[Effect of fluoride of copper and iron on polymerization of MMA/TBBO resin and adhesion to dentin].

As a model experiment to understand the mechanism of adhesion of the MMA/TBBO resin to dentin, polymerization of MMA/TBBO was investigated in the presence of a collagen sheet treated with the aqueous citric acid (CA) solutions of copper fluoride (CF), ferric fluoride (FF), or ferric chloride (FC), which is usually used as a treating agent in bonding of the resin to dentin. The curing time of MMA/TBBO resin was considerably reduced in the presence of collagen treated with CF-CA or FF-CA solutions when compared to that with FC-CA solution. Molecular weight of PMMA depended on the site of polymerization; PMMA polymerized inside the collagen sheet was the highest and that polymerized outside was the lowest. Bond strength to dentin treated with CF-CA, FF-CA solutions was as strong as that treated with FC-CA solution. Treatment of dentin with CF-CA or FF-CA was as effective as that with FC-CA in bonding the MMA/TBBO resin. These results suggested that ferric compounds adsorbed to collagen are involved in polymerization of MMA and thus influence bond strength of the MMA/TBBO resin to dentin.