Evidence-based Dental Practice

1. Evidence-based Dental Practice

2. Outline • Definition of evidence-based dentistry • The process for EBD • Systematic reviews • Limitation of EBD

3. What is Evidence?

4. Sources of Evidence • People (colleagues, specialists, experts) • Textbooks • Clinical journals • Non-systematic reviews • Systematic reviews

5. Types of Clinical Questions • Therapy • Works? • Harm • Side effects? • Diagnosis • Accurate? • Etiology • Without doubt?

6. Types of Clinical Questions • Therapy • Randomized controlled trials • Harm • Randomized controlled trials • Diagnosis • Cohort studies • Etiology • Cohort studies

7. Bias • Bias is systematic or consistent errors that are caused by explicit or implicit factors or conditions in the study: • Explicit • We know that we are biased • Implicit • Hidden or un-detected

8. Bias and Healthcare • Newsletters • MI Paste: A revolution in mineralization • Expert opinion • Continuing education • One patient (case studies) • “In my experience”

10. Hierarchy of Evidence • Systematic reviews of randomized controlled trials • Randomized controlled trials • Experimental studies without randomization • Cohort studies • Case-control studies • Observational studies • Qualitative designs • Audit of records • Conference reports, consensus conferences, or expert opinion

11. ADA Definition of 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.” ADA, 2002

12. Evidence-based Dental Practice

13. Evidence-based Dentistry Clinical problem Questions PICO Decision Evaluation Search Appraisal Synthesis Selection

14. Parachute Paradox Parachutes reduce the risk of injury after gravitational challenge, but their effectiveness has not been proved with randomized controlled trials. BMJ 2003;327:20-27.

15. Risks of EBD • Clinicians do not deal with homogenous averages • Fundamentalist EBDers • Dissemination does not guarantee assimilation • Abuse by third parties • Legal liability

16. Example of a Systematic Review Home-based chemically-induced whitening of teeth in adults. Hasson H, Ismail AI, Neiva G Cochrane Database of Systematic Reviews, 2006

17. Clinical Questions • What is the effectiveness or relative effectiveness of tooth whitening products with chemical, bleaching action, that are available for use at home (dispensed by a dentist or over the counter (OTC))? • What are the harms reported in randomized controlled trials?

18. MethodsType of studies • Randomized controlled trials • Quasi-randomized controlled trials • Placebo or other comparable products • Human subjects • Full reports • Duration? • Majority presented data after 2 weeks

19. MethodsTypes of participants Adults 18 years or older Teeth tested should be free of stains due to use of tetracycline, fluoride products, or other systemic diseases or developmental conditions

20. MethodsSearch Methods • 416 reports • 162 duplicates • 253 non-duplicates • 193 did not meet the inclusion criteria • 60 full reports were reviewed • 2 reviewers

21. MethodsTypes of interventions • Any tooth whitening product, for use at home, that has a chemical bleaching action rather than an abrasive action. • Dentist-dispensed or OTC • Gels applied in trays, paint-on films, whitening strips

22. MethodsSearch Methods • All studies published between January 1966 and September 2005 • Cochrane Center Register of Controlled Trials (182) • MEDLINE (230) • EMBASE • Hand-searching (4) • Letters to researchers and companies

23. MethodsSearch Methods • 60 full reports • 35 reports were excluded (lack of data on outcomes after 2 weeks of application; data were not comparable; statistics were incomplete). • 25 studies (trials) were included in the review • 17 trials used the Chroma Meter system • 9 trials (11 reports) used the shade guide

24. ResultsDescription • 786 adult participants in the 17 studies that used the Chroma Meter. • Age range was between 18 and 73 years. • 766 participants in the 11 studies that used the shade guides. • Age range was between 18 and 80 years.

25. ResultsTypes of outcome measures • Digital readings of ‘whiteness” obtained using a digital imaging device/colorimeter (Minolta CR-221 or Chroma Meter), either from digital images or directly from facial tooth surfaces. • Ordinal scales (Vita Shade Guide or equivalent) (16 tooth tabs)

26. ResultsQuality • 21 trials were classified with high risk of bias • 4 were rated with moderate risk of bias • Quality assessment: • Concealment of allocation • Blinding of examiners • Training of examiners • Withdrawals

27. Results

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32. Results

33. ResultsFunding • 17 studies • 9 by P&G • 4 Ultradent and Discus Dental • 3 Colgate Palmolive • 1 Pfizer • 11 studies • 2 Dentsply • 4 Colgate Palmolive • 2 Ultradent and Discus Dental • 2 P&G • 1 Pfizer • 3 studies used shade guide and Chroma Meter.

34. Conclusions • There is evidence that whitening products work when compared with placebo/no treatment. • There are differences in efficacy between the products, mainly due to the levels of active ingredients, hydrogen peroxide and carbamide peroxide. • All trials were however short term and the majority of the studies were judged to be at high risk of bias and were either sponsored or conducted by the manufacturers. • There is a need for pragmatic long-term and independent clinical studies that include participants representing diverse populations. • There is also a need to evaluate long-term harms. • Several studies reported (when measured) the common side effects of tooth sensitivity and gingival irritation, and people should be informed of this.

35. The ADA Evidence-Based Dentistry Database

36. ADA-EBD Database

37. Evidence-based Dentistry • EBD is comprehensive synthesis of scientific evidence to answer a clinically relevant question. • EBD is a useful tool for life-long learning. • EBD cannot provide answers to the question on how treat a patient; but rather provide the dentist with information to make the most appropriate decision with a patient. • Abuse of EBD can only be prevented by a learned profession.