REVIEW | doi:10.20944/preprints202306.1835.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Dental implants; bleeding disorders; haemophilia; von Willebrand disease.
Online: 26 June 2023 (16:21:16 CEST)
Background: Bleeding disorders can be divided into three categories: congenital coagulation disorders (CCDs), antiplatelet induced bleeding disorders (APBDs) and anticoagulant induced bleeding disorders (ACBDs). Implant placement can be challenging in this kind of patients. The aim of this study is to provide evidence on implant surgery in patient with bleeding disorders and to generate some practical recommendations for clinicians. Material & Methods: Pubmed/MEDLINE, Scopus, Web of Science and Cochrane Library databases were screened. The latest search was performed in July 2022. Case Reports, Case Series, Cohort Studies, Cross-Sectional Studies, Case Control Studies, Reviews, Consensus Reports, Surveys and Animal Studies were included in the analysis. Results: Seventeen articles on CCDs were found, fourteen on APBDs, twenty-six on ACBDs. Most of these articles were case report or case series. Patients with CCDs can be treated after the infusion of the missing coagulation factor. Patients with APBDs can be treated without withdrawing the therapy. Patients with ACBDs should be treated depending on the anti-coagulative medication. Conclusion: Despite the low level of evidence, dental implants can be safely placed in patients with bleeding disorders. However, careful preoperative evaluation and the adoption of local and post-operative bleeding control measures are mandatory.
REVIEW | doi:10.20944/preprints202311.0924.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: dental implants; implant survival; biological complications; mechanical complications; yttria stabilized zirconia; marginal bone loss
Online: 14 November 2023 (15:27:29 CET)
The advent of zirconia ceramics with excellent mechanical, biomechanical and optical properties has made it an attractive metal-free substitute for titanium implants. Both animal and human studies have documented shortcomings with titanium implants. A review of the current literature on 3 iterations of zirconia implant designs has been challenging due to heterogeneous success data and limited follow-up. Zirconia implants hold promise for a new generation of dental implants, but technical developments are needed for design and material enhancements that will need to be validated by long-term rigorous studies.
COMMUNICATION | doi:10.20944/preprints202106.0407.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
ARTICLE | doi:10.20944/preprints202305.0647.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental implants; osseodensification; primary stability; macrogeometry
Online: 9 May 2023 (11:56:01 CEST)
Primary stability is an important factor for dental implant success. In the past years, a new method for bone site preparation was introduced, named osseodensification (OD). OD produces a condensation of the trabecular portion of the bone, increasing bone-to-implant contact and primary stability. This study aims to compare the effect of OD in cylindrical and conical implants to conventional instrumentation. A total of 40 implants, divided in 4 groups, were placed in porcine tibia: cylindrical conventional (1a); cylindrical OD (1b); conical conventional (2a); and conical OD (2b). Each implant was measured for implant stability quotient (ISQ), insertion torque (IT) and removal torque (RT). Group 2b showed the higher values for each of the evaluated parameters; groups 1b and 2b showed better results than 1a and 2a, respectively. Regarding IT and RT, group 1b achieved higher values than group 2a, but not for ISQ. The inter-groups comparison showed significant difference between groups 1a vs 2a, 1a vs 2b and 1b vs 2b for ISQ, and 1a vs 1b and 1a vs 2b for RT analysis. OD resulted in improved ISQ, IT and RT of both cylindrical and conical implants. Conical implants groups showed higher ISQ, but cylindrical OD resulted in higher IT and RT, compared to conical conventional ones.
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
REVIEW | doi:10.20944/preprints201807.0443.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: genetic factors; dental implants; bone quality; bone regeneration; success rate
Online: 24 July 2018 (06:01:10 CEST)
Dental implants provide a predictable treatment option for partial and complete edentulism via the placement of fixed permanent artificial root to support prosthetic dental crowns. Despite the high survival rates, long-term implant failures are still reported leading to implant removal and additional financial and health burdens. While extrinsic factors that improve survival rate of implants have been well explored, the impact of genetic factors on this matter is poorly understood. A systematic review and meta-analysis study was conducted to determine whether genetic factors contribute to increase the risk of dental implant failure. A comprehensive search for peer-reviewed articles on dental implants and genetics was performed using various literature database libraries. The study design was conducted according to PRISMA guidelines, and the obtained records were registered in PROSPERO database. According to the exclusion/inclusion criteria, 11 studies were eligible for this study out of 808 articles. The meta-analysis of the combined association studies of DNA variations and dental implants did not indicate an increase risk for implant failure due to DNA variations in IL-1B, IL-10 and TNF-α. This study emphasizes the need for larger randomized controlled clinical trails to inform clinicians and patients about the role of genetic factors on dental implant survival and success rate in healthy and compromised patients.
Subject: Chemistry And Materials Science, Electrochemistry Keywords: titanium dental implant; vitamin D3; bioactive coating; anticorrosion protection; EIS; DFT
Online: 10 September 2019 (11:35:26 CEST)
In recent years extensive studies have been continuously undertaken on the design of bioactive and biomimetic dental implant surfaces due to the need for improvement of the implant-bone interface properties. In this paper, the titanium dental implant surface was modified by a bioactive vitamin D3 coating prepared by self-assembly process. Surface characterization of the modified implant was performed by field emission scanning electron microscopy (FE-SEM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and contact angle measurements (CA). Implant’s electrochemical stability during exposure to an artificial saliva solution was monitored in situ by electrochemical impedance spectroscopy (EIS). Experimental results obtained were corroborated by means of quantum chemical calculations at the density functional theory level (DFT). The formation mechanism of the coating onto the titanium implant surface was proposed. During a prolonged immersion period, the bioactive vitamin D3 coating effectively prevented the underlying titanium from corrosive attack (polarization resistance in order of 107 Ω cm2) with ~95% protection effectiveness.
ARTICLE | doi:10.20944/preprints202107.0501.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Dental implants; Thermal stress; Modeling of heat transfer; Temperature changes; Heat equation; Analytical solution.
Online: 21 July 2021 (15:37:53 CEST)
Introduction: Heat is a kinetic process whereby energy flows from between two systems; hot-to-cold objects. In oro-dental implantology, conductive heat transfer/(or thermal stress) is a complex physical phenomenon to analyze and consider in treatment planning. Hence, ample research has attempted to measure heat-production to avoid over-heating during bone-cutting and -drilling for titanium (Ti) implant-site preparation and insertion, thereby preventing/minimizing early (as well as delayed) implant-related complications and failure. Objective: Given the low bone-thermal conductivity whereby heat generated by osteotomies is not effectively dissipated and tends to remain within the surrounding tissue (peri-implant), increasing the possibility of thermal-injury; this work attempts to obtain an exact analytical solution of the heat equation under exponential thermal-stress, modeling transient heat transfer and temperature changes in Ti implants upon hot-liquid intake. Materials and Methods: We investigate the impact of the material, the location point along implant length, and the exposure time of the thermal load on temperature changes. Results: Despite its simplicity, the presented solution contains all the physics and reproduces the key features obtained in previous numerical analyses studies. To the best of knowledge, this is the first introduction of the intrinsic time, a “proper” time that characterizes the geometry of the dental implant, where we show, mathematically and graphically, how the interplay between “proper” time and exposure time influences temperature changes in Ti implants, under the suitable initial and boundary conditions. Conclusions: This work aspires to accurately complement the overall clinical diagnostic and treatment plan for enhanced bone-implant interface, implant stability and success rates, whether for immediate or delayed loading strategies.
CASE REPORT | doi:10.20944/preprints202310.0362.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Cortical Lamina; Customised Abutments; Bone Augmentation; Cervical Profile; Dental Implants.
Online: 9 October 2023 (15:07:20 CEST)
Current scientific knowledge and guidelines in bone and soft tissue augmentation, suggest the use of staged surgical workflows as gold standards in regenerative procedures during implant therapy. In this context, the process is always the same regardless of the techniques applied: an alternate series of surgical acts is following one another after the completion of a specific period of osseointegration or graft maturation. As a result, the overall surgical treatment is often long, invasive and induce scar tissue formation. This article proposes a novel, fast and less invasive biphasic protocol with the use of a well documented cortical barrier mounted on stock healing abutments that are further replaced by customised abutments on an early second stage. 2 cases are reported, one for an upper maxillary edentulous area and the other for a mandibular, with a total of 4 implants placed. Results at 4 months post op, showed an optimal soft tissue configuration for both cases with adequate cervical profile generation and sufficient supracrestal complex height above the implant platforms. Significant bone gains were also recorded through CBCT data collection either with alveolar width measurements on axial slices, superposition of preop and postop datasets and 3D visualization after bone volume segmentation. Further studies will be needed in the future to evaluate the efficacy of this protocol in both hard and soft tissue augmentation for edentulous sites in need of implant rehabilitation.
ARTICLE | doi:10.20944/preprints202109.0221.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: quasi-static load; abutment screw; dental implant; finite element method; dynamic load; mesiodistal
Online: 13 September 2021 (15:55:30 CEST)
Variations in the implant thread shape and occlusal load behavior may result in significant changes in the biological and mechanical properties of dental implants and surrounding bone tissue. Most previous studies consider a single implant thread design, an isotropic bone structure, and a static occlusal load. However, the effects of different thread designs, bone material properties, and loading conditions are important concerns in clinical practice. Accordingly, the present study performs Finite Element Analysis (FEA) simulations to investigate the static, quasi-static and dynamic response of the implant and implanted bone material under various thread designs and occlusal loading directions (buccal-lingual, mesiodistal and apical). The simulations focus specifically on the von Mises stress, displacement, shear stress, compressive stress and tensile stress within the implant and the surrounding bone. The results show that the thread design and occlusal loading rate have a significant effect on the stress distribution and deformation of the implant and bone structure during clinical applications. Overall, the results provide a useful insight into the design of enhanced dental implants for an improved load transfer efficiency and success rate.
ARTICLE | doi:10.20944/preprints202306.0732.v1
Subject: Chemistry And Materials Science, Other Keywords: artificial bone; conical implants; cylindrical implants; dental implants; implant stability quotient; insertion torque; polyurethane; post-extraction sites; removal torque
Online: 9 June 2023 (16:15:15 CEST)
Keywords: artificial bone; conical implants; cylindrical implants; dental implants; implant stability quotient; insertion torque; polyurethane; post-extraction sites; removal torque.
ARTICLE | doi:10.20944/preprints202306.1720.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Bacterial leakage; Cone-Morse connection; dental implants; equicrestal implant placement; Finite Element Analysis (FEA); implant-abutment junction; implant placement; subcrestal implant placement.
Online: 25 June 2023 (05:49:19 CEST)
Peri-implant bone resorption has been reported around some implants after loading and this could create problems for the long-term stability of peri-implant soft and hard tissues. The causes are still not completely known, but a relevant importance could be assumed by the presence of a bacterial contamination at the micro-gap level of the implant-abutment junction. In this regard, external and internal implant-abutment assemblies have been shown to be much more permeable to bacterial colonization than Cone-Morse or conical connections. A subcrestal implant placement could have aesthetic advantages allowing a better prosthetic emergence profile. In literature controversial experimental and clinical results have been reported about bone resorption around implants placed equicrestally and subcrestally. Interestingly, Finite Element Analysis (FEA) studies revealed to be extremely useful for assessing the peri-implant bone strain and stress. Thus, the aim of this study was a FEA evaluation of implants with a Cone-Morse implant-abutment assembly (Implacil De Bortoli, São Paulo, Brazil) inserted into a bone block model (width: 10 mm, vertical height: 17.5 mm, thickness of the cortical area: 1.5 mm) mimicking equicrestal and subcrestal placements (1 and 2 mm). The results demonstrated that maximum stresses were observed within the cortical bone around the equicrestally placed implants, the lowest in the implant placed 2-mm subcrestally and intermediate stresses within the implant placed 1-mm subcrestally. Cortical bone was more stressed under lateral loads than axial loads. In conclusion, this FEA study suggested that implant placement at -1 mm could be recommended.
REVIEW | doi:10.20944/preprints202111.0490.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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/preprints202001.0064.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
ARTICLE | doi:10.20944/preprints201609.0041.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental anxiety; dental fear; anxiolytics; nitrous oxide
Online: 12 September 2016 (10:32:47 CEST)
Dental anxiety (DA) negatively affects patients’ oral and overall health. This study explored attitudes and clinical practices of licensed Ohio general dentists who treat patients with DA. Methods: An anonymous self-administered mail survey was sent to 500 general dentists licensed and practicing in Ohio. Responses to 21 pre-coded questions were analyzed. Frequencies were examined; cross-tabs, Chi-Square, and Fischer’s Exact Test were calculated for statements according to dentists’ gender. Alpha was set at p = 0.05. Results: Nearly all respondents treated anxious patients; males were more likely to find it challenging than females. Dentists were most familiar with distraction, although half found nitrous oxide to be an effective tool. Female dentists were more likely than males to be familiar with anxiolytics and find them effective. Conclusion: Overall, Ohio general dentists are most familiar with using distraction and nitrous oxide during appointments for anxious patients. Gender differences exist in attitudes towards anxiolytic use for patients with DA. Practice Implications: By identifying techniques that are comfortable for patient and practitioner, oral health disparities associated with DA may be reduced.
ARTICLE | doi:10.20944/preprints202306.2227.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Dental education; Dental curriculum; E-learning; Video learning
Online: 30 June 2023 (12:31:48 CEST)
Introduction: Dental students use of online material to supplement their learning has been studied but it is unclear whether educators are aware of the findings of this research. This study aimed to investigate dental students use of online content as a learning tool from an educator’s perspective. Methods: Educators in the Dublin Dental University Hospital were invited to complete an online survey based on dental students' use of online learning. Quantitative descriptive statistical analyses were carried out as appropriate on the data collected. A focus group with interested survey participants was held to gain a deeper insight into educator’s opinions on this topic. The transcript from this discussion was analyzed by deductive and inductive coding methods. Results: From a sample of 20 educators, this study found that educators were not aware that students rely on Google and YouTube for educational videos more than university websites. Most educators believed that students are likely to refer to online videos to prepare for dental procedures that they have not done before. The same amount also believed that teachers should incorporate videos into their learning. However, 30% of educators have not uploaded or recommended online videos to their students. Most educators believed they have discussed accuracy and/or relevancy of online content with their students. Interestingly, only 20% believed that students would discuss a contradictory video with their lecturers. The focus group participants expressed concern over the accuracy of online content. They felt that this along with a lack of time were the main reasons that deter them from referring students to online videos. Conclusions: Dental educators are unaware that students access online dental content through Google and YouTube more often than through official academic platforms. Educators are concerned about the accuracy of online dental content. Many believe that they direct their students on how to determine the accuracy of online content which contrasts with other researchers’ findings. More communication is needed between educators and dental students to address each other’s concerns and enhance student’s learning.
ARTICLE | doi:10.20944/preprints202307.0354.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: Dental Caries; Dental Anxiety; Salivary Biomarker; Stress; Cortisol; Children
Online: 5 July 2023 (16:49:09 CEST)
Aim: This study aimed to investigate the relationship between dental caries, dental anxiety, and salivary cortisol levels in children visiting pediatric dental clinics and their implications on pediatric oral health. Materials and Methods: A cross-sectional study was conducted at a dental university in the UAE. A total of 60 children, aged 4-12 years, were included. Salivary cortisol levels were measured using an Enzyme-Linked Immunosorbent Assay (ELISA) kit. Dental caries status was evaluated, and dental anxiety levels were assessed using the Modified Dental Anxiety Scale (MDAS). Statistical analyses, including Mann-Whitney U test and Pearson's correlation coefficient, were performed to determine significant differences and associations. Results: The study group showed significantly higher salivary cortisol levels compared to the control group (p<0.0001). A strong positive correlation was found between salivary cortisol levels and dental caries status (p<0.001). However, no significant difference in dental anxiety levels was observed between the study and control groups (p=0.85). A strong positive correlation was found between dental anxiety levels and dental caries status (p<0.001). Conclusion: The findings indicate a significant association between salivary cortisol levels and dental caries, suggesting that higher cortisol levels are associated with active caries. Dental anxiety levels were positively correlated with dental caries. Understanding the relationship between these variables can contribute to better oral health strategies and interventions for children, emphasizing the importance of managing dental anxiety and stress in pediatric dental care. Clinical Significance: This study highlights the potential of salivary cortisol as a biomarker for assessing stress and its impact on oral health in children. By addressing dental anxiety and stress, dental professionals can provide child-friendly dental care, enhance preventive measures, and improve oral health outcomes in pediatric patients.
ARTICLE | doi:10.20944/preprints202306.0721.v1
Subject: Engineering, Control And Systems Engineering Keywords: Dental bur; Dental material; Durability; Polynomial interpolation; Reliability; Wear
Online: 9 June 2023 (12:56:55 CEST)
The paper analyzes the phenomenon that condition the durability and reliability of a type of dental bur based on the wear of the active part and with effect on its quality. For the experimental study, a conical-cylindrical dental bur and a sample dental material in cobalt-chromium alloy, cylindrical shape, tested on a specially made experimental installation were used. The paper was limited to the consideration of a single parameter (loss of mass, mw by wear of the active part of the dental bur tested) for the establishment the durability and reliability, useful for the extension of the lifetime or even optimization of its operation. The wear phenomenon of the active part of dental bur is studied based on the results and experimental data obtained in the work process that was validated by interpolation and led to polynomial functions which approximate very well the dependent parameter, mw, considered in the experimental program. The results of the interpolation showed that in the first 11 h of work, the dental bur works with high efficiency, after which it can be easily decommissioned (optimizing operation, possibly constructive solutions); i.e., it should be replaced with a new one (criterion for replacing of worn dental bur).
ARTICLE | doi:10.20944/preprints202206.0107.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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 .
BRIEF REPORT | doi:10.20944/preprints202007.0734.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
Subject: Physical Sciences, Acoustics Keywords: oral health; dental checkup; Korea National Health and Nutrition Examination Survey (KNHANES); dental care; dental service utilization
Online: 15 March 2021 (10:57:43 CET)
To identify gender- and age-related associations between adult dental checkups and unmet dental care needs, we analyzed data of 14,000 participants, ages ≥ 19, from the 7th Korea National Health and Nutrition Examination Survey (2016–2018) (KNHANES VII). Data was collected via self-report questionnaires and interviews. Complex sample chi-square test and multiple logistic regression analysis indicated 31.7% of participants had unmet dental care needs; in the prior 12months, 67.1% had not utilized dental services, and 43.3% had not received dental checkups. Odds ratios (ORs) for dental checkups and unmet dental needs were 8.87 (CI:7.80–10.09, p < 0.001) for those who used dental services and 1.28 (CI: 1.13–1.44, p < 0.001) for those who had not. Significant age-dependent associations between those not receiving dental checkups and the rate of unmet dental care include men and women aged 50–59 years (OR: 1.77; CI = 1.22–2.58 and OR: 1.43; CI: 1.02–2.02; p = 0.040, respectively) and women ≥ 70 years (OR = 1.79, CI = 1.20–2.66, p = 0.004). Reducing unmet dental care needs requires greater public health promotion and education regarding regular dental checkups; additional practical strategies could enhance dental checkup compliance.
REVIEW | doi:10.20944/preprints202305.0457.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: Dental stem cells; Mesenchymal Stem Cells; Dental Pulp Stem Cells; Dental Bud Stem Cells; bone regeneration; osteogenic differentiation
Online: 8 May 2023 (05:33:58 CEST)
Teeth include mesenchymal stem cells (MSCs), which are multipotent cells that promote tooth growth and repair. Dental tissues, specifically the dental pulp and the dental bud, constitute a relevant source of multipotent stem cells, known as dental-derived stem cells (d-DSCs): dental pulp stem cells (DPSCs) and dental bud stem cells (DBSCs). Cell treatment with bone-associated factors and stimulation with small molecule compounds are, among the available methods, the ones who show excellent advantages promoting stem cell differentiation and osteogenesis. Recently, attention has been paid to studies on natural and non-natural compounds. Many fruits, vegetables and some drugs contain molecules that can enhance MSC osteogenic differentiation and therefore bone formation. The purpose of this review is to examine research work over the past 7 years that has investigated two different types of MSCs from dental tissues that are attractive targets for bone tissue engineering: DPSCs and DBSCs. We focused on articles hypothesizing the identification and study of compounds that induce proliferation and osteogenic differentiation of the two d-DSC populations, representing an interesting issue for regenerative medicine. The reconstruction of bone defects in fact is still a challenge for personalized medicine.
ARTICLE | doi:10.20944/preprints202306.0963.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Dental implants; Dental Implant-Abutment Design; keyword 1; X-Ray Microtomography
Online: 14 June 2023 (03:15:05 CEST)
Background and Objectives: Mechanical and biological complications can lead to system fracture or screw loss on dental implants. Narrow and regular platforms have been used without a consensus about the effect of distance the abutment from the prosthetic platform margin. The aim of this study is to evaluate different insertion torques in the deformation of tri-channel platform connections through two- and three-dimensional measurements with micro-CT. Materials and Methods: 164 implants were divided into groups (platform diameter and type): 3.5, 3.75, and 4.3 mm NP (Narrow Platform), and 4.3 mm RP (Regular Platform). Each implant-platform group was then divided into four subgroups (n = 10) with different torques: T45 (45 Ncm), T80 (80 Ncm), T120 (120 Ncm) and T150 (150 Ncm). The implant-abutment-screw assemblies were scanned and the images obtained were analyzed. Results: A significant difference was observed for the linear and volume measures between the different platforms (p <0.01) and the different implant insertion torques (p <0.01). Qualitative analysis suggested higher deformation resistance for the 3.75 NP compared to the 3.5 NP, and RP was more resistant compared to the NP. Conclusions: The 0.25-mm increment in the implant platform did not increase the resistance to the applied insertion torques; the 4.3-mm implant was significantly stronger compared to the 3.5-mm implant and the proposed micro-CT analysis was considered valid for both 2D and 3D analyses of micro gaps, qualitatively and quantitatively.
REVIEW | doi:10.20944/preprints202105.0296.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: CAD/CAM; dental restoration; ceramic; all-ceramic; survival; fixed dental prosthesis
Online: 13 May 2021 (13:18:51 CEST)
Although CAD/CAM ceramics present a promising alternative to metal-ceramic fixed dental prostheses, little is known about their mid- and long-term clinical performance. This systematic review aims to estimate the survival and success rates and describes the underlying complication characteristics for CAD/CAM tooth-supported fixed dental prostheses (FDPs). We systematically searched MEDLINE and Web of Science to find relevant prospective studies with a follow-up of at least one year. We estimated pooled 1-, 5- and 10-year survival and success rates by combining the collected data in a Poisson regression model. Descriptive statistics were conducted to evaluate the distribution of failures and complications in the included studies. Risk of bias for the included studies was assessed with an adapted checklist for single-arm trials. Pooled estimated 1-, 5-, and 10-year survival rates ranged from 93.80% to 94.66%, 89.67% to 91.1%, and 79.33% to 82.20%, respectively. The corresponding success rates, excluding failures but including any other types of intervention, were 94.53% to 96.77%, 90.89% to 94.62%, and 81.78% to 89.25%. Secondary caries was the most frequent cause of failure, followed by chipping of the veneering. The most common cause of complication, excluding failures but requiring intervention, was chipping of the veneering. Risk of bias was generally acceptable for the included studies, with 7 studies associated with low risk of bias, 8 studies with a moderate risk of bias, and 3 studies with serious risk of bias. The current meta-analysis on CAD/CAM supported FDPs revealed satisfying survival and success rates for up to 10 years of exposure. More prospective studies focusing on long-term performance are needed to strengthen the evidence currently available in the literature.
CASE REPORT | doi:10.20944/preprints202309.1890.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Synthetic, Alloplast, Dental Implant,
Online: 27 September 2023 (11:12:30 CEST)
Abstract: With a resurgence in ITRT (Immediate Tooth Replacement Therapy) as a method of preserving both hard and thus soft tissues for improved aesthetic outcomes, this multi-centre, retrospective study will look at two novel products and their effect on these outcomes. A new synthetic particulate graft material along with a novel Implant design was utilized in the study and a 1 year follow up assessment, analysed for hard and soft tissue regeneration.
ARTICLE | doi:10.20944/preprints202206.0239.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Mouth; Dental diseases; Surgery
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.
ARTICLE | doi:10.20944/preprints202311.0758.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: forensic odontology; forensic dentistry; awareness on forensic odontology; dental students; dental faculty
Online: 13 November 2023 (10:12:48 CET)
This study sought to evaluate the awareness, comprehension, and practices concerning Forensic Odontology among dental students and faculty at a Dental School in Cyprus. An online, cross-sectional, descriptive survey was disseminated to the entirety of dental students and faculty of the School of Dentistry, European University Cyprus, in November 2022. Of those surveyed, 47 faculty members and 304 students responded, yielding response rates of 66.2% and 80%, respectively. The survey revealed that 87% of faculty and 65% of students were familiar with Forensic Odontology. A noteworthy 94% of faculty and 85% of students recognized teeth as DNA repositories. A high percentage, 98% of faculty and 89% of students, acknowledged the role of Forensic Odontology in the identification of criminals and deceased individuals. Awareness of age estimation through dental eruption patterns was evident in 85% of faculty and 81.6% of students. A substantial proportion (80% of faculty) maintained dental records, while 78% of students recognized the importance of dental record-keeping in ensuring quality care. Interestingly, 57% of students and 64% of faculty were aware of the possibility of dentists testifying as expert witnesses. The majority, 95.7% of faculty and 85% of students, concurred that physical harm, scars, and behavioral alterations predominantly indicate child abuse. The survey underscored a robust awareness of Forensic Odontology among respondents. Despite faculty's comprehensive understanding, there's a pronounced need to bolster their inclination towards attending relevant seminars. Emphasis on improved record-keeping practices for potential forensic applications is paramount.
ARTICLE | doi:10.20944/preprints202308.0915.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental implants; cone beam computed tomography; CBCT; predictability; predictability of dental implants
Online: 11 August 2023 (09:53:40 CEST)
Since the development of CBCT had been utilized in dentistry, the images of the CBCT can assist the surgeon to evaluate the anatomy carefully. Despite the value of the radiology evaluation, the implant procedures may require additional consideration rather than only evaluating the anatomical factors. The purpose of this study is to evaluate the predictability of using CBCT alone to plan for implant placement on the edentulous patient digitally CBCT images were analyzed by clinicians, measuring the ridge heights and widths of 4 selected implant sites in the maxillary and 2 selected implant sites in the mandibular arches for 91 patients planning for the implant-supported overdenture. (A total of 47 patients out of the 91 had completed the implant placement on the edentulous ridge, contributing to 55 upper and/or lower arches (136 dental implants). . Both predictabilities are low, implying the CBCT planning for implant placement on the edentulous ridge is not a good index and is insufficient to predict the surgical procedures as a solo method. The finding of this study indicates that digital planning by CBCT is insufficient to serve as an individual tool to predict implant procedures. Further information and evaluation must be considered for implant placement on the edentulous ridge.
REVIEW | doi:10.20944/preprints202006.0102.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
REVIEW | doi:10.20944/preprints202101.0306.v2
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Anemia; dental; management; oral manifestations
Online: 17 February 2021 (10:45:35 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 condition is essential for the dental practitioner, with emphasis on alerting signs, dental management and proper communication with patient’s physician.
ARTICLE | doi:10.20944/preprints201905.0117.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental scaling; MADM; Piezon; TOPSIS
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 And Pharmacology, Dentistry And Oral Surgery 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.
ARTICLE | doi:10.20944/preprints202104.0791.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: COVID-19 Vaccines; Cross-Sectional Studies; Decision Making; Dental Education; Dental Students; International Association of Dental Students; Mass Vaccination; Multicenter Study; Social Determinants of Health
Online: 30 April 2021 (15:26:07 CEST)
Background: Acceleration of mass vaccination strategies is the only pathway to overcome the COVID-19 pandemic. Healthcare professionals and students have a key role in shaping public opinion about vaccines. This study aimed to evaluate the attitudes of dental students globally towards COVID-19 vaccines and explore the potential drivers for students' acceptance levels; Methods: A global cross-sectional study was carried out in February 2021 using an online ques-tionnaire. The study was liaised by the scientific committee of the International Association of Dental Students (IADS), and data was collected through the national and local coordinators of IADS member organizations. The dependent variable was the willingness to take the COVID-19 vaccine, and the independent variables included demographic characteristics, COVID-19-related experi-ence, and the drivers of COVID-19 vaccine-related attitude suggested by the WHO-SAGE; Results: A total of 6639 students from 22 countries representing all world regions responded to the ques-tionnaire properly. Their mean age was 22.06 ± 2.79 (17-40) years, and the majority were females (70.5%), in clinical years (66.8%), and from upper-middle-income economies (45.7%). In general, 22.5% of dental students worldwide were hesitant, and 13.9% rejected COVID-19 vaccines. The students in low- and lower-middle-income (LLMI) economies had significantly higher levels of vaccine hesitancy compared to their peers in upper-middle- and high-income (UMHI) economies (30.4% vs 19.8%; p < 0.001); Conclusions: The global acceptance level of dental students for COVID-19 vaccines was suboptimal, and their worrisome level of vaccine hesitancy was influenced by the socioeconomic context where the dental students live and study. The media and social media, public figures, insufficient knowledge about vaccines, and mistrust of governments and the pharmaceutical industry were barriers to vaccination. The findings of this study call for further implementation of epidemiology (infectious diseases) education within undergraduate dental curricula.
ARTICLE | doi:10.20944/preprints202202.0354.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: Dental segmentation; deep learning; panoramic radiograph
Online: 28 February 2022 (10:15:46 CET)
Introduction: Dental segmentation in panoramic radiograph has become very relevant in dentistry, since it allows health professionals to carry out their assessments more clearly and helps them to define the best possible treatment plan for their patients. Objectives: In this work, a comparative study is carried out with four segmentation algorithms (U-Net, DCU-Net, DoubleU-Net and Nano-Net) that are prominent in the medical literature on segmentation and we evaluate their results with the current state of the art of dental segmentation in panoramic radiograph. Methods: These algorithms were tested with a dataset consisting of 1,500 images, considering experiment scenarios with and without augmentation data. Results: DoubleU-Net was the model that presented the best results among the analyzed models, reaching 96.591% accuracy and 92.886% Dice using the dataset with data augmentation. Another model that stood out was Nano-Net using the dataset without data augmentation; this model achieved results close to that of the literature with only 235 thousand trainable parameters, while the literature model (TSASNet) contains 78 million. Conclusions: The results obtained in this work are satisfactory and present paths for a better and more effective dental segmentation process.
BRIEF REPORT | doi:10.20944/preprints202108.0462.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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/preprints202012.0371.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental preventive care; adolescents; risk factors
Online: 15 December 2020 (10:35:17 CET)
Abstract: The study aimed to determine the factors associated with the avoidance of dental preventive care in adolescents and their parents in the framework of The Youth and Parents Risk Factor Behavior Survey in Slovakia has been initiated during the years 2015/2016. The data were collected using two separate standardized questionnaires: (i) the questionnaire for adolescents (n=515) and (ii) the questionnaire for parents (n=681). The study group consisted of 57 adolescents (54.4% males) who did not visit the dentist for preventive care in the previous year. The control group consisted of 458 adolescents (35.8% males) who visited a dentist for preventive care at least once in the previous year. A significantly higher number of males (54.4%), older adolescents (21.4%) were not visiting dental preventive care regularly. Incomplete family (56.1%), stressful situations at home (17.5%), and feeling unwell were observed as the factors contributing to the avoidance of dental preventive care. More than 34.5% of adolescents were not visiting either dental preventive care but also pediatric preventive care (AOR=5.14; 95%CI=2.40, 10.99). Divorced mothers and mothers with household income lower than 900 € had significantly higher dental care avoidance in their children. A significantly higher percentage of fathers from the exposed group were not visiting dental preventive care regularly (47.8%; p< .05). The results of the study can be used as an educational intervention steps focusing on the influence of parental and adolescent behavior in dental preventive care.
ARTICLE | doi:10.20944/preprints202305.0954.v1
Subject: Public Health And Healthcare, Public, Environmental And Occupational Health Keywords: water quality; infection control; occupational practices; dental unit; dental office; waterlines; antiseptic protocols; water sustainability, environmentalism
Online: 12 May 2023 (13:40:37 CEST)
Dental healthcare providers, staff and patients are constantly exposed to the risk of infection or cross-infection in the dental office, particularly due to the formation of biofilms within Dental Unit Waterlines (DUWLs). Good water quality, achieved with environmentally friendly means, is essential in ensuring the safe operation of the clinic. The aim of this study was to evaluate the practices and protocols used in dental offices of Metropolitan Athens in Greece with regards to water quality in DUWLs. The questionnaire about water quality was distributed to dental practitioners in 2022 and was completed by 206 dentists. Water supplied to dental units was mainly from the public network (65.0%), with 55.8% using in-office filtration. Most dentists (71.8%) do not know the active substance of the antiseptic used for the DUWLs, while 96.1% reported having an antiseptic reservoir embedded in the dental unit. Daily flushing with a small and a large amount of fluid was practiced in approximately 83% and 61% of dental offices, respectively. Dental associations should raise awareness regarding water quality and maintenance of DUWLs in dental offices, investing in lifelong learning, while implementing protocols and green strategies.
ARTICLE | doi:10.20944/preprints202310.1762.v1
Subject: Engineering, Mechanical Engineering Keywords: lateral screw retained; retrievability; retention; dental implants
Online: 27 October 2023 (08:22:07 CEST)
This study aims to develop a novel retention method combining the retrievability of the screw retention method with the ideal occlusal table and the aesthetics capability of cement retention. Coping was developed to have lateral screw access allowing the screw to lock coping using lateral forces from screw tightening and friction between the tip of the screw and the sandblasted surface of an abutment. Sandblasting parameters varied based on particle size. Results show a positive correlation to surface roughness and indicate a positive correlation to retention force. The highest surface roughness and retention force result was shown by groups that were sandblasted using 686 μm of aluminum oxide. Experiment on the tightening strength of 48 subjects measured in simulated conditions similar to assembly conditions of lateral screw retention implant resulted in a mean of 69.75 Nmm with the highest and lowest values of 120.67 Nmm and 34.67 Nmm. This result became the basis of tightening torque variation. Each group's retention capability is measured and compared to cement-retained dental implants. Results show that tightening torque correlates positively with retention force, with the highest average retention score showed by lateral screw retained under tightening torque of 200 Nmm with 317.87 N higher than cement-retained.
ARTICLE | doi:10.20944/preprints202310.0248.v1
Subject: Public Health And Healthcare, Other Keywords: oral hygiene; dentifrices; cellulose; nanoparticles; dental plaque
Online: 6 October 2023 (11:28:12 CEST)
Dentifrice performance in the removal of dental plaque is influenced by the interactions of dentifrice components with tooth surfaces. This randomized controlled clinical study assessed the effectiveness and safety of a novel fluoride dentifrice formulation that included a micro-fibrillated cellulose network with entangled microcrystalline cellulose and silica particles (ProtegeraTM), and compared this to a positive control fluoride dentifrice (Crest Cavity Protection™). Whole mouth dental plaque levels in 82 healthy adults were measured after the first supervised use, and following a week of twice daily use at home. Overall, the novel dentifrice was at least three times more effective in whole mouth plaque reductions than the reference dentifrice (p < 0.001), with a 38.6% reduction on first use, a 30.9% reduction at day 7, and a 41.6% reduction from day 1 to day 7, compared to reductions of 12.0%, 9.6%, and 11.6% respectively for the positive control. No safety issues arose from the use of the novel dentifrice. These results indicate that including micro-fibrillated cellulose enhances plaque removal effectiveness, without causing adverse changes to oral soft tissues.
ARTICLE | doi:10.20944/preprints202309.0924.v1
Subject: Engineering, Bioengineering Keywords: bioelectric effect; microcurrent; toothbrush; dental; biofilm; plaque
Online: 14 September 2023 (03:57:45 CEST)
Effective oral care is a critical requirement to maintain high quality of life. Most oral diseases are caused by plaque (oral biofilm), which is also correlated with systemic diseases. A common method to remove biofilm is brushing teeth with a toothpaste. However, 3.5 billion people in the world have oral diseases, meaning that more efficient methods of removing biofilms are needed. We have developed a toothbrush applying bioelectric effect (BE) utilizing an electric force for biofilm removal. It demonstrated significantly higher biofilm removal efficiency than non-BE manual toothbrushes. Tests were performed in saline and toothpaste conditions using various pressure. Results showed that the BE toothbrush had a significantly higher biofilm removal efficiency in saline (0.5 N: 215.43 ± 89.92 %, 2.5 N: 116.77 ± 47.02 %) and in a toothpaste slurry (0.5 N: 104.96 ± 98.93 %, 2.5 N: 96.23 ± 35.16 %) than non-BE manual toothbrushes. Results also showed that BE toothbrushes were less dependent on toothpaste. This study suggests that the application of BE can be a new solution to plaque problems in oral care.
ARTICLE | doi:10.20944/preprints202307.1109.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: Chewing ability; Cognitive function; Dental health; Denture
Online: 17 July 2023 (15:18:57 CEST)
Very poor oral health, common among older adults, is associated with cognitive decline.This study aimed to investigate the association between denture use, chewing ability, and cognitive function in Korean middle-aged adults using samples representing middle-aged people at the national level. This longitudinal study included 9,998 middle-aged adults via Korea Longitudinal Study of Aging 7th special survey data. Denture use, chewing ability, health-related factors, and general characteristics were assessed by the Computer Assisted Personal Interview. After controlling general characteristics using a generalized estimating equation model, the association of denture use and MMSE scores with chewing ability of those with or without dentures and MMSE scores were analysed. Twenty-four percent of participants wore dentures among them, 35.1% complained of difficulty chewing when wearing dentures. Among participants who did not wear dentures, 16.4% complained of difficulty chewing. MMSE scores were lower among denture-wearers than non-denture wearers (β = -0.026, p < 0.001). In both groups, MMSE scores decreased with chewing difficulty and were significantly reduced among non-denture wearers (p < 0.05). Chewing ability was closely associated with cognitive function. Given the negative effect of difficulty chewing on cognitive function, maintaining chewing ability should be of great concern.
ARTICLE | doi:10.20944/preprints202307.0665.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: surface treatment; titanium; hierarchical structures; dental implant
Online: 11 July 2023 (05:25:10 CEST)
Titanium (Ti) and Ti-based alloys are commonly used in dental implants, and surface modifications of dental implants are important for achieving osseointegration (i.e., direct connection between the implant surface and bone). This study investigated the effect of an eco-friendly etching solution—a hydrogen peroxide–sodium bicarbonate mixture—on the surface properties and contact angles of and osteoblast adhesion and proliferation on Ti surfaces. Disk-shaped Ti specimens were prepared using different surface treatments (machining, sandblasting, and sandblasting/acid-etching), and they were immersed in the etching solution and then ultrasonically cleaned. Surface characterization was performed using scanning electron microscopy, digital microscopy, contact angle analysis, and X-ray photoelectron spectroscopy. MG-63 osteoblasts were cultured on the specimens, and their adhesion to the specimen surface and their proliferation were examined using staining and the MTT assay, respectively. Additional etching with the etching solution caused the formation of nano/micro hierarchical structures, increased the surface roughness, and enhanced the hydrophilicity. Osteoblast adhesion and proliferation were found to improve on the modified surfaces. The eco-friendly etching method has the potential to enhance the biological properties of Ti implant surfaces and to thereby improve the dental implant performance.
REVIEW | doi:10.20944/preprints202305.0360.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: plants; cannabinoids; CBD; pharmacology; dental medicine; patents
Online: 5 May 2023 (11:00:26 CEST)
The medical use of Cannabis has a very long history. Although many principles are present in cannabis, called cannabinoids, Δ9tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD) and can-nabinol (CBN) are the three main cannabinoids most present and described. CBD itself is not re-sponsible for psychotropic effects of cannabis since does not produce the typical behavioral effects associated to the consumption of this drug. Cannabidiol (CBD) has recently gained growing at-tention in modern society and seems to be more and more explored in dentistry. Several subjective findings suggest some therapeutic effects of CBD, which are strongly supported by research evi-dence. However, there is a plethora of data regarding CBD’s mechanism of action and therapeutic potential, which are in many cases contradictory. We will first provide an overview of scientific evidence on the molecular mechanism of CBD’s action. Furthermore, we will map the recent de-velopments regarding possible oral benefits of CBD. In summary, we will highlight CBD’s prom-ising biological features for dentistry application, despite exiting patents suggest current the compositions for oral care as the main interest for industry.
ARTICLE | doi:10.20944/preprints202302.0167.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Oral Health; Systemic Health; Colonial Dental Health
Online: 9 February 2023 (11:31:49 CET)
The aims of this study are to determine the oral health status of a rare sample of 19th-century migrant settlers to South Australia, how oral conditions may have influenced their general health, and how the oral health of this group compares with contemporaneous samples in Australia, New Zealand, and Britain. Dentitions of 18 adults and 22 subadults were investigated using non-destructive methods (micro-CT, macroscopic, radiographic). Extensive carious lesions were identified in 17 adults and 4 subadults, from this group 1 subadult and 16 adults had antemortem tooth loss. Sixteen adults showed evidence of periodontal disease. Enamel hypoplastic (EH) defects were identified in 14 adults and 9 subadults. Many individuals with dental defects also had skeletal signs of co-morbidities. South Australian individuals had the same percentage of carious lesions as the British sample (53%), more than other historic Australian samples, but less than a contemporary New Zealand sample. Over 50% of individuals from all the historic cemeteries had EH defects suggesting systemic health insults during dental development were common during the 19th century. The overall oral health of the South Australian settlers was poor but, in some categories, (tooth wear, periapical abscess, periodontal disease), better than the other historic samples.
BRIEF REPORT | doi:10.20944/preprints202110.0285.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
ARTICLE | doi:10.20944/preprints202105.0363.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Dental composite, Methacrylated calcium phosphate, translucency, Biomineralization
Online: 16 May 2021 (22:39:21 CEST)
The aim of this study was to synthesize and characterize a novel Methacrylate- functionalized Calcium Phosphate (MCP) used as a bioactive compound for innovative dental composites. The characterization was accomplished by Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR), X-Ray Diffraction Analysis (XRDA), Scanning Electron Microscopy (SEM), and EnergyDispersive Spectroscopy (EDS). The incorporation of MCP as a bioactive filler in esthetic dental composite formulations and the ability of MCP containing dental composites to promote precipitation of hydroxyapatite (HAp) on the surfaces of those dental composites was explored. The translucency parameter, depth of cure, degree of conversion, ion release profile, and other physical properties of composites were studied with respect to the amount of MCP added to the composites. Composites containing 3 Wt.%, 6 Wt.%, and 20 Wt.% MCP were evaluated at 7, 14, and 21 days. The progress of surface precipitation of hydroxyapatite on MCP-containing dental composites was studied by systematically increasing the MCP content in the composite and the time of specimen storage in Dulbecco’s phosphate-buffered solution with calcium and magnesium. It was found that there was a direct correlation between the percentage of MCP in a composite formulation, the amount of time the specimen was stored in PBS, and the deposition of hydroxyapatite on the composite’s surface
REVIEW | doi:10.20944/preprints202008.0075.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: dental materials, nanomaterials, zeolite, graphene, nanoparticles, nanofibers
Online: 4 August 2020 (04:48:03 CEST)
The results of the bibliographic analysis show that the most explored nanomaterials in dentistry are graphene and carbon nanotubes, and their derivatives. A detailed analysis and a comparative study on their applications show that, although they are quite similar, graphene based materials seem to be more promising for most of the applications of interest in dentistry. The bibliographic study also demonstrated the potential of zeolite based materials, although the low number of studies on their applications shows that they have not been totally explored, as well as other porous nanomaterials that found important applications in medicine, such as metal organic frameworks, have not been explored. Subsequently, it is expected that the research effort will concentrate in graphene and zeolite based materials in the incoming years. Thus, present review paper presents a detailed bibliographic study, with more than 200 references, in order to describe briefly the main achievements that have been described in dentistry using nanomaterials, compare and analyze them in a critical way, with the aim of predicting the future challenges.
ARTICLE | doi:10.20944/preprints202002.0010.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: autogenous demineralized dentin matrix; osseointegration; dental implants
Online: 3 February 2020 (04:45:18 CET)
Autogenous demineralized dentin matrix (ADDM), derived from human extracted tooth, is commonly used as a bone-graft substitute to reconstruct alveolar defects when placing dental implants. The purpose of this retrospective study is to examine efficacy of ADDM in terms of surgical complications and marginal bone resorption by analyzing the medical records and radiographs of patients who received ADDM graft from 2008 to 2011 in our institute. Occurrence of complications, marginal bone loss around implants were investigated with regard to the type of defect, location of bone grafting, and types of bone graft techniques. ADDM-based bone grafting was performed on 221 sites in 82 patients and 208 implants were placed afterwards: The percentage of complications after bone grafting was 15.84%, and the implant survival rate was 95.19%. All complications were resolved with conventional treatment except for the 10 cases of osseointegration failure. The average marginal bone loss was 0.31 mm at the last examination after the average follow-up period of 7.2 years. Within the limitation of this study, the results of long-term follow-up are consistent with the short-term results of relevant studies. ADDM can produce promising clinical outcomes when used for alveolar ridge augmentation around implants.
COMMUNICATION | doi:10.20944/preprints201806.0203.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Zirconia; primer; priming; bonding; catechol; dental; prosthodontics
Online: 13 June 2018 (06:06:31 CEST)
Zirconia has recently become one of the most popular dental materials in prosthodontics being used in crowns, bridges, and to implants. However, weak bonding strength of dental adhesives and resins to zirconia surface has been a grand challenge in dentistry, thus finding a better adhesion to zirconia is urgently required. Marine sessile organisms such as mussels use a unique priming strategy to produce a strong bonding to wet mineral surfaces; one of the distinctive chemical features in the mussel’s adhesive primer proteins is high catechol contents among others. In this study, we pursued a bioinspired adhesion strategy, using a synthetic catechol primer applied to dental zirconia surfaces to study the effect of catecholic priming to shear bonding strength. Catechol priming provided a statistically significant enhancement (P < 0.05) in shear bonding strength compared to the bonding strength without priming, and relatively stronger bonding than commercially available zirconia priming techniques. This new bioinspired dental priming approach can be an excellent addition to the practitioner’s toolkit to improve dental bonding to zirconia.
REVIEW | doi:10.20944/preprints201802.0051.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: metals; dental regeneration; bioactivity; tissue regeneration; bone
Online: 6 February 2018 (05:25:46 CET)
The regeneration of bone tissue is a main purpose of most therapies in dental medicine. For bone regeneration, calcium phosphate (CaP)-based substitute materials based on natural (allo- and xenografts) and synthetic origins (alloplastic materials) are applied for guiding the regeneration processes. The optimal bone substitute has to act as a substrate for bone ingrowth into a defect, while it should be resorbed even in the time frame needed for complete regeneration up to the condition of restitution ad integrum. In this context, the modes of action of CaP-based substitute materials have been frequently investigated and it has been shown that such materials strongly influence regenerative processes such as osteoblast growth or differentiation and also on osteoclastic resorption due to different physicochemical properties of the materials. However, the material characteristics needed for the required ratio between the formation of new bone tissue and material degradation has not been found until now. The addition of different substances such as collagen or growth factors and also of different cell types have already been tested but did not allow for sufficient or prompt application. Moreover, metals or metal ions are differently used as basis or as supplement for different materials in the field of bone regeneration. Moreover, it has already been shown that different metal ions are integral components of bone tissue playing functional roles in the physiological cellular environment as well as in the course of bone healing. The present review focuses on frequently used metals as integral parts of materials designated for bone regeneration with the aim to give an overview of currently existing knowledge about the effects of metals in the field of bone regeneration.
ARTICLE | doi:10.20944/preprints202108.0413.v3
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
REVIEW | doi:10.20944/preprints202310.1771.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: forensic dentistry; age estimation; dental maturation; umbrella review
Online: 27 October 2023 (09:26:27 CEST)
Age estimation is an important tool when dealing with human remains or undocumented minors. Although the skull, the skeleton or the hand-wrist are used on age estimation as maturity indicators, they often present lack of good conditions for a correct identification or estimation. Few systematic reviews (SRs) have been recently published; therefore, this umbrella review critically assesses their level of evidence and provides a general comprehensive view. An electronic database search was conducted in four databases (PubMed, Cochrane, WoS, LILACS) up to December 2022, focusing on SRs of age estimation through forensic dentistry procedures. The methodological quality was analyzed using the measurement tool to assess SRs criteria (AMSTAR2). Eighteen SRs were included, five of critically low quality, six of low quality, three of moderate quality and four of high quality. The SRs posited that Willems’ method is more accurate and less prone to overestimation; most methods seem to be geographically sensitive; and 3D-Imaging and artificial intelligence tools demonstrate high potential. The quality of evidence on age estimation using dental approaches was rated as low to moderate. Well-designed clinical trials and high standard systematic reviews are essential to corroborate the accuracy of the different procedures of age estimation in forensic dentistry.
ARTICLE | doi:10.20944/preprints202309.1454.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: cone morse connection; dental implants; prosthesis; FEA; Implantology
Online: 21 September 2023 (05:42:29 CEST)
Today, dental implantology is a reliable technique for the treatment of partial and total edentulism. The fixing of dentures on dental implants can be achieved by a number of different techniques. The choice of technique depends on the specific needs of the patient, the condition of the jawbone and the design of the prosthesis itself. Currently, the two most common types of prosthetic abutment connections are cemented or screwed connections, both of which have disadvantages and ad-vantages. The aim of this study is to analyze, with Finite Element Analysis (FEA), a new Cone Morse connection system between the prosthesis and implant. The connection retention has been analyzed by adopting three different approaches: analytical, in vitro and the FEA method. The systems formed by abutment, healing-cap, and crown with three different inclination conditions were modeled in 3D: 0°, 15° and 30°. With Ansys finite element software, the effect of tilt on system retention was studied. The FEA analysis showed comparable results with in vitro studies regarding the retention strength for an abutment-cap system with a taper of 4°, obtaining 66.6 N compared to 68 N calculated through an in vitro study. The inclination of the abutment affects the retention of the system because the hole made on the surface of the abutment, decreases the contact area between the components. The Cone Morse prosthesis implant connection system is the most stable and efficient system compared to the threaded or cemented system. Retention is influenced by factors such as abutment conicity, insertion strength and the contact surface be-tween components.
REVIEW | doi:10.20944/preprints202308.0622.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Photodynamic Therapy; Pediatric Dentistry; oral health; dental care
Online: 8 August 2023 (14:16:31 CEST)
Microbiological control of dental pathologies presents a significant clinical challenge for dental surgeons, particularly considering drug-resistant microorganisms. To address this issue, Antimi-crobial Photodynamic Therapy (PDT) has emerged as an effective and complementary technique for microbial reduction. This therapy involves the application of a photosensitizer dye (PS) either topically or systemically, followed by exposure to low-power lasers with appropriate visible light wavelengths. PDT has found a valuable place in dentistry across various specialties, including surgery, periodontics, endodontics, dentistry, implantology, orthodontics, and pediatrics. In the realm of pediatric dentistry, managing microorganisms during dental treatments has become a major challenge.This article reviews the evidence supporting the potential of photodynamic therapy in combating bacteria, fungi, and viruses, with a particular focus on areas such as endodontics, restoration in deciduous teeth, implantology, and periodontics for bacterial control. Additionally, PDT has shown promise in stomatology, specifically in the treatment of mucositis and herpes. Considering its promising results and ease of application, photodynamic therapy presents an in-teresting alternative for clinical practice. However, it is important to note that specific protocols must be followed for each application, encompassing the type of photosensitizer, concentration, pre-irradiation time, light type, wavelength, energy, power, and mode of light delivery. Researchers have been steadily refining these protocols to facilitate PDT's integration into clinical practice.
ARTICLE | doi:10.20944/preprints202307.1668.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: porcine bone grafts; horizontal ridge augmentation; dental implant
Online: 25 July 2023 (08:29:55 CEST)
The purpose of this study was to evaluate the outcomes of implants placed in horizontally augmented alveolar ridges using porcine bone grafts and to investigate the long-term stability of the porcine bone grafts. A retrospective analysis was conducted on 55 sites that underwent horizontal ridge augmentation using porcine bone grafts and implant placement with a follow-up period longer than 5 years. Furthermore, additional analysis was conducted on 24 sites where porcine bone grafts were used exclusively and implants were placed simultaneously with horizontal ridge augmentation. The mean follow-up period after prosthesis loading was 67.3 months, with a mean marginal bone loss of 0.18 mm at 1 year and a cumulative mean marginal bone loss of 0.37 mm over the entire follow-up period. Of the 55 implants, 2 were lost and 4 did not meet the success criteria, resulting in a survival rate of 96.4% and a success rate of 89.1%. In 24 sites, the mean marginal bone loss was 0.22 mm at 1 year and 0.40 mm at 65.8 months, with 100% survival and success rates. Porcine bone grafts can be successfully used in horizontal ridge augmentation for implant placement in cases of ridges with insufficient horizontal width.
ARTICLE | doi:10.20944/preprints202306.1141.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: periodontitis; periodontal disease; hypertension; dental scaling; clinical trial
Online: 15 June 2023 (12:16:06 CEST)
We sought to evaluate the effects of non-surgical periodontal treatment (NSPT) on periodontal clinical parameters, systemic blood pressure (BP) and plasma levels of systemic inflammation markers in patients with combined refractory arterial hypertension (RAH) and stage III grade B periodontitis. Twenty-seven participants with RAH and periodontitis received NSPT. The analyzed clinical parameters were probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI). An assessment was performed for systemic BP, complete blood count, coagulogram, creatinine measurement, C-reactive protein (CRP), glycated hemoglobin, cholesterol, glutamic oxaloacetic transaminase, glutamate pyruvic transaminase, waist-hip ratio, and body mass index. In the follow-up period, twenty-two patients were evaluated at baseline and after 90 and 180 days. The data were submitted to statistical analysis (α=0.05%). As expected, the clinical results showed a significant improvement in the percentages of PI, BOP, PD and CAL, which were statistically significant at 90 and 180 days (p<0.0001). Importantly, NSPT significantly reduced the blood level of CRP (p<0.02). However, no significant reduction in BP parameters was noted in the evaluated follow-up periods. NSPT, despite the benefits in periodontal clinical parameters, reduced the plasma level of CRP but not the BP in patients with combined RAH and periodontitis.
ARTICLE | doi:10.20944/preprints202305.0312.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Nitrous-oxide inhaled sedation; Oral surgery; Dental anxiety
Online: 5 May 2023 (06:26:52 CEST)
The purpose of the study was to evaluate the success of procedural conscious sedation, using inhaled equimolar nitrous oxide-oxygen (NOIS – EMONO), in patients undergoing routine dental and oral surgery procedures in a Swiss university hospital setting. Materials and methods: The authors conducted a retrospective cohort study of patients that underwent NOIS-supported procedures between 2018 and 2022 at the oral surgery department of the University Hospital of Geneva (HUG), Switzerland. The primary outcome was the measurement of the procedure success and efficacy as defined by the European Society of Anesthesiology. Secondary objectives included the analysis of the types of treatments performed, their indications, patient behavior, and the patient - clinician satisfaction score. Results: 55 patients were included in the study, 85% underwent surgical procedures, the remaining 15% underwent restorative and preventive procedures. The overall treatment success rate was 98.2%, and 97.9% for surgically treated patients. 62% of patients appeared relaxed, calm, and serene, while 16% expressed pain or fear during the procedure. Infiltrative administration of local anesthesia caused stress in 22% of patients, this was significantly lower in sub cohorts who received local topical anesthetics (0%) or a combination of systemic and local topical analgesics (7%). Patients (75%) and clinicians (91%) were satisfied with the procedure. Conclusion: Inhaled equimolar nitrous oxide-oxygen procedural sedation used during dental procedures and oral surgery results in high treatment success and satisfaction rates. The administration of additional topical anesthetics helps reduce the anxiety and stress related to infiltrative anesthesia. Further dedicated studies and prospective trials are needed to confirm these findings.
ARTICLE | doi:10.20944/preprints202111.0147.v1
Subject: Social Sciences, Education Keywords: Diversity; Equality; Dental Education; Career Progression; Higher Education
Online: 8 November 2021 (13:40:53 CET)
IntroductionDiversity is known to be important but diversity of staff working in dental schools in the UK and Ireland is low in comparison with the dental profession and the overall population. AimsTo provide a detailed snapshot of the diversity of dental academic staff in 2021 including staff working in academic and clinical roles.MethodsAn online survey was circulated to dental schools by Dental Schools Council. Questions included dates of graduation and key career milestones, demographics and indicators of esteem. Free text questions were also included.ResultsThere was a high degree of variability in dental academic careers which made direct comparisons difficult. Neither gender nor race appeared to be associated with a faster career progression. Females and those of racialised minority were less represented at the most senior grades. For those who had completed specialty training, racialised minority staff were far less likely to be working at consultant grade than their White equivalents.ConclusionThere are differences in career progression between staff in dental schools. The high amount of individual variability makes these difficult to quantify except at the most senior positions. Qualitative information is needed to contextualise the results and provide additional information.
Subject: Social Sciences, Psychology Keywords: teeth; greyhound; intervention; brushing; calculus; gingivitis; dental; periodontal
Online: 19 May 2021 (07:53:28 CEST)
Periodontal disease is one of the most common conditions affecting dogs worldwide and is reported to be particularly prevalent in racing greyhounds. A range of potential risk factors have been hypothesised. Previous research has suggested, regular tooth brushing can reduce both calculus and gingivitis, but the frequency required is unclear. Here, we report a controlled blinded in-situ in which kennel staff brushed 160 racing greyhounds’ teeth (living at six kennel establishments), either weekly, daily or never over two-month period. All visible teeth were scored for calculus and gingivitis, using previously validated scales. We calculated average scores for each of three teeth groups and overall averaging the teeth groups. Changes were compared to baseline. After two months, the total calculus scores (controlling for baseline) were significantly different in the three treatemnet groups, (F(2,129) = 10.76, p<0.001) with both weekly and daily brushing resulting in significant reductions. Gingivitis was also significantly different (F(2,128) = 4.57, p=0.012), but in this case, only daily brushing resulted in a significant reduction. Although dogs in different kennels varied significantly in their levels of both calculus (F(5,129) =8.64, p<0.001), and gingivitis (F(5,128)=3.51 p=0.005), the intervention was generally similarly effective in all establishments. Teeth groups varied and incisors were not significantly affected by treatment. Since trainers implementing the routine, reported minimal time commitment and positive experiences, we suggest that daily brushing is recommended for racing greyhounds, and that demonstrations should include attention to all teeth groups including incisors. Similar trials need to be conducted with retired greyhounds since these have been shown to present particularly high levels of periodontal disease.
ARTICLE | doi:10.20944/preprints202104.0093.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: International student; Depression; Bangladesh; Dental; CES-D; Undergraduate
Online: 5 April 2021 (10:34:16 CEST)
Background Bangladesh has been attracting international students on various subjects in recent times. Every year students from different parts of the world come to study undergraduate and postgraduate courses, mostly at private universities in Bangladesh. This study evaluates the depression status among international students who are studying dentistry in Bangladesh. Methods This cross-sectional survey was conducted among International undergraduate dental students who enrolled in the Bachelor of Dental Surgery program in nine public and private dental colleges in Bangladesh. A total of 206 students completed the survey, and CES-D 10 items Likert scale questionnaire was used for data collection. The Cronbach alpha for CES-D 10 scale items for this population is 0.812. Results The majority of the students (79.5%) are below 24 years of age, and students who cannot communicate well in Bengali (Bangla), about 60% of them have experienced depression. About 77.3% (p< 0.00) of the international students having financial difficulties exhibited depression. The international students who went through financial problems were two times more likely to suffer from depression (OR=2.38; p-value <0.01). Conclusion This study tried to highlight the struggles faced by international students in Bangladesh studying dentistry. It is evident from the findings that several factors influence students' mental well-being during demanding dental education years.
REVIEW | doi:10.20944/preprints202012.0455.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Prognosis; prosthodontics; dental implant; clinical performance; risk factor.
Online: 18 December 2020 (11:34:49 CET)
Background: The treatment plan of prosthetic restorations supported by dental implants require comprehensive scientific knowledge to deliver prostheses with good prognosis, even before the implant insertion. This review aims to analyze the main prosthetic determinants of the prognosis of implant-supported prostheses. Methods: A systematic review of the literature was conducted with a PICO question: "For partially or complete edentulous subjects treated with implant-supported prostheses, which prosthetic factors could affect clinical outcomes?". A literature search was performed electronically in PubMed (MEDLINE), Scopus and Cochrane Library with the following equation [PROGNOS* OR RISK] FACTOR IMPLANT DENTAL, and by hand search in relevant journals and throughout the selected papers. Results: This revision was carried out based on 50 papers focused on several prosthodontics-related risk factors that were grouped as follows: implant-connection, loading protocol, transmucosal abutments, prosthetic fit, provisionalization, type of retention, impression technique, fabrication technique, and occlusion. More than a half of the studies were systematic reviews (30%), meta-analysis (16%) or prospective evaluations of prosthesis with various kinds of events (18%). But also narrative reviews of literature (14%) and in vitro/animal studies (16%) were found. Conclusions: The current literature provides insufficient evidence for most of the investigated topics. However, based on the accumulated data, it seems reasonable to defend that the best treatment approach is the use of morse taper implants with transmucosal abutments, recorded by means of rigidly splinted copings through the pick-up technique, and screwed by milled prosthesis occlusally adjusted to minimize functional overloading.
ARTICLE | doi:10.20944/preprints202011.0169.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Dental treatment outcomes; Geographic Information Systems; Neighborhood contexts
Online: 3 November 2020 (15:33:02 CET)
ABSTRACT: Aims: This study aimed to explore the impacts of neighborhood-level socioeconomic contexts (e.g., income, education) on the therapeutic and preventative dental quality outcome of children aged 3 to 15 years. Materials and Methods Anonymized billing data of 842 patients reporting to a university Children’s Dental over three years met the inclusion criteria. Their access to care (OEV-CH-A), topical fluoride application (TFL-CH-A) and dental treatment burden (TRT-CH-A) were determined by dental quality alliance (DQA) criteria. The three oral health variables were aggregated at a neighborhood-level and analyzed with census data provided by Statistics Canada within a GIS framework. The forward sortation area (FSA) was chosen as a neighborhood spatial unit and regression models were run both the individual and neighborhood level. Results: The individual-level regression models showed significant negative associations between OEV-CH-A (p=0.027) and TFL-CH-A (p=0.001) and the cost of dental care. There was a significant negative association between TRT-CH-A and median household income. Neighborhood-level Ordinary Least Squares (OLS) linear regression models show negative associations of all three dental health variables (OEV-CH-A, TFL-CH-A, TRT-CH-A) with median household income and the number of households without a college degree. Conclusion: GIS and spatial quantitative approaches may be an effective tool to explore the impacts of socioeconomic variables on oral health outcomes.
REVIEW | doi:10.20944/preprints201911.0325.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
ARTICLE | doi:10.20944/preprints201904.0124.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental care; immigrants; inequalities; health survey; economic crisis
Online: 10 April 2019 (09:44:49 CEST)
This study evaluates inequalities in the use of dental services according to place of birth before and after the economic crisis in Spain. A cross-sectional study was performed in the population aged 18 to 65 years in Spain. We used data from three Spanish National Health Surveys for years 2006 (before the crisis), 2014 and 2017 (after the crisis). Log-binomial regression was used to quantify the association between region of origin and use of dental care services before and after controlling for the selected covariates. In 2006, we found a greater probability of not using dental care services in immigrants from Asia (PR:1.36, 95% CI:1.10–1.67) and Africa (PR:1.16; 95% CI:1.05–1.28) compared to the natives. For 2014, the probability of not using dental care services was greater for all immigrants compared to the natives, with the greatest odds for those from Africa (PR:1.71; 95% CI:1.46–2.01) and Asia (PR:1.3; 95% CI:1.23–1. 47). The associations for 2017 were weaker in magnitude than the ones observed for 2014, although stronger than for 2006. This study suggests that the economic recovery did not have the same impact for natives and immigrants regardless of regions of origin, given the observed inequalities in use of dental services.
HYPOTHESIS | doi:10.20944/preprints202305.0481.v2
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: vertebrate evolution; mesencephalic nucleus; primary afferent neuron; jaw movements; dental formulas; chewing reflexes; dental occlusion; brain stem; premaxilla; trigeminal nerve
Online: 21 September 2023 (10:29:32 CEST)
Anterior-tooth (ANT) contacts induce short latency reflex inhibition of human jaw-closing muscles. The jaw is a rigid class 1 lever for pinpoint-targeting muscle force into a single bite-point, the pivoting food particle. See-saw reflex movements around the food particle fulcrum multiply the food-crushing force. Unpredictable jolts of reaction force caused by food-crushing are subjected to the rostral ANT and caudally to the two articulate ends of the jaw triangle. Compression/distraction strains of food-crushing must be monitored and inhibited by withdrawal reflexes. The mesencephalic ganglion (Vmes), neural myelin sheath, and muscle stretch receptors evolved subsequently to the advent of jaws to improve the velocity of proprioceptive and withdrawal reflexes. In mammalians, the spindles of the taut motor units, stretched by the food-fulcrum send excitatory monosynaptic feedback for the efferent neurons of the respective ipsilateral muscle units, via Vmes. In the Vmes, the spindle-input-mediating afferent neurons are coupled with another source of afferent feedback, which is also excitatory, from the back-tooth (BAT) mechanoreceptors. The two sources of excitatory pulses are summated and targeted for the efferent neurons to boost the stretched and taut motor units. Likewise, the afferent feedback from ANT mechanoreceptors is also coupled in the Vmes with concomitant feedback from spindles. The ANT output, however, is inhibitory to negate the excitatory feedback from the stretched jaw-muscle units. The inhibitory feed from ANT temporarily blocks the excitatory potential of masticatory motor efferent neurons to protect the ANT and jaw-joints from inadvertent strains. The inhibitory inputs from ANT alternate with the excitatory inputs from BAT to determine which jaw-closing muscle units are activated or inhibited at any given instant of food-crushing. The Vmes exists in all jawed vertebrates, and its’ evolution was probably motivated by demands for the control of bite force. The monosynaptic unilateral food-crushing excitatory and inhibitory reflexes (UFCR) override the coexisting bilaterally executed feed for jaw muscles from the central nervous system. Hypothesis: The Vmes-mediated UFCR combine neural inputs from tooth contacts with concomitant feedback from muscle stretch receptors for the control of mammalian food-crushing bite force.
ARTICLE | doi:10.20944/preprints202301.0363.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Periodontal Disease; Electronic Dental Record; Longitudinal Data; Data Quality; Dental Infor-matics; Clinical Course of Periodontal Disease; Periodontal Cohort Generation
Online: 19 January 2023 (13:01:27 CET)
Objective: Determine the feasibility of utilizing longitudinal electronic dental record (EDR) data to track change over time in patient periodontal disease (PD) and to generate three patient cohorts: 1) patients whose disease did not change over time, 2) patients whose PD progressed, and 3) patients whose disease improved over time using informatics approaches. Methods: We conducted a retrospective study of 28,908 patients who received a comprehensive oral evaluation between January 1, 2009, and December 31, 2014, at the Indiana University School of Dentistry (IUSD) clinics. We developed and tested three automated computer applications to: 1) diagnose periodontitis cases from periodontal charting, 2) retrieve clinician-documented diagnoses from clinical notes, and 3) track disease change over time. We also evaluated the density of longi-tudinal EDR data for the following follow-up times: 1) none, 2) up to 5 years, 3) >5 and <=10 years, and 4) >10 and <=15 years Results: Thirty-four percent (n=9,954) of the study cohort had up to five years of follow-up visits with an average of 2.78 visits with periodontal charting information. An average of three patient visits per year that contained periodontal charts (63,552) were utilized to obtain a diagnosis, which is considered excellent. For clinician-documented diagnoses from clinical notes, 42% of patients (n=5,562) had at least two PD diagnoses to determine their disease change. In this cohort with cli-nician-documented diagnoses, 72% percent of patients (n=3,919) did not have a disease status change between their first and last visits, 669 (13%) patients' disease status progressed, and 589 (11%) patients’ disease improved. Conclusions: This study demonstrated the feasibility of utilizing longitudinal EDR data to track disease changes over 15 years during the observation study period. We found excellent longitudinal data when diagnoses generated from periodontal charting were considered (three visits per pa-tient). This information can be now utilized for studying the clinical course of periodontitis.
ARTICLE | doi:10.20944/preprints202311.1635.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: FEM analysis, stress distribution, Ti6Al4V alloy, dental implant, design
Online: 27 November 2023 (11:05:24 CET)
Dental implant fracture is closely connected to the stress buildup surrounding the implant system during static loading. In areas where the cross section of the implant rapidly changes or where the geometry of the implant system has discontinuities, stress concentrations arise. Therefore, the implant's design is crucial in preventing early failure of the implant system, including fracture, screw loosening, and increased leakage, in addition to reducing stresses at the implant-abutment interface. In the current work, three-dimensional (3D) models of mechanically connected Ti6Al4V implant systems in various dimensions were constructed. Finite Element Analysis (FEA) was used to conduct a stress study of the created implants under actual acting forces static loading conditions in accordance with ISO 14801. In the created models, design elements including implant screw type, thickness, and taper angle of abutment were modified in order to increase the longevity of the implants. The results show that the equivalent stress level is dramatically reduced from 596.22 MPa to 212.72 MPa in the implant model, which exhibit more homogeneous stress pattern under static loading conditions. Furthermore, the relatively smoother stress transmission observed in this model holds promise for the development of new implants capable of withstanding the forces encountered in the oral environment.
REVIEW | doi:10.20944/preprints202310.0652.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: ytterbium trifluoride; structure; properties; solubility; dental cements; restorative materials
Online: 11 October 2023 (07:31:27 CEST)
(1) Background: The compound ytterbium trifluoride is used as a component of several dental materials, and this is reviewed in the current article. (2) Methods: Published articles on this substance were identified from PubMed, and showed that it has been included in a variety of dental restorative materials, including composite resins, glass polyalkenoate cements and calcium trisilicate cements. (3) Results: Ytterbium trifluoride is reported to be insoluble in water. Despite this, its presence is associated with fluoride release from dental materials. There is evidence that it reacts with the components of calcium trisilicate cements to form small amounts of a variety of compounds, including ytterbium oxide, Yb2O3, and calcium-ytterbium fluoride, CaYbF5. In nanoparticulate form, it has been shown to reinforce glass polyalkenoates and it also provides high contrast in X-ray images. (4) Conclusions: Ytterbium trifluoride is a useful component of dental materials, though some of the published findings suggest that there are aspects of its chemistry which are poorly understood.
ARTICLE | doi:10.20944/preprints202310.0236.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: children; dental medicine; health promotion; oral health; preventive medicine
Online: 5 October 2023 (06:43:58 CEST)
Background and objective: Research shows that 60–90% of school children have caries, representing a serious public health issue. Here, we present a model of oral health promotion that has been conducted in the Primorje-Gorski Kotar County (PGC), Croatia, from 2008 to 2019. We assessed the oral status of first and fifth grade elementary students and determined the sustainability and influence of our model on the status and behavior regarding the children’s oral status. Additionally, during the observed period, promotional and preventative activities aiming to improve oral health were conducted. Since 2014, the Program has begun to be continuously, comprehensively, and systematically introduced into preschools as well. Material and methods: We assessed the number of children with caries by analyzing the changes in the decayed, missing, and filled teeth for primary teeth (dmft)/decayed, missing, and filled teeth for permanent teeth (DMFT) index mean during the observed period. Results: From 2008 to 2019 we assessed 44422 children in the PGC (21714 first grade and 22708 fifth grade students). The average response rate throughout the Program has been 83%. We have noted a dmft/DMFT index decrease from 4,66 to 3,73 (first graders) and from 2,50 to 1,00 (fifth graders). Conclusions: The Program has improved the behavior and oral health of children; stakeholders from various professions have been included, such as health visitors, school medicine teams, and pediatricians, avoiding additional financial expenses, increasing the number of children in care, and proving the sustainability of our oral health improvement model.
ARTICLE | doi:10.20944/preprints202306.1704.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental implant; acquired pellicle; peri-implant disease; chemical decontamination
Online: 25 June 2023 (03:23:30 CEST)
Surface chemistry evaluation plays a crucial role in assessing the efficacy of chemical decontamination products for titanium implants. This study aimed to investigate the effectiveness of chemical decontamination solutions in cleaning a contaminated dental implant surface and to evaluate the potential of combining Pluronic gel with hydrogen peroxide (NuBone®Clean) by evaluating pellicle disruption and re-formation on implant surfaces. In addition, ensuring safety with in- vitro and human testing protocols. X-ray Photoelectron Spectroscopy (XPS) was utilized for surface analysis. All the tested gels had some effect on the surface cleanness except for PrefGel®. Among the tested chemical decontamination candidates, NuBone®Clean demonstrated effectiveness in providing a cleaner titanium surface. Furthermore, none of the tested chemical agents exhibited any cytotoxic effects, and the safety assessment showed no adverse events. The results of this study highlight the significance of conducting comprehensive evaluations, encompassing safety and efficacy, before introducing new chemical agents for dental treatments. The findings suggest that NuBone®Clean shows potential as a chemical decontamination solution for implant surfaces. However, further investigation through randomized clinical trials is necessary. By adhering to rigorous testing protocols, the development of safe and efficient chemical decontamination strategies can be advanced, benefiting patients and promoting progress in the field of implant dentistry.
CASE REPORT | doi:10.20944/preprints202306.1615.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Cysts; Bone Regeneration; Dental Implants; Case Reports [Publication Type]
Online: 22 June 2023 (12:06:35 CEST)
The odontogenic cysts can lead to a bone destruction that can hamper the dental implant place-ment in the ideal 3D position. Different biomaterials and techniques that allow bone regeneration are described in the literature, each with its advantages and disadvantages. This clinical case with 18 months of follow-up shows the enucleation of an odontogenic cyst fol-lowing the guide bone regeneration with fence technique. After 6 months 2, dental implants were placed at the region of tooth 11 and 21, being rehabilitated nine weeks after. The fence technique allowed the recovery of the bone morphology and the placement of the dental implants in the 3D ideal position.
ARTICLE | doi:10.20944/preprints202306.0997.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: Guided Bone Regeneration; dental implant; PLACL; resorbable bilayer membrane
Online: 14 June 2023 (07:10:22 CEST)
Insufficient oral ridge tissue presents a challenge in the treatment of dental implants. One method to enhance alveolar crest dimensions is guided bone regeneration (GBR); however, existing membranes have certain limitations. To address this issue, we aimed to compare the effectiveness of a resorbable bilayer membrane composed of poly(l-lactic acid) and poly(-caprolactone) （PLACL）with that of a collagen membrane（COL） in a rat GBR model. The rat calvaria was used as an experimental model by placing a plastic cylinder. Forty male Fisher rats underwent surgery, and micro-computed tomography and histomorphometric analyses were performed to assess bone regeneration. The results showed that bone regeneration was similar across all the groups. However, after 24 weeks, the PLACL membrane demonstrated significant resilience, occasional partial degradation, and intermittent air bubble formation. This extended preservation of the barrier effect has great potential to facilitate optimal bone regeneration. In conclusion, this study shows that the PLACL membrane is a promising alternative to GBR. By providing a durable barrier and supporting bone regeneration over an extended period, this resorbable bilayer membrane may address the limitations of the current membranes. Further studies and clinical trials are warranted to validate the efficacy and safety of this drug in humans.
ARTICLE | doi:10.20944/preprints202301.0301.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental caries; caries experience; epidemiology, prevalence; risk; public health
Online: 17 January 2023 (08:56:34 CET)
Oral health surveys are essential to assess the dental caries experience and to influence national policies. This retrospective cross-sectional study aims to analysis dental caries experience who sought dental treatment in a reference university dental hospital at the Lisbon Metropolitan Area between January 2016 and March 2020. Full-mouth examination, sociodemographic, behaviors and medical information were included. Descriptive analyses and logistic regression analysis were applied to ascertain risk indicators associated with dental caries experience. A final sample of 9,349 participants (5,592 females/3,757 males) were included, aged 18 to 99 years old. In this population, caries experience was 91.1%, higher in female participants. Age (OR= 1.01, 95% CI [1.00-1.02], occupation (OR= 2.94, 95% CI [2.37-3.65], OR= 3.35, 95% CI [2.40-4.67], OR= 2.55, 95% CI [1.66-3.91], for employed, unemployed and retired, respectively), overweight (OR= 1.52, 95% CI [1.18-1.96]), reporting to never visited a dentist (OR= 0.38, 95% CI [0.23-0.64] and self-reported week teeth status (OR= 2.14, 95% CI [1.40-3.28]) were identified as risk indicators for the presence of dental caries, according to adjusted multivariable logistic analyses. These results highlight a substantial rate of dental experience in a Portuguese cohort and will pave the way for future tailored oral public health programs in Portugal.
ARTICLE | doi:10.20944/preprints202111.0455.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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/preprints202108.0244.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
REVIEW | doi:10.20944/preprints202011.0196.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Antimicrobial polymers; dental materials; cranio-maxilifacial regeneration; tissue engineering
Online: 4 November 2020 (12:47:55 CET)
Cranio-maxillofacial structure is a region of particular interest in the field of regenerative medicine due to both its anatomical complexity and the numerous abnormalities affecting this area. However, this anatomical complexity is what makes possible the coexistence of different microbial ecosystems in the oral cavity and the maxillofacial region, contributing to the increased risk of bacterial infections. In this regard, different materials have been used for their application in this field. These materials can be obtained from natural and renewable feedstocks or by synthetic routes with desired mechanical properties, biocompatibility and antimicrobial activity. Hence, in this review, we have focused on bio-based polymers, which by their own nature, by chemical modifications of their structure, or by their combination with other elements, provide a useful antibacterial activity as well as the suitable conditions for cranio-maxillofacial tissue regeneration. This approach has not been reviewed previously, and we have specifically arranged the content of this article according to the resulting material and its corresponding application, reviewing guided bone regeneration membranes; bone cements; and devices and scaffolds for both soft and hard maxillofacial tissue regeneration, including hybrid scaffolds, dental implants, hydrogels and composites.
ARTICLE | doi:10.20944/preprints202005.0104.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
ARTICLE | doi:10.20944/preprints201610.0102.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: dental caries; Streptococcus mutans; lactic acid bacteria; biofilm; glucosyltransferases
Online: 24 October 2016 (09:37:48 CEST)
Consumption of refined foods and beverages high in sugar make the teeth susceptible to the formation of biofilm, and lead to dental caries and diseases of the oral cavity such as periodontitis and periodontal disease. The aim of the present study was to determine the ability of selected probiotics to inhibit growth and biofilm formation by the cariogenic bacterium Streptococcus mutans in vitro. We screened strains of latic acid bacteria (LAB) (n=120) from the Bioresources Collection and Research Center (BCRC), saliva of healthy adults and infant stool. The antimicrobial activity of LAB in vitro was evaluated by agar spot culture and co-culture of the S. mutans strains. We determined the effect of heating and dilution factors (2- and 4-fold) on the antagonistic activity of LAB. Antagonistic substances in the spent culture suspensions (SCS) of LAB were precipitated by extraction with ammonium sulphate and chloroform to characterise the protein and lipophilic fractions. Results of co-culturing show that the SCS of the three LAB strains (Lactobacillus pentosus 13-1, 13-4 and Lactobacillus crispatus BCRC 14618) subjected to heat treatment showed significantly high antimicrobial activity. We found that substances produced by L. pentosus 13-4 which have the potential to exhibit antimicrobial properties might be lipophilic proteins. Additionally, we infer that the mechanism of reducing biofilm formation by Lactobacillus strains is associated with sucrose-dependent cell–cell adhesion and the gtfC level of glucosyltransferases (Gtfs) in the biofilm. Native LAB strains screened in our study may be used in chewing gums and other processed foods for preventing tooth decay.
ARTICLE | doi:10.20944/preprints202310.1223.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: electrochemical impedance spectroscopy; CoCrMo dental alloy; pitting corrosion; artificial saliva
Online: 19 October 2023 (05:18:22 CEST)
Wirobond C is a commercial dental casting alloy suitable for the fabrication of crowns, bridges as well as metal-ceramic restorations. This work aims with the study of the effect of ready-to-use Listerine® and Meridol® mouthwashes and sodium fluoride on corrosion resistance of the CoCrMo dental alloy to electrochemical corrosion in artificial saliva at 37 °C. SEM, EDS, SKP, and microhardness investigations were carried out to characterize the material under study. In vitro corrosion resistance of the CoCrMo alloy was conducted by the open circuit potential method, electrochemical impedance spectroscopy, and anodic polarization curves. The presence of Co 59.8(8) wt.%, Cr 31.5(4) wt.%, and Mo 8.8(6) wt.% was confirmed. The CoCrMo alloy was characterized by Vickers microhardness of 445(31) µHV0.3. Based on EIS data, the capacitive behavior and high corrosion resistance of CoCrMo alloy was revealed. The kinetics of pitting corrosion in the artificial saliva was lower after the modification with NaF and Listerine and Meridol mouthwashes. The potentiodynamic characteristics revealed the passive behavior of CoCrMo alloy in all solutions. Based on the SKP measurements of the CoCrMo alloy after corrosion tests, the effect of artificial saliva modification on electronic properties of Bego Wirobond C dental alloy was found.
REVIEW | doi:10.20944/preprints202309.1965.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: 3D printing; digital light processing; stereolithography; digital dentistry; dental material
Online: 3 October 2023 (02:56:01 CEST)
3D printing technology has brought about a paradigm shift in the delivery of clinical care in medicine and dentistry. There are several different 3D printing technologies, which, along with different printable materials with unique biomechanical properties, allows for a wide range of applications for 3D printing in dentistry. The clinical use of 3D printing has created versatile applications which streamline our digital workflow. Technological advancements have also paved the way for the integration of new dental materials in dentistry. This paper provides an overview of the mechanisms of 3D printing, the dental materials relevant to each mechanism and the possible applications of these materials within different areas of dentistry. Understanding the existing spectrum of 3D printing applications in dentistry will serve to further expand its use in the dental field.
REVIEW | doi:10.20944/preprints202307.1415.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Medicine; β-Tricalcium Phosphate; Bonegraft; CL/P; Dental Material; Bioceramic
Online: 20 July 2023 (10:25:29 CEST)
The aim of this systematic review is to describe and to identify prospect of β-Tricalcium Phosphate (β-TCP) as Alveolar Bone Grafting (ABG) in Cleft Lip/Palate (CL/P) or alveolar bone cleft defect. A systematic review protocol based on Preferred Reporting Items for Systematic Reviews and Meta Analyses 2020 (PRISMA 2020) was drafted. The literature search was conducted with MEDLINE/PubMed, Web of Science/ ISI-Web of Knowledge, Scopus and Cochrane Library with English language and no publication year limits. The keywords yielded a total of 5824 publications. There are 3196 suitable articles to evaluate after removing duplicates and languages. Afterward, 1315 studies left after doing title and abstract reading. In addition, 85 full-articles were assessed for eligibility. The read the complete texts of those papers and eventually chose 20 that matched the inclusion requirements. Thirteen of the twenty studies included in this systematic review had a low risk of bias, one had a high risk of bias, and six had moderate bias which not report the randomization. β-TCP as ABG is biocompatible, visible and practical, offers a less invasive procedure, and does not interfere with orthodontic treatment. β-TCP as synthetic ABG can be the alternative to autologous bone grafts with several terms and conditions. Improvement of β-TCP efficacy for ABG in CL/P or alveolar bone cleft defects can be done by a tissue engineering approach combining β-TCP with growth factor, mesenchymal stem cells, or other graft materials and modification of β-TCP physical properties.
REVIEW | doi:10.20944/preprints202305.1471.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: full arch; mandibular atrophy; short dental implants; short implants; prosthetic
Online: 22 May 2023 (07:26:03 CEST)
Background: This study aimed to evaluate survival rate, marginal bone levels, and full arch prosthetic success on short implants when placed in areas of severely resorbed and edentulous mandibles. Methods: This is a systematic review of all randomized controlled trials of at least 10 patients with a control group in which bone augmentations were performed that were published between January 2010 and February 2023. Only 3 relevant studies met the inclusion criteria. Results: It obtained demonstrate that short-term dental implant survival rates ranged from 94.2% to 97.4% with a 5-year follow-up and the prosthetic success rate varied by 62% during the same follow-up. The mean marginal bone level values of the affected short implants ranged from 0.2 mm to 0.6 mm. Conclusions: The data obtained demonstrated that short dental implants positioned with criterion and precision as a full-arch fixed support are a valid therapeutic choice for the medium-long term rehabilitation of severe edentulous mandibular atrophy.
ARTICLE | doi:10.20944/preprints202112.0083.v1
Subject: Medicine And Pharmacology, Psychiatry And Mental Health Keywords: Psychological distress; Fear; Coping; COVID-19; Bangladesh; Dental; Mental health
Online: 6 December 2021 (15:22:59 CET)
Background: Psychological sufferings are observed among dental students during their academic years, which had been intensified during the COVID-19 pandemic. Objectives: This study assessed the levels and identified factors associated with psychological distress, fear and coping experienced by dental undergraduate students in Bangladesh. Methods: A cross sectional online survey was conducted during October-November, 2021. The Kessler Psychological Distress Scale (K-10), Fear of COVID-19 Scale (FCV-19S) and Brief Resilient Coping Scale (BRCS) were used in order to assess psychological distress, fear and coping strategies respectively. Results: A total of 327 students participated; the majority (72%) were 19-23 years old and females (75%). One in five participants were infected with COVID-19 and 15% reported contact with COVID-19 cases. Negative financial impact (AOR 3.72, 95%CIs 1.28-10.8), recent or past COVID-19 infection, contact with COVID-19 cases were associated with higher levels of psychological distress; but being a 3rd year student (0.14, 0.04-0.55) and being satisfied about current social life (0.11, 0.03-0.33) were associated with lower levels of psychological distress. Being a 3rd year (0.17, 0.08-0.39) and a 4th year student (0.29, 0.12-0.71) were associated with lower levels of fear. Health care service use and feeling positive about life were associated with medium to high resilience coping. Conclusions: This study iden-tified dental students in Bangladesh who were at higher risk of psychological distress, fear and coping during the ongoing pandemic. Development of mental health support system within dental institution should be considered in addition to the academic and clinical teaching.
ARTICLE | doi:10.20944/preprints202005.0493.v1
Subject: Computer Science And Mathematics, Computer Vision And Graphics Keywords: Convolutional Neural Networks; Dental Diagnosis; Image Recognition; Diabetic Retinopathy detection
Online: 31 May 2020 (18:55:43 CEST)
Retinopathy is a human eye disease that causes changes in retinal blood vessels that leads to bleed, leak fluid and vision impairment. Symptoms of retinopathy are blurred vision, changes in color perception, red spots, and eye pain. In this paper, a new methodology based on Convolutional Neural Networks (CNN) is developed and proposed to diagnose and give a decision about the presence of retinopathy. The CNN model is trained by different images of eyes that have retinopathy and those which do not have retinopathy. The performance of the proposed model is compared with the related methods of DREAM, KNN, GD-CNN and SVM. Experimental results show that the proposed CNN performs better.
ARTICLE | doi:10.20944/preprints202004.0324.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
REVIEW | doi:10.20944/preprints202003.0047.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
COMMUNICATION | doi:10.20944/preprints201806.0452.v1
Subject: Engineering, Industrial And Manufacturing Engineering Keywords: alignments, dental pulp stem cells, nanofiber, neurogenesis, reduced graphene oxide
Online: 27 June 2018 (15:53:18 CEST)
Stem cells derived from dental tissues—dental stem cells—are flavored due to their easy acquisition. Among them, dental pulp stem cells (DPSCs) extracted from the dental pulp have many advantages such as high proliferation and highly purified population. Although their ability for neurogenic differentiation has been highlighted and neurogenic differentiation using electrospun nanofibers (NFs) has been performed, graphene-incorporated NFs have never been applied for DPSC neurogenic differentiation. Here reduced graphene oxide (RGO)-polycaprolactone (PCL) hybrid electrospun NFs were developed and applied for enhanced neurogenesis of DPSCs. First, RGO-PCL NFs were fabricated by electrospinning with incorporation of RGO and alignments, and their chemical and morphological characteristics were evaluated. Furthermore, in vitro NF properties such as influence on the cellular alignments and cell viability of DPSCs were also analyzed. The influences of NFs on DPSCs neurogenesis was also analyzed. The results confirmed that an appropriate concentration of RGO promoted better DPSC neurogenesis. Furthermore, the use of random NFs facilitated contiguous junctions of differentiated cells, whereas the use of aligned NFs facilitated aligned junction of differentiated cells along the direction of NF alignments. Our findings showed that RGO-PCL NFs can be a useful tool for DPSC neurogenesis, which will help regeneration in neurodegenerative and neurodefective diseases.
ARTICLE | doi:10.20944/preprints201801.0037.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Emdogain; amelogenin; dental pulp cells; cell differentiation; cell migration; mineralization
Online: 7 January 2018 (11:00:15 CET)
Enamel matrix derivative (EMD) is used for periodontal tissue regeneration therapy, and can induce mineralization in dental pulp cells (DPCs). We designed a synthetic peptide (SP) derived from the response of cells to EMD, and investigated the effect of the SP on potentiating osteogenesis in DPCs, which have a critical role of dental pulp homeostasis. DPCs were treated with 0, 10, 100, or 1000 ng/mL SP to determine its effect on cell proliferation, cell migration, cell differentiation, and mineralization. We then examined the molecular effects of the SP, focusing on changes in the mitogen-activated protein kinases (MAPK) signaling pathway in these cells. The SP significantly promoted DPC proliferation and migration. Cultures treated with the SP also showed an enhanced expression of markers of osteogenic differentiation and mineralization. The SP also induced the activation of MAPK signaling pathway components. These results suggest that our SP could promote the dental pulp tissue repair by hard tissue formation and the mineralization through activating MAPK signaling pathway. This study provides the first evidence that SP might be a new material for dental pulp tissue treatment.
REVIEW | doi:10.20944/preprints202310.0684.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Platelet-rich fibrin; bone regeneration; dental extraction; physiological healing; imaging evaluation
Online: 11 October 2023 (07:29:32 CEST)
Tooth extraction is the most common procedure in dental practice. However, in the long term, it may cause alveolar ridge atrophy. This systematic review aimed to evaluate the role of platelet-rich fibrin (PRF) in post-exodontic alveolar ridge preservation in terms of its effectiveness in the regeneration of bone tissue as assessed by imaging and its efficacy compared to physiological bone healing. The study is presented in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. This systematic review was conducted using electronic databases such as PubMed, Scopus, Web of Science, and Science Direct. The grey literature search was conducted in the New York Academy of Medicine Grey Literature Report. All the studies in this systematic review were randomized controlled trials (RCTs). The risk of bias was performed according to the Cochrane Handbook for Systematic Reviews of Interventions 6.2 (RevMan 6.2). Considering the inclusion and exclusion criteria, we included 17 randomized clinical trials, published up to 2022 investigating the efficacy of PRF in post-exodontic bone regeneration. Based on the results of clinical studies, it can be stated that despite not being statistically significant, PRF promotes neoformation and prevents bone loss between three and four months post-extraction.
REVIEW | doi:10.20944/preprints202308.0989.v1
Subject: Public Health And Healthcare, Other Keywords: sealants; dental; fluoride; marginal integrity; caries prevention; resin-based sealants; composition
Online: 14 August 2023 (10:17:48 CEST)
The scope of this paper is to compare different dental sealants and flow materials indicated for sealing pit and fissures considering their chemical formula. The narrative review aims to address the questions: What is the essence of different dental sealants’ activity, how their chemical formula affects their mechanisms of caries prevention and what makes a dental sealant efficient mean of caries prevention. Another vital issue is whether the sealants which contain fluoride, or any other additions have potentially increased antimicrobial properties. Methods: An electronic search of the PubMed, Cochrane, Web of Science and Scopus databases was performed. The following keywords were used: (dental sealants) AND (chemical composition). Additionally, information about composition and indications for clinical use provided by manufacturers were utilized. The review aims are to find crucial elements of sealants’ composition which affect their cariostatic mechanisms.
ARTICLE | doi:10.20944/preprints202307.0058.v1
Subject: Medicine And Pharmacology, Pharmacy Keywords: lactoperoxidase; Streptococcus mutans; biofilm; dental caries; lactoperoxidase system modulators; cariogenic biofilm
Online: 3 July 2023 (12:58:53 CEST)
The lactoperoxidase (LPO) system shows promise in the prevention of dental caries, a common chronic disease. This system has antimicrobial properties and is part of the non-specific antimicrobial immune system. Understanding the efficacy of the LPO system in the fight against biofilms could provide information on alternative strategies for the prevention and treatment of caries. In this study, the enzymatic system was modified using four different (pseudo)halide substrates (thiocyanate, thiocyanate-iodide mixture, selenocyanate, and iodide). The study evaluated the effects of such modifications on the ability of Streptococcus mutans to form a biofilm, the synthesis of insoluble polysaccharides, the synthesis of lactate, the consumption of glucose and sucrose, the concentrations of intracellular NAD+ and NADH and the efficiency of transmembrane glucose transport by phosphoenolpuryvate PEP-carbohydrate phosphotransferase (PTS). The results showed that the LPO-iodide system had the strongest inhibitory effect on biofilm growth and lactate synthesis (complete inhibition). This was associated with an increase in the NAD+/NADH ratio and an inhibition of glucose PTS activity. The LPO-selenocyanate system showed a moderate inhibitory effect on biofilm biomass growth and lactate synthesis. The other systems showed relatively small inhibition of lactate synthesis and glucose PTS but no effect on the growth of biofilm biomass. This study provides a basis for further research on the use of alternative substrates of the LPO system, particularly the LPO-iodide system, in the prevention and control of biofilm-related diseases.
REVIEW | doi:10.20944/preprints202305.2239.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: oral care; oxygen therapy; oral biofilm; dental caries; periodontitis; peri-implantitis
Online: 1 June 2023 (02:37:15 CEST)
Worldwide, oral lesions and cancers are still being significant public health conditions. Thus, an introduction of new oral healthcare protocols is becoming essential. Oral diseases are related to many causative factors, manly dental plaque/biofilm due to poor hygiene. New anti-biofilm therapies are needed to develop. The strategies of anti-biofilm therapies should help to control biofilm formation and microbial attachment to dental surfaces. The present review aimed to provide a comprehensive over-view on evidence related to the potential utility of topical oxygen therapy (BlueM formula) as novel oral care therapies in clinical practice.
ARTICLE | doi:10.20944/preprints202305.0711.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Dental implants; surgical guide; irrigation channels; Thermocouples; 3D printing; CAD/CAM
Online: 10 May 2023 (08:23:56 CEST)
The purpose of this in vitro study is to evaluate the effectiveness of incorporating a new irrigation system into a surgical guide and monitor its effect on heat generation during implant bed preparation. A total of 48 surgically guided osteotomies were performed on 12 bovine ribs divided into 4 groups, using different irrigation techniques: Group A (test) had entry and exit channels incorporated into the guide; Group B had a similar design with an entry channel only; Group C had conventional external irrigation; Group D (control) had no irrigation. Heat generation during the osteotomies was measured using thermocouples placed at a depth of 2 mm and 6 mm. The lowest mean temperature was observed in Group A (22.1°C at 2mm and 21.4°C at 6mm), this was statistically significant when compared with Groups C and D (p<0.001). Group A showed a lower mean temperature compared with Group B as well, however statistically significant only at 6mm depth (p<0.05). In conclusion, the proposed guide has significantly reduced heat generation during implant osteotomy. The integration of an exit cooling channel can resolve limitations found in previously designed surgical guides and can be easily incorporated into computer designing and 3D printing software.
ARTICLE | doi:10.20944/preprints202205.0348.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: zirconia; molecular precursor method; dental-implant; osseointegration; bone-to-implant contact
Online: 25 May 2022 (10:10:35 CEST)
In previous studies regarding the osseointegration of zirconia (ZrO2) implants, a lack of consistency was observed in the surface topographies of the ZrO2 and Ti samples because of the difficult processability of ZrO2 surfaces. To resolve this problem, we used the molecular precursor method (wet process), which is a surface-modifying technique that can easily change the surface chemistry without changing the surface topography. A roughened Ti surface was prepared using sandblasting (large-grit) and acid treatment. We were able to create ZrO2-coated Ti implants with the same topography as that of roughened Ti substrates using the molecular precursor method, which solution contained a Zr complex. The uniform presence of tetragonal Zr was confirmed, and the apparent zeta potential of the surface of the ZrO2-coated Ti implant was higher than that of Ti. In animal experiments, ZrO2-coated Ti implants showed an equivalent or higher bone-to-implant contact ratio compared to that of the non-coated implants inserted into the femur bone defects of the rats. ZrO2 with the same surface topography as that of roughened Ti exhibits a promotion of osteogenesis equivalent to or better than that of Ti in the early stages of bone formation.
ARTICLE | doi:10.20944/preprints202104.0045.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: S. mutans; Phage therapy; Dental caries; S. mutans phage; Bacteriophage; Biofilm.
Online: 2 April 2021 (11:15:54 CEST)
Streptococcus mutans is a key bacterium in dental caries- one of the most prevalent chronic infectious diseases. Conventional treatment both fails to specifically target the pathogenic bacteria and at-tempts to eradicate commensal bacteria as well. Thus, caries remains one of most common and challenging diseases. The use of bacterial viruses as anti-bacterial agents, is gaining interest worldwide. Hardly any phages were described against S. mutans. The objective of this study was to isolate anti-S. mutans phages and to characterize their antimi-crobial properties. Human saliva samples were filtered and screened for potential phages. Standard double-layered agar method was used for isolation. Whole genome sequence analysis and morphology visualization by TEM, were used for anti-S. mutans phage identification. Antibacterial properties were evaluated using clinical strains and ATCC strains of S. mutans in various states. Antibacterial effect was also tested on human cariogenic dentin. One phage against S. mutans was isolated and termed SMHBZ8. This phage showed effective lytic activity in vitro against both planktonic and biofilm S. mutans cultures. Moreover, the phage showed antibacterial effect when used on cariogenic dentin. The isolation and characterization of SMHBZ8 may be the first step in developing a potential phage therapy for dental caries.
ARTICLE | doi:10.20944/preprints202012.0402.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: digital guides; CAD/CAM; metal sleeves; dental implants; time of surgery
Online: 16 December 2020 (10:18:10 CET)
Both types of surgical guides – with and without metal sleeves are founded beneficial in clinical studies. The aim of this in vitro study was to compare time of surgical procedure in dental implantology depending of used type of the surgical guide. Ten three dimensional (3D) printed models of lower jaws were prepared based on complete virtual model of patient clinical conditions with missing teeth 37, 46 and 47. Five of this models were used for implant sites preparation performed with use of surgical guide without metal sleeves and dedicated surgical kit, and next five were used for the same procedure performed with surgical guide with metal sleeves and dedicated surgical kit. Time of implant site preparation were measured and noted. Statistical analysis was performed using Student’s t test for independent samples. Difference of time in both groups were founded as statistically significant (t=-9.94; df =28; p=0.0000). Type of surgical guide is important factor which can impact on time of implant site preparation and all surgical procedure.
CASE REPORT | doi:10.20944/preprints202006.0363.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery 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.
ARTICLE | doi:10.20944/preprints201801.0152.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: sinus lift; graft bone; finite element analysis; 3D modeling; dental implant
Online: 17 January 2018 (11:15:00 CET)
Purpose: The aim of the present experimental 3D-finite element study was to evaluate the influence of an augmented sinus lift with an additional inserted bone graft block. The bone graft block stabilizes the implant in addition to conventional augmented bone. We placed the block in three different positions. The implants were loaded with axial force and forces secondary to laterotrusion and protrusion. Material and Methods: A simplified U-shaped 3D finite element model of the upper jaw and a more complex anatomical model of the left maxilla were created. The bone graft block was placed in three positions: in the lower third in contact with the sinus floor, the middle, and the upper third of the implant. Van Mises’ stress distribution was calculated and analyzed for the different models. We also compared the complex anatomical model with the simplified one. Results: The position of the bone graft block significantly influences the magnitude of stress distribution. A bone graft block positioned in the upper third or middle of the implant reduces the quantity of stress compared to the reference model without a bone graft block. The low bone graft block position is clearly associated with lower stress distribution in compact bone. We registered no significant differences in stress in compact bone with regard to laterotrusion or protrusion. Conclusions: Maximum values of von Mises stresses in compact bone can be reduced significantly by using a bone graft block. The reduction of stress is nearly the same for positions in the upper third and the middle of the implant. It is much more pronounced when the bone graft block is in the lower third of the implant near the sinus floor, which appeared to be the best position in the present study.
ARTICLE | doi:10.20944/preprints202309.1022.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: dental laser systems; low level laser theraphy; pediatric dentistry; photobiomodulation; wound healing
Online: 15 September 2023 (08:31:52 CEST)
Background:This study evaluated the effect of low-level laser therapy on postoperative pain and wound healing in children undergoing primary molar extractions.Methods:40children,6-10years of age, systemically healthy, and had atraumatic extraction indications of bilateral primary molar teeth were included in the study. First session randomly selected tooth was extracted under local anesthesia. In the control group, only the clot formation on the socket was observed and photographed. Other group extraction's performed 2weeks later. The LLLT group treated with980nm wavelength Doctor Smile Wiser diode laser and photographed. Non-epithelialized surface measurements performed with the ImageJ program. Pain assessment was performed with Wong-Baker Pain Scale. Statistical analyzes were performed with SPSS software.Results: There was no statistically significant difference in Wong-Baker values(p>0.05). The laser group had more '0' values on days 1 and7; same values as the control group were recorded on other days. In soft tissue healing 3rd day evaluations, non-epithelialized surface of laser socket was found to be smaller than control group, and measurement results were found to be statistically significant(p<0.05). The other days' measurement results were not statistically significant(p>0.05).Conclusions:Although LLLT not found to be very effective in reducing postoperative discomfort after extraction of primary molars, it provides better wound healing in extraction sockets.
ARTICLE | doi:10.20944/preprints202108.0379.v1
Subject: Engineering, Mechanical Engineering Keywords: Fatigue; oblique loading; axial loading; finite element analysis; 3D-printed dental implant
Online: 18 August 2021 (13:54:49 CEST)
Fatigue analysis plays a vital role in determining the structural integrity and life of a dental implant. With the use of such implants on the rise, there is a corresponding increase in the number of implant failures. As such, the aim of this research paper is to investigate the life of 3D-printed dental implants. The dental implants considered in this study were 3D printed according to the direct metal laser sintering (DMLS) method. Additionally, a finite element model was developed to study their performance, while fatigue life was predicted using Fe-Safe software®. The model was validated experimentally by performing fatigue tests. The life of the dental implants was analysed based on Normal strain and the Brown-Miller with Morrow mean correction factor algorithm. The model revealed that there was a strong correlation between the FEA and the experimental results. The clinical success of 3D-printed dental implant experimentally is 20.51 years and computationally under Normal strain is 19.89 years and Brown-Miller with Morrow mean correction factor is 26.82 years.