Deformation analysis of 3D-printed three-unit fixed partial dentures according to various cleaning strategies after DLP 3D printing: a geometric library matching approach.

Purpose: Three-dimensional (3D) printing must go through a post-processing procedure. This study aimed to evaluate the effects of different cleaning methods on 3D printed three-unit fixed partial dentures using 3D analysis.

Materials and methods: A three-unit fixed partial denture was designed and printed using two different printers. The evaluation was taken regarding cleaning method with ethanol (ETH) or isopropanol (IPA), and combining ultrasonic (US) technique for the following groups: group 1, ETH; group 2, ETH+US; group 3, IPA; group 4, IPA+US; and group 5, US. The 3D evaluation was conducted by calculating the mean distance between two specific points and analyzing various angular deviations, utilizing the geometry-embedded library. In addition, visual analysis was performed by creating sectional planes in different points of view. Normality test and independent t-test were performed to compare results between the two printers used in this study. In addition, one-way ANOVA was performed to compare cleaning method groups.

Results: Mean distance results showed statistical differences between printers for groups IPA, US, and IPA+US, whereas no significant differences were found among cleaning methods. Angular measurements were taken at the bucco-lingual, proximal, and occlusal planes to assess deviations in the internal surfaces. Overall results showed a tendency of shrinkage of the printed three-unit fixed partial denture.

Conclusion: Ultrasonic treatment may impact the washing efficiency when used with other cleaning solutions regarding angular and longitudinal deformation. Adequate selection of post-processing methods is crucial to decrease morphological deformities in 3D printed materials.