Comparing the effect of porcelain firing cycles on marginal adaptation of Procera all-ceramic restorations with metal ceramics Dr. Koodaryan R., 1 Dr. Sazgara H., 2 Dr. Seyedan K., 3 Dr. Hafezeqoran A. 1 1 Assistant Professor, Department of Prosthodontics, School of Dentistry , Tabriz University of Medical Sciences. Tabriz, Iran. 2 Associate Professor, Department of Prosthodontics, School of Dentistry , Shahid Beheshti University of Medical Sciences. Tehran, Iran. 3 Assistant Professor, Department of Prosthodontics, School of Dentistry , Shahid Beheshti University of Medical Sciences. Tehran, Iran. (Received 29 July, 2009 Accepted 29 June, 2010) Abstract Background and Aim : Although all-ceramic restorations are widely used, there is lack of information about how the fit is affected by fabrication procedures. This study evaluated the marginal gap of Pocera all-ceramic crowns before and after porcelain firing cycles . Materials and Methods : This was an experimental study, using ten standardized all-ceramic crown of Procera system that were fabricated on metal die crowns of the conventional metal-ceramic restorations served as control group. A device was used to retain specimen during measurement and to reposition them on the device after each manufacturing process. The specimens were not cemented and the gaps were measured on the metal die using stereo microscope. The crown systems were compared by using ANOVA and paired sample t-tests . Results : The conventional metal ceramic (69.17 ± 44.8 µ ) and Procera crowns (61.35 ± 43.79 µ ) demonstated nearly identical marginal discrepancy values. Statistical analyses demonstrated no significant differences in the marginal discrepancy values of Procera and metal ceramic crowns. The findings indicate that the addition of porcelain to the copings of Procera did not cause significant change in marginal discrepancy values (P=0.7), although there were a significant difference in marginal discrepancy values of control group after firing cycles (P=0.001) Conclusion: Within the limitation of this study, it was concluded that Procera all ceramic crown system demonstrated an acceptable marginal fit. The porcelain firing cycle did not affect the marginal fit of this system . Key words : Dental restoration – Allceram – Marginal adaptation – Procera - Dental porcelain . Corresponding Author : Dr. Hafezeqoran A ., Assistant Professor, Department of Prosthodontics, School of Dentistry , Tabriz University of Medical Sciences. Tabriz, Iran. e.mail: hafez_quran@yahoo.com |
