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Effect of metal selection and porcelain firing on the marginal accuracy of titanium-based metal ceramic restorations.

Authors :
Shokry TE
Attia M
Mosleh I
Elhosary M
Hamza T
Shen C
Source :
The Journal of prosthetic dentistry [J Prosthet Dent] 2010 Jan; Vol. 103 (1), pp. 45-52. Date of Electronic Publication: 2009 Dec 22.
Publication Year :
2010

Abstract

Statement of Problem: Titanium is the most biocompatible metal used for dental casting; however, there is concern about its marginal accuracy after porcelain application since this aspect has direct influence on marginal fit.<br />Purpose: The purpose of this study was to determine the effect that metal selection and the porcelain firing procedure have on the marginal accuracy of metal ceramic prostheses.<br />Material and Methods: Cast CP Ti, milled CP Ti, cast Ti-6Al-7Nb, and cast Ni-Cr copings (n=5) were fired with compatible porcelains (Triceram for titanium-based metals and VITA VMK 95 for Ni-Cr alloy). The Ni-Cr alloy fired with its porcelain served as the control. Photographs of metal copings placed on a master die were made. Marginal discrepancy was determined on the photographs using an image processing program at 8 predetermined locations before airborne-particle abrasion for porcelain application, after firing of the opaque layer, and after firing of the dentin layer. Repeated-measures 2-way ANOVA was used to investigate the effect of metal selection and firing stage, and paired t tests were used to determine the effect of each firing stage within each material group (alpha=.05).<br />Results: ANOVA showed that both metal selection and firing stage significantly influenced the measured marginal discrepancy (P<.001), and there was interaction between the 2 variables (P<.001). Student-Newman-Keuls multiple comparison tests showed that there were significant differences between any 2 metals compared, at each stage of measurement. Paired t tests showed that significant changes in marginal discrepancy occurred with opaque firing on milled CP Ti (P=.017) and cast Ti-6Al-7Nb alloy (P=.003).<br />Conclusions: Titanium copings fabricated by CAD/CAM demonstrated the least marginal discrepancy among all groups, while the base metal (Ni-Cr) groups exhibited the most discrepancy of all groups tested.<br /> (Copyright 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.)

Details

Language :
English
ISSN :
1097-6841
Volume :
103
Issue :
1
Database :
MEDLINE
Journal :
The Journal of prosthetic dentistry
Publication Type :
Academic Journal
Accession number :
20105684
Full Text :
https://doi.org/10.1016/S0022-3913(09)60216-X