Lassila L, et al. - In this study, researchers assessed the impact of the short glass-fiber/filler particles proportion on the fracture toughness (FT) and flexural strength (FS) of an experimental flowable fiber-reinforced composite (Exp-SFRC) with two methacrylate resin formulations. They also investigated how the fracture-behavior of composite restorations was affected by FT values of SFRC-substructure. They concluded that flowable composite resin could be significantly reinforced by the short glass-fibers and the FT value of SFRC-substructure had prior importance, as it impacted the crack arresting mechanism.