The Physiochemical Properties of Dental Resin Composites Reinforced with Milled E-glass Fibers

Abstract

The milled E-glass fibers (consist of 54.4 wt% SiO2, 14.5 wt% Al2O3, 17 wt% CaO, 4.5 wt% MgO, 8.5 wt% B2O3, 0.5 wt% Na2O) with 20 mesh and 50 mesh sizes were used to replace particle fillers in dental resin composites partially, with the aim to enhance fracture toughness of dental resin composites. The length distribution of milled E-glass fibers with different size was investigated with a polarizing microscope. The FT-IR analysis was used to determine the double bond conversion (DC) of dental resin composites. Water sorption (WS) and solubility (SL) were obtained until the mass variation of dental resin composites in distilled water kept stable. Flexural strength (FS) and modulus (FM) of dental resin composites were measured using a three-point bending set up. Fracture toughness (FT) of dental resin composites was measured according to the single-edge notched beam method. For both 20 mesh and 50 mesh milled fibers, the main aspect ratio was less than 5.2, which was considered to be the lowest aspect ratio for dental resin composites. The milled E-glass fibers showed none negative effect on DC, WS, and SL, and even some fibers containing dental resin composites had higher DC, lower WS and SL. The milled E-glass fibers could improve FM and FT of dental resin composites, but had no enhancement effect on FS. The milled E-glass fibers could be used to enhance FT of dental resin composites without influencing some other physiochemical properties negatively.