Influence of Different Build Directions on the Fracture Load and Surface Roughness of Additively Manufactured Three-Unit Provisional Restorations: An In Vitro Study.

This article investigates the effect of three different build directions (0°, 45°, and 90°) on the fracture load and surface roughness of additively manufactured (3D-printed) three-unit provisional fixed dental restorations, comparing these to conventionally fabricated provisionals made from heat-polymerized polymethyl methacrylate (PMMA), autopolymerizing PMMA, and bis-acryl composite resins. The study found that build direction significantly influenced both fracture load and surface roughness, with provisionals printed at 0° exhibiting the highest fracture load and lowest surface roughness among the 3D-printed groups. Compared to conventional materials, 3D-printed provisionals at 0° showed superior fracture load and surface roughness comparable to heat-polymerized PMMA. These findings suggest that printing orientation is a critical parameter in optimizing the mechanical performance of 3D-printed provisional restorations in clinical dentistry.