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Effect of Surface Etching on the Flexure Strength and Fracture Toughness of Dicor® Disks Containing Controlled Flaws

Department of Dental Biomaterials, College of Dentistry, University of Florida, Gainesville, Florida 32610-0446

KJ Anusavice

Department of Dental Biomaterials, College of Dentistry, University of Florida, Gainesville, Florida 32610-0446

Previous studies have shown an increase in the failure load of Dicor® glass-ceramic crowns of up to 97% when they were etched with NH₄HF ₂ and luted with a resin-based cement compared with the use of unetched crowns luted with zinc phosphate cement. The objective of this study was to evaluate the effect of the acid-etch treatment on the flexure strength and fracture toughness of Dicor® glass-ceramic specimens containing controlled flaws. Annealed disks were divided into two groups of 14 each, and microcracks were induced in the surface with a Vickers indenter. Seven specimens from each sample set were etched with 10% NH4HF2 (Dicor® etching gel) and were fractured in air using a piston-on-three-ball biaxial fixture. Fracture toughness values were determined from the flexure strengths and f ractographic measurements of fracture-initiating flaws. Analysis of data by ANOVA and the Tukey's Studentized Range Test revealed no significant difference (p > 0.05) in the mean flexure strength or fracture toughness of the etched and unetched samples within group A or group B. For the sample groups tested, flaw modification by etching had no effect on the flexure strength or on the fracture toughness of Dicor® specimens containing controlled flaws.

Key Words: Ceramics • Cracks • Etching • Fractures • Microscopy.

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Journal of Dental Research, Vol. 73, No. 2, 505-510 (1994)
DOI: 10.1177/00220345940730020401


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				J.Y. Thompson, K.J. Anusavice, A. Naman, and H.E. Morris Fracture Surface Characterization of Clinically Failed All-ceramic Crowns Journal of Dental Research, December 1, 1994; 73(12): 1824 - 1832. [Abstract] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Thompson, J.Y. Articles by Anusavice, K. Search for Related Content PubMed PubMed Citation Articles by Thompson, J.Y. Articles by Anusavice, K. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB AMMONIUM BIFLUORIDE AMMONIUM FLUORIDE Social Bookmarking                         What's this?