Protocolo para sinterização de zircônia odontológica por energia de micro-ondas

• Autor(a) principal: Barchetta, Nayara Fernanda [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/136672; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/28-03-2016/000860669.pdf
• topic: Cerâmica; Microondas; Materiais dentários; Dental materials

This study aimed to evaluate the impact of sintering and cooling temperatures in the mechanical and microstructural behavior of microwave-sintered Y-TZP ceramics. The sintering and cooling temperatures were varied at given range in order to develop a protocol, which could maintain the zirconia microstructure compatible to the one obtained by conventional sintering. Thus, in this study the sintering process was optimized with the use of the main microwave energy qualities: energy-saving, reduced processing time and volumetric energy absorption by the material. Eighty-four discs were prepared with CAD-CAM (n=84) for discs size standardization, following ISO 6872. The discs were distributed into 7 groups (n=12), Control Group = conventional sintering. Other Groups, with microwave-sintered discs, with variations in sintering (S) and cooling (R) temperatures, formed the following sub-groups: S1400RR, S1400R400, S1400R25, S1450RR, S1450R400 and S1450R25. For microstructural analysis, the following characterizations were performed: Density, XRD and SEM; mechanical analysis was performed via biaxial flexure resistance. The flexure resistance data were statistically analyzed (two-way ANOVA, Tukey, Sidak and Dunnett). The Control (806,1±105,8 MPa) and S1450 (824,7±99,12 MPa) Groups did not present differences; only discs from Groups sintered at 1400ºC (681,9±91,17 MPa) showed lower averages. The same occurred when density values were analyzed. From XRD analysis, it was observed that all groups had remained in the tetragonal phase for a larger period. In conclusion, it can be proposed a protocol for microwave sintering: temperature 1450 ° C for 15 min and fast cooling. The method of microwave sintering presents compatibility with the conventional method and allows process optimization