Effect of Silanized Zirconium Oxide (ZrO2) Filler on Hardness of Acrylic-Based Denture Teeth

Abstract

PMMA is used in dentistry as the main matrix for denture manufacture. Dentures are a substitute for natural human teeth which must have mechanical properties and are biocompatible to withstand mastication in the oral cavity. However, PMMA has poor mechanical properties, so it is necessary to add filler to the PMMA matrix. In this study zirconium oxide (ZrO2) was used as a filler because it has good mechanical properties and aesthetics. The aim of this study was to study the effect of adding ZrO2 filler on the hardness and compatibility of denture composites at concentrations ( 0%, 1%, 3%, 5%, and 7%). The bulk composite polymerization method used in the manufacture of dental composites is by mixing powdered materials in the form of PMMA, BPO as an initiator, and ZrO2 filler which has been silanized with liquid materials in the form of MMA monomer and cross-linking agent Ethylene Glycol Dimethacrylate (EGDMA). Mixing powder liquid in this method uses hand mixing in a stainless steel container until it reaches the dough phase and is packed into a mold according to ASTM for Vickers hardness tests. Heat cured polymerization technique was used for the curing process in a water bath at 74°C for 90 minutes and continued at 100°C for 30 minutes. The results obtained in this study, the addition of ZrO2 filler to a concentration of 5% showed an increase in the hardness value up to 37.6 VHN. Keywords: Denture Teeth, Composite Bulk Polymerization, Heat cured Polymerization, Zirconium Oxide