Estudo da sinterização de resíduo odontológico microparticulado do sistema cerâmico ZrO2-Y2O3

Abstract

The actual use of natural resources on accelerated economic growth, resulting in continuous increase of industrial waste, and to remove these residues, a recycling process is preferably na attractive solution. During the machining of blocks of zirconia to several types of dental implants, most of the material is loosened as a powder, which is subsequently discarded. The stabilized tetragonal zirconia with 3% yttria (Y-TZP) mol boasts a variety of applications in engineering, and biomedical, because of its great combination of strength, fracture toughness, ionic conductivity and low thermal conductivity. Besides the damage to the environment wasting of the material resulting in financial loss, reflecting the high final cost of medical treatment for patients. The starting materials used in this work were two different powders ZrO3-Y2O3ceramic system: commercial zirconia nanoparticulate and microparticulate zircônia residue. The powder was uniaxially and isostatically pressed and then sintered at 1500, 1550 and 1600 ° C for 1 hour. The techniques of laser granulometry, X-ray diffraction (XRD) and dilatometry were used for powder characterization. After sintering were performed density and porosity tests, X-ray diffraction (XRD), Flexural strength, microhardness and fracture toughness analysis, and scanning electron microscopy (SEM). Samples compacted via isostatic pressing showed values less than 0.78% porosity and demonstrated greater effectiveness compared to uniaxial compression. Was observed in X-ray diffra ction, that with increasing temperature, the intensity of the peaks of monoclinic phase is decreased. The sintering temperature moderately has influenced on the microhardness of samples, showing small increases in hardness to temperature of 1600 ° C. The flexural strength of zirconia residue increases with increasing sintering temperature for both routes of compression, showing the best values for isostatic compression.