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

METHODSThirty-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.

RESULTSThe 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.

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