Er：YAG 激光与涡轮机处理乳牙牙本质表面对树脂剪切强度影响的对比研究

目的：评价 Er：YAG 激光和高速涡轮机2种方法处理乳牙牙本质表面形态学变化及其对复合树脂剪切强度的影响。方法选取因乳牙滞留拔除的无龋坏、无充填体、无裂纹的下颌乳前牙64颗，随机分为 Er：YAG激光组（A 组）和高速涡轮机（B 组），每组32个样本，分别用功率为2 W 的 Er：YAG 激光和高速涡轮机处理乳牙牙本质表面，各组随机抽出2个样本，使用电镜扫描观察乳牙牙本质表面形态。其余样本进行酸蚀并复合树脂充填后检测乳牙牙本质与复合树脂间剪切强度。结果扫描电镜观察 Er：YAG 激光处理的乳牙牙本质表面无玷污层，牙本质小管开放。A 组剪切强度数值为（11．45±3．8）MPa，B 组剪切强度为（8．97±4．03）MPa，A 组与 B 组比较差异有统计学意义（P ＜0．05）。结论Er：YAG 激光处理乳牙牙本质可去除玷污层；乳切牙牙本质表面使用Er：YAG 激光处理后树脂剪切强度优于涡轮机，该结果为 Er：YAG 激光应用于乳牙牙体预备提供了理论依据，并为临床选择何种方法预备乳牙牙体提供了参考依据。

The comparative study on the Er:YAG laser and high speed handpiece treat primary dentin surface to the resin shear strength influence

Objective To investigate Er：YAG laser and high speed handpiece separately to treat primary teeth surface,observe its morphological changes,and evaluate the impact of this two methods treating pri-mary dentin on the shear strength of composite resin.Methods 64 mandibulars primary anterior teeth without carious,filling body,cracks because of primary teeth retain removing were selected,and divided into two groups randomly.Each group with 32 samples were treated primary teeth surface by using Er：YAG laser and high speed handpiece separately.Two samples from each group was randomly selected,and scanned with electronic microscope to observe primary teeth surface.The remaining samples were acid etched and filled with composite resin,and then evaluated the shear strength of primary teeth and compos-ite resin.Results SEM observed that the primary dentin surface treated by Er：YAG laser hasn′t smearlayer,primary dentin tubules open.Measured shear strength values were in group A （11.45±3.8）Mpa, group B （8.97±4.03）Mpa.The difference between group A and group B has statistically significant （P〈0.05）.Conclusion Er：YAG laser treated primary dentin can remove the smear layer,primary dentin sur-face used a power of 2 w of Er：YAG laser treated resin shear strength is better than high speed handpiece group.The result：Er：YAG laser used in primary teeth preparation provides theoretical basis,and refer-ence to clinical way to prepare primary teeth.