Effect of different restorative materials for use in CAD-CAM in biaxial bending resistance after accelerated aging

Abstract

ABSTRACT Objective: The aim of this study was to evaluate the effect of different restorative materials for use in CAD-CAM on biaxial flexural strength after accelerated mechanical and thermal aging. Methods: Samples were fabricated and divided into two groups: CL (leucite-reinforced ceramic: IPS Empress CAD) and NR (nanoceramic resin: Lava Ultimate). Morphological analysis of the surface was performed using Scanning Electron Microscopy, and chemical analysis was conducted using Energy Dispersive X-ray Spectroscopy on one sample from each group. All samples underwent accelerated aging, initially through fatigue testing using a mechanical cyclic loading machine (200,000 cycles, 15N force, 1Hz rotation speed) in distilled water at room temperature (37°C). Subsequently, thermal aging was carried out in a thermocycler (5,000 cycles, baths at 5°C and 55°C). Results: The CL group exhibited a more diffuse surface, and chemically, it showed the presence of Silicon, Oxygen, Aluminum, Sodium, Potassium, and Calcium. The NR group had a more compact surface and contained the following chemical elements: Oxygen, Silicon, Carbon, Zirconium, Nitrogen, Aluminum, and Sodium. The CL (193.1MPa) showed a higher mechanical strength value than the NR (52.45MPa), which was statistically significant. However, the NR (2.3) exhibited a lower average number of fragments after fracture compared to the CL (5.6). Conclusion: Restorative materials exhibited distinct morphology and chemical composition. These restorative materials had a statistically significant effect on biaxial flexural strength, with leucite-reinforced ceramics being mechanically superior to nanoceramic resin. And the ceramic matrix resin family showed a lower quantity of fragments after fracture compared to the material representing the glass-ceramic family.

Keywords

• Ceramics
• Computer-aided design
• Flexural strength