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Effect of cavity design on the fracture resistance of zirconia onlay ceramics.

Authors :
Oyar P
Durkan R
Source :
Nigerian journal of clinical practice [Niger J Clin Pract] 2018 Jun; Vol. 21 (6), pp. 687-691.
Publication Year :
2018

Abstract

Objective: The purpose of this study was to evaluate the fracture resistance and failure modes of onlay restorations prepared with different preparation designs.<br />Materials and Methods: A total of 42 extracted, mandibular first molars (36, 46) were used and divided into six groups according to preparation design, as follows 1A: Anatomic preparation of cusps/rounded shoulder margin/occlusal groove; 1B: Flat preparation of cusps/rounded shoulder margin/occlusal groove; 2A: Anatomical preparation of cusps/occlusal groove; 2B: Flat preparation of cusps/occlusal groove; 3A: Complete anatomical reduction of cusps/rounded shoulder margin; 3B: Complete flat reduction of cusps/rounded shoulder margin groups; intact tooth: No preparation. Onlays were constructed with 0.5-mm copings of Zirconia ceramic. The copings were veneered with porcelain (IPS e. max Ceram). All samples were subjected to fracture resistance testing. Data were analyzed with Kruskal-Wallis and Bonferroni-Dunn tests.<br />Results: Fracture resistance varied significantly according to preparation design. Among the anatomic occlusal preparation designs, fracture resistance was significantly lower in Group 3 when compared to Groups 1 and 2 (P < 0.05). Among the flat occlusal preparation designs, fracture resistance was significantly higher in Group 1 when compared to Groups 2 and 3 (P < 0.05).<br />Conclusion: Preparation design affected the fracture resistance of onlay restorations. Cavities with flat occlusal preparation designs, a groove and shoulder margins (1B) resulted in the highest fracture resistance, whereas teeth prepared with a complete reduction of cusps and shoulder margins (3A) had the lowest fracture resistance.<br />Competing Interests: There are no conflicts of interest

Details

Language :
English
ISSN :
1119-3077
Volume :
21
Issue :
6
Database :
MEDLINE
Journal :
Nigerian journal of clinical practice
Publication Type :
Academic Journal
Accession number :
29888712
Full Text :
https://doi.org/10.4103/njcp.njcp_424_17