Sports mouthguards play a crucial role in preventing orofacial injuries. Vacuum thermoforming with ethylene-vinyl acetate is the most common fabrication method; however, digital workflows and 3D printing have introduced promising alternatives. This in vitro study aimed to compare mouthguards produced by vacuum thermoforming and 3D printing in terms of precision, trueness and impact resistance. A maxillary plaster model was used to fabricate two groups: thermoformed mouthguards (GTherm, n = 3; Playsafe Triple Light, Erkodent™) and 3D-printed mouthguards (GPrint, n = 3; high-impact polystyrene via fused deposition modeling). The internal surfaces were scanned with a Medit T500, and precision and trueness were assessed by superimposing STL files using Geomagic software. Ten specimens of each material underwent Charpy impact testing. Data were analyzed with GraphPad Prism. The GPrint group exhibited higher precision (median RMS = 57.8 µm) than GTherm (median RMS = 812 µm), although the difference was not statistically significant (p = 0.10). Trueness in GPrint was within acceptable limits (median RMS = 118 µm). In the Charpy test, impact strength was significantly higher in thermoformable-based specimens than in printed ones (mean 17.33 ± 1.96 vs. 14.33 ± 0.65 kJ/m2, respectively). Within the study’s limitations, 3D-printed HIPS mouthguards showed superior precision and acceptable trueness, whereas thermoformed mouthguards demonstrated significantly greater impact resistance.
Gomes et al. (Sun,) studied this question.