Sustainability in Dentistry: A Systematic Literature Review of Environmental, Economic, and Social Dimensions in Dental Practice

1. Introduction

1.1. Context and Urgency

The global healthcare sector's substantial environmental footprint, contributing an estimated 4.4% of global net emissions, has positioned sustainability as a critical priority for all medical disciplines [1]. Within this context, dentistry faces unique sustainability challenges due to its intensive use of single-use materials, energy-intensive equipment, and complex waste streams [2]. The urgency of addressing these challenges is amplified by growing awareness of climate change impacts on public health and the healthcare sector's responsibility to minimize its environmental burden while maintaining high-quality patient care [3].

1.2. Conceptual Framework

Sustainability in healthcare is best understood through the Triple Bottom Line (TBL) framework, encompassing three interconnected dimensions: environmental (reducing ecological impact), economic (ensuring financial viability), and social (promoting equity and community well-being) [4]. This framework aligns with global sustainability goals, such as those outlined in the 2030 Agenda for Sustainable Development [5] and provides a comprehensive lens for evaluating dental practice transformation.

Environmental sustainability in dentistry involves minimizing resource consumption, reducing waste generation, and decreasing carbon emissions through practices such as using energy-efficient equipment, selecting sustainable materials, and optimizing waste management. The discourse surrounding "green dentistry" [6] often focuses on these aspects. Economic sustainability encompasses cost-effective resource utilization, the long-term financial viability of sustainable practices, and value-based care delivery models, aligning with broader principles of value-based healthcare [7]. Social sustainability addresses workforce development, community health equity, and stakeholder engagement in sustainable practice adoption.

1.3. Knowledge Gaps

While general awareness of sustainability is growing, a preliminary review of the literature suggests the evidence base required to inform practice and policy is constrained by specific limitations. This systematic review is designed to rigorously investigate three suspected gaps that may be hindering the translation of sustainability principles into widespread, effective action.

a. The Dimensional Gap: A Potential Imbalance in Research Focus.

The first gap relates to the coverage of the TBL framework. There is a need to determine if the current research landscape is balanced or if it concentrates heavily on the environmental dimension. An overemphasis on ecological topics, while important, would leave practitioners and policymakers without an evidence base for the financial business case (economic dimension) or the impacts on staff, patients, and communities (social dimension). Without this integrated evidence, sustainability initiatives may be perceived as a costly burden rather than a strategic investment, leading to poor adoption rates.

b. The Methodological Gap: Nature and Quality of Evidence.

The second gap concerns the scientific rigor of the existing research. The type of study design determines the strength of its conclusions. Descriptive designs, such as Knowledge, Attitude, and Practice (KAP) surveys, are valuable for establishing baseline awareness but are insufficient for determining the effectiveness of an intervention. They cannot establish causality or provide guidance on which specific practices yield the greatest positive impact. A field dominated by such studies remains in a perpetual state of describing the problem rather than testing solutions. This review will therefore systematically categorize the methodologies employed in the literature to assess the maturity of the field and its capacity to generate actionable, cause-and-effect evidence.

c. The Measurement Gap: A Lack of Standardization.

The third gap pertains to the tools used to collect data. The reliability and validity of research findings are contingent upon the quality of measurement instruments. If researchers predominantly use unvalidated, ad-hoc questionnaires, the ability to compare findings across studies, populations, and settings is severely compromised. This lack of standardization prevents the cumulative synthesis of knowledge—such as through meta-analysis—and forces the field to perpetually "reinvent the wheel" rather than building upon a common foundation of reliable data. An investigation into the prevalence of validated versus non-validated instruments is therefore essential for evaluating the overall robustness of the literature.

1.4. Objectives

To address the gaps, this systematic review has three primary objectives:

• To systematically map and quantify the distribution of empirical research across the environmental, economic, and social dimensions of the Triple Bottom Line framework, thereby providing a clear picture of the field's current focus and identifying any significant imbalances.
• To conduct a critical appraisal of the methodological landscape by categorizing the predominant research designs and assessing the prevalence of validated versus non-validated measurement tools. This will evaluate the overall quality and strength of the existing evidence base.
• To formulate a targeted, evidence-based research agenda based on the synthesis of the identified dimensional, methodological, and measurement gaps, with the aim of guiding future research towards greater rigor, balance, and practical impact.

2. Materials and Methods

2.1. Protocol and Guidance

This systematic review was designed, conducted, and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement [8]. The PRISMA checklist provides a robust, evidence-based framework for ensuring the transparent and complete reporting of systematic reviews. A protocol for this review was established prior to the literature search, outlining the objectives, inclusion criteria, and methods for analysis.

2.2. Information Sources and Search Strategy

A systematic literature search was performed on September 19, 2025, to identify relevant empirical studies published between January 1, 2010, and the search date. The search strategy was developed in consultation with information specialists and designed to be comprehensive, utilizing three major electronic databases recognized for their coverage of medical and interdisciplinary research: PubMed/MEDLINE, Web of Science (Core Collection), and Google Scholar.

The search strategy combined two core concepts: "dentistry" and "sustainability." For each concept, a set of keywords and subject headings (including MeSH terms) were developed. Boolean operators ("AND", "OR") were used to combine the search terms. To ensure comprehensiveness, the reference lists of included studies and relevant review articles were also manually screened. The detailed search terms and syntax used for each core database are provided in Appendix A (Table A1).

2.3. Eligibility Criteria and Study Selection

A two-stage screening process was conducted by two independent reviewers.

• inclusion and exclusion criteria were established. Studies were included if they were original empirical research published in English between 2010-2025, and focused on at least one dimension of sustainability within a dental context. Non-empirical articles, studies without a specific dental focus, and non-English publications were excluded.
• the study selection process was executed. All retrieved records were imported into a reference management software for deduplication. Two reviewers then independently screened titles and abstracts against the eligibility criteria. Potentially relevant articles advanced to a full-text screening, which was also conducted independently by both reviewers. Any disagreements at either stage were resolved through discussion and consensus, with a third reviewer available for arbitration if needed.

2.4. Data Extraction and Synthesis

A standardized data extraction form was designed and pilot-tested. One reviewer extracted data for each study, and a second reviewer verified the information for accuracy and completeness. The extracted data included bibliographic details, study characteristics, population, sustainability dimension(s), key findings, and author-reported limitations.

Due to the significant heterogeneity observed in study designs, populations, and outcome measures, a quantitative meta-analysis was not feasible. Therefore, a narrative synthesis approach was employed. The findings were grouped thematically based on the Triple Bottom Line framework and key methodological characteristics to identify patterns, gaps, and areas for future research.

2.5. Quality Assessment (Risk of Bias)

While a formal meta-analysis was not conducted, a quality assessment of the included studies was performed to understand the overall risk of bias in the literature. The Joanna Briggs Institute (JBI) Critical Appraisal Checklists were adapted for this purpose, with specific tools used for cross-sectional, experimental, and qualitative studies. Two reviewers independently assessed the quality of each study, focusing on potential biases in sampling, measurement, and analysis. The results of this assessment were not used to exclude studies but to inform the narrative synthesis, particularly in the discussion of the evidence base's limitations.

3. Results

3.1. Study Selection and Publication Trends

The study selection process is detailed in the PRISMA flow diagram (Figure 1). The search yielded 140 records, from which 18 unique empirical studies were identified as meeting all inclusion criteria. A key characteristic of this body of literature is its recent emergence. As shown in Figure 2, while the review period began in 2010, the vast majority of included studies (n=16, 89%) were published between 2022 and 2025. This trend indicates that dental sustainability is a rapidly accelerating area of research, but as the grouped bars reveal, this growth is predominantly driven by an increase in cross-sectional surveys, with higher-level evidence appearing only sporadically.

3.2. Geographic Distribution of Research

The geographic origins of the included studies reveal a global but uneven distribution of research activity (Figure 3). Research is most concentrated in Asia (n=8) and Europe (n=6). However, the composition of research reveals a critical thematic divergence. In Asia, the research focus is almost exclusively on the Environmental dimension, while Europe is the primary source of the few studies that address the Economic and Social dimensions. This geographic and thematic imbalance suggests that the current evidence base may not fully represent the diverse challenges and contexts of dental practice worldwide.

3.3. Thematic and Methodological Landscape

The most profound finding of this review is the intertwined nature of the thematic and methodological imbalances within the available evidence. Table 1 provides detailed study-by-study data that forms the basis for the following analysis.

3.3.1. Dimensional Imbalance

Figure 4, a Sankey diagram, provides a powerful visualization of the relationship between thematic focus (TBL dimensions) and the methodological approaches used. The diagram clearly shows that the vast majority of scientific effort, represented by the thickest flow, originates from the Environmental dimension and is channeled directly into Cross-sectional Surveys. This indicates that the dominant research paradigm is to ask practitioners about their environmental awareness.

In stark contrast, the critically under-researched Economic and Social dimensions show only weak and scattered flows to various methodologies. The diagram also starkly illustrates that objective methods like LCA are applied exclusively to Environmental questions. This cross-analysis reveals a critical disconnect: the methods best suited for determining effectiveness and impact are not being applied to the economic and social questions that are crucial for practice implementation.

3.3.2. Methodological Immaturity

The overall quality of the evidence base is best understood when mapped onto a traditional evidence hierarchy, as shown in Figure 5. This annotated pyramid provides a stark visual summary of the field's methodological immaturity, revealing a structure that is broad at the base but hollow at the top. The following sections provide a deeper analysis of the key findings from each level of this pyramid and the overarching limitations of this evidence base.

3.4. Key Findings by Study Design and Quality of Evidence

Beyond the thematic focus, the methodological quality of the evidence base is a critical determinant of its utility. The analysis reveals a heavy reliance on descriptive, non-interventional study designs, which has significant implications for the field's capacity to generate actionable, cause-and-effect conclusions. Figure 3 visually represents this methodological landscape.

• Descriptive Evidence from Cross-Sectional Surveys (n=11, 61%):

Most of the evidence base consists of KAP surveys. These studies have been instrumental in establishing a baseline understanding of awareness and attitudes [9,10,13]. A recurring theme is the "attitude-practice gap," where a high level of willingness to be sustainable does not translate into consistent implementation. Interestingly, this positive attitude is not limited to practitioners; research also indicates that patients are generally supportive of their dentists adopting more sustainable practices [11]. These surveys also provide detailed analyses of specific topics, such as dental waste management practices [21].

• Objective Quantification from Life Cycle Assessments (n=2, 11%):

A small but highly significant cluster of studies utilized Life Cycle Assessment (LCA) to provide objective environmental data. The work which quantified the carbon footprint of a tooth extraction (4.9 kg CO2-eq) [15], and on endodontic procedures [16], represent a methodological high point. These studies offer the kind of robust, quantitative data necessary to prioritize clinical interventions based on their actual environmental impact, moving beyond subjective perception.

• Emerging Evidence from Intervention and Implementation Studies (n=5, 28%):

A nascent but growing body of research includes mixed-methods studies, action research, and educational interventions. For instance, a work demonstrated that targeted educational programs can improve student awareness [12]. Similarly, implementation studies [14,18,24] showed the real-world feasibility of transforming practice. These studies are critical as they begin to answer the "how-to" questions of sustainability, although they are often single-site case studies, which limits their generalizability.

3.5. Methodological Quality and Limitations

A comprehensive synthesis requires a critical appraisal of the methodological rigor of the included studies. Three primary limitations pervade the current literature, constraining the strength of any conclusions that can be drawn and highlighting the immaturity of the field.

• Predominance of Self-Reported Data: With over 60% of studies relying on surveys, the evidence base is heavily skewed by self-reported data. This introduces a high risk of social desirability bias (participants reporting what they believe is the "correct" or desirable answer) and recall bias. This reliance limits the validity of the findings, as stated attitudes and practices may not reflect real-world behaviors.
• Lack of Standardized and Validated Instruments: A significant weakness identified is the scarcity of standardized measurement tools. Most KAP surveys employed ad-hoc, unvalidated questionnaires. This was explicitly identified as a major research gap [22], whose work focused on the psychometric validation of a KAP tool. Without common, validated instruments, it is nearly impossible to compare findings across studies, conduct meta-analyses, or reliably track progress in the field over time.
• Limited Generalizability: Many studies, particularly the interventional and implementation research, were conducted in single-institution settings (e.g., a single dental school or clinic), as noted in Table 1 for studies like [14,18]. While providing valuable proof-of-concept, the findings from these studies may not be generalizable to different cultural, economic, or healthcare contexts. The field currently lacks the multi-site, large-scale studies needed to generate broadly applicable evidence.

4. Discussion

4.1. The Self-Reinforcing Cycle of Low-Level Evidence

The findings of this review, when synthesized, suggest more than just a series of isolated gaps. Instead, they point towards a systemic issue: a self-reinforcing cycle of low-level evidence that currently defines the field of dental sustainability, as conceptualized in Figure 6. This cycle provides a deeper explanation for why the evidence map (Figure 3) is so uneven and why the evidence pyramid (Figure 5) is hollow at the top.

The cycle begins with a focus on readily answerable, descriptive questions (e.g., "What are dentists' attitudes?"). This narrow focus contributes directly to the dimensional imbalance seen in Figure 4, as environmental awareness is easier to measure than complex economic or social outcomes. This, in turn, necessitates only reliance on simple, descriptive methods, primarily cross-sectional surveys. The long-term dominance of these methods means the field has underinvested in the skills and infrastructure needed for more complex research. This results in an inability to answer complex, causal questions (e.g., "What is the ROI of this intervention?"). Faced with this complexity, researchers may revert to the more feasible, descriptive questions, thus perpetuating the cycle. Breaking this cycle is the central challenge for maturing the field.

It is important to frame this cycle not as a failure, but as a marker of a necessary, completed first phase. The descriptive studies [9,10,11,13,19,20,21] that form the base of the pyramid (Figure 5) were essential for establishing the field, identifying the core "attitude-practice gap" [9], and confirming broad support for sustainability [11,18]. The central argument of this review is not to devalue this foundational work, but to declare it 'mission accomplished.' The risk now lies in perpetuating this first phase. This evidence map suggests the field has now built a sufficient descriptive foundation and is ready—and required—to mature collectively toward the next phase of testing solutions.

4.2. Comparison with Existing Literature and Contribution of This Review

These findings align with earlier narrative reviews that called for a multifaceted approach [26,27]. However, this systematic review makes three unique contributions. First, it quantifies the problem through a suite of novel data visualizations (Figure 2, Figure 3, Figure 4 and Figure 5). Second, it moves beyond describing the gaps to proposing an explanatory model for their existence—the self-reinforcing cycle (Figure 6). While some studies have successfully demonstrated an integrated approach [25], our review reveals these are exceptions rather than the norm. Third, this review translates its diagnosis into a strategic, evidence-based roadmap designed to break the cycle (Table 2), offering a clear path from a descriptive to an interventional science.

4.3. Implications for Policy, Education, and Practice

The identified gaps have profound implications for different stakeholders within the dental community.

• For Practitioners and Clinic Managers: The lack of economic data is a major barrier to adoption. Without clear evidence of return on investment or long-term cost savings, transitioning to sustainable—and often more expensive—materials and equipment remains a financially risky proposition. The findings of this review should caution practitioners against adopting trends without first demanding robust evidence of their environmental, economic, and clinical efficacy.
• For Dental Educators: The documented knowledge gaps among students [19,20], coupled with strong support from both students and faculty for curriculum integration [18], underscore the urgent need for curriculum reform. However, this reform must be evidence-based. It is no longer sufficient to teach "green dentistry" as a set of aspirational principles. Curricula must be developed to teach sustainability as a science, grounded in concepts from LCA, health economics, and implementation science. The development of validated competency assessment tools, building on the work of [22], is a critical first step.
• For Policymakers and Professional Associations: Given that even foundational practices like waste management are not universally optimized [21], this review suggests that the current evidence base is likely insufficient to support strong, specific policy mandates. Policymakers should prioritize funding research that addresses the gaps identified here, particularly multi-site intervention studies and economic analyses, before issuing widespread guidelines.

4.4. A Proposed Research Agenda for the Future

To accelerate the field's maturation from describing problems to testing solutions, this review proposes a structured research agenda. This agenda, detailed in Table 2, is directly derived from the dimensional, methodological, and measurement gaps identified in the Results section. It is designed to guide future research towards greater rigor and balance by recommending specific high-priority research questions and the advanced methodologies required to answer them.

4.5. Strengths and Limitations of This Review

The primary strength of this review is its rigorous construction of the available evidence map. However, the most significant limitation of this map—and a core finding in itself—is that the available evidence base is small. This review does not claim the entire field is methodologically immature; rather, it concludes that the portion of the field that is currently visible through the lens of peer-reviewed, empirical research is methodologically immature.

This distinction is critical. The findings, particularly the 'Economic Gap' and 'Social Gap,' should therefore be precisely understood as a lack of academic, empirical publications on these topics, not as a definitive claim that no practical data (e.g., in manufacturer reports or non-empirical white papers) exists. This review's focus on peer-reviewed, empirical evidence [179, 180] was a deliberate methodological choice to map the scientific evidence base. This potential 'academic-practice gap' itself reinforces this review's core conclusion: the urgent need to translate these critical economic and social questions into rigorous, peer-reviewed research.

5. Conclusions

The map of the peer-reviewed evidence on sustainability in dentistry reveals a field of stark contrasts: rapid growth in interest is coupled with a profound lack of methodological rigor and dimensional balance. The evidence base is geographically concentrated, thematically narrow, and built upon a foundation of low-level evidence, rendering it insufficient to guide meaningful policy or practice transformation. To mature, the field must undergo a strategic and collective shift, moving away from describing awareness towards rigorously testing the effectiveness, cost, and equity of sustainability interventions. The research agenda proposed in this review (Table 2) offers a clear, evidence-based roadmap for this essential transformation.