Summary of findings 1. Summary of findings: antibiotic prophylaxis versus no antibiotic prophylaxis for preventing bacterial endocarditis in dentistry.

Antibiotic prophylaxis compared with no antibiotic prophylaxis for the prevention of bacterial endocarditis in dentistry
Population: adults or children at risk of endocarditis Setting: dental setting Intervention: antibiotic prophylaxis Comparison: no antibiotic prophylaxis
Outcome	Results	No of participants (studies)	Certainty of the evidence (GRADE)	Comments
Mortality or serious adverse events requiring hospitalisation	No data reported	248 (1 study)	‐	‐
Development of endocarditis (in those with definite indication for prophylaxis)	There was no difference in the number of people (with a definitive indication for prophylaxis) who developed endocarditis between those receiving prophylaxis and those not receiving prophylaxis (OR 1.62; 95% CI 0.57 to 4.57).	248 (1 study)	⊕⊝⊝⊝ Very lowa	‐
Adverse effects of antibiotics	No data reported	248 (1 study)	‐	‐
CI: confidence interval; OR: odds ratio
GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

^aDowngraded 3 levels for high risk of bias and serious imprecision.