Comparison of The Mechanical Properties for Fiber Reinforced And Bulkfill Composites

Abstract

purpose: To assess and compare specific mechanical characteristics including ; flexural strength (FS), fracture toughness (FT) and diametral tensile strength (DTS) of two short fiber reinforced composites formulation (SFRCs) (everXPosterior and everXFlow , GC Corporation ,Tokyo, Japan)  with one of  conventional bulkfill composite (CBF) (Tetric R N-Ceram, Ivoclar Vivadent AG, Schaan, Liechtenstein). Methods: The properties investigated were flexural strength (FS), fracture toughness (FT), and diametral tensile strength (DTS) following ISO standards. For each investigated test the prepared specimens were divided in to three groups, G1 were fabricated from conventional bulkfill composite (TetricR N-Ceram, Ivoclar Vivadent AG), G2 were fabricated from SFRCs (everXPosterior, GC Corp) and G3 from SFRCs (everXFlow, GC Corp).  Consequently, they were incubated in distilled water at 37˚C for 24 h before operating the mechanical tests. The specimens were assessed in a universal material testing machine at 1.0 mm/min crosshead speed until failure. The data were be statistically evaluated with SPSS (Statistical Package for Social Science Ver.25) using Analysis Of Variance (ANOVA) followed by a Tukey HSDa test to define the differences between the tested groups. Results: The SFRC everXPost. and  everXFlow exhibited significantly higher flexural strength (100.2 MPa, 99.1 MPa) and fracture toughness (1.23 MPa m1/2 , 1.16 MPa m1/2,) values respectively than bulk fill conventional composite (TetricR N-Ceram)( 58.2 MPa, 0.6 MPa m1/2). The DTS of everXFlow was statistically superior (54.3 MPa) than the everXPost. composite (44 MPa) and conventional bulkfill (TetricR N-Ceram) composite (37.3MPa). Conclusion: According to the obtained results the SFRCs everXPost. and everXflow showed better mechanical properties than conventional bulkfill composite and could be applied well in posterior restorations