Abstract：
The aim of this study was to evaluate the effectiveness of a laser-assisted in-office tooth bleaching treatment, employing a diode laser (445 nm) using different power and time settings. Two hundred human incisors were collected for evaluating tooth color change (ΔΕ00) and whiteness index in dentistry (ΔWID) following laser-assisted tooth bleaching treatment. The specimens were distributed into 25 groups (n = 8) according to laser output power (0.5-2 W) and duration of irradiation (10-60 s) that was applied. ΔΕ00 and ΔWID were evaluated using a spectrophotometer at three points of time (24 h, 1 week and 1 month after treatments). Three-way ANOVA revealed that power, duration of laser irradiation, and time of measurement after bleaching treatments significantly affected both ΔΕ00 and ΔWID(p < 0.05). Furthermore, laser irradiation increased ΔΕ00 and ΔWID at all applied powers compared to the control group (p < 0.05), but this increase was dependent on the duration of irradiation. Laser irradiation significantly increased ΔΕ00 when the duration of operation was 50-60 s at 0.5-1 W, while at 1.5-2 W was significantly increased when the duration was 30-60 s. ΔWID was significant higher in the laser groups compared to the control group at all powers, except for 0.5 W where it was significant higher when the duration was 50-60 s. The outcomes of the study can help in selecting the suitable power settings and duration of laser exposure to achieve the optimal whitening results while ensuring the safety of the tooth pulp.
摘要：
这项研究的目的是评估激光辅助办公室牙齿漂白治疗的有效性，采用二极管激光器（445nm）使用不同的功率和时间设置。收集了两百个人门牙，用于评估激光辅助牙齿漂白处理后牙齿的颜色变化（ΔE00）和牙齿白度指数（ΔWID）。根据激光输出功率（0.5-2W）和照射持续时间（10-60s）将样品分为25组（n=8）。使用分光光度计在三个时间点（24小时，治疗后1周和1个月）。三因素方差分析揭示了这种力量，激光照射的持续时间，和漂白处理后的测量时间显著影响ΔE00和ΔWID(p<0.05)。此外，与对照组相比，激光照射在所有应用功率下都增加了ΔE00和ΔWID（p<0.05），但是这种增加取决于照射的持续时间。当在0.5-1W下操作时间为50-60s时，激光照射显着增加ΔE00，当持续时间为30-60s时，1.5-2W显着增加。与所有功率的对照组相比，激光组的ΔWID显着更高，除了0.5W，当持续时间为50-60s时，其显着较高。研究结果可以帮助选择合适的功率设置和激光暴露持续时间，以达到最佳的美白效果，同时确保牙髓的安全性。
