Bleaching efficacy of at home 16% carbamide peroxide. A long‐term clinical follow‐up study

Abstract Objective To assess the whitening efficacy of a 16% carbamide peroxidase (CP) gel after 42 months of clinical follow‐up. Materials and methods A retrospective clinical study was carried out involving 95 participants. CP 16% was applied for 90 minutes a day for 4 weeks using individualized trays. Tooth color was assessed using spectrophotometry at baseline, 1 week after the end of treatment, and every 6 months until completing 42 months of follow‐up. Color parameters were compared using analysis of variance for repeated measures. The analysis by teeth groups was performed using two‐way ANOVA. Results The mean baseline L * was 81.7 ± 5.2 versus 83.6 ± 8.8 after 42 months ( P <.01). L * showed a decrease of 2.3 after 30 months. The values corresponding to a * before treatment were 0.4 ± 1.1 versus −1.0 ± 1.0 after 42 months ( P <.01). The initial values corresponding to b * were 23.4 ± 3.3 versus 15.8 ± 1.3 after 42 months ( P <.01). Values of Δ E 00 and Δ E , at the end of the treatment were 4.6 ± 1.2 and 7.8 ± 1.8, respectively. Teeth groups remained stable after 42 months of follow‐up. Conclusions The home application of 16% CP gel for 90 minutes a day for 4 weeks using individualized trays resulted in whitening that remained stable over the 42 months of follow‐up. Clinical significance Treatment with 16% CP is an effective and safe tooth whitening procedure, and the color obtained remains stable over the long term.