[Study on adhesion mechanism of MMA-TBBO resin to dentin. A model experiment using decalcified dentin].

As a model experiment to understand the mechanism of adhesion of the MMA-TBBO resin to dentin, MMA-TBBO was polymerized using a decalcified dentin sheet treated with aqueous citric acid (CA) solutions of copper fluoride (CF), ferric fluoride (FF), or ferric chloride (FC), which are usually used as treating agents in the bonding of the resin to dentin. The curing time for MMA-TBBO resin was considerably reduced on the decalcified dentin sheet treated with FC-CA, CF-CA or FF-CA at an appropriate concentration. Polymerization of MMA-TBBO resin was accelerated in the presence of a fluoride ion. Molecular weight of PMMA depended on the site of polymerization; PMMA polymerization inside the decalcified dentin sheet gave the highest and that outside gave the lowest molecular weight in the presence of an appropriate amount of ferric or cupric ion. These results suggested that ferric compounds adsorbed to decalcified dentin are involved in the polymerization of MMA and thus will influence the bond strength of the MMA-TBBO resin to dentin.