Several 1-bottle dentin adhesive resins have been introduced to the market; however, their shear bond strength still requires further investigation.This study was designed to evaluate the shear bond strength of five 1-bottle fifth generation dentin adhesive resin materials.Bond 1, Single Bond, One-Step, Prime & Bond 2.1, and Tenure Quick with fluoride were evaluated. Tenure All-Surface Bonding System, a fourth generation dentin adhesive resin, was used as the control group. Twelve specimens were prepared from each material, and the shear bond strength was measured by using a universal testing machine at a crosshead speed of 0.5 mm/min. Fracture patterns were studied with the use of light and SEM. The results were analyzed with the use of ANOVA.The mean shear bond strength for each resin was as follows: Bond 1: 18.36 +/- 3.19 MPa; Single Bond: 16.22 +/- 2.11 MPa; One-Step: 22.51 +/- 3.69 MPa; Prime & Bond: 16. 64 +/- 3.66 MPa; Tenure Quick: 16.43 +/- 3.2 MPa; and Tenure All-Surface Bonding System: 15.06 +/- 3.5 MPa. The shear bond strength values of One-Step dentin adhesive resin showed significant differences compared with the other 5 groups (P P>.1). Eighty percent or more of the specimens for each adhesive failed at the dentin/adhesive interface. An exception was Tenure All-Surface Bonding System in which all specimens failed at the dentin/adhesive interface.The 1-bottle systems tested bond to dentin with a strength similar to that of the control group. In addition, the shear bond strengths of 4 of the 1-bottle systems tested were not significantly different.