脉冲Nd：YAG激光照射对牙本质通透性的影响

本实验用不同能量参数的脉冲Ｎｄ：ＹＡＧ激光；分别照射牙本质窝洞底部，电镜观察和测定牙本质通透性，研究激光对牙本质的作用，初步探讨Ｎｄ：ＹＡＧ激光脱敏的机制。结果显示：０．６Ｗ（４０ｍＪ、１５Ｈｚ）组的牙本质通透性与对照组无统计学差异；０．９Ｗ（６０ｍＪ、１５Ｈｚ）和１．２Ｗ（８０ｍＪ，１５Ｈｚ）组的牙本质通透性明显增加。ＳＥＭ示所有激光组牙本质融熔、牙本质小管口模糊不清，洞底小管口部分被融熔物质阻塞。提示Ｎｄ：ＹＡＧ激光脱敏，可能存在其他的生物学脱敏机制。

Effect of pulsed Nd:YAG laser treatment on dentinal permeability

The purpose of this study was to examine the morphological change and the permeability of lased dentine by a pulsed Nd:YAG laser with different energy levels by SEM and measuring the dye penetration of dentine and to evaluate the mechanism of reduction of dentin hypersensitivity by Nd: YAG laser. Results indicated that there were significant differences in permeability between Nd: YAG laser treatment group of 0. 6W(40mJ, 15Hz) and control group. The dentinal permeability showed significantly increase in groups of 0. 9W(60mJ, 15Hz) and 1. 2W(80mJ, 15Hz). SEM examinations of the lased dentine revealed that the surfaces had melted, the tubules turned to be vague or sealed and the orifices were partly obstructed by melted dentine. The study indicated that the mechanism of reducing of dentin hypersensitivity by Nd: YAG laser could be explained by other biological mechanism .