Influence of occlusal anatomy on acrylic resin CAD/CAM crowns fracture load and stress distribution.

Objectives: This study compared the influence of occlusal anatomy on acrylic CAD/CAM crowns fracture load and stress distribution. The null hypothesis was that there would be no difference between the provisional crowns fracture load and stress according to different occlusal anatomy. Methods: A full-crown preparation was simulated using dentin analogue (G10, Protec, São Paulo, Brazil) totaling 20 identical preparations. Next, twenty acrylic crowns were milled using different occlusal design parameter (Young or Adult) available in the software database. The crowns were cemented (Temp-bond, NE Kerr Dental, Brea, CA, USA) and fractured using a compressive load (0.5 mm/min of cross-head speed). Data were analyzed by using one-way ANOVA and Tukey tests (p< 0.05). A similar geometry was modeled and exported to the analysis software to perform a static structural analysis. The maximum principal stress was calculated using the finite element method with 300 N chewing load simulation. Results: The occlusal anatomy significantly influenced the load-to-fracture (p