The Effect of Demineralization and Remineralization Cycles on the Bond Strength of Resin Composite to Enamel

Toothwear is a growing concern, particularly in young adults. Prevention strategies remain of utmost importance and may involve the use of remineralising agents. If restorative treatment is indicated, adhesive techniques are recommended. It is unknown whether remineralising agents affect adhesion. Method: 77 bovine incisors were subjected to simulated toothwear by erosion (0.3% citric acid) and abrasion (oscillating toothbrush). Samples were randomly arranged into 5 test and 2 control groups (n=11). Each test group had a remineralising agent applied. Subsequently, composite was bonded to each sample and subjected to shear bond testing. Shear bond strength, mode of failure and enamel surface changes were analysed. Results: There was no statistically significant difference for bond strength between groups (p=0.262). Mode of failure was statistically significant between groups (p<0.0001). Qualitative analysis showed a surface layer on samples remineralised by calcium silicate and stannous fluoride. Both groups had more adhesive failures. Conclusion: Within the limitations of this study, it can be concluded that the remineralising agents tested do not affect shear bond strength though surface layers created on the enamel influence the mode of failure. These ‘sacrificial’ surface layers have the potential to protect the underlying enamel structure.