Effectiveness and one-year whiteness stability of different in-office bleaching agents and alternative protocols Gabardo Perez Mariano da Rocha, Bibiana Ruiz López, Javier Pérez Gómez, María Del Mar Gaidarji, Bruna Teixeira Frasson, Giovanna Brandão Durand, Letícia Bleaching agents Clinical protocols Color visual thresholds Tooth bleaching Color difference Statement of problem In-office bleaching has been widely researched. However, few studies have evaluated alternative protocols for this procedure. Moreover, information on the long-term stability of in-office whitening is limited. Purpose The purpose of this in vitro study was to evaluate the effectiveness and 1-year stability of in-office bleaching with 35% hydrogen peroxide (35%HP) and 37% carbamide peroxide (37%CP) using traditional and alternative protocols. Material and methods Forty human third molars were stained with tea and allocated to groups (n=10). Traditional protocols consisted of 3 applications of 35%HP for 15 minutes and 1 application of 37%CP for 45 minutes. Alternative protocols consisted of 1 application of 35%HP for 45 minutes and 3 applications of 37%CP for 45 minutes. Protocols were applied for 3 weeks. CIELab color coordinates were measured at baseline and weekly during treatment and at 1-week, 6-month, and 1-year follow-ups. Effectiveness and stability of the bleaching treatments were interpreted using 50:50% perceptibility and acceptability thresholds. CIELab, chroma, hue angle, and whiteness index were analyzed using the Wilcoxon signed-rank test (α=.05). Results All protocols showed improvement in bleaching after the first week (P≤.005). All bleaching procedures presented excellent whitening outcomes. Alternative protocols showed a larger rebound effect after 1 year, indicating less stability. For the whiteness index, no differences between the completion of the treatments and 1-year follow-up was found for the bleaching treatments and protocols (P>.05), except for the 37%CP alternative protocol (P=.005). Conclusions All tested protocols presented excellent effectiveness in bleaching. Traditional protocols exhibited a greater whiteness stability, while the alternative protocols showed a greater rebound effect after 1 year. Clinical Implications Excellent bleaching effectiveness was observed for all tested protocols using 35% hydrogen peroxide and 37% carbamide peroxide. In addition to the effectiveness of the bleaching, the stability and possibility of a rebound effect should be considered while making treatment decisions. The protocols recommended by the manufacturers for both bleaching agents were more stable, while alternative protocols presented a greater rebound effect after 1 year. 2024-07-30T10:57:53Z 2024-07-30T10:57:53Z 2024-07-08 journal article https://hdl.handle.net/10481/93635 10.1016/j.prosdent.2024.06.011 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier