冷热循环对Er：YAG激光以及车针备洞后牙本质和玻璃离子粘结剪切强度的影响

摘要

目的：评价冷热循环对Er：YAG激光以及车针备洞后牙本质与玻璃离子粘结剪切强度的影响。方法：40个离体牙分为颊舌两半，完全去除颊舌侧牙釉质，暴露牙本质后自凝塑料包埋，制成80个试件后随机分为A、B、C、D 4组（n＝20）。A组采用Er：YAG激光照射后粘结Fuji IX；B组采用Er：YAG激光照射后粘结Fuji IX，再进行12000次冷热循环；C组采用车针预备牙本质后粘结Fuji IX；D组采用车针预备牙本质后粘结Fuji IX，再进行12000次冷热循环。所有样本置于万能材料力学测试机进行剪切强度测试。结果：A、B、C组之间的剪切强度无显著差异（P＞0．05），D组剪切强度明显小于其他3组（P＜0．05）。结论：经过冷热循环之后，Er：YAG激光组的剪切强度未见明显变化，但车针备洞组的剪切强度明显降低。%AIM:To study the influence of thermocycling on the shear bond strength of a glass-ionomer ce-ment to Er:YAG irradiated or bur-prepared dentin.METHODS:40 premolars were selected and the roots were re-moved.Each premolar was separated into two parts.80 samples were individually embedded in polyester resin.Sam-ples were randomly assigned into 4 groups (n=20)according to the method of cavity preparation:Er:YAG laser or bur-preparation,with or without thermocycling for 12000 times.Fuji IX was adhered to the surface of the samples in each group.The shear bond strength of samples was measured by an universal testing machine.RESULTS:The thermocy-cle had no significant effect on the shear bond strength of glass ionomer to laser-irradiated dentin (P>0.05).In bur-prepared samples,the thermocycling decreased shear bond strength value (P<0.05 ).CONCLUSION:Thermocy-cling can decrease the shear bond strength of glass-ionomer cement bonded to bur-prepared dentin.