The three-point beam test for the evaluation of dental porcelain

The three-point beam test is simple and extremely sensitive to surface conditions. It appears to be ideally suited to the evaluation of dental porcelain, but specimen fabrication is difficult. In this study, specimens of porcelain fired on platinum foil have been constructed using an alumina former. The results showed excellent specimen consistency and reproducibility. Of the surfaces investigated, the use of tin-oxide-coated platinum foil did not result in an increase in transverse strength.