Er,Cr:YSGG激光制备对牙体抗剪切强度影响的实验研究

目的　比较Er,Cr:YSGG激光与传统高速手机两种切割方法对牙体抗剪切强度的影响 ,分析Er,Cr:YSGG激光是否可以提高牙面的黏结强度。方法　选取新鲜离体牛上中切牙 4 6颗 ,分为两组 ,分别采用Er,Cr :YSGG激光和高速手机切割牙体。通过分组对照 ,进行抗剪切强度实验、扫描电镜观察、能谱分析及X线衍射分析。结果　Er,Cr:YSGG激光组的抗剪切强度高于高速手机组 (P <0 .0 0 1) .扫描电镜下观察 ,激光组的牙体表面清洁、粗糙 ,无玷污层存在 ,牙本质小管口开放 ,无裂化、熔融等热损伤迹象 ;能谱分析与X线衍射分析结果表明 ,两组样本在表面成分、结构上无明显差异。结论　Er,Cr:YSGG激光制备牙体不会引起牙体组织成分及结构的改变 ;Er,Cr:YSGG激光制备后的牙体抗剪切强度高于高速手机制备后的牙体 ,Er,Cr:YSGG激光制备牙体可以提高牙体的黏接强度。

Effects of Er, Cr:YSGG Laser on Dental Shear Bond Strength

Objective To investigate the effects of Er,Cr:YSGG laser on dental shear bond strength. Methods Forty six vitro bovine incisors were divided into two groups.They were cut by Er,Cr:YSGG laser and high-speed dental handpiece(KaVo), respectively.Then,the shear bond strength tests,the observation of scanning election microscope(SEM),election microprobe analysis of dispersive energy(EDX) and X-ray diffraction(XRD) were respectively conducted.Results Er,Cr:YSGG laser group had significantly higher shear bond strength than high-speed dental handpiece group(P<0.001).Through the observation of SEM,laser-cut surfaces were clean and devoid of a smear layer, and also it had no fissuring,recrystallization or crateriform foci of melting.As to the structural and atomic composition of dental surfaces,there were no significant differences between the two groups.Conclusion Er, Cr:YSGG laser irradiation of the dental surfaces could not cause the structure and atomic composition changes. And Er, Cr:YSGG laser could improve the shear bond strength of the dental surfaces.