Investigation of the marginal fit and fracture resistance of fixed provisional restorations fabricated using conventional, substractive and additive methods

Aim: The aim of this study is to compare the marginal fit and fracture resistance of fixed provisional restorations prepared using traditional, subtractive (Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM)), and additive (3D printing) methods. Materials and Methods: In this study, fixed provisional restorations were fabricated on 60 epoxy resin dies using traditional, subtractive, and additive methods. The marginal gaps of the fixed provisional restorations, which were cemented onto the epoxy resin dies using temporary cement, were measured with a stereomicroscope. Half of the samples from each group were stored in artificial saliva at 37°C, while the other half underwent 5000 cycles of thermocycling. After the aging process, the edge distances were measured again with a stereo microscope. Scanning Electron Microscope (SEM) images were taken of one sample prepared with different techniques, both before and after the aging process. Fracture resistance was evaluated using an Instron Universal testing machine. The obtained data were analyzed using the Jamovi statistical software (version: 2.3.28) with two-way ANOVA and Tukey's multiple comparison test. Results: Variance analysis indicated that both the method used and the aging process were significant (p<0.05). Conclusion: For long-term use, fixed provisional prosthetic restorations can be prepared using the subtractive method (CAD/CAM) instead of the conventional method. Keywords: Fixed provisional restorations, Conventional method, Subtractive method, Additive method, Marginal fit, Fracture resistance