Wear resistance of 3D printed, milled, and prefabricated methacrylate-based resin materials: An in vitro study.

Statement of problem: Three-dimensional (3D) printing and milling technologies have been increasingly used in prosthodontic practice for fabricating digital prostheses. Nevertheless, evidence relating to the wear resistance of denture teeth fabricated using these methods is lacking.

Purpose: The purpose of this in vitro study was to compare the wear resistance exhibited by denture teeth fabricated using 3D printing and milling technologies with prefabricated denture teeth.

Material and methods: Fifty specimens of resin denture teeth from 3 types of manufacturing processes were prepared and divided into 5 groups: 1 group of 3D printed denture teeth (NextDent C&B MFH), 2 groups of milled denture teeth (Ivotion Dent and VIPI Block), and 2 groups of prefabricated denture teeth (Major Dent and Cosmo HXL). Each group of specimens was occluded with a zirconia antagonist under a 49-N load with thermocycling conditions for 120 000 cycles. The antagonist was horizontally displaced back and forth at a 2-mm distance and a frequency of 1.6 Hz. The quantification of the volume loss and the maximal wear depth of the worn specimens were recorded, while the wear characteristics were assessed with a scanning electron microscope (SEM). Data were analyzed using the Kruskal-Wallis test followed by pairwise comparison tests (α=.05).

Results: Significantly different wear depths and volume losses were found among groups (P<.05). The highest wear depth and volume loss were observed in the VIPI Block (0.513 ±0.147 mm and 3.094 ±0.790 mm³), followed by Cosmo HXL group (0.312 ±0.020 mm and 1.446 ±0.134 mm³), Major Dent (0.261 ±0.034 mm and 1.219 ±0.196 mm³), Ivotion Dent (0.253 ±0.021 mm and 1.082 ±0.089 mm³), and NextDent C&B MFH (0.208 ±0.059 mm and 0.843 ±0.372 mm³). Based on the analysis of the SEM images, distinct groups of specimens exhibited varying degrees of crack formation. Furthermore, their worn surfaces showed diverse characteristics in terms of wear patterns and roughness attributes.

Conclusions: The manufacturing methods for fabricating 3D printed, milled, and prefabricated denture teeth exhibit comparable wear resistance, with 3D printed denture teeth demonstrating the highest level of wear resistance.