Abstract: Objective    To observe the bond strength between dentin and VITA MarkⅡblocks after Er：YAG laser. Methods    Thirty human premolars extracted were chosen，grinding the mesial and distal surface of each premolar，then get 30 dentin samples for 3 mm×3 mm respectively. All the dentin samples were randomly divided into four groups，10 samples in each group：Group 1，Er﹕YAG laser（60mj，2Hz）；Group two，acid etching（35% phosphoric acid）；Group 3，acid etching combined with Er﹕YAG laser. 2 samples were randomly chosen from each group and observe the morphological changes of dentin with SEM；the other 8 samples of each group were bonded with VITA MarkⅡblocks by 3M ESPE RelyX Unicem. Compare the bond strength between dentin and VITA MarkⅡblocks after bond strength test. Result    The bond strength in the group of acid etching combined with Er﹕YAG laser showed the highest（20.4504），and there was statistically significant difference with the other groups（P＜0.001）. There was no statistically significant difference between the group of acid etching （15.2624）and Er﹕YAG laser（15.2360）. Conclusion    Acid etching combined with Er﹕YAG laser could significantly enhance the bond strength between dentin and VITA MarkⅡblocks.

Key words: Er﹕YAG laser, acid etching, dentin, bond strength

摘要： 目的    评价Er﹕YAG激光照射对牙本质与瓷块间粘接强度的影响。方法    选取2010年9月至2011年9月山西医科大学口腔医院颌面外科因正畸拔除的完整无龋坏、无隐裂的前磨牙30颗，分别制备3 mm ×3 mm的牙本质面，随机分为以下3组：Er﹕YAG激光组、酸蚀组、酸蚀+Er﹕YAG激光组，每组10个样本。通过扫描电镜观察各组样本的表面形态，并检测牙本质与瓷块间的粘接强度。结果    酸蚀+Er：YAG激光组粘接强度值最高，与酸蚀组和Er﹕YAG激光组相比较，差异有统计学意义（P＜0.01），而酸蚀组与Er﹕YAG激光组间差异无统计学意义（P＞0.05）。结论    酸蚀联合Er﹕YAG激光照射能够增强牙本质与瓷块间的粘接强度，是牙体组织粘接前有效的表面处理方式。

关键词: Er﹕YAG激光, 酸蚀, 牙本质, 粘接强度