Er∶YAG激光切割对牙本质粘接耐久性的影响

Micro-shear bond durability to Er∶YAG lased dentin

采用Er∶YAG激光或快机切割牙本质,SE Bond粘接修复后浸水6个月,用微剪切实验测试评估两种切割方法对粘接效果的影响.20颗离体磨牙制备获40片牙本质切片,随机分为激光组(Er∶YAG激光切割,20片)和快机组(#600沙砾磨砂纸打磨,20片).每切片用SE Bond粘接8个树脂柱,在浸水24h、7 d和6个月后,依次用微剪切实验测试粘接强度.测试结果用one-way ANOVA和t-test统计分析(标准差为0.05).并采用走查扫描电镜观察粘接破折面形态.结果显示,激光切割牙本质粘接强度在浸水6个月后显著低于激光组浸水24 h和7 d后,且低于对照快机组的粘接强度.说明采用两步法自酸蚀粘接系统SE Bond在激光切割的牙本质上未获得长期稳定的粘接效果.

The purpose of this study was to investigate the micro-shear bond strength of SE Bond to Er：YAG laser irradiated or bur-cut dentin after immersion in water for 24 h, 7 d and 6 months, respectively. Forty dentin slices obtained from twenty extracted human molars were prepared and divided into two groups： twenty specimens for laser group and twenty specimens for bur group. The surfaces of dentin slices of twenty specimens were exposed to pulsed laser-irradiation. The other twenty specimens were polished by 600-grit silicone paper. Applying SE Bond system, each prepared dentin surface was adhered to eight resin cylinders. The micro-shear bond strength tests were performed after the slices had been immersed in deionized water for 24 h, 7 d and 6 months, respectively. The bond strength results were statistically analyzed using one-way ANOVA and t-test at a significance level of 0.05. The bond strength results of lased dentin after 6-month immersion were significantly lower than those in other groups. The bond strength of SE Bond to Er： YAG lased dentin was significantly decreased in the long term. The conclusion can be used for the improvement in the method of lased dentin adhesive restorations.