Purpose: The aim of this study was to evaluate the fracture resistance of primary tooth crowns fabricated at different thicknesses using two different 3D printing technologies: stereolithography (SLA) and digital light processing (DLP). Materials and Methods: A typodont primary second molar tooth was scanned. Using the scanned model, three dies and crowns with thicknesses of 0.5 mm, 1.0 mm and 1.5 mm were created digitally. A total of 60 dies were fabricated from Crom-Cobalt (Cr-Co) using a laser sintering device. Ten crowns per thickness were produced using two types of 3D printers: SLA and DLP. The fracture resistance of the crowns was tested after thermal aging (5/55 oC and 30 s dwell time). The data were analyzed with Independent sampleT-test. Results: There was no significant difference in fracture resistance between the manufacturing methods for crowns in all three thickness groups (p > 0.05). The highest average fracture value was observed in crowns with a thickness of 1.5 mm manufactured using SLA 3D printing. Conclusion: Within the limits of this study, the 3D printing manufacturing method did not affect the fracture resistance of 3D printed primary tooth crowns. It was concluded that these crowns have sufficient fracture resistance and can be used as an alternative treatment option for complete crown of primary teeth.
