IN-VITRO MARGINAL ADAPTATION OF ALUMINA PORCELAIN CERAMIC CROWNS

This study evaluated the dimensional stability during firing of In-Cer am alumina porcelain ceramic and examined the marginal fit for three d ifferent configurations of tooth preparation. A stereomicroscope was u sed to measure the space between the margin of restorations and tooth preparations. The three methods of tooth preparation were statisticall y compared and revealed suitable dimensional stability during the firi ng and glazing process. A better marginal fit was recorded for artific ial crowns fabricated on a chamfer or 50-degree shoulder tooth prepara tion.