[Adhesion of 4-META/MMA-TBB resin to dentin treated with EDTA metal ammonium solutions. Effect of Fe.NH4, Co.NH4 or Cu.NH4 salts].

EDTA metal ammonium salt solution containing Fe3+, Co3+ or Cu2+ was studied to determine the pretreatment reagent that causes no denaturation of dentin collagen and promotes good adhesion to dentin. After application of EDTA 3-2 (Fe.NH4), EDTA 3-2 (Co.NH4) or EDTA 3-2 (Cu.NH4) at pH 7.4 on the dentin surface, the amount of Ca2+ demineralized and the tensile bond strength were measured. The pretreated dentin surfaces were also observed with SEM. No correlation was obtained between the amount of Ca2+ demineralized and the tensile bond strength. On the EDTA 3-2 (Fe.NH4) treated dentin a small amount of smear remained partially, but the tensile bond strength of 4-META/MMA-TBB resin to the dentin was higher than 13 MPa. This indicates that complete removal of the smear on dentin is not always necessary for better bonding.