Comparison 6. HP paint‐on gel versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Tooth whitening ‐ assessed by the dentist	2		Std. Mean Difference (IV, Random, 95% CI)	Subtotals only
1.1 6% HP ‐ 2 weeks	2	148	Std. Mean Difference (IV, Random, 95% CI)	0.67 [0.19, 1.14]