Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Av. do Café, Western Subsector, 11 (N-11), Ribeirão Preto, SP 14040-904, Brazil.
Department of Dentistry, Dental School, Federal University of Sergipe, Brazil.
Photodiagnosis Photodyn Ther. 2022 Sep;39:102929. doi: 10.1016/j.pdpdt.2022.102929. Epub 2022 May 26.
To evaluate in vitro the whiteness index (WID) and the whiteness index variation (ΔWID), as well as the color stability of stained endodontically treated teeth after bleaching with violet LED (VL) and with hydrogen peroxide 35% (HP) associated or not to VL.
Twenty-four lower incisors were selected. The color was measured using a spectrophotometer at the following times: baseline, after staining, bleaching, and thermocycling, to determine the whiteness index and variation (WID and ΔWID). For the staining process, the teeth were immersed in human blood and centrifuged. After biomechanical preparation, the specimens were distributed into three groups (n = 8): control group (HP); violet LED (VL); and HP 35% + VL (HP+VL), and one session was performed for both bleaching procedures every week for three weeks, followed by thermocycling, where 10,000 cycles were performed. After color analysis, the data obtained were submitted to statistical analysis (RM ANOVA, p < 0,05).
The staining of the teeth reduced the WID values for all experimental groups compared to baseline, and the bleaching protocols increased WID values, with the lowest WID values for group VL. There was no statistically significant difference after thermocycling for all groups compared to bleaching. Staining and thermocycling reduced the ΔWID values, and no difference was found between treatments at these assessment times. Bleaching increased the ΔWID values, with less pronounced changes in the VL group.
VL used alone has a lower bleaching effect compared to the bleaching treatment with HP, whether or not associated with VL, and the color stability was observed for all groups.
评估经紫色发光二极管（VL）和 35%过氧化氢（HP）漂白以及联合 VL 漂白后牙本质内染色的离体牙齿的白度指数（WID）和白度指数变化（ΔWID）以及颜色稳定性。
选择 24 颗下切牙。使用分光光度计在以下时间测量颜色：基线、染色后、漂白后和热循环后，以确定白度指数和变化（WID 和 ΔWID）。对于染色过程，将牙齿浸入人血中并离心。经过生物力学制备后，将标本分为三组（n=8）：对照组（HP）；VL（VL）；和 HP 35%+VL（HP+VL），两种漂白程序每周进行一次，持续三周，然后进行热循环，进行 10000 次循环。进行颜色分析后，将获得的数据提交给统计分析（RM ANOVA，p<0.05）。
与基线相比，所有实验组的牙齿染色均降低了 WID 值，漂白方案增加了 WID 值，VL 组的 WID 值最低。与漂白相比，所有组在热循环后均无统计学差异。染色和热循环降低了 ΔWID 值，在这些评估时间点，处理之间没有差异。漂白增加了 ΔWID 值，VL 组的变化不太明显。
VL 单独使用的漂白效果低于 HP 的漂白处理，无论是否联合 VL，所有组的颜色稳定性均得到观察。
