Bond strength of one-bottle dentin bonding agents on human dentin.

PURPOSE

To evaluate the shear bond strength of one-bottle dentin bonding agents (DBA's) (Prime & Bond 2.1, ART Experimental, Syntac Single Component) on pressurized human dentin.

MATERIALS AND METHODS

Freshly prepared dentin specimens of human teeth were perfused with horse serum which was diluted 1:5 in physiologic saline. Three different types of surface treatment were evaluated on the freshly prepared dentin. Group 1: One of the three one-bottle DBA's was applied onto freshly prepared dentin together with a cylinder of composite luting resin and cured. Group 2: A provisional cement (Freegenol, without eugenol, or Temp Bond, containing eugenol) was applied first on the dentin surface for 24 h. Only then was one of the three the one-bottle DBA's added onto the dentin together with a cylinder of composite luting resin after cleaning the dentin surface with pumice. Group 3: One of the three one-bottle DBA's was applied first on the dentin surface and light-cured. Then a provisional cement (Freegenol, without eugenol, or Temp Bond, containing eugenol) was added for 24 h. After cleaning with pumice, the respective one-bottle DBA was applied for a second time onto the dentin together with a cylinder of composite luting resin and light-cured. As control for Group 1 (freshly prepared dentin), the two- or three-step DBA's ART Bond and Syntac were used in a similar way. As control for Group 2 (single application of the DBA's after contamination of the dentin with a provisional cement) and Group 3 (dual application of the DBA's with intermediate contamination of the dentin with a provisional cement) the two-step DBA ART Bond was used. After 1500 thermal cycles with constant imitation of intrapulpal pressure, shear bond strengths were measured. Resulting shear bond strength values were displayed by means of a box plot and they were analyzed statistically by Student's t-Test or one-way ANOVA.

RESULTS

Lowest and highest mean shear bond strength values were 0.26 +/- 0.47 MPa (single use of ART Bond with prior application of Temp Bond) and 16.34 +/- 5.02 MPa (dual use of ART Bond with intermediate application of Temp Bond). With respect to the surface treatment significant differences between the DBA's could be found in all groups.