Abstract
Modification of tooth surfaces with metallic ion for tooth-bonding was investigated by treatments with chelating agent and metallic ion. Phytic acid (PYA) was used as a chelating agent and tin (II) fluoride (SnF2) was used as a source of metallic ion. The effects of these treatments were evaluated by the shear bond strength of Photo Bond® to bovine dentin and enamel.
The bond strength to dentin treated with 3〜10% solutions of PYA and then with saturated solution of SnF2 was in the range of 9〜10 MPa.These values were the same as that of dentin treated with K-etchant®(40%-phosphoric acid) and higher than 6〜7 MPa of dentin treated with PYA solutions only. The bond strength to enamel treated with 5 and 7% solutions of PYA and then with SnF2 solution was 16 and 18 MPa, respectively. These values were higher than that 14 MPa of enamel treated with K-etchant and 11 MPa of enamel treated with PYA solutions only. The bond strength to dentin and enamel treated with PYA and SnF2 solutions was maintained after 3, 000 thermo-cycles (4-60℃). Innumerable spherical deposits, which were suspected to be chelate compound of PYA and Sn2+, were observed on the dentin surface treated with PYA and SnF2 solutions. From these results, it was suggested that the interaction between the functional monomer, MDP, contained in Photo Bond and Sn2+ contributed to the bonding.
