Shear bond strength vs interfacial fracture toughness - Adherence to CAD/CAM blocks.

Autor: Ilie N; Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität, Goethestrasse 70, Munich, 80336, Germany. Electronic address: nilie@dent.med.uni-muenchen.de., Ruse ND; Biomaterials, Faculty of Dentistry, UBC, 2199 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada. Electronic address: dorin@dentistry.ubc.ca.
Jazyk: angličtina
Zdroj: Dental materials : official publication of the Academy of Dental Materials [Dent Mater] 2019 Dec; Vol. 35 (12), pp. 1769-1775. Date of Electronic Publication: 2019 Nov 02.
DOI: 10.1016/j.dental.2019.10.003
Abstrakt: Objective: To compare shear bond strength (SBS) and interfacial fracture toughness (IK IC ) results when assessing the effect of surface roughness and thermocycling on the adherence of a resin composite luting agent (RCLA) to a CAD/CAM resin composite block (RCB).
Methods: Tetric CAD HT along with the recommended bonding system, Adhese Universal and Variolink Esthetic LC, were used. Surface roughness was achieved with 600/320/60 grit SiC papers. Samples were stored 24h in 37°C water or thermocycled 10000× (5°C-55°C) prior to testing. Results were analyzed by univariate ANOVA and Scheffé modified t-tests (α=0.05). Fractured specimens were viewed with a stereo microscope and selected specimens with a scanning electron microscope.
Results: SBS results showed a significant difference between the 60 grit group and the other groups, both after 24h and thermocycling. A large number of SBS samples showed cohesive fracture or subsurface damage in RCB. Thermocycling led to a significant decrease in SBS in all groups. IK IC results showed no significant differences due to surface preparation after 24h storage in 37°C. After thermocycling, there was a significant difference between the 60 and the 600 grit groups. All K IC samples fractured adhesively at the RCB surface. K IC of the RCLA was significantly higher than IK IC of all groups.
Significance: The results endorse the use of fracture mechanics methodology for the assessment and characterization of adherence, while identifying difficulties in its implementation. The results suggest also that adherence to CAD/CAM RCB may be limited by the strength of the resin composite block - adhesive interface.
(Copyright © 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: