Microshear Bond Strength of Silorane Composite to Dentin with Additional Application of Enamel Bonding

Objectives: To evaluate microshear bond strength of a silorane-based composite to different dentin bondings, half of which covered with a layer of enamel bonding; to assess the correlation between bond strengths and theta angles of bondings.
Methods: 108 Flat dentin specimens were prepared and randomly divided to 6 groups with attention to application of following bondings: Group 1) Single bond, Group 2) SE bond, Group 3) Silorane system adhesive bond, Group 4) Single bond + Margin bond, Group 5) SE bond + Margin bond, and Group 6) Silorane primer + Margin bond. Filtek P90 composits (Silorane) were attached to the bonding surfaces. Applying microshear testing machine, forces were inserted at the speed of 1mm/min. Moreover, the water contact angles on the surface of dentin bondings were evaluated using ImageJ software. Data of microshear bond strength and theta angles were analyzed using one-way ANOVA and Tukey HSD tests and the correlation between them was evaluated by Pearson correlation coefficient.




Results: Silorane system adhesive (Group 3) demonstrated the most powerful bond strength; however, this difference was not significant comparing to other groups except Group6. There was significant difference among the groups for contact angle measurement (P<0.001). Nevertheless, Pearson correlation coefficient showed a weak negative correlation (P=0.296) between bond strengths and contact angles.
Conclusions: Filtek P90 can have acceptable bond strengths with some dissimilar adhesives. Margin bond does not affect the bond strengths. There is no clear correlation between theta angle of the adhesives and the bond strength to Filtek P90.