Fracture resistance of analog and CAD-CAM long-span fixed provisional restorations: An in vitro experimental study.

Abstract

Purpose: This study aimed to evaluate and compare the fracture resistance of long-span fixed provisional restorations fabricated using milling, three-dimensional (3D) printing, and conventional methods.

Materials and methods: Sixty specimens were prepared, divided into four groups of 15 each, corresponding to four fabrication methods: computer-aided design and computer-aided manufacturing (CAD-CAM) milled provisional resins, 3D-printed provisional resins, 3D-printed permanent resins, and conventional bis-acryl restorations reinforced with wire. The specimens underwent a three-point bending test using a universal testing machine to measure fracture resistance, quantified as maximum force (in Newtons). Statistical analysis was performed using one-way ANOVA and Tukey's HSD post-hoc tests to compare the fracture resistance across the four groups.

Results: Significant differences in fracture resistance were observed among the materials tested (p < 0.001). Both the CAD-CAM milled and 3D-printed resins exhibited significantly higher fracture resistance than the conventional bis-acryl method.

Conclusion: The results highlight the mechanical advantages of digital fabrication methods for long-span provisional applications in prosthodontics. These techniques may provide improved durability and reliability, addressing the mechanical demands of complex restorations.