Mese, AysePalamara, Joseph E. A.Bagheri, RafatFani, MehdiBurrow, Michael F.2024-04-242024-04-2420160287-4547https://doi.org/10.4012/dmj.2016-140https://hdl.handle.net/11468/19457This study compared the fracture toughness values of seven resin composites and analyzed the consistency of data values using three methods: compact tension, three point and four point bending for Mode I failure. Seven resin composites were selected: Estellite Sigma Quick, Esthet X HD, Filtek Supreme XTE, Heliomolar, Ice, Rok, and Vit-l-escence. For each material, 18 specimens (n=6 for each test) were prepared. Maximum load to failure was recorded using a universal testing machine and fracture toughness was calculated. There was a direct significant correlation among all tested methods. Rok showed the highest and Estelite the lowest K-Ic values. SEM of the fractured surface of compact tension method showed propagation of the cracks from stresses concentrating at the corner of the notch and the surface of the sample. Four-point test gave the largest range in K-Ic, and was a simple method to discriminate between the resin composite values of K-Ic.eninfo:eu-repo/semantics/openAccessFracture ToughnessFour-Point MethodThree-Point MethodCompact Tension MethodResin CompositeArticle356893899WOS:0003925565000092-s2.0-850010733712768003610.4012/dmj.2016-140Q1Q4