Fiber-reinforced composite substructure: load-bearing capacity of an onlay restoration and flexural properties of the material.

Original article


Garoushi SK, Lassila LV, Tezvergil A, Vallittu PK.

Institute of Dentistry, University of Turku, Finland.

J Contemp Dent Pract. 2006 Sep 1;7(4):1-8.


Aim: The aim of this study was to determine the static load-bearing capacity of composite resin onlay restorations made of particulate filler composite (PFC) with two different types of fiber-reinforced composite (FRC) substructures. In addition, flexural properties of the material combination and the effect of polymerization devices were tested. Methods And Materials: Specimens were prepared to simulate an onlay restoration, which consisted of 2 to 3 mm of FRC layer as a substructure (short random and continuous bidirectional fiber orientation) and a 1 mm surface layer of PFC. Control specimens were prepared from plain PFC. In Group A the specimens were incrementally polymerized only with a hand-light curing unit for 40 s, while in Group B the specimens were post-cured in a light-curing oven for 15 min before they were statically loaded with a steel ball. Bar-shaped test specimens were prepared to measure the flexural properties of material combination using a three-point bending test (ISO 10477). Results: Analysis of variance (ANOVA) revealed all specimens with a FRC substructure have higher values of static load-bearing capacity and flexural properties than those obtained with plain PFC (p<0.001). Conclusion: The load-bearing capacity of all the specimens decreased after post-curing and water storage. Restorations made from a material combination of FRC and PFC showed better mechanical properties than those obtained with plain PFC. Keywords: Fiber-reinforced composite, FRC, load-bearing capacity, flexural properties, posterior composite restorations Link/DOI: