59 - Characterization of Experimental Short Fiber Reinforced Dual-Cure Core Build-Up Composites

Abstract

As a core build-up material, dual-cured (DC) resin-based composites are getting popular. This study aimed to evaluate certain physical properties of a new experimental short fiber-reinforced DC resin composites (SFRCs) in comparison with different commercial conventional DC materials (Gradia Core, Rebilda DC, Luxa Core and Visalys CemCore). Degree of monomer conversion (DC%) was determined by FTIR-spectrometry using either self or light-curing mode. The flexural strength (FS), modulus (FM), and fracture toughness (FT) were measured using a three-point bending setup. The surface microstructure of each resin composite was investigated with scanning electron microscopy (SEM). Data were statistically analyzed with analysis of variance ANOVA (p = 0.05). The light-curing mode showed significant (p<0.05) effect on the DC% and flexural properties of tested DC resin composites and differences were material-dependent. SFRC exhibited the highest fracture toughness (2.3 MPa m1/2) values and Luxa showed the lowest values (1 MPa m1/2) among the tested materials (p<0.05). Gradia and SFRCs showed the highest flexural modulus (p<0.05), while the other resin composites had comparable values. The new DC short fiber-reinforced core build-up resin composite differed significantly in its fracture toughness compared to the tested conventional DC composites.