[Influence of eugenol-containing temporary cement on efficacy of dentin-bonding systems].

Objective: This study investigated the influence of eugenol-containing temporary cement on the efficacy of two relatively new dentin-bonding systems.

Methods: Thirty-two freshly extracted bovine central incisors were randomly divided into four groups. Dentin was exposed and polished with 320#, 400#, and 600# sand papers. After embedded, Group 3 and 4 specimens were covered with ZOE. Specimens in Group 1 and 2 were served as control. All specimens were stored for 1 week in distilled water at 37 degrees C. Then, the ZOE was mechanically removed. The dentin surfaces of Group 1 and 3 were treated with Prime & Bond NT bonding system and the dentin surfaces of Group 2 and 4 were treated with GLUMA adhesive system according to manufacturer's instructions. Thereafter composite resin columns (6 mm diameter, 2 mm high) were applied. After specimens stored in distilled water at 37 degrees C for 24 hours, the shear bond testing was carried out using a SHIMADZU universal testing machine with a cross-head speed of 0.5 mm/minute. The mode of failure was examined using SEM. The data were analyzed using ANOVA test at a significance level of 0.05.

Results: The medians of shear bond strength for each group were as follows: Group 1 (Prime & Bond NT) 9.57 MPa, Group 3 (Prime & Bond NT + ZOE) 10.72 MPa, Group 2 (GLUMA) 16.89 MPa, Group 4 (GLUMA + ZOE) 16.78 MPa. Group 1 and 3 had significantly lower bonding strength than did Groups 2 and 4. But no significant difference was found between the control groups and the groups treated with ZOE temporary cement.

Conclusion: Pretreatment of the dentin with ZOE temporary cement has no adverse influence on the efficacy of two relatively new dentin-bonding systems.