Denture base polymers for analog and digital manufacturing: comparative study of the flexural strength, elastic modulus, and compressive strength of their mechanical properties

Abstract

Introduction: the emerging manufacture technologies for dental restorations have brought new materials with them, such as 3D-printing resins and CAD/CAM discs for the manufacturing of denture bases. Currently, there is no rigorous mechanical characterization for these materials in the literature, apart from the ones reported in technical datasheets. Method: samples for mechanical characterization were manufactured with a conventional heat cure acrylic, a CAD/CAM polymethyl methacrylate (PMMA) disc and two 3D-printing resins. The samples were tested in a universal testing machine, according to ISO 20795-1 for flexural strength and elastic modulus. Compression strength was also determined under dry conditions. The average value of each property was calculated (n = 5). One-way ANOVA and Tukey’s multiple comparisons tests were used. Results: mean flexural strengths ranged from 78.35±2.99 to 87.48±4.47MPa, elastic moduli were between 2125.43±57.05 and 2277.72±58.46MPa, and compression strengths values ranged from 85.03±2.14 to 119.15±2.87MPa. Statistical analyses showed significant differences for flexural and compression strengths but did not show any difference for elastic moduli. Conclusions: all the tested materials met the minimum required specification for mechanical properties given by ISO 20795-1. From a mechanical point of view, the new materials for digital technologies, i.e., CAD/CAM disc and 3D-printing resins, are suitable for denture-base applications.

Keywords

• dental materials
• acrylic resins
• denture bases
• 3d printing
• materiales dentales
• resinas acrílicas
• bases de dentadura
• impresión 3d
• cad-cam