In vitro analysis of the fracture resistance of CAD-CAM monolithic zirconia molar crowns with different occlusal thickness.

Autor: Sorrentino R; Department of Medical Biotechnologies, School of Dental Medicine, University of Siena, Viale Bracci, 53100 Siena, Italy. Electronic address: errestino@libero.it., Triulzio C; Department of Medical Biotechnologies, School of Dental Medicine, University of Siena, Viale Bracci, 53100 Siena, Italy. Electronic address: triulzio.clementina@gmail.com., Tricarico MG; Department of Medical Biotechnologies, School of Dental Medicine, University of Siena, Viale Bracci, 53100 Siena, Italy. Electronic address: marella86@hotmail.it., Bonadeo G; Department of Medical Biotechnologies, School of Dental Medicine, University of Siena, Viale Bracci, 53100 Siena, Italy. Electronic address: bonadeogianni@gmail.com., Gherlone EF; Department of Dentistry, University 'Vita Salute San Raffaele' of Milan, Via Olgettina 60, 20132 Milan, Italy. Electronic address: gherlone.enrico@hsr.it., Ferrari M; Department of Medical Biotechnologies, School of Dental Medicine, University of Siena, Viale Bracci, 53100 Siena, Italy. Electronic address: ferrarm@gmail.com.
Jazyk: angličtina
Zdroj: Journal of the mechanical behavior of biomedical materials [J Mech Behav Biomed Mater] 2016 Aug; Vol. 61, pp. 328-333. Date of Electronic Publication: 2016 Apr 14.
DOI: 10.1016/j.jmbbm.2016.04.014
Abstrakt: Objectives: To compare the fracture resistance and mode of failure of CAD-CAM monolithic zirconia crowns with different occlusal thickness.
Material and Methods: Forty CAD-CAM monolithic zirconia crowns with different occlusal thickness were randomly distributed into 4 experimental groups: 2.0mm (group 1), 1.5mm (group 2), 1.0mm (group 3) and 0.5mm (group 4). The restorations were cemented onto human molars with a self-adhesive resin cement. The specimens were loaded until fracture; the fracture resistance and mode of failure were recorded. The data were statistically analyzed with the one-way ANOVA followed by the Fisher׳s Exact test with Bonferroni׳s correction (p=0.05).
Results: The fracture resistance values of all the specimens exceeded the maximum physiological occlusal loads in molar regions. All the crowns showed cohesive microcracks of the zirconia core; only 1 crown with a thickness of 0.5mm was interested by a complete fracture.
Conclusions: The occlusal thickness of CAD-CAM monolithic zirconia crowns did not influence either the fracture resistance and the mode of failure of the restorations; the occlusal thickness of CAD-CAM monolithic zirconia crowns can be reduced up to a lower bound of 0.5mm keeping a sufficient strength to withstand occlusal loads; CAD-CAM monolithic zirconia crowns showed sufficient fracture resistance to be used in molar regions, even in a thin configuration (0.5mm).
(Copyright © 2016 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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