Summary of findings 10. CP gel in tray versus HP gel in tray for whitening teeth.
| Carbamide peroxide (CP) gel in tray compared to hydrogen peroxide (HP) gel in tray for whitening teeth | ||||||
| Patient or population: adults undergoing bleaching Setting: home‐based Intervention: CP gel in tray Comparison: HP gel in tray | ||||||
| Tooth whitening ‐ assessed by the dentist | ||||||
| Comparisons | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with CP gel in tray | Risk with HP gel in tray | |||||
| 10% CP versus 7.5% HP ‐ 2 weeks (higher shade indicates whiter) | The mean shade change in the CP gel in tray group was 3.40 | Mean difference in shade change was 1 lower in the HP group (2.86 lower to 0.86 higher) | ‐ | 48 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| 20% CP versus 9% HP ‐ 2 weeks (higher shade indicates whiter) | The mean shade change in the CP gel in tray group was ‐6.97 | Mean difference in shade change was 0.58 lower in the HP group (8.01 lower to 6.85 higher) | ‐ | 37 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| 20% CP versus 7.5% HP ‐ 12 days (higher shade indicates whiter) | The mean shade change in the CP gel in tray group was ‐2.59 | Mean difference in shade change was 0.99 lower in the HP group (2.32 lower to 0.34 higher) | ‐ | 56 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| 20% CP versus 7.5% HP ‐ 12 weeks (higher shade indicates whiter) | The mean shade change in the CP gel in tray group was ‐2 | Mean difference in shade change was 0.25 lower in the HP group (0.40 lower to 0.10 lower) | ‐ | 24 (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | ‐ |
| 10% CP versus 6% HP (darker shade) ‐ 2 weeks (higher shade indicates whiter) | The mean shade change in the CP gel in tray group was ‐11.10 | Mean difference in shade change was 4.30 lower in the HP group (5.02 lower to 3.58 lower) | ‐ | 164 teeth (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | Analysis done at tooth level |
| 10% CP versus 6% HP (medium dark and lighter shade) ‐ 2 weeks (higher shade indicates whiter) | ‐ | Mean difference in shade change was 2.22 lower in the HP group (2.63 lower to 1.81 lower) | ‐ | 349 teeth (1 RCT) | ⊕⊝⊝⊝ VERY LOW1, 2 | Analysis done at tooth level |
| Adverse effects | ||||||
| No difference was found between HP and CP in tray groups in relation to tooth sensitivity and oral irritation | ||||||
| *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 lack of allocation concealment. 2Downgraded for imprecision ‐ low sample size and event rate.