Development and characterization of SiC nanofiber and hybrid reinforced composites for dental restorations

Abstract

Enhancing the mechanical reliability of dental restorative materials is essential for improving long-term clinical performance. This study examined the mechanical, tribological, morphological, and thermal properties of Bis-GMA/TEGDMA (50/50 wt%) composites reinforced with silicon carbide (SiC) nanofibers and nanoparticles. Seven formulations were prepared: a control, three nanofiber composites (0.1–0.3 wt%), and three nanohybrid systems. All samples were photo-cured using strong, flashing, and gradually strong LED modes. Mechanical behavior was evaluated via Shore hardness and compression testing, while tribological performance was assessed using pin-on-disc wear analysis. SEM, XRD, and DSC provided structural and thermal characterization. SiC incorporation produced clear composition-dependent effects. Hardness increased by 3.5% in the 0.2% nanofiber composite relative to the control. The same formulation showed the greatest mechanical enhancement, with a 13.2% increase in compression strength, whereas the 0.3 wt% hybrid composite exhibited a 34% decrease, indicating overloading effects at higher hybrid content. Tribologically, both the 0.2% nanofiber and 0.3% hybrid composites demonstrated improved resistance to wear, exhibiting minimal weight loss. Curing mode significantly influenced all measured properties, with strong-mode curing yielding the highest overall performance. These findings highlight the potential and limitations of SiC-based reinforcement strategies for developing next-generation dental composites.