Wear resistance of 3D-printed denture tooth resin opposing zirconia and metal antagonists

Statement of problem: Additive manufacturing technology can be used for denture bases and also denture teeth. Therefore, the mechanical properties of 3D-printed resin denture teeth should be evaluated. Purpose: The purpose of this in vitro study was to compare the wear resistance of 3D-printed denture tooth resin with that of conventionally prefabricated denture teeth. Material and methods: Eighty substrate specimens were prepared with 5 kinds of resin denture teeth: 3D-printed denture tooth resin (DENTCA denture tooth resin; DENTCA, Inc), Artic 6 (Kulzer GmbH), Preference (Candulor AG), Premium 6 (Kulzer GmbH), and Surpass (GC Corp). The 3D-printed denture tooth specimens were made of methacrylate-based photopolymerized resin by stereolithography 3D printing. Antagonistic surfaces were made from zirconia by milling and from cobalt-chromium (Co-Cr) alloy by 3D printing and casting. The specimens were loaded at 49 N for 30 000 cycles under thermocycling conditions in a mastication simulator. Wear resistance was measured by calculating the volume of substance lost. Wear surface characteristics were observed by using a scanning electron microscope (SEM). Two-way ANOVA was used to analyze the data (α=.05). Results: The influence of the resin denture teeth and the type of antagonist were both statistically significant. The wear volume loss of the 3D-printed denture tooth resin was higher than that of Artic 6 and Preference when opposing the zirconia and the metal antagonists (P<.05). The 3D-printed denture tooth resin did not show a significant difference from Premium 6 with the zirconia and the metal antagonists or Surpass with the zirconia antagonist. From the SEM images, the specimens of the 3D-printed denture tooth resin showed a relatively smooth surface with the zirconia antagonist and exhibited cracks when opposed by the metal antagonist. Conclusions: The results suggest that 3D-printing by using resin materials provides adequate wear resistance for denture tooth use.restrictio