铒激光不同参数对牙本质小管即刻封闭影响的实验研究

摘要

目的：比较不同工作参数下铒激光处理后牙本质小管封闭的效果，探求铒激光即刻封闭牙本质小管的最佳参数。方法：制备54个牙本质盘，0．5 mol／L EDTA脱矿形成敏感牙本质模型。以铒激光的输出功率、照射时间、照射距离为实验指标，设计正交优化实验表，样本随机分成9组，每组6个样本，铒激光照射后扫描电子显微镜观察，评估各组牙本质小管封闭情况。结果：脱矿组牙本质小管口开放，清晰可见，激光照射组牙本质小管表面有明显熔融物沉积，各组牙本质小管封闭率有显著性差异（P＜0．05）。结论：铒激光照射对牙本质小管有一定封闭作用，且受工作参数影响。本实验条件下，照射距离影响最大，最佳工作参数组合是：距离2．0 cm，照射功率0．2 W，照射时间30 s。%Objective:To compare the influences of Er:YAG laser irradiation with different working parameters on dentinal tubule occlusion, and to find the best combination of parameter settings.Methods:54 dentin discs and dentin hypersensitivity models formed by 0.5 mol/L EDTA demineralization were prepared and randomly divided into 9 groups each containing 6 specimens according to dif-ferent output power, irradiation time and irradiation distances of the Er:YAG laser.A table for orthogonal optimization experiment was designed.Specimens were evaluated with regard to dentin orifice occlusion under scanning transmission electron microscopes (SEM). Results:SEM showed most of the dentinal tubules in the demineralization group were clearly open, while they were partially or fully oc-cluded by Er:YAG irradiation.There were significant differences between groups (P<0.05).Conclusions:Subject to working parame-ters, Er:YAG laser irradiation can be effective in narrowing or occluding the dentinal tubules.The best combination of working parame-ters with the most influential irradiation distance is:Distance =2.0 cm, Power =0.2 W and Time =30 s.