Saberi Sogol, Rouzsaz Mahboubeh, Shafie Farhad, Einizadeh Sadra, Kharazifard Mohammad Javad, Shahabi Sima
Laser Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Tehran University of Medical Sciences, Tehran, Iran.
Photodiagnosis Photodyn Ther. 2020 Sep;31:101952. doi: 10.1016/j.pdpdt.2020.101952. Epub 2020 Aug 18.
The appearance of the teeth is of great importance to patients, particularly tooth color. In recent years, tooth whitening has been one of the most popular ways to restore tooth color. Bleaching gels can be affected by heat, light or laser, which can improve its effects. This study intends to examine the effects of two different wavelengths of diode laser (445 & 915 nm) after the bleaching process, on the enamel micro-hardness.
A total of 65 caries-free humans third molars were randomly divided into five groups (N = 13): first group: bleaching gel activated with 915 nm diode laser (1.5 W), second: bleaching gel activated with 915-nm (2.5 W), third: bleaching gel activated with 445-nm (1 W), fourth: bleaching gel activated with 445-nm (1.5 W), fifth (control group): bleaching gel without laser activation. Micro-hardness test (Vickers test) was performed before and after the treatment. The data were submitted to repeated measurement ANOVA and Tukey's HSD post hoc test (α = 0.05).
Enamel micro-hardness did not change significantly in groups 3 and 4 but decreased in groups 1 and 2. Group 2 showed the most reduction in micro-hardness. There were no significant changes in the control group.
According to the results of this study, 445 nm Diode laser did not reduce enamel micro-hardness, making it suitable for bleaching treatments. However, more studies are required to consider other factors, such as color changes and pulp temperature.
牙齿外观对患者非常重要，尤其是牙齿颜色。近年来，牙齿美白一直是恢复牙齿颜色最流行的方法之一。漂白凝胶会受到热、光或激光的影响，这可以提高其效果。本研究旨在探讨两种不同波长的二极管激光（445和915纳米）在漂白过程后对牙釉质微硬度的影响。
总共65颗无龋的人类第三磨牙被随机分为五组（N = 13）：第一组：用915纳米二极管激光（1.5瓦）激活的漂白凝胶，第二组：用915纳米（2.5瓦）激活的漂白凝胶，第三组：用445纳米（1瓦）激活的漂白凝胶，第四组：用445纳米（1.5瓦）激活的漂白凝胶，第五组（对照组）：未用激光激活的漂白凝胶。在治疗前后进行微硬度测试（维氏测试）。数据进行重复测量方差分析和Tukey's HSD事后检验（α = 0.05）。
第三组和第四组的牙釉质微硬度没有显著变化，但第一组和第二组的微硬度降低。第二组的微硬度降低最多。对照组没有显著变化。
根据本研究结果，445纳米二极管激光不会降低牙釉质微硬度，使其适用于漂白治疗。然而，需要更多研究来考虑其他因素，如颜色变化和牙髓温度。
