Wear and Mechanical Properties of Nano-silica-fused Whisker Composites

Abstract

Resin composites must be improved if they are to overcome the high failure rates in large stress-bearing posterior restorations. This study aimed to improve wear resistance via nano-silica-fused whiskers. It was hypothesized that nano-silica-fused whiskers would significantly improve composite mechanical properties and wear resistance. Nano-silicas were fused onto whiskers and incorporated into a resin at mass fractions of 0%-74%. Fracture toughness (mean ± SD; n = 6) was 2.92 ± 0.14 MPa•m½ for whisker composite with 74% fillers, higher than 1.13 ± 0.19 MPa•m½ for a prosthetic control, and 0.95 ± 0.11 MPa•m½ for an inlay/onlay control (Tukey’s at 0.95). A whisker composite with 74% fillers had a wear depth of 77.7 ± 6.9 μm, less than 118.0 ± 23.8 μm of an inlay/onlay control, and 172.5 ± 15.4 μm of a prosthetic control (p < 0.05). Linear correlations were established between wear and hardness, modulus, strength, and toughness, with R = 0.95–0.97. Novel nano-silica-fused whisker composites possessed high toughness and wear resistance with smooth worn surfaces, and may be useful in large stress-bearing restorations.