Evaluation of composite materials with different viscosities on the accuracy of in-office aligner attachments

Introduction: To evaluate the accuracy of two different composites with low and high viscosity in different attachment designs, in-office clear aligner therapy was used. Methods: The study consisted of two main groups: the flowable composite group (n = 60) and the nanofilled composite group (n = 60), and in each group, five attachments (rectangular, beveled, ellipsoid, pentagon, and concave) (n = 12, per group) were used. The typodont model was scanned with an intraoral scanner to obtain a stereolithography file. The stereolithography data was transferred to the software, and attachments were placed on the teeth. A total of five models with attachments and 60 models without attachments were obtained with digital light processing technology. Attachments were applied to test models using two different types of composites with guide plates. Models with attachments applied were scanned with an intraoral scanner, and the attachments on the models were separated through the software. As a result of the comparison, the root mean square and the depth, width, and height linear dimensional measurements of the attachments were obtained. The 1-way analysis of variance test was used to compare attachment shapes, and the Tukey test was used in post-hoc comparisons. Results: According to the 3-dimensional digital comparison data, there is a statistically significant difference between flowable composite and nanofilled composite groups in root mean square values and width, height, and depth measurements (P = 0.034, P <0.001, P = 0.007, and P = 0.001, respectively). Conclusions: Although the flowable composite used in this study provides more accurate results compared with the nanofilled composite, both composite types have clinically applicable accuracy. © 2024 American Association of Orthodontists