Abstract: Objective: To investigate the effects of different tooth preparation methods on ultrastructure of non-carious sclerotic dentine. Methods: 20 molar teeth with typical sclerotic dentin on the occlusal surface were randomly divided into 4 groups: Teeth in group A were prepared with high-speed turbine dental drill; Teeth in group B were prepared by dental drill and 35% phosphoric acid for 15s; Teeth in group C were prepared by Er,Cr:YSGG laser; Teeth in group D were prepared by laser and 35% phosphoric acid for 15s. Scanning electron microscope was used to observe the ultrastructure of the sclerotic dentin surface. Results: Group A: the sclerotic dentin surface was relatively flat, and covered by smear layer. Group B: the sclerotic dentin surface became rough, the smear layer had been removed and sclerotic column protruded from dentinal tubules. Group C: the sclerotic dentin surface was rough, the intertubular dentin were honeycombing changed, and the dentinal tubules protruded. Group D: the opening of dentinal tubules increased and sclerotic column protruded. Conclusions: Prepare the dentin surface by Er,Cr:YSGG laser can obviously improve the non-carious sclerotic dentine surface, combined 35% phosphoric acid etching at the same time can obtain a better bonding surface.

Key words: Scanning electron microscope, Er, Cr:YSGG Laser, Non-caries sclerotic dentin

摘要： 目的: 探讨两种牙体预备方法对非龋性硬化牙本质超微结构的影响。方法: 20颗咬合面有典型硬化牙本质的磨牙随机分为四组：A组用高速涡轮牙钻预备,B组用牙钻预备后35%磷酸酸蚀15s,C组用Er,Cr:YSGG激光预备,D组用激光预备后35%磷酸酸蚀15s。扫描电镜观察各组磨牙硬化牙本质表面的超微结构。结果: A组硬化牙本质表面较平整,有玷污层;B组酸蚀后硬化牙本质表面变得粗糙,玷污层被去除,可见硬化结晶柱突出于牙本质小管口。C组硬化牙本质表面粗糙,管间牙本质有蜂窝状改变,牙本质小管突出;D组酸蚀后牙本质小管开口增大,有硬化结晶柱突出。结论: 使用Er,Cr:YSGG激光预备非龋性硬化牙本质能明显改善其表面形态,结合35%磷酸酸蚀可获得更佳的粘接表面。

关键词: 扫描电子显微镜, Er, Cr:YSGG激光, 非龋性硬化牙本质