[Effect of fluoride releasing composite resin on bovine enamel].

FluorEver is one kind of fluoride releasing composite resin. The first aim of this study was to investigate the amount of fluoride released from FluorEver. The second aim of this study was to determine the uptake of fluoride with bovine enamel, which was immersed in distilled water for 28 days in contact with FluorEver, compared with Fuji Ionomer cement which released fluoride. The results obtained were as follows. 1) A great amount of fluoride was released from FluorEver immediately after immersion. Twenty-four hours after immersion, the amount of released fluoride decreased quickly. From the 3rd day of immersion, the amount of fluoride released decreased gradually. The fluoride could be detected on the 28th day. 2) The amount of fluoride released from FluorEver was almost directly proportional to the volume of FluorEver blocks used. 3) The uptake of fluoride on enamel in contact with FluorEver was significantly high. 4) The release pattern of the fluoride of Fuji Ionomer was similar to that of FluorEver. The amount of fluoride released from Fuji Ionomer was greater than that of FluorEver immediately after immersion. However, from the 7th day of immersion, that of Fuji Ionomer was less than that of FluorEver. 5) The uptake of fluoride from FluorEver on the surface enamel was less than that of Fuji Ionomer. However, the uptake of fluoride from FluorEver on the subsurface enamel was greater than that of Fuji Ionomer.