evidence on periodontology

1. EVIDENCE-BASED PERIODONTICS
P R E S E N T E D B Y:
D R S WA P N I L P. B O R K A R
1

2. • INTRODUCTION
• PRINCIPLE
• WHAT IS TRADITIONAL CLINICAL PRACTICE
• TRIAD OF EVIDENCE BASED PERIODONTOLOGY (EBP)
• EVIDENCE BASED VS TRADITIONAL PERIODONTOLOGY
• DEVELOPMENT
• COMPONENTS
• SOURCES OF EVIDENCE
• SYSTEMATIC REVIEWS
• META-ANALYSIS
• CRITICAL APPRAISAL
• BIAS
• CONFOUNDING
• CHANCE
• INTERPRETATION
• CONCLUSION
2

3. WHAT IS EVIDENCE ?
NEED FOR EVIDENCE
WHAT IS EVIDENCE BASED PRACTICE ?
“Evidence based practice involves integrating individual clinical practice with the
best available external clinical evidence from systematic research”. Sacketts et al
EVIDENCE BASED HEALTH CARE
“An approach to decision making in which the clinician uses the best available
evidence , in consultation with the patient, to decide upon the option which suits the patient the
best”. Muir Gray et al
EVIDENCE BASED MEDICINE
The integration of the best research evidence with clinical expertise and patient
values. (Sackett et al, 2000)
3

4. EVIDENCE BASED DENTISTRY “ an approach to health care that requires the judicious
integration of-
 Systematic assessment of clinically relevant scientific evidence,relating to the patient’s oral
and medical condition and history.
 Dentist’s clinical expertise.
 Patient’s treatment needs and preferences.”( According to the ADA-)
PRINCIPLES OF EVIDENCE BASED DENTISTRY
To define a clinically relevant and focussed question-
 Getting the best information quickly
 Assessing it’s quality
 Deciding whether it is relevant
 Best identified valid and relevant evidence used in the patient care
4

5. HURDLES IN EVIDENCE BASED DENTISTRY
 Amount of evidence
 Quality of evidence
 Authority rather than evidence
5

6. ADVANTAGES OF EVIDENCE BASED DENTISTRY
 objective
 scientifically sound
 Uses resources effectively
 patient focussed
 Incorporates clinical experience
 Stresses on good judgement
 Relies on evidence rather than authority
 Uses transparent methodology
 Enables practitioners to monitor and develop clinical performance
6

7. • TRADITIONAL CLINICAL PRACTICE
• CLINICAL DECISIONS BASED ON PERSONAL BELIEFS AND EXPERIENCES
7

8. EVIDENCE BASED PERIODONTOLOGY
WHAT IS EVIDENCE BASED PERIODONTOLOGY?
 The application of evidence-based health care to periodontology.
 It is a tool to support decision-making and integrating the best evidence available with clinical practice.
Needleman,Moles,et al,Perio 2000
8

9. TRIAD OF EVIDENCE BASED PERIODONTOLOGY (EBP)
GOAL OF EVIDENCE BASED PERIODONTOLOGY
To help the periodontist provide the best care for their patient
9How evidence-based periodontology fits into healthcare. Reproduced with permission from Clarkson, J, Harrison, JE,
Ismail, AI, Needleman, IG, Worthington, H, eds. Evidence Based Dentistry for Effective Practice. London: Martin Dunitz,

10. EVIDENCE BASED VS TRADITIONAL PERIODONTOLOGY
SIMILARITIES:
 High value of clinical skills and experience.
 Fundamental importance of integrating evidence with patient values.
Unclear basis of evidence.
Unclear or absent appraisal of quality of
evidence.
More subjective,more opaque and biased
process.
Greater tendency to make black and white
conclusions.
Uses the best evidence
Systematic appraisal of quality of evidence.
More objective,more transparent and less
biased process.
Greater acceptance of levels of uncertainty.
DIFFERENCES:
• EVIDENCE BASED
PERIODONTOLOGY
• TRADITIONAL PERIODONTOLOGY
10Clarkson, J, Harrison, JE, Ismail, AI, Needleman, IG, Worthington, H, eds. Evidence Based Dentistry for Effective
Practice. London: Martin Dunitz, 2003

11. DEVELOPMENT OF EVIDENCE BASED PERIODONTOLOGY
coined by the clinical epidemiology group at Mc Master University.
 1994: Alexia et al challenged the methods and quality of the periodontal clinical research in the mid-
1980s.; Set up an Oral Health Group as part of the Cochrane Collaboration in Boston, USA.
 1996: WWP held by the AAP included elements of evidence-based health care, supported by
Michael Newman at the University of California, Los Angeles.
 1997: The Editorial Base of the Oral Health Group moved to Manchester University , with Bill Shaw
and Helen as the co-ordinating editors.
11

12. 2001: The first Cochrane Systematic review in periodontology was published and researched the
effect of GTR for the intrabony defects.
2002: The EWP became the first international workshop to use rigorous Systematic Reviews to
inform the consensus.
2003: Similar approach by the AAP for Contemporary Science Workshop.
12
Evidence-based periodontology, systematic reviews and research quality IAN NEEDLEMAN et al perio 2000, vol 37 , 2005

13. COMPONENTS OF EVIDENCE BASED PERIODONTOLOGY
13The steps of evidence-based periodontology. Reproduced with permission from Clarkson, J, Harrison, JE, Ismail, AI, Needleman, IG,
Worthington, H, eds. Evidence Based Dentistry for Effective Practice. London: Martin Dunitz, 2003

14. SOURCES OF EVIDENCE
PRIMARY SOURCES:
The primary sources are original research publications that have not been filtered or synthesized .
SECONDARY SOURCES:
Secondary sources are synthesized publications of the primary literature.
These resources include:-
 Summaries of Systematic Reviews
 Individual research articles
 Clinical practice guidelines and protocols
14
Evidence-based periodontology, systematic reviews and research quality IAN NEEDLEMAN et al perio 2000, vol 37 , 2005

15. DATABASES FOR SEARCH
MEDLINE ( PUBMED)
EMBASE
HEALTH STAR
CINALH ( Cumulative Index To Nursing and Allied Health)
The COCHRANE COLLABORATION LIBRARY
 Pub Med is designed to provide access to both primary and secondary research from the biomedical literature.
Pub Med provides access to MEDLINE which contains-
o Bibliographic citations
o Authors’ abstracts from more than 4800 biomedical journals published in the US and 70 other countries.
The database contains over 12 millon citations dating back to 1966, and it adds more than 5,20,000 new
citations each year.
15

16. SYSTEMATIC REVIEWS
 A systematic review is a literature review focused on a single question that tries to identify,
appraise, select and synthesize all the high quality research evidence relevant to that question.
 Systematic reviews of high quality RCT are crucial to EBP
 An understanding of systematic reviews and how to implement them in practice is becoming
mandatory for all professionals involved in the delivery of health.
“ In patients with chronic periodontitis,what is the effect of smoking or smoking cessation on the
response to non-surgical periodontal therapy in terms of clinical and patient-centered outcomes?”
( Labriola et al. )
16

17. OBJECTIVES OF SYSTEMATIC REVIEWS
 To provide a comprehensive and contemporary appraisal of research using transparent methods
while aiming to minimize the bias.
 To aid in clinical decision making.
17

18. WHAT A HIGH QUALITY SR CAN DO
• Find and summarize all the available studies.
• Provide an assessment of the quality of the research and in particular the degree of protection from
bias within the original studies.
• Estimate research effects across the multiple studies with meta-analysis.
• It is possible to generalize the results if the effect is consistent across multiple studies.
CANNOT DO
• Cannot be used in isolation to dictate clinical practice.
• Can only be used in context with clinical judgment and patient preference.
• Cannot give strong conclusions if the research base is weak in quality.
• Cannot overcome limitations of narrowly designed clinical research.
• Cannot exclude irrelevant studies. 18
Evidence-based periodontology, systematic reviews and research quality IAN NEEDLEMAN et al perio 2000, vol 37 , 2005

19. COCHRANE COLLABORATION
 Many health care journals now published systematic reviews, but the best known source isThe Cochrane
Collaboration, a group of over15,000 specialists in health care who systematically review randomized trials
of the effects of treatments, and when appropriate, the results of other research.
 Cochrane reviews are published in The Cochrane Database Of Systematic Reviews section of The
Cochrane Library, which upto January 2009 contained 3,625 complete reviews and 1,921 protocols for
additional reviews being conducted.
19

20. REQUIREMENTS FOR SR
The Cochrane group provides a handbook for systematic reviewers of intervention , where they
suggest that each systematic review should contain the following main sections:-
 Background
 Objectives
 Methods of the review
 Results
 Conclusion and discussion
20

21. STEPS FOR PREPARING AND MAINTAINING A SYSTEMATIC REVIEW
Formulating a problem
Locating and selecting studies
Critical appraisal of studies
Collecting data
Analyzing and presenting results
Interpreting results
Improving and updating reviews
21

22. QUALITY ASSESSMENT CHECKLIST FOR SR IN DENTISTRY
 Did the review address a focused question?
 Did authors look for appropriate papers?
 Do you think authors attempted to identify all the relevant studies?
 Search for published and unpublished literature?
 Were the inclusion criteria carried out by atleast 2 reviewers?
 Are the results clearly displayed?
 Was an assessment of heterogeneity made and reasons for variation discussed?
 Were the results of the review applicable?
22

23. COMPARISON OF CHARACTERISTICS OF SYSTEMATIC REVIEWS AND TRADITIONAL LITERATURE
REVIEWS
CHARACTERISTIC SYSTEMATIC REVIEW LITERATURE REVIEW
Focus of review Specific problem : Narrow focus.
Eg : Effectiveness of Periostat as an
adjunct to scaling and root planing for the
treatment of adult periodontitis.
Range of issues on a topic:
Broad focus.
Eg : Effectiveness of adjunctive
antimicrobial agents for treating
periodontitis.
Who conducts Multidisciplinary team Individual
Selection of studies to
include
Pre-established criteria based on validity
of the study design and specific problem;
All studies that meet the criteria are
included.
Criteria not pre-established or
reported in the methods;search on
range of issues.may include or
exclude studies based on personal
bias or support for the hypothesis,if
one is stated.
23

24. CHARACTERISTIC SYSTEMATIC REVIEW LITERATURE REVIEW
Reported findings Search strategy: databases searched.
Number of studies that met or did not
meet the criteria: why certain studies were
excluded.
Description of study design, subjects,
length of trial,state of health /
disease,outcome measures.
Literature presentation format
crafted by the individual author.
Search strategy,databases and
total number of studies(pros and
cons)are rarely identified.
Descriptive in nature, reporting
the outcomes of studies rather
than their study design.
Synthesis of selected
studies
Critical analysis of the included studies.
Determination of the results could be
statistically combined.
Reporting of studies that support a
procedure or position and those that
do not;rather than combining data or
conducting a statistical analysis.
24

25. CHARACTERISTIC SYSTEMATIC REVIEW LITERATURE REVIEW
Main results Summary of trials;
Total number of subjects.
Definitive statements about findings in
relation to objectives and outcome
measures
Summary of the findings by the
authors in relation to the purpose
of literature review and specific
objectives.
Conclusions or
comments
Discussion of key findings with the
interpretation of the results, including
potential biases and recommendations
for future trials.
Discussion of key findings with
the interpretation of the results,
including recommendations and
limitations for future trials.
25

26. META-ANALYSIS
DEFINITION: by Huque
“ A statistical analysis that combines or integrates the results of several independent clinical trials
considered by the analyst to be ‘combinable’.
“ statistical overview”, “quantitative synthesis” , “pooling” and “weighted averaging” .
HISTORY
• The term coined in 1976 by the psychologist Glass .
• The first meta-analysis has been identified as the 1940 book-length publication “Extra- Sensory
Perception after 60 years”, J.G.Pratt et al
• The meta-analysis of a medical treatment was first published in 1955.
• In oral health care, the first meta-analysis indexed in the MEDLINE database was published in 1989 .
26

27. TYPES OF META-ANALYSIS
POOLED ( QUANTITATIVE ) ANALYSIS :
• The analysts pool the observations of many studies and then calculate parameters such as risk ratios
or odds ratios from the pooled data. ( Grebarg and Horowitz,1988 )
• Pooled analysis should report both relative risk and reductions and absolute risk and risk reductions.
METHODOLOGIC (QUALITATIVE ) ANALYSIS:
• The quality of the research concerning the intervention is scored according to a list of objective
criteria.
• The analyst then examines the methodological superior studies to determine whether or not the
question of benefits is answered correctly by them.
• termed methodological analysis ( Grebarg and Horowitz, 1988 ) or ‘ quality scores analysis’
(Greenland, 1994 ).
• In some cases, the methodologically strongest studies agree with one another and disagree with the
weaker studies, which may or may not be consistent with one another.
27

28. WEAKNESSES OF META-ANALYSIS
 A good meta-analysis of badly designed studies will result in bad statistics.
 Another weakness of the method is the heavy reliance on published studies, which may increase the
effect as it is very hard to publish studies that show no significant results.
 This publication bias or “ file-drawer effect” should be seriously considered when interpreting the
outcomes of a meta-analysis.
28

29. STUDY DESIGNS
 Effectiveness of a treatment option is best answered by Randomized Controlled Trial (RCT).
 Systematic Review of RCTs is the GOLD STANDARD .
 However for questions on etiology and prognosis cohort studies are more appropriate.
29

30. STUDY DESIGN AND THE TYPE OF QUESTIONS THEY ADDRESS
D E F I N I T I O N O F S T U D Y
D E S I G N
EXPERIMENTAL STUDIES:
1.Randomized controlled trial:
2.Randomized controlled trial: split-mouth
design
3. Non-randomized controlled trial:
U S E D F O R
Evaluating the effectiveness of an intervention.
RCT comparing the effectiveness of surgical
therapy and non-surgical therapy.
30

31. :
1.Cohort studies:.
2. Case-control studies.
3. Cross-sectional studies: a study or a survey
undertaken on a defined population at a single
point in time( snap-shot ).
Measuring the incidence of a disease; Looking at
the cause of disease; determining the
prognosis.
Identifying the potential risk factors for a disease;
Looking at the possible causes of disease.
Measuring the prevalence of a disease or risk
factor in a defined population at a specific time.
OBSERVATIONAL STUDIES
31
Evidence-based periodontology, systematic reviews and research quality IAN NEEDLEMAN et al perio 2000, vol 37 , 2005

32. CRITICAL APPRAISAL
Evidence needs to be critically appraised.
 Quality of evidence may vary according to the study design.
 The publication of the results in a high ranking journal is not an absolute guarantee of quality.
32

33. BIAS
• Bias is any systematic error in design, conduct or analysis of a study which leads to an erroneous
conclusion ( Soben Peter )
• Bias leads to an incorrect estimate of the effect of a risk factor or exposure on the development of a
disease or outcome.
• The observed effect will be either above or below the true value.
TYPES OF BIAS
1. SELECTION BIAS ( How the subjects were selected for inclusion in the study?)
2. PERFORMANCE BIAS ( Provision of care )
3. DETECTION / MEASUREMENT BIAS (Assessment of outcomes)
4. PUBLICATION BIAS
33

34. CONFOUNDING
• Term that describes the situation where an estimate of the association between an exposure and the disease
is mixed up with the real effect of another exposure on the same disease, the two exposures being correlated.
Coffee drinking
Poor
treatment
response
Smoking
habits
(confounder)
Risk factorAssociation
34
Evidence-based periodontology, systematic reviews and research quality IAN NEEDLEMAN et al perio 2000, vol 37 , 2005

35. Confounding can be dealt with at the design stage of the investigation by:-
1. RANDOMIZATION
2. RESTRICTION
3. MATCHING
35

36. CHANCE
• Chance is a random sampling error.
• The extent to which the sample results reflect the likely result in the population is assessed by
performing statistical significance tests , and more importantly, by calculating the confidence
intervals.
INTERPRETATION
• The authors may also fail to interpret their experimental results correctly. So, even if the study
has been well conducted and appropriately analyzed , there is still the potential to draw incorrect
conclusions from the results
36

37. • Personal oral hygiene and chronic periodontitis
• Does oral health promotion improve oral hygiene and gingival health?
• How effective is surgical therapy compared with nonsurgical debridement?
• Which reconstructive procedures are effective for treating the periodontal intraosseous defect?
• Systematic review of the effect of smoking on nonsurgical periodontal therapy
37
Evidence-based periodontology, systematic reviews and research quality perio 2000, vol 37 , 2005

38. CONCLUSION
• The principles of evidence-based healthcare provide structure and guidance to facilitate the
highest levels of patient care.
• Evidence-based health care is not an easier approach to patient management , but should provide
both the clinicians and the patients with greater confidence and trust in their mutual relationship.
38

39. REFERENCES
1. Carranza’s Clinical Periodontology, 10th edition, 2006.
2. Ian Needleman, David R.Moles, Helen Worthington; Evidence-based Periodontology;
Systematic Reviews and Research Quality; Periodontology 2000; vol.37;2005;12-28.
3. Soben Peter , 3rd edition.
4. Newman MG, Caton JG, Gunsolly JC; The use of Evidence-based Approach in a Periodontal
Therapy; Contemporary Science Workshop; Ann Periodontology 2003;8; 1-11.
39