Tiu J, Belli R, Lohbauer U (2021)
Publication Type: Journal article
Publication year: 2021
Book Volume: 37
Pages Range: 477-485
Journal Issue: 3
DOI: 10.1016/j.dental.2020.12.002
OBJECTIVE: Short fiber reinforced composites (SFRC) require a veneering layer of conventional composite when used as restorations in the oral environment. The current study investigates the toughening effects during the path of a preexisting crack propagating through the bilayer system as it confronts the interface, through the attempted alignment of fibers and matrix-fiber interactions in the SFRC, and the distance it travels in the SFRC. METHODS: Bilayer systems of SFRC and conventional composite were produced with aligned fibers perpendicular to load direction. Single-edge-notched bend (SENB) specimens (25 × 5 × 2.5 mm3) with pre-crack length (a) to width (W) ratios (a/W = 0.2-0.8) were produced and tested in 3-point bending configuration until complete fracture. The specific work of fracture (we) was deduced from calculating the area under the load-displacement curves. Fiber alignment was digitally evaluated from images taken from the top and side planes of the specimen. RESULTS: The toughness of the bilayer system is optimal when maximum SFRC thickness is used. EWF methods showed toughness and increasing nonessential work of fracture scaling with ligament length. A longer distance is accompanied by a higher distribution of aligned fibers bridging behind the crack wake, reducing crack driving forces at the crack tip. SIGNIFICANCE: SFRC materials provide increasing toughening potential with increasing thickness, and have the ability to be more anisotropic than other composite materials. Clinically, the layer must have a conventional composite cover layer, but which thickness does not affect toughness potential. Therefore the thickness of the conventional composite can be dictated by wear behavior.
APA:
Tiu, J., Belli, R., & Lohbauer, U. (2021). Thickness influence of veneering composites on fiber-reinforced systems. Dental Materials, 37(3), 477-485. https://doi.org/10.1016/j.dental.2020.12.002
MLA:
Tiu, Janine, Renan Belli, and Ulrich Lohbauer. "Thickness influence of veneering composites on fiber-reinforced systems." Dental Materials 37.3 (2021): 477-485.
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