Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 20 0 2023 05 03 1 7 Fateme Azizi Dental Materials Research Center, Department of Operative Dentistry, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran Fariba Ezoji Dental Materials Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, IR Iran Soraya Khafri Department of Social Medicine and Health, Faculty of Medicine, Babol University of Medical Sciences, Babol, Iran Behnaz Esmaeili Dental Materials Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, IR Iran 2021 08 31 2023 02 12 Objectives: The durability of composite restorations is directly affected by the mechanical properties of the composite. The aim of this study was to evaluate the hardness and wear resistance of self-adhesive flowable composite (SAF) in comparison with conventional flowable composites. Materials and Methods: In this in vitro study, 50 composite specimens were prepared in brass molds with 10mm ×10mm ×2mm and divided into five groups (n=10). Specimens included three conventional flowable composites (Grandio flow, Filtek flow and Admira fusion flow), one self-adhering flowable composite (SAF, Vertise flow) and a microhybrid composite (filtek z250). After polishing, the micro-hardness of the specimens was measured in a Vickers hardness device, and the specimens were then subjected to 5000, 10000, 20000, 40000, 80000 and 120000 wear cycles in a wear tester. One-way ANOVA/Games-Howell, Kruskal Wallis, and Friedman tests were used for statistical analysis. The significance level was set at P<0.05. Results: The surface micro-hardness of the SAF was significantly lower than that of the microhybrid composite (P=0.01). There was no significant difference between the surface hardness of the different tested flowable composites (P>0.05). Also, the wear resistance of the studied composites was not significantly different in various cycles (P>0.05). Conclusion: Based on our results, SAF would not be an ideal substitute for conventional flowable composites in high-stress areas. https://fid.tums.ac.ir/index.php/fid/article/view/4166