Abstract
Several new monomers which are effective to give adhesion to tooth substrates have been discussed based on the concept that monomers with hydrophobic and hydrophilic groups have biocompatibility with the tissues and promote the interpenetration of monomers into the substrates. The bond strength between dentin treated with 10 % citric acid and 3 % ferric chloride and 4-META/MMA-TBB resin was 18 MPa, but it decreased to 6 MPa when dentin was etched with phosphoric or citric acid. Ferric chloride in citric acid prevents the denaturation of collagen during the demineralization. Control of the higher structure of collagen is very important to get good bond to the dentin. The monomers interpenetrated into dentin or enamel and polymerized was confirmed by SEM observation on partially demineralized specimen of the bonded tissue. A HCl insoluble dentin or enamel band modified by the interpenetration in the subsurface of the tissue was identified. The band is a resin reinforced dentin or enamel and has better resistance against decalcification than the original. The band is a hybrid of natural tissues with biocompatible artificial materials.
