EFFECT OF SILANE COUPLING AGENT CONTENT ON MECHANICAL PROPERTIES OF HYDROXYAPATITE/POLY(METHYL METHACRYLATE) DENTURE BASE COMPOSITE

Abstract

In removable prosthodontics, poly(methyl methacrylate) (PMMA) is the most suitable for the construction of denture bases. Intra-orally, the subjected stress intensity during the function accelerate the fracture of acrylic resin denture bases. Extra-orally, fracture occurs when dentures are accidentally dropped on a hard surface. The aim of the current study was to investigate the effect of coupling agent concentration on the mechanical properties of Hydroxyapatite/Poly(methyl methacrylate) (HA/PMMA) denture base composite. The Hydroxyapatite (HA) treated with four different ratios (i.e. 0, 5, 7 and 10 wt%) of 3-(trimethoxysily) propyl methacrylate (γMPS) silane coupling agent was added into the PMMA matrix. The mechanical performance of the composite was evaluated by conducting fracture toughness, flexural and tensile tests. An improvement of 13.83% and 9.62% in the tensile and flexural strength respectively, was achieved. The tensile and flexural modulus of the composite increased by 19.04% and 12.5% respectively. A significant improvement of 29.26% in the fracture toughness was observed at 10 wt% of γ-MPS. 10 wt% of γ-MPS is the optimum amount of coupling agent for obtaining balanced mechanical properties