Fluoride-releasing materials can be expected to inhibit secondary caries and enhance remineralization of decalcified dentin underneath restorations. The aim of this study was to evaluate the inhibitory effect on secondary caries and remineralization of decalcified dentin by fluoride-releasing adhesives. Two commercial fluoride-releasing adhesives, Reactmer bond (RB, Shofu) and One-up bond F (OB, Tokuyama), and a commercial adhesive without fluoride release, Mac-bond II (MB, Tokuyama), were used in this study. For examination of the inhibitory effect, class V cavities were prepared on extracted human premolars and restored with a restorative material following the application of each adhesive. The restored teeth were incubated in bacterial medium for 14 days after storage for 14 days at 37°C, 100% humidity. For examination of remineralization of decalcified dentin, decalcified dentin was promoted by using a bacterial caries induction system at the cavity wall. The cavities were then restored with resin composite after application of each adhesive and incubated for 4 weeks at 37°C, 100% humidity. Microradiographs in the inhibitory test showed an acid-resistant layer adjacent to the restoration in the caries-like lesions. The acidresistant layers in the RB and OB groups with fluoride release were thicker than that in the MB group. Microradiographs in remineralization tests showed that the radiopacities of the decalcified dentin layers in the RB and OB groups were significantly higher than that in the MB group without fluoride release. These results indicated that fluoride-releasing adhesives are effective in inhibiting wall lesions and in enhancing the remineralization of decalcified dentin.