
Online: 27 January 2021 (16:35:15 CET)
In the pursuit of better treatments, the concept of a chemically-active material, responding to local conditions by causing reactions, or reacting to produce substances that are deemed beneficial, seems laudable. Ultimately, the goal appears to be to recruit natural biological processes such that a natural ‘repair’ is effected. This goal seems to be the reason for prefixing “bio-“ to many terms with a view to advertising the desire, yet without presenting evidence that it has occurred, or indeed that it is capable of occurring, relying instead on non-biological processes to justify the claims. The dogma is such that all work where local ‘responsive’ chemistry is involved must receive the label “bioactive” to legitimize and promote. Nevertheless, the primary evidence adduced is flawed, and the claim must fail. A rethink to restore scientific sense and confidence in the endeavour is essential if real progress is to be made.
REVIEW | doi:10.20944/preprints202101.0418.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: health workforce; operational models; planning; skill mix; integration
Online: 21 January 2021 (12:35:46 CET)
Over the last decade, there has been a renewed interest in oral health workforce planning. The purpose of this review is to examine oral health workforce planning models on supply, demand and needs, mainly in respect to their data sources, modelling technique and use of skill mix. A search was carried out on PubMed, Web of Science, and Google Scholar databases for published scientific articles on oral health workforce planning models between 2010 to 2020. No restrictions were placed on the type of modelling philosophy, and all studies including supply, demand or needs based models were included. Rapid review methods guided the review process. Twenty-three studies from 15 different countries were included in the review. A majority were from high income countries (n=17). Dentists were the sole oral health workforce group modelled in 13 studies; only five studied included skill mix (allied dental personnel) considerations. The most common application of modelling was a workforce to population ratio or a needs-based demand weighted variant. Nearly all studies presented weaknesses in modelling process due to the limitations in data sources and/or non availability of necessary data to inform oral health workforce planning. Skill mix considerations in planning models were also limited to horizontal integration within oral health professionals. Planning for the future oral health workforce is heavily reliant on quality data being available for supply, demand and needs models. Integrated methodologies that expand skill mix considerations and account for uncertainty are essential for future planning exercises.
CASE REPORT | doi:10.20944/preprints202101.0400.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: ameloblastoma; conventional; segmental resection; titanium plate
Online: 20 January 2021 (13:32:46 CET)
Ameloblastoma is an aggressive slow growing benign epithelial odontogenic tumor usually associated with an unerupted third molar. In this report, we present the case of a 71-year-old male with a large swelling on the left mandibular region causing a remarkable facial asymmetry. After clinical, radiological, and histopathological examinations the diagnosis of conventional ameloblastoma was made. To avoid probable recurrence our treatment choice was a segmental mandibular resection with the placement of a reconstructive titanium plate to maintain the space for subsequent bone graft.
REVIEW | doi:10.20944/preprints202101.0306.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Anemia; dental; management; oral manifestations
Online: 18 January 2021 (09:09:12 CET)
Anemia is a condition of decreased red blood cell number or hemoglobin concentration, or of disturbance in their function, ultimately leading to decreased oxygen transport to tissues. Many factors and diseases may lead to anemia, with wide manifestations systemically as well as orally. Therefore, a sound understanding of this syndrome is essential for the dental practitioner, with emphasis on alerting signs, dental management and proper communication with patient’s physician.
ARTICLE | doi:10.20944/preprints202101.0196.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Sialolith; salivary gland; panoramic radiograph
Online: 11 January 2021 (13:01:34 CET)
Aim: Sialoliths are salivary gland calcifications that mainly affect submandibular and parotid glands. They are detected incidentally on dental panoramic radiographs. This study aimed to determine the prevalence of sialoliths in a Lebanese sample and evaluate the site, gender and age distribution of such findings. Methods: In this retrospective study, 500 digital panoramic radiographs, belonging to 219 males and 281 females aged 18-88 years, were examined to identify sialoliths seen as radiopacities in the parotid, submandibular and sublingual glands regions. Findings were analyzed statistically using IBM SPSS Statistics for Windows, version 20 (IBM Corp., Armonk, N.Y., USA). Descriptive statistics were presented and Chi-square tests and Spearman correlation coefficient were used to assess relationships between sialoliths and gender, age and site. Statistical significance was set at p=0.05. Results: In our sample of 500 radiographs, sialoliths were identified in 15 (3%). Submandibular sialoliths were the most common (1.8%) followed by parotid sialoliths (1.2%); no sublingual sialoliths were detected. Females were slightly more affected by submandibular sialoliths while males had higher prevalence of parotid sialoliths. No significant age or gender predilections were detected. Conclusion: Identifying sialoliths on panoramic radiographs by dental professionals is essential to avoid possibility of confusion with other soft tissue calcifications very common in the head and neck regions.
REVIEW | doi:10.20944/preprints202101.0139.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Dentistry; hyperthyroidism; hypothyroidism; management; oral manifestations; thyroid gland.
Online: 8 January 2021 (10:41:21 CET)
The thyroid gland secretes essential hormones for the growth regulation and the metabolic activity of the body. Thyroid dysfunction includes many conditions that can indirectly affect dental treatments. Therefore, the practitioner must be aware of these pathologies and their signs and symptoms in order to elaborate specific dental treatment plans, thus avoiding any per- and/or postoperative complications. Moreover, the dentist can help in the screening of undiagnosed thyroid dysfunction among patients.
ARTICLE | doi:10.20944/preprints202101.0121.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: mixed dentition period; temporomandibular joint; mandibular condyle; panoramic radiograph
Online: 6 January 2021 (14:45:07 CET)
Introduction: During mixed dentition period, the growth and development process of dentocraniofacial complex occurs, with temporomandibular joint as one of its centers of growth. The condition of temporomandibular joint can be seen from its condylar head shape; therefore, it is essential to understand the normal morphology of condylar head during mixed dentition period. Objective: this research aims to view the general morphology of condylar head during mixed dentition period. Method: Samples of panoramic radiographs were collected from Ma-ranatha Dental Hospital, Bandung, Indonesia. It consists of 70 male and 70 female subjects, di-vided into three groups according to their phase of mixed dentition period. Shape of subjects' condylar heads was determined by analyzing and comparing the tracing results of condyle in panoramic radiograph. Result: Study showed in first transitional period of mixed dentition, condylar head shape is dominated by round, as growth and development go on, the domination of condylar head shape is changed into convex on second transitional period. Conclusion: Mostly condylar head shape morphology during mixed dentition period is round-headed in first transitional and inter-transitional period, and convex-headed in second transitional period.
REVIEW | doi:10.20944/preprints202012.0685.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Addison’s disease; adrenal crisis; adrenal gland; corticosteroid; primary adrenal insufficiency.
Online: 28 December 2020 (11:19:22 CET)
Adrenal crisis (AC) is an unexpected and possibly lethal situation of stressful interventions in patients with Addison’s disease (AD). Despite being rare in dentistry, it is to be noted that evidence indicates that 5-8% of patients with AD necessitate emergency glucocorticoid administration to treat AC annually. For that, dentists must be aware of this condition and be prepared when the clinical signs and symptoms occur.
Subject: Medicine & Pharmacology, Dentistry Keywords: odontogenic infection; dental abscess; head and neck infection; dental epidemiology; racial discrepancy; gender discrepancy
Online: 2 November 2020 (10:33:47 CET)
Odontogenic infections are infections of the orofacial structures arising from dental disease. Despite its preventability, it exerts a significant burden on healthcare infrastructure worldwide. Our study explored the various different microbiological, social, and epidemiological characteristics of 103 cases of odontogenic infections at our regional center which demonstrated specific predilections for the young and middle-aged, those with diabetes mellitus, African American/Black and Hispanic ethnicities, posterior teeth, left-sided dentition, and male gender. However, nuances and exceptions to these trends were also seen with specific groups that may complicate treatment.
REVIEW | doi:10.20944/preprints202009.0439.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: KAP; Dental professionals; COVID-19; Pandemic; risk of infection, SARS-CoV-2
Online: 18 September 2020 (12:15:24 CEST)
Background: Dental professions are at high risk of contracting novel corona virus (COVID-19) infections during the dental procedure due to the droplets and aerosols generated during various dental procedures on infected patients. To prevent and avoid the cross-infection of the infection to dental professionals or the patients attending the dental clinic, good knowledge of the infection and its prevention mechanisms is mandatory among the professionals. Until to date, there is no pooled estimate on the knowledge,attitude and practice (KAP) of dental professionals to COVID-19 in the globe. Hence, this study aimed to determine the pooled estimate of KAP of dental professionals in this pandemic disease. Methods: Article search was done electronically using Medline, Scopus, Web of Science, EMBASE, SciELO and Google Scholar from June 1, 2020 to August 20, 2020. All studies that assessed the KAP of dental professionals to COVID-19 were searched and included in this review after passing the inclusion criteria. The pooled analysis of their knowledge (sign and symptom, mode of transmission and prevention mechanisms), attitude (their concern, intention to treat suspected patients) and practice (face mask usage, hand washing and alcohol based hand rub usage, handshaking practice, deferred procedures and checkup of patients temperature) was computed using RevMan 5.3 and random effect model was used. The presence of publication bias was assessed using the funnel plot. Results: Twelve articles with a total of 5,362 study participants were included in this study. The pooled estimate revealed that 59.91% of the dental professionals had good knowledge of the signs and symptoms of COVID-19. Two-third of dental professionals know the prevention mechanisms of the infection, and 70.13% had enough knowledge of the transmission modalities of the infection. The professional attitude revealed that only 36.43% of the participants had intention to treat a patient with cough or suspected COVID-19 (36.43%, 95%CI: 8.57, 64.29). Moreover, 47.85% of the dentists were concerned about their life, and the fate of their profession due to this pandemic disease (47.85%, 95%CI: 26.74, 68.97). The pooled analysis showed only 50.86% (95%CI: 18.64, 83.09) of the study participants worn face mask and 52.63% (95%CI: 10.54, 94.71) had avoided handshaking practice during this pandemic period. Non-emergency dental procedures were canceled by 83.98%. Conclusion: The dental professional KAP is not optimal. Thus, dental professionals should be aware of the recently updated knowledge about COVID-19 and practice according to the standards of treatment guidelines, and the recommended infection control measures in dental settings. Moreover, as saliva and droplets are the major sources of infection, dentists should follow essential protocols to regulate droplet and aerosol contamination in the dental practice
ARTICLE | doi:10.20944/preprints202009.0358.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Covid-19; HVE; Aerosol; Dentistry; Particle; Suction; External; PM1; PM2.5; PM10; Drilling
Online: 16 September 2020 (11:12:31 CEST)
(1) Introduction: External high volume extraction devices may offer a way to reduce any aerosol particulate generated. The aim of this study was to measure the particle count during dental aerosol procedures and compare the results to when a High Volume Extraction device is used; (2) Methods: A comparative clinical study measuring the amount of PM1, PM2.5 and PM10 aerosol particulate with and without the use of an external High Volume Extraction device was undertaken. In total, 10 restorative procedures were monitored with an an industrial Trotec PC220 particle counter. The air sampler was placed at the average working distance of the clinicians involved in the study - 420mm.; (3) Results: In the present study aerosol particulate was recorded at statistically significantly increased levels during dental procedures without an external high volume extraction device versus with the device. The null hypothesis was rejected, in that significant differences were found between the results of the amount of aerosol particle count with and without a High Volume Extraction device.; (4) Conclusion: If the results of the present study are repeated in an in vivo setting, an external high volume suction device may potentially lower the risk of transmission of viral particulate.
ARTICLE | doi:10.20944/preprints202009.0220.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: feasibility; acceptability; adherence; attrition rate; periodontal therapy; milk fortification; pregnancy
Online: 10 September 2020 (04:44:05 CEST)
This study aims to assess the acceptability, adherence, and retention of a feasibility trial on milk fortification with calcium and vitamin D (Ca+VitD) and periodontal therapy (PT) among low income Brazilian pregnant women with periodontitis (IMPROVE trial). This 2x2 factorial feasibility trial used a mixed-methods evaluation. 69 pregnant women were randomly allocated to four groups: 1.fortified sachet with Ca+VitD and milk plus early PT (throughout gestation); 2.placebo and milk plus early PT; 3.fortified sachet with Ca+VitD and milk plus late PT after childbirth; 4.placebo and milk plus late PT. Data were collected via questionnaires, field notes, participant flow logs, treatment diary, and focal group discussions. Quantitative and qualitative data were analysed using appropriate descriptive statistics and content analysis, respectively. Eligibility rate (12%) was below the target of 15%, but participation (76.1%) and recruitment rate (2 women/week) exceeded the targets. Retention rate (78.6%) was slightly below the target (80%). Adherence to the PT was significantly higher in the early treatment groups (98.8%) compared to the late treatment groups (29%). All women accepted the random allocation and baseline groups were balanced. There was no report of adverse events. This multi-component intervention is acceptable, well-tolerated, and feasible among low-risk pregnant women in Brazil.
ARTICLE | doi:10.20944/preprints202009.0054.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: periodontitis; diagnosis; saliva; biomarkers; matrix metalloproteinase; cytokines.
Online: 3 September 2020 (04:43:01 CEST)
This study was to investigate and assess salivary biomarkers as a means of diagnosing periodontitis. A total of 121 subjects were included: 28 periodontally healthy subjects, 24 with stage I, 24 with stage II, 23 with stage III, and 22 with stage IV periodontitis. Salivary proteins including active matrix metalloproteinase-8 (MMP-8), pro-MMP-8, total MMP-8, C-reactive protein, secretory immunoglobulin A and planktonic bacteria including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Porphyromonas nigrescens, Parvimonas micra, Campylobacter rectus, Eubacterium nodatum, Eikenella corrodens, Streptococcus mitis, Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Actinomyces viscosus were measured from salivary samples. The performance of the diagnostic models was assessed by receiver operating characteristics (ROC) and area under the ROC curve (AUC) analysis. The diagnostic models were constructed based on the subjects’ proteins and/or microbial profiles, resulting in two potential diagnosis models, which achieved better diagnostic powers with an AUC value > 0.750 for the diagnosis of stage II, III, and IV periodontitis (Model PC-I; AUC: 0.796, sensitivity: 0.754, specificity: 0.712) and for the diagnosis of stage III and IV periodontitis (Model PC-II; AUC: 0.796, sensitivity: 0.756, specificity: 0.868). This study can contribute to screening for periodontitis based on salivary biomarkers.
ARTICLE | doi:10.20944/preprints202009.0050.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Parkinson’s disease; Periodontitis; Periodontal disease; protein-protein network interaction; Bioinformatics
Online: 3 September 2020 (04:13:12 CEST)
Recent studies supported a clinical association between Parkinson’s Disease (PD) and periodontitis. Hence, investigating possible protein interactions between these two conditions is of interest. In this study, we conducted a protein-protein network interaction analysis with recognized genes encoding proteins for PD and periodontitis. Genes of interest were collected via GWAS database. Then, we conducted a protein interaction analysis using STRING database, with a highest confidence cut-off of 0.9. Our protein network casted a comprehensive analysis of potential protein-protein interactions between PD and periodontitis. This analysis may underpin valuable information for new candidate molecular mechanisms between PD and periodontitis and may serve new potential targets for research purposes. These results should be carefully interpreted giving the limitations of this approach.
REVIEW | doi:10.20944/preprints202008.0557.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: transplantation; dental implant; marginal bone loss; implant failure rate; systematic review; periodontitis; periodontal diseases; oral health
Online: 25 August 2020 (13:45:34 CEST)
This systematic review investigates the failure rate and marginal bone loss (MBL) of dental implants placed in Solid-organ transplant (SOT) patients compared to healthy controls. Three databases (PubMed, Web of Sciences and the Cochrane Library) were searched up to June 2020 (PROSPERO CRD42019124896). Case-control and cohort studies reporting data failure rate and marginal bone loss (MBL) of dental implants placed in SOT patients were included. The risk of bias of observational studies was assessed through the Newcastle-Ottawa Scale (NOS). Four case-control studies fulfilled the inclusion criteria, all of low risk of bias. Meta-analyses revealed consistently lower implant failure rate than control populations at patient and implant levels. SOT patients had a significant difference of -18% (p-value <0.001) of MLB towards healthy patients. SOT status poses no serious threat to implant survival. Overall, this group of patients presented lower levels of dental implant failure rate and marginal bone loss compared to otherwise healthy patients. Further intervention trials with wider sample size and longer follow-ups are necessary to confirm these summary results.
ARTICLE | doi:10.20944/preprints202008.0449.v1
Online: 20 August 2020 (08:36:03 CEST)
Objectives: to assess the knowledge level of parents from the central region of Saudi Arabia about oral health and care of preschool children and its relation with sociodemographic variables, parents‟ self-perception toward their dental health, importance of teeth and frequency of dental visits. Methods: a random sample of 754 parents participated in this cross-sectional study and completed an internationally accepted questionnaire. Chi square test and logistic regression analysis were used to analyze the data (p<0.05). Results: mean knowledge score of the parents was 4.8 (out of 11). Less than 20% of the parents were knowledgeable about the best position for tooth brushing, the concentration of fluoride in a child‟s toothpaste, timing of first dental check-up, and best time to give a sugary snack. Mothers, parents with high educational level and family income, parents with positive attitude towards teeth and excellent self-perception of their dental health were significantly more likely to score higher (p<0.05). Conclusions: knowledge of parents about oral health and care of preschool children in the central region of Saudi Arabia was deficient. Gender, education level of parents, family income, attitude about teeth and self-perception of parents‟ own dental health were factors which influenced their knowledge. To improve parents‟ knowledge, role of health professionals should be improved and TV commercials directed toward the areas which had gaps in knowledge.
REVIEW | doi:10.20944/preprints202008.0372.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: sars-cov-2, covid, covid-19, masks, dentistry, respirator, n99, n95, ffp2, ffp3,
Online: 18 August 2020 (04:30:45 CEST)
This literature review has been compiled to form an evidenced-based review on the standards for Dental Practices in their choice and use of personal protective equipment (PPE) within the COVID-19 Pandemic and beyond: it is prepared on the basis of the current best available evidence. The review encompasses risk management strategies for both Dental Personnel and Patients in the application and use of Face Masks & Respirators.In summation, from the evidence available, it is apparent that in the lab setting N95/FFP2 masks are superior in their efficiency but in the clinical setting such a difference is not seen as clearly. As such the minimum standard of care should be that of a standard surgical mask. Faced with the emergence of the virulent disease that is Covid-19, it is logical to use FFP2/N95 respirator masks in aerosol generating procedures where they offer greater resistance to fluid penetration and a better face seal when adequately fit tested as a gold standard. But if a dry field isolation technique involving high volume evacuation is used, there is no clear benefit of respirator masks (N95/FFP2 or N99/FFP3) when balanced with the extra risk of compliance, cost and comfort in wearing a standard fluid-resistant surgical mask.
ARTICLE | doi:10.20944/preprints202008.0259.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: DMTU; Multispecies biofilms; Porphyromonas gingivalis; Quorum sensing
Online: 11 August 2020 (08:11:20 CEST)
Imbalance of homeostasis between the microbial communities and the host system leads to dysbiosis in oral micro flora. DMTU (1,3-di-m-tolyl-urea), is a biocompatible compound that was shown to inhibit Streptococcus mutansbiofilms by inhibiting its communication system (quorum sensing). Here, we hypothesized that DMTU is able to inhibit multispecies biofilms. We developed a multispecies oral biofilm model comprising an early colonizer Streptococcus gordonii, a bridge colonizer Fusobacterium nucleatum, and late colonizers Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans. We performed comprehensive investigations to demonstrate the effect of DMTU on planktonic cells and biofilms. Our findings showed that DMTU inhibits and disrupts multispecies biofilms without bactericidal effects. Mechanistic studies revealed significant down regulation of biofilm and virulence related genes in P. gingivalis. Taken together, our study highlights the potential of DMTU to inhibit polymicrobial biofilm communities and their virulence.
REVIEW | doi:10.20944/preprints202008.0155.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: temporomandibular joint disorders; arthrocentesis; TMJ; arthralgia; lavage
Online: 6 August 2020 (10:36:53 CEST)
The aim of this study was to assess the best timing to perform arthrocentesis in the management of temporomandibular disorders with regards to conservative treatment. A systematic search based on PRISMA guidelines, including a computer search with specific keywords, reference list search, and manual search was done. Relevant articles were selected after 3 search rounds for final review based on 6 predefined inclusion criteria, followed by a round of critical appraisal. Eleven publications, including 5 randomized controlled trials and 6 prospective clinical studies informed this review. The studies were divided into 3 groups based on the timing of arthrocentesis: 1). Arthrocentesis as the initial treatment, 2). Early arthrocentesis, and 3). Late arthrocentesis. Meta-analyses compared the efficacy of improvement in mouth opening and pain reduction in the 3 groups. The results were statistically significant and favoured early arthrocentesis, followed by late arthrocentesis in terms of both improvements in mouth opening and pain reduction. All 3 groups showed improvement in mouth opening and pain reduction. We conclude that early arthrocentesis may be able to produce the best clinical results, while arthrocentesis before attempting conservative treatment may produce less favourable outcomes.
ARTICLE | doi:10.20944/preprints202007.0754.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: ME/CFS; dentistry; interdisciplinary care; oral health
Online: 31 July 2020 (14:02:48 CEST)
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disabling condition affecting millions of adults and children worldwide. Despite the development of multiple criteria sets for defining this disorder, agreement on the core symptoms and other implications of ME/CFS point to the importance of understanding their role in oral health care. Overall, care for the homebound and bedbound population with ME/CFS issues has been under-addressed in the literature to date and there has been little consideration of the oral health needs of this population. Evaluation, diagnosis and treatment of dental concerns may be hindered by many of the diverse symptoms of ME/CFS. The present paper utilizes the International Consensus Criteria (ICC) in discussing treatment considerations for the most severely affected patients with ME/CFS, both in oral evaluation and active care. While no specific dental pathology is linked to ME/CFS, proper care for the patient so affected must take into account the disorder’s symptoms and severity.
BRIEF REPORT | doi:10.20944/preprints202007.0734.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: cannabinoid; CBD; dental care; dental plaque; tooth polish; polishing powder
Online: 31 July 2020 (06:02:24 CEST)
Introduction: Dental health problems including dental plaque are common health problems affecting people of different age groups globally. Air-polishing is a safe tooth polishing technique used by dental professionals for stain and plaque removal and as preventive procedure for dental health. Here we report the technical improvisation of existing air-polishing technique by supplementing cannabinoid powder into the classic polishing powder for effective removal of supragingival and subgingival plaque and inhibition of plaque forming bacteria. Methods: The cannabidiol (CBD) powder was added to the tooth polishing powder (AIR-N-GO, classic) at 1% (wt/wt) ratio. The study was conducted on 12 patients, of which 6 received regular polishing treatment and 6 received CBD-supplemented polishing treatment. The dental plaque samples were collected before and after each treatment and subjected to in vitro microbiological analysis and the colony forming units (CFU) were analyzed using automated colony counter. Results: Based on in vitro microbiological analysis, the average CFU of interdental space samples collected from post-CBD-supplemented polishing treatment was significantly reduced (linear fold change between 3.9-18.4) compared to that of post-regular polishing (linear fold change between 1.0-2.6) treatment. Conclusions: CBD-supplemented polishing powder can help in effective removal and killing of dental plaque bacteria during the polishing treatment. CBD powder can be added as enhancing supplement to the existing polishing powders.
ARTICLE | doi:10.20944/preprints202007.0635.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: burning mouth syndrome; photobiomodulation therapy; capillaroscopy
Online: 26 July 2020 (15:26:40 CEST)
Burning Mouth Syndrome (BMS) is an idiopathic condition that manifests itself primarily with the onset of burning sensation. The aim of the research was to perform Photobiomodulation Therapy (PBM) using a diode laser on the oral mucosa of BMS patients, followed by an objective evaluation of the morphological changes in the vascular bed underlying the mucosa using polarized light videocapillaroscopy. A group of 40 patients were included in the study. The patients were randomly divided into two groups (using simple randomization): 20 patients were assigned to the laser group and 20 patients were assigned to the placebo group. Each patient of the laser group received 8 irradiations (with 4 Watt of power, wavelength 800nm, energy 1200 Joules, irradiation time for 300 seconds of time, energy density 50J/cm2 , 60 mW continuous wave laser, irradiance 180mW/cm2 ), twice a week, blinded to the type of irradiation administered, for four consecutive weeks. The patients in the placebo group underwent the same sessions as the others, the only difference being the non-emission of the laser. An initial check of the vascular bed was performed with a polarized light videocapillaroscope. This was followed by treatment with a therapeutic diode laser and a subsequent check with a videocapillaroscope. It was possible to observe that in the group of patients that underwent laser therapy, there was a lasting improvement in symptoms. The capillary oral bed in the placebo groups did not show any statistically significant difference (P>0.05). In the laser group we observed: in the buccal mucosa the diameter of the capillary had a reduction of 3μm; in the upper lip mucosa a reduction of 3μm; in the lower lip mucosa, there was a reduction of 3μm; in the dorsal lingual surface, there was a reduction of 2 μm. An increase in capillary length was also obtained in all irradiated regions in the laser group patients (P < 0.05). PBM induces microcirculatory changes that are still present at a distance of time, such as an improvement in the clinical picture. The improvement in the symptoms has been correlated to the reduction of the capillary diameter. Placebo effect only leads to a temporary improvement in symptoms that are unrelated to changes in the microcirculatory pattern.
Subject: Medicine & Pharmacology, Dentistry Keywords: tissue-level; bone-level; dental implants; transmucosal; marginal bone loss; review
Online: 13 July 2020 (03:18:26 CEST)
Purpose: to assess any differences on marginal bone loss between bone-level or tissue-level dental implants through a review of literature until September 2019. Materials and methods: MEDLINE, Embase and other database were searched by two independent authors. The search was limited to articles in English. Results: The search provided 1028 records and, after removing the duplicates through titles and abstracts screening, 45 full-text articles were assessed for eligibility. For qualitative analysis 20 articles were included, 17 articles of them for quantitative analysis. A total of 1161 patients (mean age 54,4 years) and 2933 implants were observed, 1427 (Tissue-level) and 1506 (Bone-level). The survival rate and the success rate were more than 90%, except for 2 studies with a success rate of 88% and 86.2%. No studies reported any differences between groups in term of success and survival rates. Three studies showed that BL-implants had statistically less marginal bone loss (P< 0.05). Only one study reported statistically less marginal bone loss in TL-implants (P< 0.05). In the most part of the studies, differences between implant types in marginal bone loss were not statistically significant. Conclusion: Despite to the peri-implant tissue around transmucosal implants has been reported to be inﬂammation-free because of the absence of bacterial infiltration in the micro-gap between the fixture and abutment, no clinical and radiological differences were highlighted between groups from the included studies after a variable period of follow-up ranged between 1 to 5 years.
CASE REPORT | doi:10.20944/preprints202007.0183.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: High frequency vibration; clear aligners; skeletal Class II; non-surgical treatment; malocclusion
Online: 9 July 2020 (11:45:30 CEST)
This study presents a novel technique utilizing high frequency vibration to shorten treatment time and preserve alveolar bone in challenging orthodontic cases treated with Invisalign® clear aligners. Four non-growing orthodontic patients (age range 14-47 years old) with Class II skeletal patterns (convex profiles with retrognathic mandibles) who sought correction of their crowded teeth and non-surgical correction of their convex profiles were included in this study. These patients were treated using Invisalign clear aligners together with high frequency vibration (HFV) devices (120 Hz) (VPro5™) that were used by all patients for five minutes per day during active orthodontic treatment. Vertical control and forward rotation of the mandible for each patient was achieved through pre-programming the Invisalign to produce posterior teeth intrusion. Successful forward rotation of the mandibles achieved in all patients led to improvement of their facial convex profiles (ANB improved 2.1 + 0.5 degrees; FMA improved 1.2 +1.1 degrees). Dental decompensation was achieved by lingual tipping of the lower incisors and palatal root torque of upper incisors. The use of HFV together with Invisalign facilitated achieving these results within a 12+6 month period. In addition, more bone labial to the lower incisors after their lingual movement was noted. In conclusion, the use of HFV concurrent with SmartTrack Invisalign aligners allowed complex tooth movement and forward projection without surgery in non-growing patients with skeletal Class II relationships. The clinical impact and implications of this case series is that the use of HFV facilitates complex orthodontic tooth movement including posterior teeth intrusion and incisor decompensation in addition to increased bone formation labial to lower incisors that may minimize future gum recession due to their labial inclination.
CASE REPORT | doi:10.20944/preprints202006.0363.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Oral lichen planus; Koebner phenomenon; mechanical trauma; dental cusps; psychological distress
Online: 30 June 2020 (10:09:06 CEST)
Mucosal irritation caused by cusps of upper and lower teeth represents a source of persistent, low grade mechanical trauma. This type of trauma can initiate and/or perpetuate oral lichen planus in a few susceptible patients. Here, we report a rare case of bilateral white linear striations in the buccal mucosa of a young patient, associated with sharp cusps. Oral lesions demonstrated a unique cuspal signature highlighting the causal role of subtle mucosal trauma in the genesis of reticular-oral lichen planus. Lesions appeared to be exacerbated by significant psychological distress experienced by the patient. Although the Koebner phenomenon is well reported in the cutaneous lichen planus literature, such presentations are relatively rare in the oral cavity. This report emphasizes the potential role of low-grade cuspal trauma/irritation in conjunction with psychological distress in the genesis of oral lichen planus.
REVIEW | doi:10.20944/preprints202006.0307.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: bio-aerosol; reduction; procedures; dentistry; review
Online: 25 June 2020 (12:24:48 CEST)
Microbe laden air particles, known as bio-aerosols, are routinely generated, in clinical dentistry due to the operative instrumentation within a milieu rich in salivary organisms. As the major mode of transmission of SARS-CoV-2 appears to be airborne aerosols and droplets, there has been an intense focus on such aerosol generating procedures (AGP). As there has been no systematic reviews on the efficacy of bio-aerosol reducing measure in dentistry, the objective of this systematic review was to evaluate the literature on three major AGPs, rubber dam application, pre-procedural oral rinse, and high-volume evacuation (HVE) aimed at reducing dental bio-aerosols. Method: PubMed via Ovid MEDLINE, EBSCO host, Cochrane Library, and Web of Science databases between January 01, 1985, and April 30, 2020, were searched.Results: A total of 156 records in the English language literature were identified, of which 17 clinical studies with 724 patients were included in the final analyses. The eligible reviewed articles revealed the inadequacy of the afore mentioned three principal AGPs used in contemporary dental practice to minimise bio-aerosols. HVE appears to be the most efficacious method, although no single approach provides total elimination of bio-aerosols. Conclusion:This, the first systematic review on methods of controlling bio-aerosols in dental operatory settings, indicates that employing combination strategies of rubber dam, with a pre-procedural antimicrobial oral rinse, and HVE can significantly minimize bio-aerosols. As the quality of the currently available data on dental bio-aerosols are rather poor, further, controlled, multi-centre studies are essential to address this critical issue.
ARTICLE | doi:10.20944/preprints202006.0137.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Crown removal; Debond; Er:YAG; Laser; Lithium disilicate; Zirconia
Online: 11 June 2020 (12:06:51 CEST)
The study examined the effect of noninvasive crown retrieval/reuse process using erbium-doped yttrium aluminum garnet laser (Er:YAG). Twenty-six extracted human teeth were prepared for a crown. The crown was milled using lithium disilicate (LD) and zirconia (Z) materials, n=13 per group, 3 for scanning electron microscopy (SEM). The crown was luted using composite resin cement and subjected to a laser retrieval process. After the retrieval process, the crown was cleaned, recemented and laser-retrieved two more times, without and with additional tooth reduction mimicking clinical refreshment of dentin. Retrieval time and temperature were analyzed using analysis of variance (ANOVA). Surface changes were observed through SEM. The retrieval times were 267.1±130.43, 220±79.09, 277.1±126.44, 368.4±136.14, 355±159.39, and 419.2±121.36 seconds for first, second, third LD and Z groups, respectively (p=.009). The maximal temperatures were 23.95.1±1.89°C, 24.86±2.01°C, 24.17±1.53°C, 22.88±1.51°C, 24.03±1.74°C, and 21.99±1.32°C for for first, second, third LD and Z groups, respectively (p=.006). Er:YAG laser crown removal is an effective retrieval tool for all-ceramic crowns. Minimal changes to teeth and crowns were observed following laser irradiation.
REVIEW | doi:10.20944/preprints202006.0102.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: COVID-19; COVID pandemic; COVID and dental practise; dental public health; infection control
Online: 7 June 2020 (15:44:33 CEST)
Background: SARS-CoV-2 has resulted in a global pandemic, COVID-19. The disease has spread outrageously from Wuhan, china to rest of the world affecting millions of people. The human transmission is mainly known to occur by aerosols. As almost every dental procedure is associated with aerosol production, oral health care professionals are at a high risk of getting the infection. An attempt has been made to render cohesive practical suggestions for dental professionals amid COVID-19 outbreak. Objectives: The paper aims at providing evidence based information in managing dental patients during this pandemic. Material and Methods: The paper provides a broad overview of predominant findings based on electronic database search regarding COVID-19 outbreak and its effect on dental practice. Conclusion: Dental care should not be neglected due to the pandemic. Thorough knowledge about the disease and its prevention will not only help us in providing care to these patients but will also help in preventing the nosocomial spread of infection.
ARTICLE | doi:10.20944/preprints202005.0442.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: COVID-19; knowledge; awareness; perceptions; Indian dentists; coronavirus
Online: 27 May 2020 (07:56:19 CEST)
Introduction: COVID-19 is an unprecedented global public health emergency currently impacting India in an unprecedented manner. Aim of this study was to assess knowledge, awareness, perceptions and related factors of Indian dentists on COVID-19. Methodology: A cross-sectional, on-line questionnaire-based study was conducted over one week between 3rd May, 2020 to 10th May, 2020. The sample comprised 403 Indian dentists in solo, group practices and in the academic arena. The self-administered questionnaire assessed 1) knowledge/awareness on factors related to COVID-19 patient identification and symptomatology, 2) knowledge/awareness of COVID-19 transmission and 3) perceptions of COVID-19 history taking procedure. Statistical analyses were conducted using Statistical Package for Social Sciences for Windows, version 21.0 (IBM Corp., Armonk, NY., USA). Frequency distributions and logistic regression analyses were used. Results: Indian dentists demonstrated an overall modest level of knowledge on identification of patients with COVID-19. Moreover, they had a high level of awareness of the COVID-19 transmission means, and the generally accepted procedural perceptions on patient history taking. However, there were some gaps in specific aspects of knowledge and perceptions. Those who were aged ≥ 30-years had a significantly higher level of knowledge of patient identification means than those who were < 30-years (OR=1.78:1.12-2.83); p=0.01. Moreover, specialized dentists were significantly knowledgeable of COVID-19 transmission means than the general dentists (OR=1.89:1.22-2.93; p=0.004). Conclusions: Our findings demonstrate identifiable gaps in knowledge/awareness and perceptions of COVID-19 in Indian dental professionals. These gaps should be fulfilled, at the earliest, due to the rising burden of COVID-19 in India, to ensure safe dental care delivery.
ARTICLE | doi:10.20944/preprints202005.0427.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Isolation; Neural Crest-derived Stem Cells; Mechanical Dissociation; Regenerative Periodontology, Enzymatic Digestion
Online: 26 May 2020 (08:37:48 CEST)
Periodontitis is microbial infection affecting periodontium, the tooth supporting structure and affects >743 million people worldwide. Neural crest-derived stem cells (NCSCs) hold the promise to regenerate the damaged periodontium. These cells have been identified within adult adipose tissue, periodontal ligament, and palatal tissue. Typical enzymatic isolation protocols are expensive, time consuming and often not clinically compliant. Enzyme-free, mechanical dissociation has been suggested as an alternative method of generating cell suspensions required for cell separation and subsequent expansion ex vivo. In our study, samples of rat skeletal muscle tissue were used to appraise the suitability of a novel mincing method of mechanical dissociation against enzymatic digestion with collagenase and dispase. Skeletal muscle is readily available and has been shown to contain NCSC populations. We used a Rigenera-Human Brain Wave® prototype mincer to produce a suspension of NCSCs. We have compared the resulting cell cultures produced via mechanical dissociation and enzymatic dissociation, producing single cell suspensions suitable for Magnetic Cell Sorting (MACs) and Fluorescence-activated cell sorting (FACS). Despite the Countess Automated Cytometry data demonstrating that cell suspensions produced by mechanical dissociation (n=24) contain on average 26.8 times as many viable cells as enzymatic cell suspensions (n=18), enzymatic suspensions produced more successful cell cultures. Spheroids and subsequently adherent cells formed from 4 enzymatic cell suspensions (44.4%) vs. 1 mechanical cell suspension (8.3%). Enzymatic digestion protocols formed spheroids faster and more plentifully than mechanical cell suspensions. Adherent cells and spheroids isolated via both methods appear morphologically similarly to NCSCs from our previous studies.
ARTICLE | doi:10.20944/preprints202005.0335.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: knowledge; attitude; practice; children’s oral health practice; school going children; rural area
Online: 21 May 2020 (04:01:10 CEST)
Introduction: Oral health knowledge, beliefs and attitudes of parents have a direct influence on their child’s oral health maintenance, dietary habits and encourage healthy behaviors. The aim of this study was to assess the knowledge, and attitude of parents with regards to the oral health practice of their children and its associated factors. Methods: A self -administered structured questionnaire was administered to parents or guardians of learners aged 5 to 12 years at a low socio-economic rural primary school in the uGu district, KwaZulu Natal, South Africa to collect demographic variables, knowledge of dental health, use of toothbrush, use of toothpaste, dietary practices and dental visits; practice with respect to dental care and attitudes towards oral health. The questionnaire was translated from English to IsiZulu was used. Bivariate and multivariate logistic regressions were used to assess the association between parent’s sociodemographic factors with their oral health knowledge and practice scores. Results: One hundred and forty four completed survey instruments were received with an eighty percent (118) representation of mothers. Ninety five percent of the parents (136) had a positive attitude towards oral health with 86% (124) of the children brushed their tongue and 89% (128) of the children brushed their teeth happily. The mean knowledge score was 70% with a median of 72%. Children were significantly more likely to brush their tongues (AOR: 3.20 95% CI: 1.06-9.66) and were more likely to be happier when brushing their teeth (AOR: 4.65 95% CI: 1.41-15.38) when the caregivers were their mothers, and when parents had an above average knowledge score (AOR: 1.86 95% CI: 0.72-4.85) and had positive attitudes (AOR: 3.20 95%CI: 0.46-22.00). Conclusion: To reduce the gaps in knowledge, oral health promotion should be integrated into all point of care contact with parents at health facilities, increased community awareness and advertising campaigns as well as a more focused school health oral program that addresses primary prevention, screening and appropriate referrals to health facilities
Subject: Medicine & Pharmacology, Dentistry Keywords: COVID-19; pandemics; pediatric dentistry; oral health prevention; coronavirus
Online: 16 May 2020 (18:11:49 CEST)
During the period of health emergency linked to the current COVID-19 pandemic, the management of children's oral health presents specific problems related to the infectious spread of the disease. These problems must be faced on the one hand by acting on the oral health prevention methods, and on the other by implementing specific protocols relating both to the conditions of oral pathologies that normally do not represent an emergency, and to those clinical situations that fall into the category of pediatric dental emergencies. In this perspective, in addition to defining rigorous and highly effective infection control protocols in the dental settings, it is of fundamental importance to work on remote communication and education aimed at maintaining the oral health of the children. This article, after an analysis of the risk factors from COVID-19 associated with pediatric dental treatment, presents a series of considerations on potential oral prevention strategies and on the management of emergency and non-emergency dental procedures in a context of disease transmission control, proposing new approaches and models of treatment based also on remote interaction techniques which will then retain their usefulness even at the end of the current emergency period.
ARTICLE | doi:10.20944/preprints202005.0104.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: COVID-19; dental care; infection control; universal precautions; aerosol
Online: 7 May 2020 (05:21:20 CEST)
Dental services are significantly impacted by the COVID-19 pandemic. Almost all dental procedures carry a high infection risk for providers and patients due to spread of aerosols. As a consequence, national public health agencies, and dental professional associations have issued guidelines for enhanced infection control, personal protection equipment and limiting care to urgent or emergency services. However, there is no dental service concept for disaster preparedness or response that might be applied. Similarly, pathways to care provision in a post-pandemic future are missing. We propose Safe Aerosol-free, Emergent Dentistry (SAFE Dentistry) as one approach to dental services during and emerging from pandemics. The concept’s starting point is the identification of the most common patient needs. The next step is to replace common treatments relating to the most common needs with alternative interventions with less infection risk because they do not generate aerosols. SAFE Dentistry is innovative, safe, and responds to the requirements of a pandemic and post-pandemic emergence where the risk of disease transmission remains high. SAFE Dentistry thereby ensures continuity of dental services while protecting providers and patients from infectious pathogens. Moreover, SAFE Dentistry allows dental service providers to remain operational and generate income even under pandemic conditions. Implementation and policy options for SAFE Dentistry include universal availability without co-payments by patients and a uniform bundled payment scheme for providers to simplify budgeting, reimbursement and to provide easier administration during a pandemic. Adaptations and adjustments of the concept are possible and encouraged, as long as the principle of avoiding aerosol-generation is maintained.
REVIEW | doi:10.20944/preprints202005.0003.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Anti-platelets; Anti-rheumatic drugs; Bisphosphonates; Oral anticoagulants; Oral contraceptives; Vitamin K antagonist
Online: 2 May 2020 (11:50:24 CEST)
More than 15,000 prescriptions and over the counter drugs are available according to the US Food and Drug Administration website. Moreover, several herbal medicines and dietary supplements are readily available to add to the list of possible drugs, which can potentially cause adverse drug interactions. These are a pressing concern for all as they can interfere with many dental procedures. Additionally, the number of geriatric patients seen in routine dental practice has increased over time. This implies that there are more patients with multiple diseases and health conditions like hypertension, diabetes, problems associated with the cardiovascular, renal and gastrointestinal systems, arthritis, osteoporosis, etc. All these require patients to be on certain medications. Furthermore, advancement in the dental field has led to more complex dental procedures (implants, grafts) being carried out in a general dental practice. These advanced and slightly more invasive treatments require the use of certain drugs before, during and after the treatment like local anesthetics, vasoconstrictors, anxiolytics, analgesics and antibiotics. All of these can possibly interact with medications a patient is already taking and can also interfere with the current dental treatment and create complications. This article aims to provide necessary information about commonly encountered systemic diseases and associated treating medications, their mechanism of action, possible complications and their management. The classes of drugs discussed include anti-platelet agents, vitamin K antagonists, novel oral anticoagulants, bisphosphonates, disease-modifying anti-rheumatic drugs and oral contraceptives.
REVIEW | doi:10.20944/preprints202004.0357.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: coronavirus; COVID-19; SARS-CoV2; dentistry; oral health; transmission
Online: 20 April 2020 (02:14:36 CEST)
On March 11th 2020, the World Health Organization (WHO) declared the coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus (SARS-CoV2) as a pandemic. Until an effective treatment or a vaccine is developed, the current recommendations are to contain the disease, and control its transmission. It is now clear that the primary mode of SARS-CoV2 transmission is aerosol/droplet spread, and by contacting virus contaminated surfaces acting as fomites (inanimate vectors). Furthermore, recent data indicate that the live virus particles are present in saliva, and, more alarmingly, asymptomatic individuals may transmit the infection. By virtue of the nature of the practice of dentistry where intrinsically, a high volume of aerosols are produced, as well as the close proximity of dentists and patients during treatment, dentists and allied dental staff are considered the highest risk health professional group for acquiring SARS-CoV2 during patient management. Therefore, several organizations and specialty associations have proposed guidelines and recommendations for limiting the transmission of SARS-COV2 from carriers to dentists and vice versa. This paper aims to provide a review of these guidelines, and concludes with a brief look at how the practice of dentistry may be impacted by COVID-19, in the post-pandemic era.
ARTICLE | doi:10.20944/preprints202004.0324.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: hepatitis B; hepatitis C; occupational health; dental education; needlestick injury
Online: 19 April 2020 (04:37:08 CEST)
Introduction: Dental health care workers, particularly dental medicine students (DMS), are at an increased risk of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. The aim of our study was to assess the level of knowledge on HBV and HCV, estimate needlestick injury (NSI) prevalence and reporting practice in DMS at the University of Zagreb and analyze how enrolment in obligatory and supplemental courses affects knowledge and needlestick injury reporting practice. Materials and methods: The knowledge was assessed by our questionnaires based on Centers for Disease Control general handouts. Additional information was collected to examine the prevalence and reporting practice of NSI. Data was analyzed by descriptive statistical analysis, independent-samples t-tests, proportion analyses and combined factor analyses of categorical and quantitative variables in SPSS and R. Results: In total, 206 students participated. The overall level of HBV and HCV-related knowledge was poor with average scores being 61.90% and 51.35% respectively. Moreover, students enrolled in the first year demonstrated significantly lower levels of knowledge in comparison with their older peers. Of all participants 18.2% sustained a needlestick injury, and majority of them (78.95%) never reported the injury. Conclusion: In conclusion, DMS have low levels of knowledge on important occupational pathogens and poor NSI reporting practice. Moreover, formal education in the current form failed to significantly improve competence of students and theoretical knowledge translates poorly into more conscientious injury reporting practice. We should look for a better way to increase student awareness and level of knowledge on this topic.
ARTICLE | doi:10.20944/preprints202003.0224.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: fibrin matrix; g-force; growth factors; scanning electron microscopy; fibrinolysis
Online: 13 March 2020 (03:05:18 CET)
Blood Concentrates (BCs) are autologous non-transfusional therapeutical preparations with biological properties applied in tissue regeneration. These BCs differ in the preparation method, in fibrin network architecture, growth factors release as well as in platelet/cell content. Methodological changes result in distinct matrices that can compromise their clinical effectiveness. The present study evaluated the influence of different g-forces and types of tubes in the release of vascular endothelial growth factor (VEGF) from platelet-rich fibrin (PRF) as a function of time. The PRF-like samples were obtained with three g-forces (200, 400, and 800 x g) for 10 minutes in pure glass tubes or in polystyrene-clot activator tubes. Scanning and Transmission electron microscopy was used to morphometric analyzes of PRF’s specimens and flow cytometry was used to quantify VEGF slow release until 7 days. Our results showed that platelets were intact and adhered to the fibrin network, emitting pseudopods and in degranulation. The fibrin network was rough and twisted with exosomic granulations impregnated on its surface. An increase in the concentration of VEGF in the PRF supernatant was observed until 7 days for all g forces (200, 400 or 800 x g), with the highest concentrations observed with 200 x g, in both tubes, glass or plastic. Morphological analyzes showed a reduction in the diameter of the PRF fibers after 7 days. Our results showed that g-force interferes with the shape of the fibrin network in the PRF, as well as affect the release of VEGF stored into platelets. This finding may be useful in applying PRF to skin lesions, in which the rapid release of growth factors can favor the tissue repair process. Our observations point to a greater clarification on the methodological variations related to obtaining PRF matrices, as they can generate products with different characteristics and degrees of effectiveness in specific applications.
REVIEW | doi:10.20944/preprints202003.0047.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: socket shield; dental Implants; root membrane; buccal shield; aesthetic zone
Online: 4 March 2020 (04:45:00 CET)
There are different treatment options in modern dentistry for the replacement of lost dentition. Of these the most upcoming and acceptable treatment option is Dental implants. The common problem usually with immediate implant placement in the anterior region is the post-operative soft tissue contour as a part of the bone modelling during healing. Hurzeler et al in 2010 introduced a new technique called the “socket shield technique”. This technique has been used as an alternative treatment modality for immediate implant placement in the aesthetic zone.This review articles provides a detailed information regarding the clinical concept of Root membrane technique.
Subject: Medicine & Pharmacology, Dentistry Keywords: Insertion torque; Pullout strength; Gripping volume; Micro-implant
Online: 10 February 2020 (11:32:53 CET)
This study evaluated the mechanical strengths of three types of orthodontic micro-implants by analyzing their structural configurations. Thirty micro-implants of three types (diameter 1.5 mm, Types A, B, C) were assessed. All micro-implants were manually driven into artificial bones at an 8-mm depth. The insertion torque (IT), pullout strength (PS), and gripping volume (GV) of each type were measured. Intergroup comparisons and intragroup correlation were investigated by statistical analysis. Type B had the greatest inner–outer diameter ratio (0.67), and Type A had the smallest (0.53). The IT of Type A (5.26 Ncm) was significantly (p = 0.038) lower than that of Type C (8.8 Ncm). There was no significant difference in the pullout strength (p = 0.868). The GV of Type A (9.7 mm3) was significant (p < 0.01) greater than Type C (8.4 mm3). Type C was significant (p < 0.01) greater than Type B (7.2 mm3). Spearman’s rho rank correlation test showed that PS of Type B was correlated significantly with GV. In conclusion, the design of thread and its GV were the important factors on the mechanical strengths of micro-implant.
ARTICLE | doi:10.20944/preprints202001.0064.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: dental enamel; dental caries; genomics; odontogenesis
Online: 8 January 2020 (06:35:12 CET)
Objectives: The hierarchical structure of enamel gives insight on the properties of enamel and can influence its strength and ultimately caries experience. Presently, past caries experience is quantified using the decayed, missing, filled teeth/decayed, missing, filled surface (DMFT/DMFS for permanent teeth; dmft/dmfs for primary teeth) or international caries detection and assessment system (ICDAS) scores. By analyzing the structure of enamel, a new measurement can be utilized clinically to predict susceptibility to future caries experience based on a patient’s individual’s biomarkers. The purpose of this study was to test the hypothesis that number of prisms by square millimeter in enamel and average gap distance between prisms and interprismatic areas, influence caries experience through genetic variation of the genes involved in enamel formation. Materials and Methods: Scanning electron microscopy (SEM) images of enamel from primary teeth were used to measure number of prisms by square millimeter and interprismatic spaces, prism density and gap distances between prisms in the enamel samples. The measurements were tested to explore a genetic association with variants of selected genes and correlations with caries experience based on the individual’s DMFT+ dmft score and enamel microhardness at baseline, after an artificial lesion was created and after the artificial lesion was treated with fluoride. Results: Associations were found between variants of genes including ameloblastin, amelogenin, enamelin, tuftelin, tuftelin interactive protein 11, beta defensin 1, matrix metallopeptidase 20 and enamel structure variables measured. Significant correlations were found between caries experience and microhardness and enamel structure. Negative correlations were found between number of prisms by square millimeter and high caries experience (r value= -0.71), gap distance between prisms and the enamel microhardness after an artificial lesion was created (r value= -0.70), and gap distance between prisms and the enamel microhardness after an artificial lesion was created and then treated with fluoride (r value= -0.81). There was a positive correlation between number of prisms by square millimeter and prism density of the enamel (r value= 0.82). Conclusions: our data support that genetic variation may impact enamel formation, and therefore influence susceptibility to dental decay and future caries experience. Clinical Relevance: The evaluation of enamel structure that may impact caries experience allows for hypothesizing that the identification of individuals at higher risk for dental caries and implementation of personalized preventative treatments may one day become a reality.
REVIEW | doi:10.20944/preprints201911.0325.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: dental caries; prevention; clinical trials; herbal; scoping review
Online: 27 November 2019 (03:57:04 CET)
It is currently recognized that an injudicious strategy in the last decades has been not only focusing of research typically on caries in children, but also the narrow focusing on fluoride, because despite sufficient availability of fluoride in water and oral healthcare products, caries levels escalate steadily as people get older and caries remain a main public health issue to be settled. In the last two decades the scientific community intensified efforts of exploring other products for caries prevention, herbal products being one of these approaches. Because preliminary evidence indicated that clinical trials for caries prevention with herbal products are heterogeneous in design, quality and products evaluated, we performed a scoping review intended to explore the main characteristics of such clinical trials. From an initial collection of 1986 unique papers from different literature databases, 56 articles satisfied the inclusion and exclusion criteria. The species investigated, dosage forms, study designs, duration of intervention, controls, endpoints, quality of reporting and risk of bias are discussed. 85.71% of the trials reviewed here reported positive results but given the methodological flaws and biases affecting them, it is difficult to conclude on the efficacy of those products based on the studies published thus far.
REVIEW | doi:10.20944/preprints201910.0042.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: adherence; endocarditis; fimbriae; jp2; leukotoxin; periodontitis
Online: 3 October 2019 (14:04:07 CEST)
Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium that is part of the oral microbiota. The aggregative nature of this pathogen or pathobiont is crucial to its involvement in human disease. It has been cultured from non-oral infections for more than a century, while the portrayal as an aetiological agent in periodontitis has emerged more recently. Although A. actinomycetemcomitans encodes several putative toxins, the complex interplay with other partners of the oral microbiota and the suppression of the initial host response may be central for inflammation and infection in the oral cavity. The aim of this review is to provide a comprehensive update on the clinical significance, classification, and characterisation of A. actinomycetemcomitans, which has exclusive or predominant host specificity for humans.
ARTICLE | doi:10.20944/preprints201909.0161.v1
Online: 16 September 2019 (10:51:10 CEST)
Among the different applicable irrigants for root canal disinfection, sodium hypochlorite 5.25% is one of the most attractive ones. The quality of root canal disinfection is dependent on some factors such as the employed approach, type of flow rate of irrigant and the size of needle. The majority of studies in the field of root canal disinfection are experimentally carried out. In the current article, Computation Fluid Dynamic (CFD) is used for modeling the antimicrobial liquid flow in the root canal and evaluate the effects of needle size and flow rate. Two needles, G28 and G30, are used for irrigation in three volumetric rates of flow including 0.10 mL⁄s , 0.20 mL⁄s and 0.30 mL⁄s. The results of numerical simulations revealed the improved quality of root canal disinfection by augmentation in the rate of flow and decrease in the inner diameter of the needle. According to the outcomes of the modeling, the highest average wall shear stress obtained in the case of using G28 needle and 30 mL⁄s flow rate, which was approximately 10.21 Pa.
ARTICLE | doi:10.20944/preprints201908.0285.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: oral health , pre-diabetic, diabetic, oral systemic, screening, H1A1c, Findrisk , periodontal
Online: 27 August 2019 (11:58:44 CEST)
Pre-diabetes is a serious health condition where blood sugar levels are higher than normal, but not high enough yet to be diagnosed as type 2 diabetes. Pre-diabetes puts one at an increased risk of developing type 2 diabetes and heart disease Methodology: A cross-sectional study was carried out on 384 patients aged 20-70 years old, attending the dental clinics to assess the risk for diabetes, using the FINDRISC questionnaire, HbA1c blood test and a periodontal examination. Results: The mean age of participants was 38.90±10.74. 32.3% were categorized as no risk, 46.6% low risk, while 19% and 2.1% moderate and high risk of developing diabetes respectively. Tests for serum HbA1c Level showed 46.1 % had normal HbA1c followed by 18.0% and 3.6 % were pre-diabetic and diabetic respectively. 19.3% of participants had periodontal pockets measuring more than 4mm and 15.9% measuring more than 6mm. Conclusion: The study has proven to be useful in identifying patients at high-risk of developing diabetes. Controlling and managing periodontal disease could be a new aspect to include in the standards for diabetes care. Dental settings could be a successful platform to carry out the screening and risk stratification of pre-diabetic patients.
ARTICLE | doi:10.20944/preprints201905.0322.v2
Subject: Medicine & Pharmacology, Dentistry Keywords: primary teeth; pulpotomy; furcal perforation; perforation size
Online: 11 August 2019 (12:09:02 CEST)
Aim: aim of this study is to evaluate the clinical and radiographic healing after repairing mechanical furcal perforations that occurred in primary molars by using MTA (Mineral Trioxide Aggregate) and search in some factors that may affect the prognosis of the treatment. Materials & Methods: we had 34 primary molars in 32 children aged 5–10 years, were treated by using MTA material after the occurrence of furcal perforation during pulpotomy procedure. Cases had been followed clinically and radiographically within 12 months. Statistical analyses were performed at p-value = 0.05. Results: All teeth were asymptomatic at the first week. Overall success rate was 79.3%. There was no significant statistically differences between overall-success rates according to the perforation size and continues bleeding in the furcation area (p-value > 0.05). Conclusions: Iatrogenic furcal perforations that may occur during pulpotomy in primary molars can be treated successfully by using MTA, and small sized-perforations may have more favorable prognosis than the large ones. Iatrogenic furcal perforations that may occur during pulpotomy in primary molars can be treated successfully by using MTA, and small sized- perforations may have more favorable prognosis than the large ones.
REVIEW | doi:10.20944/preprints201906.0007.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Vitamin C, Periodontal disease, Periodontitis, Gingivitis
Online: 3 June 2019 (08:46:35 CEST)
Vitamin C is important in preventing and slowing the progression of many diseases. There is significant evidence linking periodontal disease and vitamin C. We aimed to systematically review studies addressing the relationship between vitamin C and periodontal disease and the preventive ability of vitamin C against periodontal disease. Electric searches were performed using PubMed, EMBASE, Cochrane Library, and Web of Science. Studies addressing the relationships between periodontal disease and vitamin C in adults aged over 18 years were included. Quality assessment was done using Critical Appraisal Skills Program guideline and GRADE-CERQual. Seventy hundred and sixteen articles were retrieved and fifteen articles (7 cross-sectional studies, 2 case-control studies, 2 cohort studies, and 4 randomized controlled trial [RCT]) were selected by reviewing all articles. Vitamin C intake and blood level were negatively related to periodontal disease in all 7 cross-sectional studies. Subjects who suffer from periodontitis presented lower vitamin C intake and lower blood vitamin C level than subjects without periodontal disease in the two case-control studies. Patients with lower dietary intake or lower blood level of vitamin C showed greater progression of periodontal disease than did the controls. Intervention using vitamin C administration improved gingival bleeding in gingivitis but not in periodontitis. Alveolar bone absorption was also not improved. The present systematic review suggested that vitamin C contributes to reduced risk of periodontal disease.
ARTICLE | doi:10.20944/preprints201905.0117.v1
Online: 10 May 2019 (10:30:14 CEST)
Dental scaling has high importance in oral health due to its effect on preventing the teeth root destruction. Moreover, it can influence other health aspects such as reducing the risk factor of infective endocarditis. There are various devices applicable to dental scaling. It is essential to select the most appropriate type of instrument to achieve more efficient scaling. Multi-Attribute Decision Making (MADM) is a mathematical approach widely applied in for selecting the best alternative based on essential criteria. In the present research, several criteria including cost, ease of use and sterilization, durability and effectiveness considered as criteria for device selection. The experts in the related field were asked to score the criteria and corresponded alternative. According to the results, obtained by applying the TOPSIS method, Piezon Master is the most option which is mainly due to its durability and effectiveness. The second rank belongs to Cavitron due to its ease of use and sterilization in addition to affordable cost.
Subject: Medicine & Pharmacology, Dentistry Keywords: allograft, resorption, sclerotic bone, exfoliation, bone failure
Online: 24 April 2019 (12:33:49 CEST)
AbstractCadaver bone is possibly the most common transplant material used today. Common types of cadaver bone transplants are freeze-dried bone allografts and xenografts. Studies have shown that mineralized freeze-dried bone allografts have the same percentage of retained bone graft particles at different time points, indicating that these materials are never resorbed. However, it is commonly accepted by clinicians that these materials are resorbed and convert the graft site into normal bone. This histologic study was undertaken to determine the fate of mineralized freeze-dried bone allograft particles grafted into human extraction sockets. Materials and Methods:This study is a photographic, radiologic, and histological analysis of mineralized freeze-dried bone allograft healing in human sockets after mineralization at different time points. The mineralized freeze-dried bone allografts used for evaluation in this study were particulate bone graft materials in maxillary or mandibular extraction sockets. Patient selection was random, based on the following time periods: 6 months, 2 years, 5 years, 7 years, 10 years and 15 years. No block bone grafts were evaluated. Results:No resorption of cadaver bone graft particles was found at any time point. No osteoclasts were found in any of the histology at any time point. At different time points from 6 months through 15 years, mineralized freeze-dried bone allograft particles were found to be exfoliated out of the alveolar crest as a result of the formation of a hypervascular zone surrounding the grafted site. The embedded graft particles remain embedded in sclerotic bone until the particles reach the alveolar crest at which time the sclerotic bone and graft particles break up and are released into the gingiva. All histologic samples from 6 months to 15 years contained residual graft particles. The sclerotic bone formed around graft particles did not integrate to the graft particles or the implant surface. Conclusions:Mineralized freeze-dried bone allograft particles are not resorbed after mineralization. A hypervascular zone forms around the grafted site and exfoliates the bone graft particles into the gingiva. The mineralization process produces sclerotic bone which never remodels into normal bone. Sclerotic bone covers but does not integrate to the retained bone graft particles or implant surface resulting in a weakened structure with an increased likelihood of bone failure and implant loss.
ARTICLE | doi:10.20944/preprints201904.0169.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: esthetic archwires; coating stability; backscattered electron microscopy
Online: 15 April 2019 (11:55:14 CEST)
Background/Aim: There is continuing interest in engineering esthetic labial archwires. The aim of this study was to coat nickel-titanium (NiTi) and beta-titanium (β-Ti), also known as titanium molybdenum (TMA), archwires by plasma electrolytic oxidation (PEO) and to analyze the characteristics of the PEO-surfaces. Materials and Methods: PEO-coatings were generated on 0.014-inch NiTi and 0.19x0.25-inch β-Ti archwires. The surfaces were analyzed by scanning electron microscopy and stereomicroscopy. Cytocombability testing was performed with ceramized and untreated samples according to EN ISO 10993-5 in XTT-, BrdU- and LDH-assays. The direct cell impact was analyzed using LIVE-/DEAD-staining. In addition, the archwires were inserted in an orthodontic model and photographs were taken before and after insertion. Results: The PEO coatings were 15 to 20 µm thick and esthetically pleasing. The cytocompatibility analysis revealed good cytocompatibility results for both ceramized NiTi and β-Ti archwires. In the direct cell tests, the ceramized samples showed improved compatibility as compared to those of uncoated samples. However, bending of the archwires resulted in loss of the PEO-surfaces. Nevertheless, it was possible to insert the β-Ti PEO-coated archwire in an orthodontic model without loss of the PEO-ceramic. Conclusion: PEO is a promising technique for the generation of esthetic orthodontic archwires. Since the PEO-coating does not resist bending, its clinical use seems to be limited so far to orthodontic techniques using straight or pre-bended archwires.
Subject: Medicine & Pharmacology, Dentistry Keywords: hyaluronic acid; biphasic bone substitute; biocompatibility; tissue reaction; inflammation; macrophage; M1; M2; multinucleated giant cells
Online: 28 March 2019 (06:54:57 CET)
Biphasic bone substitutes (BBS) are nowadays established biomaterials. Through their constant development even natural components like hyaluronic acid (HY) are added to improve both their handling and also their regenerative properties. However, low knowledge exists regarding the consequences of the HY addition for their biocompatibility and the inflammatory tissue reactions. Thus, the present study was conducted aiming to analyze the influence of two different amounts of high molecular weight HY (HMWHY) combined with a BBS on the in vitro biocompatibility and the in vivo tissue reaction. Established in vitro procedures using L929 cells were used for cytocompatibility analyses under the test conditions of DIN EN:ISO 10993-5. For the in vivo study part, calvarial defects were created in 20 Wistar rats and subsequently filled with the BBS and the BBS combined with two different HMWHY amounts, i.e., BBS+HY(L) and BBS+HY(H). As controls empty defects were used. Established histological, immunohistochemical and histomorphometrical methods were applied to analyze the tissue reactions to the three different materials, including the induction of pro- and anti-inflammatory macrophages and multinucleated giant cells (BMGCs). The in vitro results showed that none of the materials or compositions caused biological damages to the L929 cells and can considered to be non-toxic. The in vivo results showed that only the addition of high doses of HY to a biphasic bone substitute significantly decreases the occurrence of proinflammatory macrophages (* p < 0.05) comparable to the numbers found in the control group, while no significant differences within the three study groups for M2-macrophages nor BMGCs were detected. In conclusion, the addition of different amounts of HMWHY does not seem to affect the inflammation response to the BBS while improving the material handling properties.
ARTICLE | doi:10.20944/preprints201902.0169.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Tooth size; Tooth size discrepancy; Bolton ratios; Meta-analysis; Systematic review
Online: 18 February 2019 (17:17:20 CET)
Introduction: The purposes of this study were to seek for overall ratio (OR) and anterior ratio (AR) patients data in normal occlusion and Angle’s malocclusion studies, and to assess if such results support Bolton’s standards as general references. Methods: Pubmed, Medline, CENTRAL and Scholar databases were searched up to February 2018 (CRD42018088438). Gray literature was explored through OpenGray. Non-randomized clinical studies, published in English and assessing Bolton’s OR and AR in normal occlusion and Angle’s malocclusion groups (Class I, Class II, Class II division 1, Class 2 division 2, Class III) patients were included. OR and AR means and standard deviations (SD) were collected. Potential covariates (study design, publication year, country where the study was conducted, number of cases, gender, mesiodistal measurement method, and calibration method) were also extracted. The National Health Heart Lung, and Blood Institute’s Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies was used to assess each included studies quality. Pairwise Random-Effects and Multilevel Bayesian Network Meta-Analyses were used to synthesize available data. Results: Fifty-two observational studies were included (8872 participants; male/females 2674/3272; 16 studies lacked gender information). For normal occlusion, global pooled estimates for OR and AR means were 91.74% (95% CI: 91.37-92.10) and 78.24% (95% CI: 77.85-78.63), respectively. We could identify on Angle’s Class III patients meaningful OR and AR mean deviations from normal occlusion (0.89, 95% credible interval [CrI], 0.66-1.12, and 0.66, 95% CrI, 0.38-0.94, respectively), while on Class I patients we found a meaningful mean deviation from normal occlusion only for OR (0.25, 95% CrI, 0.03-0.47). Concerning gender impact, male patients presented higher OR (0.30, 95% CI 0.00-0.59) and AR (0.41, 95% CI 0.00-0.83) mean values than females in Class I. Conclusions: The results show that global pooled OR and AR mean values for normal occlusion patients are slightly above Bolton’s original values. Class I, for OR mean values, and Class III, for both OR and AR, are proportionally larger than normal occlusion patients. Gender had almost no impact on teeth mesiodistal proportion.
ARTICLE | doi:10.20944/preprints201902.0145.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: multilevel analysis; periodontal disease; nonsurgical periodontal therapy; risk factor; modelling; periodontal healing
Online: 18 February 2019 (07:31:01 CET)
This retrospective study aimed to investigate the effect of known risk factors on nonsurgical periodontal treatment (NSPT) response using a pocket depth fine-tuning multilevel linear model (MLM). Thirty-seven patients (24 males and 13 females) with moderate to severe chronic periodontitis were treated with nonsurgical periodontal therapy. Follow-up visits at 3, 6, and 12 months included measurement of several clinical periodontal parameters. Data were extracted from a database system. Probing depth (PD) and Clinical Attachment Loss (CAL) reductions after NSPT in an overall of 1416 initially affected sites (baseline PD ≥ 4 mm), distributed on 536 teeth, were analyzed against known risk factors at three hierarchical levels (patient, tooth and site). The variance component models fitted to assess the three-level variance of PD and CAL decrease for each post-treatment follow-up showed that all levels contributed significantly to the overall variance (P < 0.001). Patients that underwent NSPT and were continually monitored had very curative results. All three hierarchical levels included risk factors who had impact on the to influence the magnitude of PD and CAL reduction. Specifically, the tooth’s type, surfaces involved and teeth mobility site-level risk factors showed the highest influence on these reductions, being highly relevant factors for the NSPT success.