Graduate Student of the Postgraduate Program in Dentistry at the Federal University of Maranhão, São Luís, Maranhão, Brazil.
Graduate Student of the Department of Restorative Dentistry, School of Dentistry, University of Sao Paulo (USP), Sao Paulo, SP, Brazil.
Photodiagnosis Photodyn Ther. 2022 Sep;39:102965. doi: 10.1016/j.pdpdt.2022.102965. Epub 2022 Jun 19.
The light-emitting diode (Led) in the violet spectrum associated or not with hydrogen peroxide (HP) has been suggested as a promising technique for dental bleaching. Violet led has a wavelength of 405-410 nm, which is very close to that of ultraviolet (UV) radiation, and this has raised biological safety concerns.
To investigate the effectiveness of the violet led dental bleaching technique by evaluating color parameters, enamel surface microhardness, and biological safety analysis.
One hundred bovine dental blocks were divided into groups according to the bleaching technique (G1 - only HP; G2 - HP associated with blue led; G3 - only blue led; G4 - HP associated with a violet led; and G5 - only violet led). The color analysis (ΔE, ΔL, and WID) and enamel surface microhardness were assessed before and after bleaching (immediately, 5, 14, and 30 days). The biological safety of the violet led irradiation was assessed by measuring the number of micronuclei formed in human cells in culture in response to irradiation. Data analysis included Kruskal-Wallis test, Friedman test, and Mann-Whitney test.
In groups G4 and G5 there was the formation of precipitates on the enamel surface. At the time of 14 days, it was observed that the G2 group had lower values of microhardness than G5. ΔL and ΔE showed differences between groups in experimental times. Mean percentages of micronuclei occurrence were similar in the control group and the violet led group.
The violet led irradiation can be applied for dental bleaching because this approach produces significant color changes preserving tooth enamel integrity and causes no genotoxic effects on vital cells.
与过氧化氢（HP）相关或不相关的光谱中的发光二极管（Led）已被提议作为一种有前途的牙齿漂白技术。紫色 Led 的波长为 405-410nm，非常接近紫外线（UV）辐射的波长，这引起了人们对生物安全性的关注。
通过评估颜色参数、牙釉质表面显微硬度和生物安全分析，研究紫色 Led 牙齿漂白技术的有效性。
将 100 个牛牙块根据漂白技术分为五组（G1 - 仅 HP；G2 - HP 与蓝色 Led 联合；G3 - 仅蓝色 Led；G4 - HP 与紫色 Led 联合；G5 - 仅紫色 Led）。在漂白前后（立即、5、14 和 30 天）评估颜色分析（ΔE、ΔL 和 WID）和牙釉质表面显微硬度。通过测量在照射下培养的人细胞中形成的微核数量来评估紫色 Led 照射的生物安全性。数据分析包括 Kruskal-Wallis 检验、Friedman 检验和 Mann-Whitney 检验。
在 G4 和 G5 组中，牙釉质表面形成了沉淀物。在第 14 天，观察到 G2 组的显微硬度值低于 G5 组。在实验时间上，ΔL 和 ΔE 显示出组间的差异。对照组成核细胞微核发生率的平均百分比与紫色 Led 组相似。
紫色 Led 照射可用于牙齿漂白，因为这种方法在保持牙釉质完整性的同时产生显著的颜色变化，并且对活细胞没有遗传毒性作用。
