低能量Er:YAG激光预处理对根面组织粘接强度的影响

Effect of low energy Er:YAG laser pretreatment on the bonding strength of root surface

目的 比较低能量掺铒:钇铝石榴石(erbium-doped:yttrium aluminum garnet,Er:YAG)激光照射与常规酸蚀处理对根面组织的蚀刻效果,为增强根面粘接的临床应用及相关研究提供参考。方法 选取2022年1月至2022年8月在树兰杭州医院进行正畸治疗而拔除的92颗完整无龋、无隐裂人离体前磨牙,按不同表面预处理方法分为4组,磷酸组(A组)作为对照组,采用磷酸酸蚀处理,试验组(B~D组)分别经30mJ、50mJ、70mJ的Er:YAG激光照射处理,每组23颗。通过微观形貌、微拉伸粘接强度、断裂模式的分析,比较各组间差异。结果 扫描电镜观察显示,磷酸组表面可见网状繁多的山脊状突起,少量玷污层及孔洞结构。各激光组根面表面清洁、粗糙,无玷污层,30mJ激光组表面呈片状结构,少量牙本质小管暴露;50mJ激光组表面呈蜂窝状结构,部分牙本质小管开放,胶原纤维暴露与羟基磷灰石混合形成混合物;70mJ激光组根面呈现鱼鳞状改变,牙本质小管进一步开放,胶原纤维呈细长状并大量暴露。微拉伸粘接强度测试结果显示,磷酸组粘接强度与30mJ激光组比较,差异无统计学意义(P>0.05),与50mJ、70mJ激光组比较,差异均有统计学意义(P<0.05);其中50mJ激光组最高,为(30.40±10.79)MPa,与70mJ激光组比较,差异无统计学意义(P>0.05)。各组断裂模式均以混合断裂模式为主,差异无统计学意义(P>0.05)。结论 本研究中,一定能量的Er:YAG激光根面蚀刻预处理法可代替磷酸酸蚀预处理法,达到完全去除表面玷污层,有效粗化粘接面,提高粘接强度的效果。

Objective To study the etching effect of root surface irradiated by low-energy erbium-doped:yttrium aluminum garnet(Er:YAG) laser, and compare it with the effect of acid etching, so as to provide reference for clinical application and related research of enhancing root surface bonding. Methods From January 2022 to August 2022, 92 intact human premolars extracted by orthodontic treatment in Shulan(Hangzhou) Hospital were randomly divided into four groups according to different surface pretreatment methods. The phosphate group(group A) was treated with phosphate etching as a control group, and the experimental groups(group B-D) were treated by 30mJ, 50mJ and 70mJ Er:YAG laser respectively, with 23 teeth in each group.The differences among the groups were compared by analyzing the micromorphology, microtensile bond strength and fracture mode. Results Scanning electron microscopy showed that the surface of phosphoric acid group showed a wide network of ridge protrusions, including a small amount of smear layer and pore structurea. The root surface of each laser group presented clean,rough and no stained layer. In the 30mJ laser group, the surface showed a lamellar structure with a small amount of dentin tubules exposed. The surface of the 50mJ laser group showed honeycomb structure, some dentin tubules were open, collagen fibers were exposed and mixed with hydroxyapatite to form a mixture. The 70mJ laser group surface showed fish scale changes with further opening of dentin tubules and a large amount of collagen fibers exposed in an elongated form. The results of microtensile bond strength test showed that the bonding strength of phosphoric acid group was not significantly different from that of 30mJ laser group(P>0.05), but statistically different from that of 50mJ laser group and 70mJ laser group(P<0.05). The 50mJ laser group was the highest, which was(30.40±10.79) MPa, and there was no statistical difference between the 50mJ laser group and the 70mJ laser group(P>0.05). The mixed fracture mode was dominant in all groups and there was no statistical significance between groups(P>0.05). Conclusion Under the experimental conditions, the Er:YAG laser etching pretreatment method with certain energy can replace the phosphoric acid on the root surface, which can completely remove the surface stain layer, effectively coarser the bonding surface, and improve the bonding strength.