Apparent Interfacial Fracture Toughness of Resin/Ceramic Systems

• Published in: Journal of dental research Vol. 85; no. 11; pp. 1037 - 1041
• Main Authors: Bona, A. Della, Anusavice, K.J., Mecholsky, J.J.
• Format: Journal Article
• Language: English
• Published: United States SAGE Publications 01-11-2006; SAGE PUBLICATIONS, INC
• Subjects: Acid Etching, Dental; Aluminum Silicates - chemistry; Analysis of Variance; Composite Resins; Dental Bonding; Dental Porcelain - chemistry; Dental Stress Analysis; Dentistry; Elasticity; Hardness; Linear Models; Lithium Compounds - chemistry; Materials Testing; Microscopy, Electron, Scanning; Pliability; Random Allocation; Resin Cements; Silanes; Silicon Dioxide; Surface Properties; Survival Analysis; Tensile Strength; Zirconium; structural reliability; fractography; Weibull modulus; fracture toughness; fracture
• ISSN: 0022-0345; 1544-0591
• DOI: 10.1177/154405910608501112

We suggest that the apparent interfacial fracture toughness (KA) may be estimated by fracture mechanics and fractography. This study tested the hypothesis that the KA of the adhesion zone of resin/ceramic systems is affected by the ceramic microstructure. Lithia disilicate-based (Empress2-E2) and leucite-based (Empress-E1) ceramics were surface-treated with hydrofluoric acid (HF) and/or silane (S), followed by an adhesive resin. Microtensile test specimens (n = 30; area of 1 ± 0.01 mm2) were indented (9.8 N) at the interface and loaded to failure in tension. We used tensile strength (σ) and the critical crack size (c) to calculate KA (KA = Yσc1/2) (Y = 1.65). ANOVA and Weibull analyses were used for statistical analyses. Mean KA (MPa·m1/2) values were: (E1HF) 0.26 ± 0.06; (E1S) 0.23 ± 0.06; (E1HFS) 0.30 ± 0.06; (E2HF) 0.31 ± 0.06; (E2S) 0.13 ± 0.05; and (E2HFS) 0.41 ± 0.07. All fractures originated from indentation sites. Estimation of interfacial toughness was feasible by fracture mechanics and fractography. The KA for the systems tested was affected by the ceramic microstructure and surface treatment.