An Experimental Investigation Of Composite material Properties Used for Denture Applications

Abstract

Denture is a method that has been used for treatment of missing teeth. The material, which is used widely as a denture base material is the polymethyl methacrylate (PMMA). Denture base acrylic resins are usually subjected to different kinds of stresses which led to fracture. To decrease the fracture of denture and to prevent propagation of the crack particles and fibers have been used. An experimental investigation of the mechanical and physical properties behavior of a composite material that is used for denture has been achieved in this study. To select the optimal combination of the natural filler that will be added, the Taguchi technique was used. And selecting three natural materials (siwak, pomegranate and olive kernel powder). The filler was prepared by grinding the material and sieving it to get the filler with grain size (50, 75 and 100) μm. The filler was added to the PMMA with three different weight fractions (0.3, 0.6 1.2 wt%), four parameters (pomegranate powder, siwak powder and olive kernel powder ) with three levels (50, 75 and 100μm). Using the standard Taguchi’s array L9 (34). The analysis of mean, signal to noise ratio and analysis of variance was used to determine the optimum process parameters with its significant factor. The specimens were manufactured by hand layup. The results show that the use of different forms of natural reinforcing fillers had a significant effect on the consistency of the prepared base dentures. The siwak filler has most parameters, effect among of other parameters on the mechanical and absorbability properties, with contribution effect more than 20%, followed by the pomegranate filler. Whereas, the olive kernel filler has the less effect. Improved the optimal combination of fillers which added. The mechanical and physical properties have been improved up to 23% by adding the optimal combination of the fillers, while the hardness has been improved by 3% rather than the pure denture base material properties. the optimum combinations for all properties: (tensile strength (A3B2C2D3), Modulus of elasticity (A2B2C1D3), Impact strength(A2B2C2D2),Bending strength (A2B3C1D3),Compression strength (A3B2C1D1), Hardness test (A3B3C1D2),and Absorbability (A3B2C1D2). The maximum tensile strength, compression strength and hardness with minimum absorbability value present with using 100 μm filler grain size. But the better modulus of elasticity, impact strength and bending strength appeared with using 75 μm filler grain size. The 0.6% weight fraction of pomegranate filler showed more influence on the most physical and mechanical properties (compression strength, absorbs test, bending strength and modulus of elasticity) except the( impact strength and tensile strength) was be influenced with 1.2% pomegranate filler weight fraction. The tensile strength, modulus of elasticity and bending strength have the maximum value with using 0.9% siwak filler weight fraction. While using 0.6% weight fraction, the impact strength, hardness and absorbability showed the good results. But the compression strength was be influenced with 0.3% siwak filler weight fraction. The experimental and predicted results showed a good agreement with a difference value, that not exceed 4.88% in modulus of elasticity.