Effect of overglaze of internal surface of machined and pressed ceramic on marginal fit
Internal surface of pressable and CAD/CAM ceramic restorations are glazed to improve mechanical properties. However its effect on marginal adaptation is not studied.
Objective: Objective of the study was to evaluate the effect of overglaze of internal surface of machined and pressed ceramic restorations on the marginal fit.
Methodology: An aluminum die, having cervicocclusal height of 5mm, axial convergence of 160 and a shoulder finish line of 1.5mm was prepared. Copings were prepared of lithium disilicate material using press able and CAD/CAM technology. Specimens were placed in a jig and analyzed at ten points on the margins of the copings for marginal fit before glazing using stereomicroscope magnification 10 x. Glaze was applied on the internal surface of the copings and the marginal gap was measured again.
Results: After glazing the internal surface there was a decrease in marginal gap of copings made using pressable and CAD/CAM techniques. Before glazing the inner surface of the coping (0.071μm and 0.070 μm respectively) and after glazing(0.038μm and 0.042μm respectively).
Conclusions: Marginal fit of ceramic restoration made using CAD/CAM technology and press able technique improved after application of over glaze on the internal surface of the copings. The difference in marginal adaptation of pressable and CAD/CAM copings was not found to be statistically significant (P>0.05) after internal glazing of the copings.