Evaluation of the fracture resistance of all-ceramic zirconia posts by 3 different methods.
- Author:
Seung Mi JEONG
1
;
Chae Heon CHUNG
;
Dong Wan KANG
;
Klaus LUDWIG
;
Matthias KERN
;
Alfons HUELS
Author Information
1. Department of Prosthodontics, School of Dentistry, University of Chosun, Korea.
- Publication Type:Original Article
- Keywords:
Zirconia post;
IPS Empress;
CosmoPost;
Celay/copy-milled;
core build-up;
fracture resistance
- MeSH:
Adhesives;
Axis, Cervical Vertebra;
Joints
- From:The Journal of Korean Academy of Prosthodontics
2000;38(6):757-764
- CountryRepublic of Korea
- Language:English
-
Abstract:
STATEMENT OF THE PROBLEM: All-ceramic post-and-core restorations offer a number of advantages compared with systems that use metal build-ups. In certain clinical cases, however, fractures at the joint between the post and core build-up have been reported. PURPOSE: The objective, therefore, is to improve the joint between the post and the core build-up. MATERIAL AND METHODS: Three different methods were used to prepare all-ceramic post-andcore restorations; pressing IPS Empress core build-ups to CosmoPost zirconia posts, cementing IPS Empress core build-ups to CosmoPost zirconia posts and Celay-milling of zirconia blanks. A series of ten restorations was prepared for each of the three methods. The post-and-core complexes were tested to failure with the load applied perpendicular to the post axis. The load and deflection at fracture were recorded. RESULTS: The highest breaking load and highest deflection were recorded for the cementing technique with values of 25.3 N and 394 micrometer, respectively. The corresponding values for the pressed core build-ups and the milled zirconia core build-ups were 22 N and 301 micrometer, and 13 N and 160 micrometer, respectively. All the differences are statistically significant (p=0.05). Regarding the load-dependence of the deflection, the cemented core build-ups again demonstrated the highest value with 15.5 micrometer/N. The difference in the values of 13.6 micrometer/N and 13 micrometer/N recorded for the pressed-on and milled core build-ups, respectively, were statistically insignificant. CONCLUSION: In regard to the high fracture resistance of zirconia post, adhesive cementing the core build-up to the post offers a viable alternative to the conventional pressing technique. The elastic bond between the rigid high-strength zirconia post and the core build-up presents an additional advantage.
