Design and performance evaluation of biphenyl-based high-performance dental composite resins reinforced with porous lithium disilicate.

Abstract

Objective: This study aims to design and investigate the mechanical, aesthetic, tribological, and biocompatibility performance of a tetramethyl-biphenyl dimethacrylate (TMBP-EMA)-based dental composite resin reinforced with porous lithium disilicate (Li₂Si₂O₅) microcrystalline particles.

Materials and methods: Porous Li₂Si₂O₅ fillers were obtained by hydrofluoric acid (HF) etching and subsequently characterized. The TMBP-EMA resin matrix was synthesized and analyzed. The structure, mechanical behavior, optical properties, and polymerization performance of the Li₂Si₂O₅/TMBP-EMA composite resins were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and other methods, with mechanical properties evaluated in terms of flexural modulus, flexural strength, and Vickers hardness.

Results: Porous Li₂Si₂O₅ fillers were successfully fabricated, and their porosity increased with prolonged HF etching. The Li₂Si₂O₅/TMBP-EMA composite resins showed improved degree of conversion, reduced polymerization shrinkage, favorable wettability and solubility, enhanced optical properties, and improved friction behavior. Mechanical properties improved continuously with increasing porosity, with the 120-s group achieving the best results. Both SEM and finite element analysis confirmed that the porous structure enhanced interfacial bonding and optimized stress distribution, thereby improving overall properties.

Significance: Incorporation of porous Li₂Si₂O₅ improved the mechanical, optical, and tribological properties of the composite resin, while improving interfacial bonding and stress distribution. Its comprehensive performance surpassed that of conventional fillers, indicating promising potential for clinical translation.