[Physiological remineralization of artificially decalcified monkey dentin under adhesive composite resin restoration]

This study was planned to investigate the remineralization potential of the inner carious dentin layer preserved under adhesive resin restoration in comparison with that under cement filling. Dentin caries models were artificially produced in vivo with acid on the Class V cavity floors of 25 bilateral tooth pairs from 3 monkeys. Thirteen cavity pairs were filled with adhesive composite and twelve pairs with polycarboxylate cement, 120 days and immediately before sacrificing the monkeys. The sections through the floor dentin layer were examined by an optical microscope, Knoop hardness tester, EPMA and SEM. The findings obtained were as follows: 1. Two different dentin layers were recognized on the decalcified floor dentin. 2. The outer highly decalcified layer of about 100 microns thickness was not found to be remineralizable in vivo. 3. The inner partially decalcified layer of about 80 microns thickness was proved to be physiologically remineralizable even under adhesive resin restoration, having the possible irritation of acid-etching or resin monomers. 4. Increase in the Ca content in the inner decalcified layer under resin restoration observed after 120 days was more remarkable than that under cement.