USING TAGUCHI, PCR-TOPSIS AND GENETIC ALGORITHM TO OPTIMISE OF DIAMETRAL TENSILE STRENGTH AND DENSITY OF PMMA-ZIRCONIA COMPOSITE

Abstract

Acrylic bone cement of PMMA (poly-methylmethacrylate) have been used for more than 40 years in dental implant and orthopedic surgery for the fixation of artificial joints. Zirconia (ZrO2) has been widely used in medical application because of their chemical and physical properties such as good mechanical strength and good thermal stability. In this study, acrylic bone cement reinforced with bioceramic was prepared by mixing beads of PMMA and ZrO2 powder. Diametral tensile strength and density were tests to determine the mechanical properties of PMMA-ZrO2 composite. Simultaneous optimization of diametral tensile strength and density of PMMA-ZrO2 composite were done by Taguchi method, PCR-TOPSIS and genetic algorithm. Experiments have been carried out using Taguchi L16(45 ) orthogonal arrays. Experimental data have been transformed into new data set using SNR and PCR-TOPSIS. The new data set were used to find simultaneous optimization of DTS and density of PMMA-ZrO2 composite using genetic algorithm. According to the hybrid method, global optimum of DTS and density of PMMA-ZrO2 composite are 8.758 MPa and 68.8 %. This result occurred when 5 wt% ZrO2 in PMMA, sintering temperature at 1570C and holding time at 75 minutes.