Fracture resistance of three porcelain-layered CAD/CAM zirconia frame designs
| Autor: | Michele Carrabba, Alessandro Vichi, G. Bonadeo, Marco Ferrari, Francesca Monticelli, Carlo Rengo, Agostino Giovannetti |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Orthodontics
Universal testing machine Chamfer Materials science Dental Porcelain Crosshead Dental Veneers Flexural strength Mechanics of Materials Materials Testing Fracture (geology) Tukey's range test Computer-Aided Design General Materials Science Cubic zirconia Zirconium Composite material General Dentistry Abutment (dentistry) |
| Zdroj: | Dental materials : official publication of the Academy of Dental Materials. 30(7) |
| ISSN: | 1879-0097 |
| Popis: | Objectives Chipping is the most frequent clinical failure of zirconia crowns. Causes of chipping have not been completely understood and different possible reasons have been considered. The study was aimed at evaluating the fracture resistance of 3 different CAD/CAM zirconia frame designs veneered with porcelain. Methods Thirty extracted sound premolars were divided into 3 groups ( n = 10). Chamfer preparations were performed, impressions were taken. Three zirconia frame designs (Aadva, GC) were realized: reproduction of the abutment contour (flat design, FD); wax-up as for porcelain-fused-to-metal crowns (PFM); anatomically guided, designed to keep constant the thickness of the overlying porcelain veneering (AG). Porcelain veneering was made with pressure layering technique (Initial Zr, GC). Crowns were cemented utilizing a self-adhesive resin cement (G-Cem, GC). After a 24-h water storage at 37 °C, using a universal testing machine (1 mm crosshead speed), crowned teeth were loaded in the central fossa in a direction parallel to the longitudinal axis of the tooth. Load at fracture was recorded in Newtons (N). Digital photographs of the specimens were taken in order to assess failure patterns. Between-group differences in fracture strength were statistically analyzed (One-Way Analysis of Variance, Tukey test, p Result Load at fractures differed significantly among the groups ( p = 0.004). AG exhibited significantly higher fracture resistance 1721.6 (488.1) N than PFM 1004.6 (321.3) N and FD 1179.5 (536.2) N, that were comparable. Repairable failures occurred in 80% of AG, 70% of PFM, and 50% of FD specimens. Significance Anatomically guided zirconia frames resisted significantly higher loads than flat and PFM-like frame designs. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect