Abstract：
The risk of enamel deterioration that frequently coexists with debonding of orthodontic teeth brackets elevates the mandate for finding an optimum approach for debonding them without harmful effects. This in-vitro study is intended to compare the effects of two different laser modes (scanning and circular) and a conventional method on the enamel surface after debonding orthodontic brackets. 66 extracted premolars were assigned into 3 groups. After that, light-cure composite resin was used to attach the ceramic brackets to the teeth. Amongst the test groups, Group I: specimens that were debonded using conventional debonding using pliers; Group 2: specimens that were debonded using Er, Cr: YSGG laser applications using the circular motion method; and Group 3: specimens that were debonded using Er, Cr: YSGG laser applications using the scanning motion method. Adhesive Remnant Index (ARI) assessment, intra-pulpal temperature increase, enamel surface roughness after polishing, and assessment of the microstructure of enamel were carried out with scanning electron microscopy. The gathered information was examined statistically. The conventional debonding method had a significantly higher proportion of adhesive remnant index (ARI) scores of 2 and 3 in comparison to the circular (p < .004) and scanning laser groups (p < .001). There was no significant difference in ARI scores between the circular and scanning laser groups (p > .05). Moreover, the circular and scanning laser debonding methods resulted in a significantly higher proportion of Enamel Surface Roughness (ESR) scores of 0 and a lower proportion of ESR scores of 3 compared to the conventional technique group (p < .001). However, there was no significant difference in ESR scores between the circular and scanning laser methods (p = .945). Lastly, the average intra-pulpal temperature was significantly higher in the circular laser group (1.9 ± 0.5 ) compared to the scanning laser group (0.9 ± 0.2) with p < .001. Er, Cr: YSGG laser irradiation is a tool that shows promise for debonding ceramic brackets with minimal harm to the enamel surface. The scanning laser technique is more desirable due to the lower intra-pulpal temperature increase.
摘要：
牙釉质变质的风险通常与正畸托槽的脱粘并存，这提高了寻找一种最佳方法使其脱粘而不会产生有害影响的任务。这项体外研究旨在比较两种不同的激光模式（扫描和圆形）和常规方法在脱粘正畸托槽后对釉质表面的影响。将66颗提取的前磨牙分为3组。之后,光固化复合树脂用于将陶瓷托架连接到牙齿上。在测试组中，I组：使用钳子常规脱粘的标本；第2组：使用Er脱粘的标本，Cr：使用圆周运动方法的YSGG激光应用；第3组：使用Er脱粘的样品，Cr:YSGG激光应用采用扫描运动法。粘合剂残留指数（ARI）评估，牙髓内温度升高，抛光后的搪瓷表面粗糙度，用扫描电镜对牙釉质的微观结构进行了评价。对收集的信息进行了统计检查。与圆形（p<.004）和扫描激光组（p<.001）相比，常规的脱粘方法具有2和3的粘合剂残留指数（ARI）得分比例明显更高。圆形激光组和扫描激光组之间的ARI评分无显著差异(p>.05)。此外，与常规技术组相比，圆形和扫描激光脱粘方法导致牙釉质表面粗糙度（ESR）评分为0的比例明显更高，而ESR评分为3的比例较低（p<.001）。然而,圆形和扫描激光方法的ESR评分无显著差异(p=.945).最后,与扫描激光组(0.9±0.2)相比,圆形激光组的平均牙髓内温度(1.9±0.5)显著较高,p<.001.呃，Cr：YSGG激光照射是一种工具，显示出脱粘陶瓷托槽的希望，对搪瓷表面的伤害最小。由于牙髓内温度升高较低，因此更需要扫描激光技术。
