The micro-shear bond strength of resin cements to aged laser bleached enamel after using different desensitizing agents.

OBJECTIVES

To evaluate the micro-shear bond strength of two resin cements to aged laser bleached enamel after the application of three different desensitizing agents.

MATERIALS AND METHODS

Forty extracted human central and lateral incisors were prepared and bleached using laser activation bleaching protocol. The teeth were assigned randomly into four groups for desensitization; G1: No post-bleaching treatment, G2: GC MI Paste Plus, G3: Hydroxyapatite nanoparticles (n-HAP) and G4: Flor-Opal. Specimens were subjected to aging for 6 months. All groups were subdivided into two subgroups according to the resin cements used (dual-curing resin cement and light-curing resin cement).

RESULTS

Flor-Opal groups showed the highest statistically significant micro-shear bond strength (MSBS), followed by GC MI Paste Plus and n-HAP groups with no statistically significant difference between them. The light-curing resin cement had statistically higher MSBS than dual-curing resin cement in case of no-post bleaching treatment and n-HAP groups, and no statistical difference in case of GC MI Paste Plus and Flor-Opal groups.

CONCLUSION

Usage of desensitizing agents containing, CPP-ACP, n-HAP or fluoride after laser bleaching can enhance the bond strength of the resin cements to enamel.

CLINICAL SIGNIFICANCE

The composition of the desensitizing agents applied after laser bleaching could interfere in bond strength values.