Comparison 1. Plaque.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Plaque at 6 to 7 months (Quigley‐Hein Plaque Index)	20	2675	Mean Difference (IV, Random, 95% CI)	‐0.47 [‐0.60, ‐0.34]
1.1 Baseline prophylaxis	16	2211	Mean Difference (IV, Random, 95% CI)	‐0.44 [‐0.58, ‐0.30]
1.2 No baseline prophylaxis	4	464	Mean Difference (IV, Random, 95% CI)	‐0.61 [‐0.82, ‐0.41]
2 Plaque at 6 to 7 months (Plaque Severity Index)	13	1850	Mean Difference (IV, Random, 95% CI)	‐0.15 [‐0.20, ‐0.10]
2.1 Baseline prophylaxis	10	1496	Mean Difference (IV, Random, 95% CI)	‐0.13 [‐0.18, ‐0.08]
2.2 No baseline prophylaxis	3	354	Mean Difference (IV, Random, 95% CI)	‐0.20 [‐0.26, ‐0.14]
3 Plaque at 6 to 7 months (Löe‐Silness Plaque Index)	2	148	Mean Difference (IV, Fixed, 95% CI)	‐0.05 [‐0.10, ‐0.01]