In vitro evaluation of bracket transfer accuracy and success of two indirect bonding techniques on three-dimensional digital models

The aim of this study was to evaluate the transfer accuracy and success of two different indirect bonding techniques. A total of 60 plaster models were divided into two groups as 15 working models and 15 transfer models for each group. Single and double vacuum formed transfer trays were prepared for the first and second groups, respectively. Study and transfer models were scanned with an intraoral scanner. By digitally overlaying the scanned study and transfer models, changes in bracket positions in the transfer stage were measured as linear (insizo-gingival, mesio-distal, bucco-lingual) and angular (angulation, rotation, and torque). Transfer errors between the two groups were compared with Mann-Whitney U-test. The teeth were divided into four groups as incisors, canines, premolars and molars, and the transfer errors of these groups were compared with the Kruskal-Wallis/Dunn-Bonferroni tests. Both techniques showed high transfer success. Linear control of both techniques were shown to be better than angular control. It has been shown that double vacuum formed trays provide better transfer accuracy only in the incisogingival direction than single vacuum formed trays (p<0.01). While the percentage of clinically acceptable transfer error was significantly higher in the incisogingival direction in the double vacuum form than in the single vacuum form (p<0.01); it is significantly higher in the mesiodistal direction in the single vacuum form than in the double vacuum form (p<0.05). Both techniques can be used depending on the orthodontist's preference in terms of bracket transfer accuracy and success; however, it can be said that the single vacuum form is more advantageous in laboratory and clinical stages. KEYWORDS: Indirect Bonding, Three Dimension, Digital, Model, Transfer