PURPOSE The purpose of this in vitro study was to investigate the wear resistance and surface roughness of three interim resin materials, which were subjected to chewing simulation. MATERIALS AND METHODS Three interim resin materials were evaluated: (1) three-dimensional (3D) printed (digital light processing type), (2) computer-aided design and computer-aided manufacturing (CAD/CAM) milled, and (3) conventional polymethyl methacrylate interim resin materials. A total of 48 substrate specimens were prepared. The specimens were divided into two subgroups and subjected to 30,000 or 60,000 cycles of chewing simulation (n = 8). The wear volume loss and surface roughness of the materials were compared. Statistical analysis was performed using one-way analysis of variance and Tukey's post-hoc test (α=.05). RESULTS The mean ± standard deviation values of wear volume loss (in mm 3 ) against the metal abrader after 60,000 cycles were 0.10 ± 0.01 for the 3D printed resin, 0.21 ± 0.02 for the milled resin, and 0.44 ± 0.01 for the conventional resin. Statistically significant differences among volume losses were found in the order of 3D printed, milled, and conventional interim materials ( P <.001). After 60,000 cycles of simulated chewing, the mean surface roughness (Ra; μm) values for 3D printed, milled, and conventional materials were 0.59 ± 0.06, 1.27 ± 0.49, and 1.64 ± 0.44, respectively. A significant difference was found in the Ra value between 3D printed and conventional materials ( P =.01). CONCLUSION The interim restorative materials for additive and subtractive manufacturing digital technologies exhibited less wear volume loss than the conventional interim resin. The 3D printed interim restorative material showed a smoother surface than the conventional interim material after simulated chewing.

No abstract

A straightforward digital method of evaluating wear volume loss is described. This method allows the measurement of the wear by analyzing only the three-dimensional scan dataset of the worn specimen without needing a separate baseline scan. Compared to the conventional method, involving superimposition of the two datasets scanned before and after the wear test, this method can reduce labor and accuracy errors caused by repeated scans and superimposition procedures. Further, this analysis can be conducted using free computer-aided design software, which makes it more efficient for the analysis of wear volume loss of restorative materials.