Flexural strength of composites: influences of XXXX fiber reinforcement and type of composite.

@entity691 @entity174
MAIN PROBLEM: The microfill veneering of hybrid composite restorations has been indicated to improve esthetics. Also, @entity691 fiber reinforcement has been proposed for use in composite restorations in high-stress clinical situations. However, minimal information in the literature addresses the influence of such combinations on the resistance to @entity174 . The purpose of this study was to investigate the flexural strength of two composites, a microfill and a hybrid, the effect of their combination, and the influence of @entity691 fiber reinforcement. MATERIALS AND METHODS: Twenty-eight specimens were prepared using a standard metallic mold (20x2x2 mm) and divided into groups of seven each: Filtek Z-250 (3M ESPE, St. Paul, Minn., USA) (group I), Filtek A-110 (3M ESPE) (group II), Filtek Z-250 combined with Filtek A-110 (group III), and Filtek Z-250 combined with @entity691 fiber (Ribbond, Seattle, Wash., USA) (group IV). The specimens were stress-loaded to @entity174 in a three-point bending device according to International Standardization Organization (ISO) 4049. RESULTS: Data were analyzed using analysis of variance and Tukey's test at a 0.05 level of significance. No statistically significant differences were observed between groups I and IV. Group II, however, exhibited statistically lower resistance to @entity174 than the other groups. Group III presented intermediate results, showing statistically higher @entity174 resistance than group II but lower than group I. CONCLUSIONS: With the methodology employed, microfill composite presented the lowest flexural strength, but its association with hybrid composite increased the resistance to @entity174 . The combination of @entity691 fiber and hybrid composite did not present higher flexural strength than hybrid composite alone.
