Summary of findings 3. HP strips versus placebo for whitening teeth.
| Hydrogen peroxide (HP) strips compared to placebo for whitening teeth | ||||||
| Patient or population: adults undergoing bleaching Setting: home‐based Intervention: HP strips Comparison: placebo | ||||||
| Tooth whitening ‐ assessed by the dentist | ||||||
| Comparison | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo | Risk with HP strips | |||||
| 10% HP strip versus placebo ‐ day 8 (higher shade indicates whiter) | The mean change in shade in placebo group was 0.21 | Mean difference in shade change is 2.24 units higher in the HP strip group (1.72 higher to 2.76 higher) | ‐ | 36 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| 6% HP strip versus placebo ‐ 2 weeks (higher shade indicates whiter) | ‐ | Mean difference in shade change is 2.24 units higher in the HP strip group (1.83 higher to 2.66 higher) | ‐ | 195 (4 RCTs) | ⊕⊕⊝⊝ LOW1, 2 | ‐ |
| 10% HP strip versus placebo ‐ 15 days (higher shade indicates whiter) | The mean change in shade in placebo group was 0.90 | Mean difference in shade change is 1.93 units higher in the HP strip group (1.34 higher to 2.52 higher) | ‐ | 40 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| 14% HP strip versus placebo ‐ 3 weeks (higher shade indicates whiter) | The mean change in shade in placebo group was 1.90 | Mean difference in shade change is 7.60 units higher in the HP strip group (6.18 higher to 9.02 higher) | ‐ | 28 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| 6% HP strip versus placebo ‐ 6 weeks (higher shade indicates whiter) | The mean change in shade in placebo group was 1.82 | Mean difference in shade change is 2.90 units higher in the HP strip group (1.73 higher to 4.07 higher) | ‐ | 37 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| 14% HP strip versus placebo ‐ 6 weeks (higher shade indicates whiter) | The mean change in shade in placebo group was 0.45 | Mean difference in shade change is 5.16 units higher in the HP strip group (4.21 higher to 6.11 higher) | ‐ | 35 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| 5.3% HP strip versus placebo ‐ 6 months (higher shade indicates whiter) | The mean change in shade in placebo group was 1.02 | Mean difference in shade change is 1.21 units higher in the HP strip group (0.67 higher to 1.75 higher) | ‐ | 52 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| Adverse effects | ||||||
| Main adverse events reported in majority of trials were mild and transient tooth sensitivity and oral irritation which occurred more in the intervention group compared to placebo | ||||||
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI) CI: confidence interval; RCT: randomised controlled trial | ||||||
| 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 | ||||||
1Downgraded for risk of bias ‐ unclear risk of bias due to selection, performance, detection bias. 2Downgraded for imprecision ‐ low sample size and event rate.