Light-curable dental composites are, nowadays, the most frequently used restoratives as a replacement of lost hard dental tissues (Asmussen & Peutzfeldt, 1998). This is due to noticeable advantages of polymeric composites over amalgams, such as biocompatibility, handling, inexpensive and teeth colour, that are making them more appealing and widely used dental materials. A dental resin-composite is made of an organic matrix and filler system, in which the resin part consists of multifunctional methacrylate, a dimethacrylate diluent and a photo-initiating system, and dispersed fillers that can be modified to get improved and designed mechanical properties and wear resistance (Amirouche-Korichi, Mouzali, & Watts, 2009; Fugolin & Pfeifer, 2017). Based on dental composition, shrinkage of the restorative, residual stress and gap formation mainly relate to the organic matrix; however, mechanical and tribological properties are considerably depend on filler composition, content and shape (Feng, Suh, & Shortall, 2010; Lawson & Burgess, 2015). Lohbauer et al. investigated the strength and fatigue performance of three types of dental restoratives as flowable, aesthetic hybrid and nanofilled hybrid composites validating highly dependence of elastic modulus and fatigue life on filler content, specifically for flowable resins as compared with others (Lohbauer, Frankenberger, Krämer, & Petschelt, 2006). Filler shape influence on elastic modulus, fracture toughness and bending strength was investigated by Kim et al. showing all properties increased with elastic modulus having a higher rate based on the content of the spherical filler (Kim, Park, Imai, & Kishi, 1994). Similar results showed that increasing fillers improve mechanical properties like wear resistance, fatigue resistance and flexural strength that are essential for the long durability of restorative materials (Htang, Ohsawa, & Matsumoto, 1995). Increasing the wear resistance of restorative resins is an important parameter, which increases their lifespan. Occlusal interactions are the main cause of wear, and material loss in dental restoratives, which if not controlled, could impair masticatory function, and impose possible decline of systemic health (Miura et al., 2000; Watts,

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