Effect of different cement materials on the failure load of CADCAM-generated crowns and copings

Date
2012
DOI
Authors
Kaddi, Ahmed
Version
OA Version
Citation
Abstract
Objectives: The aim of this study was to compare failure load of adhesively and non-adhesively cemented (a) Vitablocs Mark II, IPS e.max CAD and Paradigm MZl00 crowns (b) VITA In-Ceram YZ copings made with computer-aided design/computer-aided manufacturing (CAD/CAM). Materials and Methods: In the first part of the study, two sets of monolithic posterior crowns each with uniform occlusal and lateral wall thickness of 1.5 mm were fabricated from three types of block ceramic: lithium disilicate glass, millable composite resin and feldspathic ceramic using CEREC 3 CAD/CAM. Crowns (n=6) of each ceramic material were glass-ionomer cemented and adhesively cemented on resin-based composite dies and loaded until fracture. In the second part of the study, two sets of copings (n=6) each with uniform occlusal and lateral wall thickness of 0.5 mm were fabricated from VITA In-Ceram YZ using the same CEREC machine used for the first part of the study. One set was glass-ionomer cemented, and the other was adhesively cemented and loaded until fracture. The third part of the study compared the shear bond strength of the ceramic and composite materials used in the load-to-failure test to the resin and the glass-ionomer cements. Load data was analyzed using ANOVA and Tukey tests. Results: Analysis of variance revealed a statistically significant influence of the luting agent on the failure load of CAD/CAM milled ceramic crowns, composite crowns and ceramic copings. Comparison between crowns with non-adhesive and adhesive cementation showed significant differences. Fracture load data of resin-cemented crowns was significantly higher than the glass-inonomer cemented crowns. Comparing the fracture load data of VITA In-Ceram YZ copings with adhesive and non-adhesive cementation, VITA In-Ceram YZ copings cemented with resin cement showed significantly higher fracture load data than those copings cemented with glass-ionomer cement (P[less than] 0.05). Shear bond strength for the ceramic and composite materials with resin cement was higher than those with glass-ionomer cement. Conclusion: Within the limitations of the study, glass-ionomer cement reduced the fracture load of CAD/CAM milled ceramic crowns, composite crowns and zirconium oxide copings and its bond strength to these materials was lower than the resin cement.
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Thesis (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2012 (Department of Restorative Sciences and Biomaterials).
Includes bibliographic references: leaves 57-60.
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This work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.