Wear and Fracture Resistance of 3D-Printed Denture Teeth: An In Vitro Comparative Study

Abstract

Purpose: The longevity of removable prostheses is mostly influenced by the properties of the used materials. The ability of the material to withstand high occlusal loads without deformation can enhance patient satisfaction and quality of life. This in vitro study aimed to investigate the wear and fracture resistance of three-dimensional (3D)-printed teeth compared with commercially available acrylic resin teeth. Materials and methods: A total of 40 prefabricated acrylic teeth and 40 3D-printed teeth were prepared in two forms: anatomical for fracture resistance or flat for wear resistance (n = 10). For wear evaluation, specimens were scanned at baseline and then subjected to thermal cycling (10,000 cycles). This was followed by a chewing simulator (60,000 cycles) against either metal or natural tooth. Then, the specimens were scanned again. Wear analysis was performed by superimposing the standard tessellation language (STL) files from baseline and the final scans with the aid of GOM Inspect 2020 software. Fracture resistance was assessed with a universal testing machine at a crosshead speed of 0.5 mm/min before and after thermal cycling. Data were analyzed with two-independent t-test and two-way ANOVA (α = 0.05). Results: The 3D-printed teeth showed significantly lower wear resistance than the prefabricated ones with both antagonists (metal, p = 0.049; natural tooth, p = 0.021). The fracture resistance of the 3D-printed teeth was significantly higher than that of the prefabricated teeth before thermocycling (p = 0.042). After thermal cycling, the fracture resistance of both groups was decreased with no significant differences between them (p = 0.266). Conclusions: The 3D-printed teeth showed lower wear resistance and higher fracture resistance than the prefabricated ones. Thermal cycling negatively affected the fracture resistance of 3D-printed teeth.