Effects of the desensitizing agents Gluma and Hyposen on the tensile bond strength of dentin adhesives.

Purpose: To evaluate the influence of two desensitizers (Gluma Desensitizer and Hyposen) on the tensile bond strength of three different dentin adhesives.

Methods: 90 freshly extracted third molars were specially prepared to allow simulation of dentin perfusion. The specimens were divided at random into nine groups: Group AC: Clearfil New Bond/Clearfil Core; Group AX: Xeno III/Tetric Flow; Group AA: AdheSE/Tetric Flow; Group BC: Gluma/Clearfil New Bond/Clearfil Core; Group BX: Gluma/Xeno III/Tetric Flow; Group BA: Gluma/AdheSE/Tetric Flow; Group CC: Hyposen/Clearfil New Bond/Clearfil Core; Group CX: Hyposen/Xeno III/Tetric Flow; Group CA: Hyposen/AdheSE/Tetric Flow. Tensile bond strength of the above mentioned bonding agents was measured using a universal testing machine.

Results: The following tensile bond strengths were obtained (mean values and standard deviations in MPa): Group AC: 11.05 +/- 1.92, Group AX: 6.01 +/- 1.35, Group AA: 8.91 +/- 1.20, Group BC: 10.25 +/- 1.44, Group BX: 7.17 +/- 1.24, Group BA: 10.35 +/- 1.26, group CC: 8.11 +/- 0.70, Group CX: 8.03 +/- 1.20, Group CA: 9.22 +/- 1.75. Statistical analysis showed a significant influence of the variable, dentin bonding agent on tensile bond strength (ANOVA, Tukey's, P < 0.05). Treatment with Hyposen in combination with Clearfil New Bond resulted in significantly lower bond strength values. Gluma had no significant influence on bond strength of the three adhesive systems. Within the limitations of an in vitro investigation it can be concluded that Gluma did not significantly affect the bond strength of any of the adhesive systems tested. Hyposen significantly decreased the bond strength values of Clearfil New Bond.