Comparative Analysis of Flexural Strength and Surface Hardness of Denture Base Resins Fabricated via Conventional,...

This study evaluates and compares the mechanical properties flexural strength and surface hardness of denture base resins fabricated using conventional, CAD/CAM, and 3D printing techniques. Additionally, the effects of thermal cycling on these properties were investigated to simulate intraoral conditions.

A total of 80 specimens were prepared and divided into four groups based on fabrication methods: conventional heat-polymerized acrylic resin, pre-polymerized CAD/CAM-milled PMMA, and photopolymerized 3D-printed resins using DLP and LCD technologies. Flexural strength was assessed via a three-point bending test, and surface hardness was measured before and after thermal cycling (5000 cycles between 5°C and 55°C). Statistical analysis was performed using two-way ANOVA and Tukey's post hoc test with a significance level of p<0.05.

CAD/CAM specimens exhibited the highest flexural strength, followed by DLPprinted resins, LCD-printed resins and conventional resins. Thermal cycling significantly reduced flexural strength across all groups, with 3D-printed resins being the most affected. Surface hardness improved in 3D-printed materials post-thermal cycling, while CAD/CAM and conventional resins showed stable values.

CAD/CAM-produced denture base resins demonstrated superior mechanical properties, making them the most clinically viable option. While 3D-printed resins show promise in terms of adaptability and surface resilience, enhancements in material formulations and polymerization techniques are necessary to improve their mechanical strength.