Effect of adding nanosilica particulate filler on the wear behavior of dental composite

The aim of this study was to fabricate BisGMA based nanosilica filled dental composites and to study the effect of varying nanosilica filler content on their wear characteristics. The composites were developed by varying filler content of silane treated nanosilica from 0 to 9 wt%, into the resin matrix consisting of 51 wt% Bisphenol-A glycidyl methacrylate, 46.5 wt% Tri-ethylene glycol dimethacrylate, 0.24 wt% Camphorquinone, 1.5 wt% Butyl hydroxyl toluene and 0.76 wt% Dimethylamino ethyl methacrylate. The hardness was determined using Vickers's micro hardness tester. The two body abrasive wear experiments were performed in the artificial saliva medium as per Taguchi Orthogonal Array and steady state condition by varying parameters such as filler content, normal load, and chewing speed. The finding of results indicated that the wear resistance and hardness were improved with increase in filler fraction. The dental composite filled with 9 wt% of nanosilica filler exhibited maximum hardness (31.4 HV), maximum compression strength (360.5 MPa) and flexural strength (120.5 MPa) and minimum volumetric wear rate. Also, the wear volume increased with the increase in normal load, chewing speed and number of cycles but decreased with the increase in filler content. Statistical significance of each factor as per generalized linear model of Analysis of Variance showed that filler content was the most influencing factor followed by applied normal load, numbers of cycle and chewing speed. Worn surfaces were studied using a scanning electron microscope (SEM) to give an insight into the wear mechanisms. POLYM. COMPOS., 39:E332-E341, 2018. (c) 2017 Society of Plastics Engineers