Comprehensive micro-mechanical characterization of experimental direct core build-up resin composites with different amounts of filler contents

Abstract

Dual-cured resin-based composites are gaining popularity as core build-up materials. Physical and elastoplastic characteristics of new experimental core build-up materials with variable filler contents (+2.5 and +5 wt%) were investigated using classic macroexperiments and nanoindentation. Flexural fracture strength increased from 91.7±11.8 to 114.1±9.1 and 116.6±14.7 MPa in the +2.5 and +5 wt% groups, respectively; similarly, elastic moduli increased from 12.6±0.9 to 15.4±1.2 and 15.3±2.0 MPa, respectively. Fracture toughness increased from 1.82±0.60 to 2.28±0.53 and 2.67±0.88 MPa•m^1/2 for the +2.5 and +5 wt% groups, respectively; indentation hardness increased significantly from 0.45±0.03 to 0.55±0.04 and 0.60±0.10 GPa, respectively. The addition of +5 wt% filler content led to a mechanically superior material; the addition of +2.5 wt% filler led to better reliability.