The aim of this work was to study mold filling during casting of standardized five-unit Ti bridges vs. the gas permeability of the investments.

A vacuum/Ar pressure casting machine was used to study porosity and mould filling of cast bridges of Ti. Two series of experiments were carried out

Ti has a strong affinity to elements like O, N, and C. During melting a non-reacting crucible and vacuum and/or Ar-gas protection therefore have to be used. If the impurity content becomes too high, the material turns hard and brittle. In the present work vacuum/Ar-pressure casting of crowns has been carried out at different air pressure levels.

Abstract

The effect of three different lining materials on the investment expansion during the casting procedure, was compared. The accuracy of the castings was assessed by measuring slits at the gingival shoulder of a cast veneer crown. The liners were made of asbestosos, paper and a glassfiber material.