About EBD

 Image: Venn diagram showing the intersection of Evidence, Clinical Expertise, and Patien's Needs & PreferencesEvidence-based dentistry (EBD) is based on three important domains: the best available scientific evidence, a dentist's clinical skill and judgment, and each individual patient's needs and preferences.  Only when all three are given due consideration in individual patient care is EBD actually being practiced. The first domain, evidence, is there to inform dentists and patients, but never to mandate a specific course of treatment. If we think about Evidence, Clinical Judgment, and Patient Needs and Preferences as three circles, then EBD is right in the center where all three circles overlap.

This Web site helps clinicians identify systematic reviews, the preferred method for assembling the best available scientific evidence, through our database and provides appraisal of the evidence through our critical summaries


Evidence-based dentistry (EBD) is an approach to oral healthcare that requires the judicious integration of systematic assessments of clinically relevant scientific evidence, relating to the patient's oral and medical condition and history, with the dentist's clinical expertise and the patient's treatment needs and preferences.

By saying "relating to the patient's oral and medical condition and history", this definition takes a patient-centered approach to treatment decisions. It is important to understand that EBD is an approach to practice, an approach to making clinical decisions, and is just one component used to arrive at the best treatment decision.  EBD is about providing personalized dental care based on the most current scientific knowledge.


1. What can I find on this EBD Web site (PDF)? 

- A database of systematic reviews.  This searchable database has citations for over 1200 systematic reviews.  The database, which is updated monthly, includes systematic reviews on all oralhealth topics.
- Critical Summaries of systematic reviews. One-page synopses of the key elements of a systematic review with clinical implications written by practicing dentists trained in critical assessment of published studies. 
- Clinical Recommendations/Guidelines. Developed or endorsed by the ADA Council on Scientific Affairs and the ADA Center for Evidence-Based Dentistry, clinical recommendations/guidelines are useful tools that can be applied in making evidence-based clinical treatment decisions.
- Links to many other useful resources. This is a central resource for EBD information, and includes links to many outside resources including  tutorials, glossaries, and databases.

2. Where do I search for evidence?

The ADA's EBD Web site has a database of systematic reviews dedicated to oral health topics.  This is a great place to start your search.  There are other databases that can also be searched.

- PubMed
- TRIP Database
- DARE (Database of Abstracts of Reviews of Effectiveness)
- National Guideline Clearinghouse
- Cochrane Library

3. What is a Systematic Review?

A review that identifies and evaluates all of the evidence with which to answer a specific, narrowly focused clinical question.

4. What are the hallmarks of a Systematic Review?

 - Exhaustive search for studies (the evidence)
 - Elaborate procedures to maximize objectivity and minimize bias
 - Identification, presentation, and consideration of the best available evidence (the strongest studies)
 - Quality of each included study explicitly evaluated using standard criteria
 - If possible, statistical combination of available evidence for a single estimate of effect
 - Interpretation of the evidence for clinicians and researchers

5.Why is a Systematic Review better than a traditional review?

- Specific clinical question is addressed, rather than a general topic
- All information is considered, not just that favored by the reviewer
- The quality of each study, and overall quality of the evidence are objectively assessed
- Information is organized so that comparison across relevant studies is facilitated

6. What would you expect to see in a Systematic Review?

- A stated clinical question, preferably in "PICO" format that identifies the population (the individuals or groups for whom an answer is sought), intervention (the treatment or clinical condition of interest, i.e. patient type, disease), comparison (an alternative treatment or control group for comparison to intervention) and outcome (the measure(s) used to assess the effects of the intervention)
(Example: "In persons with adult periodontitis, how does scaling and root planing combined with local antimicrobial therapy affect bleeding and pocket depths compared to scaling and root planing alone?")
- A search strategy that uses several databases as well as additional searching of specific journals, references in included articles, and unpublished data
- Selection criteria for inclusion and exclusion in the review of studies identified in the search
- Application of the selection criteria to produce groups of included and excluded studies that are fully identified
- Assurances that the application of selection criteria at every stage of the search was performed independently by more than one individual, with all differences resolved after discussion
- An evidence table that summarizes key features and results from all included studies
- A narrative summary of the highlights of the evidence table
- If possible, a statistical combination of the results for the studies in the evidence table
- An interpretation of the evidence, including discussions of:
- The overall strength of the evidence available to apply to the question
- The implications of the evidence for clinicians
- The implications for any additional research that will address the question
- Any limitations of the search strategy and review methods

7. What is a Critical Summary?

A critical summary is a short (1-2 page) summary and discussion of a systematic review.

8. What should I expect to see in a Critical Summary?

- A summary of the Systematic Review in abstract form
- An evaluation of the strength and weaknesses of the review as well as the evidence within the review
- A discussion and critique of the review's interpretation of the evidence and implications for clinicians

9. Why is a Critical Summary useful?

- Efficiency: they present a means of rapidly learning the principal findings of a systematic review
- Oversight: they offer a second opinion concerning the quality of the review and the validity of the interpretations drawn by its authors
- Commentary: they offer additional insight into the implications for clinicians

10. Where can I find a Critical Summary on this Web site?

- Critical Summaries are available through the database of systematic reviews on this website
- An icon next to the title of the systematic review indicates that a critical summary is available

11. What is a Clinical Recommendation?

A clinical recommendation is a recommendation for patient treatment made by an expert panel based on the best evidence available

12. What should I expect to see in a Clinical Recommendation?

- Comprehensive search for all the available evidence including systematic reviews and clinical studies
- Critical appraisal of the evidence with objective statements summarizing the evidence along with an assessment of evidence quality
- Clear statements of recommendations with appropriate classification of the strength of recommendations
- Description of the rationale used in translating evidence into clinical recommendations
- Detailed description of patient groups to whom the recommendations are intended to apply
- Identification and discussion of all relevant issues for which expert opinion was divided and how consensus was reached
- Qualifications of panel members and conflict disclosures

13. Why are Clinical Recommendations useful?

- Validity -  they represent multiple-expert oversight of all available evidence
- Guidance - they represent the combined opinion of expert clinicians about implications for practice
- Patient Education and Assurance - the presence of recommendations may improve patient confidence in making informed treatment decisions

This glossary is designed to assist dental professionals and public policymakers in developing a common language for discussion of issues pertaining to evidence-based dental care.

Best Evidence
The highest level of evidence available represents the current best evidence for a specific clinical question. Based on a hierarchy of levels of evidence, systematic reviews of randomized controlled trials constitute the highest level of current best evidence, and expert opinion is lower-level evidence.

Case-Control Study
A clinical study that involves identifying subjects with a clinical condition (cases) and subjects free from the condition (controls), and investigating if the two groups have similar or different exposures to risk indicator(s) or factor(s) associated with the disease.

Case Series
A report on a series of patients with an outcome of interest. No control group is involved.

Clinical Protocol
A step-by-step decision-making tool that describes how a health condition is diagnosed and managed.

Cochrane Collaboration
An international nonprofit organization that develops evidence-based systematic reviews on health care interventions.

Cohort Study
A clinical study that with two groups (cohorts) of subjects, one that did receive the exposure of interest and another that did not, and following these cohorts forward for the outcome of interest.

An alternative treatment or control group.

Controlled Clinical Trial
A clinical study that uses the same design features of a randomized controlled clinical trial but, for reasons beyond the control of the investigators, the subjects are assigned using a non-random process into control or experimental groups.

Critical Appraisal
A process followed by the ADA's EBD experts to evaluate the strength and content of a systematic review. The process of critical appraisal results in a Critical Summary intended to focus on the clinical utility or application of the systematic review findings.

Critical Summary
The process of critical appraisal results in a Critical Summary, which focuses on the clinical utility or application of the systematic review findings.

Crossover Study Design
The administration of two or more experimental therapies, one after the other in a specified or random order, to the same group of patients.

Cross-Sectional Study
The observation of a defined population at a single point in time or in a specified time interval. Exposure and outcome are determined simultaneously.

Evidence-Based Clinical Recommendations
Recommendations developed through critical evaluation of the collective body of evidence on a particular topic. The recommendations provide practical applications of scientific information that can assist dentists in clinical decision-making. The strength of the recommendation is classified according to the existing level of evidence. An example of evidence-based clinical recommendations is the ADA Evidence-Based Clinical Recommendations on Professionally Applied Topical Fluoride.

Evidence-Based Dentistry
An approach to oral health care that requires the judicious integration of systematic assessments of clinically relevant scientific evidence, relating to the patient's oral and medical condition and history, with the dentist's clinical expertise and the patient's treatment needs and preferences.

Evidence-Based Medicine
The conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence-based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.

A diagnostic test or procedure, prescribed therapy, or other action intended to detect, prevent or treat a health condition.

Levels of Evidence
Hierarchical rating systems used to grade individual or multiple studies based on type of study design and effectiveness in answering a specific research question. Evidence levels follow a structured hierarchy of criteria for grading strength of evidence.Some include assessment of a study's methodological quality, precision of statistical data for the population being studied (internal validity), and other considerations.

The National Library of Medicine's searchable database of over 12 million indexed citations from more than 4,600 medical, dental, health and scientific journals. Additional information is available through the ADA Library.

A review that uses quantitative methods to combine the statistical measures from two or more studies and generates a weighted average of the effect of an intervention, degree of association between a risk factor and a disease, or accuracy of a diagnostic test.

Measures used to assess effects of an intervention or exposure.

An acronym used to identify four primary components of a well-formulated clinical question: Patient Population or Problem (P), Intervention or Exposure (I/E), Comparison (C), and Outcome (O).

Individuals or groups for whom an answer is sought.

Probability of Success
A ratio of the number of patients who benefit from an intervention to all those who receive an intervention. A probability figure, such as 0.5 or 50%, means that out of 100 patients, 50 would benefit from an intervention and 50 would not benefit. Neither the dentist nor the patient can determine beforehand to which of the two groups a patient will belong.

The National Library of Medicine's free-access Web site for searching the MEDLINE database. For more information, visit this online tutorial.

Randomized Controlled Clinical Trial
A clinical study in which participants are randomly (i.e., by chance) assigned to either an experimental group or control group. The experimental group receives the new intervention and the control group receives a placebo or standard intervention. These groups are followed for the outcomes of interest.

Systematic Review
A process of systematically locating, appraising and synthesizing evidence from scientific studies to obtain a reliable overview. The aim is to ensure a review process that is comprehensive and unbiased. Findings from systematic reviews may be used for decision making about research and the provision of health care.

Some of these definitions are based on information provided in the glossary of the Oxford Centre for Evidence-Based Medicine.