Accuracy of two 3D printed guide plates in bonding orthodontic brackets

This study aims to compare the effects of two 3D printed guide plates in indirect bonding and to explore the factors affecting the accuracy of transferring brackets. The study is conducted to provide experimental evidence for the design improvement of 3D printed guide plates and clinical guidance for orthodontic treatment. A total of 17 patients, including 7 females and 10 males, aged 12 to 30 years old, receiving orthodontic treatment from January 2021 to February 2024, were assigned to two groups based on consecutive enrollment. One group (n = 8) used ligature-fixed guide plates (LFGP) to bond brackets, and the other (n = 9) used jig-fixed guide plates (JFGP). Their upper and lower dental models were constructed by an intraoral scanner before and after bonding brackets. The deviations of the bracket position before and after bonding were measured in Geomagic Wrap software (version 2021.0.0.3008, 3D Systems Corporation) to compare the bracket transfer accuracy of two guide plates in occlusogingival, mesiodistal, and buccolingual dimensions. The data included middle incisors, lateral incisors, canines, the first premolars, the second premolars and the first molars. The data was analyzed in SPSS 26.0. A level of P < 0.05 was set for significance. A total of 191 brackets were bonded with LFGP, and 207 brackets were bonded with JFGP in the experiment. In the inter-group comparisons across the three-dimensional directions, significant differences were observed in the occlusogingival and buccolingual dimensions (P < 0.05). The JFGP group exhibited less deviation across these two dimensions, indicating higher precision. In the intra group comparison based on tooth classification, premolars showed significantly greater deviation compared to other tooth types in the buccolingual dimension of JFGP. Statistically significant differences were observed in the incisor-premolar and canine-premolar comparisons (P < 0.05). Both LFGP and JFGP achieved good results in accurate bracket placement in vivo, while JFGP demonstrated higher bracket transfer accuracy than LFGP in three linear dimensions.