烧灼法与Er:YAG激光处理金属托槽底板黏结剂再粘接效能的比较

Bracket Adhesive for Re-Bonding with Er:YAG Laser and Flame

目的 比较Er:YAG激光与烧灼法去除金属托槽底板黏结剂的效果和再粘接强度。方法 (1)托槽底板黏结剂的效果。研究对象为粘接于玻璃板后脱粘接的64个托槽,按照随机数字表随机分为两组:烧灼组和Er:YAG激光组,分别采用烧灼和激光方法去除底板的黏结剂,其中激光参数为能量300 mJ,频率20 Hz,光斑大小1.3 mm。记录两组托槽底板黏结剂去除时间,并观察托槽底板形态和底板黏结剂去除效果。(2)再粘接强度比较。研究对象为前磨牙60颗,按照随机数字表随机分为三组。烧灼组、Er:YAG激光组与新托槽组。将托槽与离体前磨牙再粘结,比较三组间再粘接强度和黏结剂残余指数的差异。结果 激光处理后托槽颜色与新托槽比较,差异无统计学意义(P>0.05),且托槽底板黏结剂去除时间更短(P<0.05),烧灼后托槽变暗。扫描电镜观察烧灼组托槽底板有剥脱迹象,激光组底板上可见细小刻痕。托槽底板网格内黏结剂残留计分激光组和烧灼组间比较差异无统计学意义(P>0.05)。激光组抗剪切强度最高且与新托槽组比较,差异无统计学意义(P>0.05),但其与烧灼组比较差异具有统计学意义(P<0.05)。烧灼组牙面残余黏结剂表面有较多黑色氧化物残留,黏结剂残余指数与激光组和新托槽组比较,差异具有统计学意义(P<0.05)。结论 Er:YAG激光能够有效地去除托槽底板的粘结剂,增加了脱落托槽再利用率。

Objective To compare the effectiveness of Er:YAG laser and flame method in removing adhesive residue from metal bracket base and re-bonding strength.Methods(1)Effect of bracket base adhesive removal.The study involved 64 brackets that were bonded to glass and subsequently debonded.They were randomly divided into two groups,i.e.,the flame group and Er:YAG laser group,for removing the adhesive from the base,and the time used was recorded.The morphology of the bracket base and the effectiveness of adhesive removal were observed.(2)Comparison of re-bonding strength.The study included 60 premolar teeth,which were randomly divided into three groups:the flame group,Er:YAG laser group and new bracket group.The brackets were re-bonded to the extracted premolar teeth,and the differences in re-bonding strength and adhesive residue index among the three groups were compared.Results The color of the bracket did not change a lot after the laser treatment but became darker after the burning,and the removing process of the former took less time than that of the latter(P<0.05).It was revealed via electron microscopy scanning that there were signs of delamination on the bracket base in the flame group and fine scratches on the base in the laser group.There was no statistically significant difference in adhesive residue within the bracket base mesh between two groups(P>0.05).The shear bond strength of the laser group was the greatest,and the difference between the laser group and new bracket group was not significant(P>0.05).However,the difference between the laser group and flame group in shear bond strength was statistically significant(P<0.05).In the flame group,there were more black oxide residues on the tooth surface from the remaining adhesive,and the adhesive residue index of the flame group was statistically different from that of the laser group and new bracket group(P<0.05).Conclusions Er:YAG laser will effectively remove adhesive from bracket bases,increasing the reusability of debonded brackets.