Title: 0396 - Firing-cycle Effect on Crown-fit of Restorations Fabricated by Different Techniques


Nazli Aydin, Cukurova University College of Dentistry
Orhun Ekren (Presenter)
Cukurova University College of Dentistry

Yurdanur Ucar, Cukurova University College of Dentistry


Objectives: Marginal fit is crucial if long-term survival of metal-ceramic restorations is to be expected.
The aims of the study were to examine 1) the internal and marginal fit and 2) the effect of ceramic firing cycles on internal and marginal fit of restorations fabricated using casting, laser sintering and soft metal milling.

Methods: Metal substructures were produced by using soft metal milling, laser sintering and conventional casting (n=15/group). The internal fit was measured using silicon replica technique. The marginal adaptations were measured by a light microscope. Ceramic was applied on each substructures. The measurements were repeated following the porcelain application and glazing. Statistical analyzes were performed using Three-way ANOVA and Tukey-HSD (α = 0,05) tests.

The mean marginal gap values were 31.4±13.8 μm for soft metal, 20.8±14.4 μm for casting and 7.3±6 μm for laser sintering. There was statistically significant difference (p=.000) between the metal and ceramic, metal and glaze measurement steps.The mean internal gap values were 37±5.7 mg for casting, 28±6.1 mg for laser sintering and 21.6±7.3 mg for soft metal. There was no statistically significant difference between the porcelain firing cycles (p>.05).

Conclusions: The porcelain firing cycle did not cause a statistically significant difference in the internal gap. However, a statistically significant increase in the marginal gap was observed.

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE