Analysis of the marginal gap of complete crowns made by using wet and dry ceramic ring liners - an in vitro study

Abstract

The ultimate assessment of cast restoration lies in the accuracy of fit of the casting. Ring liners, through their compressibility, act as a buffer of pliable material between the expanding investment material and the rigid metallic ring. Asbestos, the traditionally used buffer, has now been found to be a potential carcinogen, leading to its withdrawal from use and subsequent introduction of its alternatives i.e. cellulose and ceramic ring liners. This in vitro study was undertaken to evaluate the marginal gap of complete crowns made by using wet and dry ceramic ring liners using a scanning electron microscope. Two groups of thirty castings each were prepared with dry and wet ceramic ring liners respectively and assessed for marginal fit. Results showed that crowns made by using dry ceramic ring liners had significantly less marginal gap as compared to the crowns made by using wet ceramic ring liners.