Background: Bond stability relies on the mechanical characteristics of dentin collagen fibers. Proanthocyanidin (PA) has the ability to enhance dentin stiffness by stimulating collagen crosslinking.
Objectives: The study was conducted to measure the effect of 6.5% PA on the dentin shear bond strength of resin-modified glass ionomer cement (RMGIC) and composite resin and to evaluate its effect on the dentin bonding interface by scanning electron microscopy (SEM).
Materials and Methods: Twenty-four primary teeth were collected, randomly and equally allocated into 2 groups according to the pre-treatment of dentin: Group I (study): Dentin was pretreated with 6.5% PA before applying the restorative materials, and group II (control): Dentin was not pretreated with 6.5% PA. The teeth were divided equally and restored with either RMGIC or composite. Each sample was subjected to universal testing machine to measure shear bond strength. Then the debonded area was then examined under a stereomicroscope to assess mode of failure. Additionally, sixteen teeth were collected for assessment of the bonding interface by SEM.
Results: Regarding the shear bond strength, there was no statistically significant difference detected in the application of PA compared to the control group using both restorative materials, while there was a statistically significant difference found between the different tested restorative materials. Regarding the mode of failure assessed in the fractured specimens, mixed and adhesive failure patterns were predominantly observed in all groups, with no significant difference observed between them.
Conclusion: PA did not compromise the dentin shear bond strength of composite resin and RMGIC.