Assessment of variations in wear test methodology

Gouvêa, Cresus V.D; Weig, Karin; Filho, Thales R.M; Barros, Renata N

The properties of composite resin for dental fillings were improved by development, but its weakness continues to be its wear strength. Several tests have been proposed to evaluate wear in composite resin materials. The aim of this study was to verify how polishing and the type of abrasive can influence the wear rate of composite resin. The test was carried out on two groups. In one group we employed an ormocer and a hybrid composite that was polished only with 600 and 1200 grit abrasive papers, whereas in the other group the composite was polished with the same abrasive paper plus a 1 μm and 0.25 μm grit diamond paste. A three-body wear test was performed using the metal sphere of the wear test machine, the composite and an abrasive. A diamond paste and aluminum oxide dispersion were used as abrasive. Analysis of the results showed that there was no difference between polishing techniques, but revealed a difference between abrasives.

Com a evolucao dos compositos para restauracoes dentarias varias propriedades sofreram melhoras, porem o desgaste sofrido pelo material continua conduzindo a falha de varias restauracoes. Existem varios testes propostos para avaliar o desgaste sofrido por estes materiais. O objetivo deste trabalho foi verificar como o polimento e o tipo de abrasivo pode influenciar o desgaste deste material. Para realizacao dos testes utilizou-se um ormocer e um composito hibrido, que foram polidos com lixa de granulacao 600 e 1200 e com as lixas seguidas de pano de polimento e pasta de diamante de granulacao 1 μm e 0,25 μm. Foi realizado um desgaste tri-corporeo que envolvia a esfera metalica da maquina de desgaste, o composito e um abrasivo. Como abrasivo foram utilizados uma pasta de diamante e uma dispersao de alumina. Atraves dos resultados podemos concluir que a diferenca no polimento nao afetou os resultados, mas que existiu diferenca entre os testes realizados com a pasta de diamante e a dispersao de alumina.