Er,Cr:YSGG激光处理正常及龋坏牙本质的扫描电镜观察

目的：利用扫描电镜观察Er，Cr：YSGG激光处理龋坏牙本质的形态学改变，并与常规方法进行比较。方法：将24颗新拔除的患龋牙随机分成2组，每组12颗牙。第1组常规处理组：分别用金刚砂石针、碳钢裂钻和挖器处理正常及龋坏牙本质；第2组激光处理组：分别用2WEr，Cr：YSGG激光、4WEr，Cr：YSGG激光处理正常及龋坏牙本质。常规制片，扫描电镜下观察。结果：与常规方法相比，激光处理后的牙本质表面不平，呈鱼鳞状、片状的粗糙外观；表面清洁，无玷污层，牙本质小管口清晰可见；4W激光作用时偶见微裂；激光处理后的牙本质表面具有增加树脂黏结性的形态学改变．结论：Er，Cr：YSGG激光能有效地清除龋坏牙本质及玷污层，并可使牙体组织发生一定的形态学改变。因此，Er，Cr：YSGG激光能够替代常规去龋备洞方法。

Scanning Electron Microscopic Analysis of Carious and Healthy Dentin after Er,Cr:YSGG Laser Irradiation

Objective:To treat sound dentin,carious dentin either with conventional methods or with a Er,Cr:YSGG laser,to evaluate the morphological changes by Scanning Electron Microscopy(SEM),and to compare with the results.Methods:24 freshly extracted human teeth were randomly divided into two groups of twelve each.ln the first group,lesions were treated with burs in a dental handpiece and excavator;in the second group,we used the Er,Cr:YSGG laser at 2W and 4W.After treatment,the teeth were prepared for SEM microscopic observation.Results:On lasertreated teeth,scaly,flaky,rough surfaces were seen;surfaces were free of smear layer and clean with several morphological reliefs that may enhance bonding resin restoration.The laser at 4W appeared microcracks occasionally.Conclusions:The Er,Cr:YSGG laser beam can ablate carious dentin at 2W and 4W.The Er,Cr:YSGG laser seems to be effective in the treament of carious and in cavity preparation in vitro.