Improvements have been made with each successive generation of dentin bonding agents. Objective: The aim of this in vitro investigation was to compare two current total-etch adhesive systems (Optibond Solo Plus and Single Bond), with their corresponding self-etch adhesives (Optibond Solo Plus Self Etch and Prompt L-Pop) using shear bond strength testing. Methods: Forty extracted non-carious third molar teeth were randomly assigned to 4 treatment groups (n=10), mounted in phenolic rings with acrylic resin and ground flat on the occlusal surface to expose dentin. A 5-mm diameter cylinder of resin composite (Point 4) was bonded according to manufacturer’s instructions to the exposed dentinal surfaces with each of the adhesives (n=10). Specimens were placed in a 37° C water bath for 24h hours and then subjected to a shear test to failure using an Instron Universal Testing Machine at a crosshead speed of 0.5 mm/min. Data were analyzed by ANOVA and Tukey HSD (a=0.05). Results: A significant difference was determined among the adhesives. O (8.14 MPa) yielded statistically higher shear bond strengths than both self-etch systems; Op (5.32 MPa) and P (2.88 MPa). In addition, a significant difference between the shear bond strength values for S (6.14 MPa) and P (2.88 MPa) was also determined. Conclusion: In conclusion, in vitro results showed a decrease in dentin bonding strength in composite restorations with the self-etch adhesives compared to their total-etch counterparts. Supported in part by Kerr Corp.