Produção de materiais mulíticos porosos pelo método de réplica e pesquisa sobre suas aplicações na implantologia óssea

Abstract

The first purpose of this work is to investigate the mechanical properties and the morpho- logical and microstructural characteristics that favor the application in bone implants to evaluate the viability of the use of mullite in this application. The second aim, in turn, was to obtain some of the required properties by performing three experiments to produce porous ceramic materials with the presence of mullite, using kaolin as the raw material and the polymeric sponge replica method as the manufacturing technique. Burning for sponge decomposition and subsequent sintering of the ceramic material consisted of 4 phases: heating at a rate of 0,90oC/min from room temperature (approximately 25oC) to 400oC; heating at a rate of 10oC/min from 400oC to 1000oC; maintenance of the oven at a temperature of 1000oC; and cooling the sample to room temperature. At the end of Experiment 1, an X-ray diffraction analysis indicated the presence of mullite along with other crystalline phases of the Al2O3-SiO2 system. Also in Experiment 1, it was observed, visually, the fragility presented by the material produced. With this information, further experiments were performed, changing some conditions such as the number of dips (Experiment 2) and the use of binder in the suspension (Experiment 3), aiming at the production of more resistant porous ceramic materials. At the end of Experiment 3, the average pore size of (0, 4 ± 0, 1)mm and the average porosity of 79% of the samples produced were obtained. Another purpose of this work is to investigate the feasibility of using porous ceramic materials constituted predominantly by the mullitic phase in bone implants. For this research the mechanical properties and the morphological and microstructural characteristics that favor the application in bone implants and which of these aspects the mullite presents, as well as examples of its applications in this area were raised. The applications of other ceramic materials in the area of bone implantology were also researched.