Er:YAG激光不同能量预处理对自粘结树脂水门汀剪切粘结强度的影响

目的探讨Er:YAG激光不同能量预处理对自粘结树脂水门汀剪切粘结强度的影响。方法按照纳入标准收集人离体磨牙70颗,根据对牙本质表面Er:YAG激光预处理能量的不同随机分为7组:A组(空白对照)、B组(50 m J,10 Hz)、C组(100 m J,10 Hz)、D组(150 m J,10 Hz)、E组(200 m J,10 Hz)、F组(250 m J,10 Hz)、G组(300 m J,10 Hz)。每组10颗牙中随机取2颗切取3 mm厚的牙本质片,按相应分组用不同激光能量预处理后扫描电镜观察;每组剩余8颗牙包埋后,制备一致标准牙本质表面,按相应分组要求预处理后,用自粘结树脂水门汀Rely XTMUnicem将其与Everest ZS氧化锆瓷片粘结,24 h后测试各组剪切粘结强度并进行统计学分析。结果扫描电镜观察显示Er:YAG激光预处理后牙本质表面形态改变明显,变得粗糙不平,牙本质小管开放,无玷污层,管周和管间牙本质脱矿,一定能量范围内呈现较好的粘结表面;剪切粘结强度结果显示Er:YAG激光预处理可增强自粘结树脂水门汀Rely XTMUnicem的剪切粘结强度(P<0.01);C、D、E组的剪切粘结强度与A组有显著性差异(P<0.05)。结论粘结强度与牙本质的粘结表面密切相关,合适能量下的Er:YAG激光预处理能获得较好的牙本质粘结表面,提高自粘结树脂与牙本质和氧化锆瓷的剪切粘结强度。

Effects of different energies of Er:YAG laser pretreatment on the shear bond strength of self-adhesive resin cement

Objective To investigate the effects of different energies of Er： YAG laser pretreatment on the shear bond strength of self-adhesive resin cement. Methods Seventy extracted human molars collected in accordance with the inclusion criteria were random- ly divided into 7 groups according to the different Er：YAG laser energy pretreatments on the dentin surface ：Group A（control） , GroupB （ 50 m J, 10 Hz ）, GroupC （ 1 O0 m J, 10 Hz ）, GroupD （ 150 m J, 10 Hz ）, GroupE （ 200 m J, 10 Hz）, GroupF （ 250 m J, 10 Hz ）, GroupG （ 300 m J,10 H z）. Two teeth were selected randomly from each group and 3mm thick dentin slices cut from the teeth were observed under scanning electron microscopy after being pretreated according to the respective requirements . The remaining eight teeth were prepared into the consistent standards dentin surface after being embedded,and then bonded with the self-adhesive resin cement RelyXTM Unicem and Everest ZS zirconia ceramic after pretreatment according to the respective requirements. 24 h later,the shear bond strength was test- ed and a statistical analysis was performed. Results Scanning electron microscopy showed that the dentin surface morphology pretrea- ted by Er：YAG laser changed into tough irregular one significantly,and the dentinal tubules became open without the smear layer. Per- itubular dentin and intertubular dentin suggested demineralization and presented a better bonding surface in a appropriate energy range. The results showed that the Er：YAG laser pretreatment could enhance the bong strength of RelyXTM Unicem self-adhesive resin （P 〈 0.01 ） ;there was significant difference between Group C, D, E and Group A （ P 〈 0.05 ）. Conclusions The study shows that bond strength is closely related to the dentin bonding surface, and suitable energy of Er： YAG laser pretreatment can obtain better dentin bonding surface,improve the shear bond strength of the self-adhesive resin and dentin and zirconia ceramic.