Microtensile Bond Strength of Seven Self-Etch Adhesives to Dentin

Objectives: This in vitro study compared the dentin bonding performance of seven self-etching bonding systems by using the microtensile bond strength testing method. Methods: 35 extracted human non-carious third molar teeth were used in the study. 4 two-step (Clearfil SE Bond, Tyrian SPE&One Step Plus, Fluorobond, Protect Bond) and 3 one-step self-etch systems (Xeno III, Reactmer Bond, AQ Bond) were evaluated. Each bonding system was applied according to the manufacturers' instructions and Clearfil AP-X composite blocks (5 mm height) was applied on to whole occlusal dentin surfaces. Immediately after bonding, the teeth were prepared for microtensile testing. Bond strength to dentin was measured using a universal testing machine at a crosshead speed of 1.0 mm/min. The mean microtensile bond strength for each material was calculated from the values obtained with 25 slices and expressed in MPa. Mann Whitney-U test was used for statistical analyzes. Results: Clearfil SE Bond exhibited significantly (p<0.05) higher bond strength values (38.56±5.61 MPa) than all other materials. The bond strengths of other materials were (from highest to lowest): Tyrian SPE&One Step Plus (26.71±4.12 MPa); Xeno III (25.12±5.04 MPa); Reactmer Bond (24.27±4.67 MPa); ABF Bond (Protect Bond) (23.88±6.93 MPa); Fluorobond (23.37±4.63 MPa); AQ Bond (12.13±2.23 MPa). Among these six materials there were no statistically significant differences except for AQ Bond. Conclusions: Although Clearfil SE Bond, a two-step self etch system, showed the highest bond strength to dentin among the groups. It can not be concluded that the two step self-etch systems are more effective than the one-step self-etch systems. Because there were not any significant differences among the other self etch systems except for AQ Bond.