三种间接粘接方法转移托槽的准确性比较

目的:比较间接粘接技术中使用不同转移托盘转移托槽的准确性。方法:选择2019年7月至2021年1月空军军医大学口腔医院正畸科就诊的患者28例，分为A、B、C三组，分别使用3D打印托盘、双层压膜塑料托盘、双层硅橡胶托盘粘接托槽。A组口内扫描获取工作模型，使用软件定位托槽，再导出数字化模型，作为该组托槽转移前的数字化模型。B组和C组在工作石膏模型上定位托槽，使用口内扫描仪扫描，获取B组和C组托槽转移前的数字化模型。A、B、C组制作相应的转移托盘，将托槽粘接至患者口内后对患者口内扫描，获取三组托槽实际粘接的数字化模型。使用Geomagic软件测量转移前后的数字化模型，获取使用不同托盘时，托槽粘接的实际位置距离预设在近远中方向、龈 方向、颊舌方向上的线距误差，超过0.5 mm的托槽转移线距误差定义为严重误差。 结果:近远中向上B组与A组间、C组与A组间严重误差发生率的差异存在统计学意义( P<0.05)。龈 向上3组组间的严重误差发生率差异均存在统计学意义( P<0.05)。颊舌向上3组组间的严重误差发生率差异无统计学意义。 结论:(1)3D打印托盘转移托槽时严重误差的发生率显著高于双层硅橡胶托盘与双层压膜塑料托盘。(2)双层硅橡胶托盘粘接托槽时严重误差的发生率最低。

Comparison of bracket transfer accuracy of three indirect bonding techniques

Objective:To compare the accuracy of bracket transfer using different transfer trays in indirect bonding technology.Methods:Twenty-eight patients who received their orthodontic treatment at ortho-department of the Fourth military medical university from July 2019 to January 2021 were randomly divided into three groups: group A, group B and group C, the brackets were bonded with 3D printing transfer tray, double vacuum-form transfer tray and double polyvinyl silicone transfer tray. In group A, the working model was obtained by intraoral scanning, the brackets were located by software, and then this cmodel with virtual brakects was used directly as the digital model before the bracket transfer. In group B and group C, the brackets were positioned on the working plaster model and then scanned with an intraoral scanner, and then the scanned data served as the digital model before the bracket transfer. The corresponding transfer tray was made, and the brackets were bonded to the mouth of the patients. Then the patients were scanned to obtain the digital model of the actual bonding positions of the brackets. Geomagic software was used to measure the digital model before and after transfer to obtain the line distance errors in the mesiodistal direction, occlusogingival direction and buccolingual direction when using different trays. The line distance error exceeding 0.5mm was defined as serious error.Results:In the mesiodistal direction, there were statistically significant differences in serious error rate between group B and group A, and between group C and group A ( P<0.05). In the occlusogingival direction, there were significant differences in serious errors rate among the three groups ( P<0.05). In the buccolingual direction, there were no significant differences in serious errors rate among the three groups ( P>0.05). Conclusions:1. The incidence of serious errors of 3D printing tray was significantly higher than that of double vacuum-form transfer tray and double polyvinyl silicone transfer tray. 2. The incidence of serious errors was the lowest when double-layer silicone rubber tray was used.