Properties of glass-ceramic materials for fixed partial denture construction

In order to determine the feasibility of constructing fixed partial dentures using glass-ceramic materials, the flexural strength and marginal fit of three experimental glass ceramic materials, and DICOR as control, were studied. The flexural strength ranged from 105.8 MPa to 129.5 MPa. Ceramic and alumina addition provided significant strength as tested by ANOVA and multiple range tests (P < 0.05). The range for the cemented bridge margins was from 48.9 microns to 80.4 microns. The tested ceramics had no statistically significant differences in margin openings for the same sites (P < 0.05). However, the openings on the mesial side of the premolar abutment and the distal end of the molar abutment of the fixed partial denture did have statistically significant differences (P < 0.01). Appropriate addition of alumina led to an increase in bending strength. The alumina stabilizes and strengthens the glass-ceramic material by incorporation into the silicone network.