Comparison 14. HP strip versus CP tray.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Tooth whitening ‐ assessed by the dentist	9		Mean Difference (IV, Random, 95% CI)	Subtotals only
1.1 6% HP strip versus 5% CP + 5% KN tray ‐ 1 week	1	32	Mean Difference (IV, Random, 95% CI)	‐0.71 [‐1.35, ‐0.07]
1.2 6% HP strip versus 10% CP tray ‐ 2 weeks	4	149	Mean Difference (IV, Random, 95% CI)	‐0.42 [‐0.92, 0.09]
1.3 6.5% HP strip versus 16% CP tray ‐ 21 days	1	55	Mean Difference (IV, Random, 95% CI)	2.10 [1.16, 3.04]
1.4 6% HP strip versus 10% CP tray ‐ 6 weeks	1	36	Mean Difference (IV, Random, 95% CI)	‐0.30 [‐0.95, 0.35]
1.5 6.5% HP strip versus 10% CP tray ‐ 2 months	1	33	Mean Difference (IV, Random, 95% CI)	‐2.63 [‐4.45, ‐0.81]
1.6 6.5% HP strip versus 15% CP tray ‐ 3 months	1	24	Mean Difference (IV, Random, 95% CI)	3.15 [‐0.15, 6.45]
2 Tooth whitening ‐ assessed by the dentist	1		Mean Difference (Fixed, 95% CI)	Subtotals only
2.1 14% HP strip versus 35% CP tray ‐ 30 days	1	24	Mean Difference (Fixed, 95% CI)	0.58 [‐0.61, 1.77]
3 Tooth whitening ‐ reported by the patient	1	43	Mean Difference (IV, Fixed, 95% CI)	‐0.41 [‐2.05, 1.23]