Kuramoto Júnior M, Matson E, Turbino M L, Marques R A
Department of Dentistry, Faculty of Dentistry, University of São Paulo, São Paulo, SP, Brazil.
Braz Dent J. 2001;12(1):31-3.
Several studies have been conducted in order to verify effects of laser irradiation on dental structures. However, different settings and methods employed have led to inconclusive results. The aim of this study was to evaluate the effects of several settings of Nd:YAG laser irradiation on enamel microhardness. Fifteen groups of 10 human third molars each were submitted to Vickers microhardness indentations prior to and after laser irradiation. The data were submitted to the t-test for dependent samples (P < 0.05) for statistical evaluation. Lower total delivered energy (under 30 J) resulted in no statistically significant difference of microhardness between irradiated and non-irradiated samples, whereas higher energy settings decreased enamel surface microhardness significantly. This can be due to the significant temperature rise during irradiation. Thus, we conclude that laser irradiation, under the conditions of this study, is not suitable for improving enamel properties, because of decreased microhardness of irradiated samples.
为了验证激光照射对牙齿结构的影响，已经进行了多项研究。然而，所采用的不同参数设置和方法导致了不确定的结果。本研究的目的是评估不同参数设置的钕钇铝石榴石（Nd:YAG）激光照射对牙釉质显微硬度的影响。将15组，每组10颗人类第三磨牙在激光照射前后进行维氏显微硬度压痕测试。数据采用配对样本t检验进行统计评估（P < 0.05）。较低的总输出能量（低于30焦耳）导致照射组和未照射组之间的显微硬度没有统计学上的显著差异，而较高的能量设置则显著降低了牙釉质表面的显微硬度。这可能是由于照射过程中温度显著升高所致。因此，我们得出结论，在本研究条件下，激光照射不适合改善牙釉质性能，因为照射后的样本显微硬度降低了。
