Summary of findings 1. Rubber dam versus cotton rolls for restorative treatment in dental patients.

Rubber dam versus cotton rolls for restorative treatment in dental patients
Patient or population: dental patients requiring restorative treatment Settings: dental clinics in China and Brazil; primary school in Kenya Intervention: rubber dam Comparison: cotton rolls
Outcomes	Illustrative comparative risks* (95% CI)		Relative effect (95% CI)	Number of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Cotton rolls	Rubber dam
Survival rate of restorations Assessed clinically and radiographically Follow‐up: mean 6 months	Study population		OR 2.29 (1.05 to 4.99)	192 (2 studies)	⊕⊕⊝⊝ Lowa,b	The use of rubber dam may result in a higher survival rate of the restorations compared to cotton rolls at 6 months' follow‐up Other time points: Survival rate of restorations at 12 months: the use of rubber dam may have little to no effect on the survival rate of restorations compared to cotton rolls at 12 months' follow‐up but the evidence is very uncertain (OR 1.38, 95% CI 0.45 to 4.28; 1 study, 30 participants; very low‐certaintya,b,c evidence) Survival rate of restorations at 18 months: the use of rubber dam may have little to no effect on the survival rate of restorations compared to cotton rolls at 18 months' follow‐up but the evidence is very uncertain (OR 1.00, 95% CI 0.45 to 2.25; 1 study, 30 participants; very low‐certaintya,b,c evidence) Survival rate at 24 months: the use of rubber dam may result in a higher survival rate of the restorations compared to cotton rolls at 24 months' follow‐up but th evidence is very uncertain (HR 0.80, 95% CI 0.66 to 0. 97; 1 study, 559 participants; very low‐certaintya,d evidence)
	811 per 1000	908 per 1000 (818 to 955)
Adverse events	Outcome not reported
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; HR: hazard ratio; 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.

^aThe certainty of the evidence was downgraded by 1 level for high risk of bias.
^bThe certainty of the evidence was downgraded by 1 level for imprecision due to small sample size which did not meet the optimal information size (OIS).
^cThe certainty of the evidence was downgraded by 1 level for imprecision due to wide CIs overlapping no effect.
^dThe certainty of the evidence was downgraded by 2 levels for imprecision (single study).