Bond strength of resin to dentin treated with calcium phosphate desensitizer.

In a previous study we proposed a new method utilizing immediate precipitation of calcium phosphate (CaP) in situ for treatment of dentin hypersensitivity. Sequential application of 5% disodium phosphate followed by 10% calcium chloride on patent dentin surface resulted in instant occlusion of dentin tubules and immediate relief from the hypersensitivity. To guarantee long-lasting effectiveness of the CaP treatment, resin coverage of the treated dentin surface will be the next practical approach. However, the CaP covering the surface may possibly affect bonding of resins. This study determined the effect of the CaP treatment on tensile bond strength of adhesive resins to dentin. Independent of the type of resin used, a bond strength of 4-5 MPa was obtained; cohesive failure occurred within the resin-CaP hybridized composite layer rather than at the dentin surface. The CaP treatment produced a significant increase in the bond strength of one resin.