Aim: The purpose of this study was to evaluate the wear resistance of paste-like bulk-fill composite resins and conventional paste-like composite resin after simulated mastication.

Materials and Methods: The in vitro 2-body wear resistance of 6 dental composite materials was assessed and compared with the wear resistance of human enamel. Five paste-like bulk-fill composite materials [Filtek Bulk Fill Posterior Restorative-FBR (3M Dental Products. St. Paul, USA), x-tra fill-XTF (VOCO GmbH, Cuxhaven, Germany), Sonicfill-SCF (Kerr Corp. , Orange, USA), Admira Fusion X-tra-AFX (VOCO GmbH, Cuxhaven, Germany), Tetric EvoCeram Bulk Fill-TEB (Ivoclar Vivadent AG. , Schaan, Liechtenstein), and one conventional paste-like composite [Clearfil Majesty Posterior-CMP (Kuraray Noritake Dental Inc. , Okayama, Japan) ] as control, were used. Bulk-fill composite materials were applied as one layer and conventional composites were applied as two horizontal layers into the cylindrical teflon molds (height: 4 mm, diameter: 4 mm and each layer was cured with a LED unit (SDI Radii Plus, SDI Limited, Australia) according to the manufacturers’ instructions. Specimens were subjected to a wear test in a dual axis chewing simulator (Esetron chewing simulator, Ankara, Turkey) with load at 1.6 Hz for a total of 120, 000 chewing cycles. Subsequently, samples were scanned using a CAD/CAM three-dimensional scanner (Trios 4,3Shape, Copenhagen, Denmark). Wear volume of specimens calculated by MeshLab (v2021.07) software. Mean and standard error (SE) of surface loss volume analyzed using one-way analysis of variance (ANOVA) with a significance level at p < 0.05.

Results: The mean wear volume (mm3) and standard errors of tested materials were FBR (0,3465-0,1103), XTF (0,9879-0,1479), SCF (0,4989-0,1339), AFX (0,9040-0,1694), TEB (0,8167-0, 06822), CMP (0,6472-0,1542) and enamel (0,1466-0, 02155). There was significant difference between tested specimens (p<0, 05).

Conclusion: Wear resistance of paste-like bulk-fill composite resins were significantly different. When compare with enamel; FBR, CMP, SCF were more resistant to wear then other paste-like bulk-fill composite resins.