RESUMO
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 ΔE00 and ΔE, 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.