Studies comparing heat-polymerized, CAD-CAM milled, and 3D-printed resins are limited and contradicting results have been reported regarding their mechanical and physical properties. The purpose of this study was to compare flexural strength, elastic modulus, and surface hardness of CAD-CAM milled (Avadent and IvoCad), 3D-printed (ASIGA, FormLabs, and NextDent), and heat-polymerized acrylic denture base resins.

A total of 120 specimens were fabricated and divided into 6 groups according to the type of denture base material (n = 20/material) (10/flexural properties and 10/hardness). Flexural strength and elastic modulus of the specimens were evaluated by 3-point bending test and surface hardness by Vickers hardness test. Scanning electron microscopy tool was applied to evaluate the surface morphology of the fractured specimens of all groups.

CAD-CAM milled resins had greater flexural properties and hardness compared to heat-polymerized acrylic resin and 3D-printed resins. Although 3D-printed samples showed the lowest values of tested properties, the flexural strength and modulus were above clinically acceptable values. 3D-printed resins require further improvement in the chemical composition or the manufacturing process to improve their mechanical properties for clinical applicability.

The authors recommend that future studies investigate the properties of CAD-CAM denture base materials after aging to determine the durability of these materials in clinical use. Other factors that may influence the mechanical properties of 3D-printed resins such as the post curing time, thickness and orientation of printed layers, and reinforcement with fillers also need further study.

Fouda SM, Gad MM, Abualsaud R, et al: Flexural properties and hardness of CAD-CAM denture base materials. J Prosthodont 2022; 1– 7. https://doi.org/10.1111/jopr.13535