Influence of the Printing Angle on the Accuracy of 3D-Printed Interim Fixed Partial Dentures: An In Vitro Study

Background: The aim of this study was to assess the accuracy of printed interim fixed partial dentures (i-DPSs) fabricated on 3D-printed models using different printing angles. Materials and Methods: Six printing angles were chosen, namely 90°, 75°, 60°, 45°, 30° and 15°, to fabricate sixty i-DPSs, ten for each. The measurements were performed at 100 points cervical and 100 points axial occlusal. Statistical analyses were carried out using Med Calc software and the Kolmogorov–Smirnov and Kruskal–Wallis tests. Results: The marginal fit ranged between 39.302 µm and 74.470 µm, with the best values for the 60° (39.302 µm) and 30° (43.287 µm) printing angles. The mean values for the internal fit were between 72.876 µm and 114.26 µm, with the best values for the 30° (72.876 µm) and 60° (78.049 µm) printing angles. The Kruskal–Wallis test returned a p value of p < 0.0001.