Immediate Bond Strength of Seventh Generation Dentin Adhesives

Objectives: The purpose of this study was to evaluate the immediate bond strength of two sixth generation and two seventh generation dentin bonding agents to superficial dentin.

Methods: 24 recently extracted human molars were embedded in acrylic resin and polished using a 600 grit SiC paper until superficial dentin was exposed. Teeth were divided into four groups (n=6) each group received either Clearfil SE (CSE), Clearfil S3 (CS#3, Adper Prompt-l-pop (A-Pop) or G-bond (GB) on the dentin surface, following manufacturer's instructions before the dentin adhesive was light cured for 20 seconds. Then composite resin Z-100  was applied over the treated surface using the "Ultradent jig" and light-cured in two increments. All specimens were stored at 23¼ C at room humidity of 45%, before being tested, 15 minutes after they were made, for shear bond strength at 0.01 cm/min in an universal testing machine (Tinius Olsen H10k-S). Data were stored in MPa and analyzed using a one way analysis of variance calculated at 0.05 significance level. Tukey-Kramer interval for comparison of means was 11.3 also calculated at 0.05 significance level.

Results: CSE had statistically higher bond strength than the other three adhesives evaluated (42.9 MPa). There was no statistical difference among CS3, A-Pop and GB. Of all the materials studied, CSE requires that an acidic primer is placed over dentin first before applying the adhesive, the other three, have all components applied at the same time.

	Clearfil SE	G-Bond	Prompt-l-pop	Clearfil S3
MPa	42.9 (6.5)	27.2 (4.3)	31.5 (10.0)	27.9 (6.1)

Conclusion: The dentin adhesive with an application of an acidic primer before the application of the adhesive showed better immediate bond strength.