Made available in DSpace on 2014-12-17T14:06:54Z (GMT). No. of bitstreams: 1 ClaudiaAMS_DISSERT.pdf: 2577371 bytes, checksum: 741bbb91aaccd5dd4b233f1b8017a831 (MD5) Previous issue date: 2010-03-29 / The continuous advances in ceramic systems for crowns and bridges infrastructure getting researchers and manufacturers looking for a material that has good mechanical properties and aesthetic. The purpose of this study was to verify in which composition and sintering temperature the ceramic system for infrastructure composed of alumina and zirconia would have the best mechanical properties. With this objective we made in UFRN laboratories 45 test bodies in the form of rectangular bars with the following dimensions: 30mm x 8mm x 3mm, where we separated by the sintering temperature: 1200?C, 1300?C and 1400?C, and by comp osition: 33% Zirconia + 67% Alumina; 50% Zirconia + 50% Alumina and 25% Zirconia + 75% Alumina, these test bodies were not infiltrated with glass. Also, were made nine test bodies by a technical from a laboratory with a commercial ceramic system: in the Ceram Zirc?nia (Vita - Zahnfabrik) with the following dimensions: 20mm x 10mm x 0.5mm, these test bodies following all recommendations of the manufacturer and were infiltrated with glass. Were realized optical and electronic microscopy analyses, hardness testing, resistance to bending in three points, porosity and bulk density. After analysis of the results we verified that with the increasing of sintering temperature, increased the value of resistance to bending, but with the same temperature there was no significant difference between the different compositions, samples made with the commercial ceramic that were infiltrated, presented a resistance to bending six times greater than the samples sintered to 1400?C and which have not been infiltra ted. There was no significant difference between the values of apparent porosity for the samples made in UFRN laboratories, but the samples of commercial ceramic obtained 0% in porosity apparent value. In tests of Rockwell Hardness there is an increase in the value of Hardness, with the increase of sintering temperature for the samples not infiltrated. Samples infiltrated showed similar values as the samples sintered in 1400?C. There was no significant difference between the values of apparent density among samples manufactured in UFRN laboratories and samples made with a commercial ceramic / Os avan?os constantes dos sistemas cer?micos para infra-estruturas de coroas e pontes fazem com que os pesquisadores e fabricantes busquem um material que tenha boas propriedades mec?nicas e est?ticas. O intuito deste trabalho foi verificar em qual composi??o e temperatura de sinteriza??o o sistema cer?mico a base de alumina e zirc?nia para infra-estrutura teria as melhores propriedades mec?nicas. Com este objetivo confeccionamos nos laborat?rios da UFRN 45 corpos-e-prova em forma de barras retangulares com as seguintes dimens?es: 30mm x 8mm x 3mm, onde os separamos por temperatura de sinteriza??o: 1200?C, 1300?C e 1400?C; e por composi??o: 33% Zirc?nia + 67% Alumina; 50% Zirc?nia + 50% Alumina e 25% Zirc?nia + 75% Alumina, estes corpos-de-prova n?o foram infiltrados com vidro. Foram confeccionados ainda nove corpos- e-prova por um t?cnico de laborat?rio com um sistema cer?mico comercial o In Ceram Zirc?nia (Vita Zahnfabrik) com as seguintes dimens?es: 20mm x 10mm x 0,5mm, estes corpos-de-prova seguiram todas as recomenda??es do fabricante e foram infiltrados com vidro. Foram realizadas an?lises por microscopia ?tica e eletr?nica, ensaios de dureza, de resist?ncia ? flex?o em tr?s pontos, porosidade e densidade aparente. Ap?s a an?lise dos resultados verificamos que com o aumento da temperatura de sinteriza??o, aumentamos o valor da resist?ncia ? flex?o, sendo que dentro da mesma temperatura n?o houve diferen?a significante entre as diferentes composi??es, as amostras confeccionadas com a cer?mica comercial e que foram infiltradas apresentaram uma resist?ncia ? flex?o seis vezes maior que as amostras sinterizadas ? 1400?C e que n?o foram infiltradas. N?o houve diferen?a significante entre os valores da porosidade aparente para as amostras confeccionadas nos laborat?rios da UFRN, j? as amostras da cer?mica comercial obtiveram um valor de 0% de porosidade aparente. Nos ensaios de Dureza Rockwell verifica-se um aumento no valor da Dureza, com o aumento da temperatura de sinteriza??o das amostras n?o infiltradas. As amostras infiltradas apresentaram valores similares aos das amostras sinterizadas ? 1400?C. N?o houve diferen?a significante entre os valores de densidade aparente entre as amostras confeccionadas nos laborat?rios da UFRN e as amostras confeccionadas com a cer?mica comercial