Evidence-Based Dentistry

Question 1

Peer-reviewed journals are the ideal reference source.

Answer 1

Oxford Centre for Evidence-Based Medicine (OCEBM)

Question 2

Hierarchy of Levels of Evidence (6)

Answer 2

Systematic Review
Randomized controlled trial
Cohort
Case control
Case series
Expert opinion
(OCEBM)

Question 3

Quality of a systematic review relies on

Answer 3

The quality of the studies included. OCEBM

Question 4

Systematic reviews vs Meta-analysis

Answer 4

SR = comprehensive search and review of all the existing literature on a topic.
MA = delves deeper through statistical analyses to make direct comparisons between studies. OCEBM

Question 5

Highest level of evidence for clinical research

Answer 5

Randomized controlled trials. OCEBM

Question 6

Difficulties of randomized controlled trials.

Answer 6

Resource- and time-intensive, ethical concerns (children and the disabled).

Question 7

Cohort studies

Answer 7

Prospective. Longitudinal, measure incidence of new cases of a disease and assess risk factors. Not practical for rare outcomes.

Question 8

Case-control studies

Answer 8

Retrospective. Compare past risk factors and exposures in a disease group vs a control group. More useful for rare outcomes.

Question 9

Case series

Answer 9

Present an outcome without provision of a control.

Question 10

Expert opinion

Answer 10

Lowest level of evidence, often the starting point for further higher-level research.

Question 11

How to increase the odds of obtaining statistically significant results. (How to increase power)

Answer 11

Sample population is large and diverse

Question 12

Most common measure of statistical significance.

Answer 12

P value

Question 13

Likelihood of an outcome having occurred by chance

Answer 13

P value

Question 14

P value that indicates statistical significance

Answer 14

less than or equal to 0.05. The probability of the results being obtained by chance is less than 5%

Question 15

Separated NiTi instrument success rates

Answer 15

Spili et al
91.8% with separated NiTi
94.5% with control
P value of 0.49 = 49% chance that results were by chance, no statistical significance.

Question 16

Probability of a positive test in a diseased individual.

Answer 16

Sensitivity

Question 17

Probability of a negative test in a healthy individual.

Answer 17

Specificity

Question 18

Likelihood of a positive result correctly identifying a diseased individual.

Answer 18

Positive predictive value

Question 19

Likelihood of a negative result correctly identifying a healthy individual.

Answer 19

Negative predictive value

Question 20

Cold testing sensitivity

Answer 20

Jespersen et al
sensitivity of 0.92
92% of necrotic teeth were correctly identified

Question 21

Cold testing specificity

Answer 21

Jespersen et al
specificity of 0.90
90% of vital teeth were correctly identified

Question 22

Cold Testing predictive values

Answer 22

Jespersen et al
0.86 positive predictive value
0.94 negative predictive value
86% of positive results correctly identified pulpal necrosis while 94% of negative results correctly identified vital pulp.

Question 23

Prevalence

Answer 23

Number of cases at one point in time

Better for chronic conditions (apical periodontitis)

Question 24

Incidence

Answer 24

Number of new cases during a range of time

Better for acute conditions (toothache)

Question 25

Prevalence of apical periodontitis

Answer 25

Eriksen et al

26% to 70%

Question 26

Incidence of toothache in US

Answer 26

Lipton et al

12% over 6 months

Question 27

Success

Answer 27

The absence of symptoms and radiographic periapical pathology.

Question 28

Survival

Answer 28

Absolute presence or absence of a tooth in the mouth.

Question 29

Impact of CBCT on success vs survival

Answer 29

Wu et al

CBCT will inevitably detect more lesions, so the lines between success and survival may become more blurred.