BackgroundThe calcium fluoride-like material deposited on the enamel surface is important as a fluoride reservoir. Elevated temperatures significantly increase the acquisition of KOH-soluble fluoride on sound tooth surfaces in vitro. MethodsWe investigated the efficacy of warmed APF solution on remineralization of subsurface enamel lesions, both in vitro and in situ. Hardness recovery was measured every week for 4 weeks to assess remineralization efficacy, and the behavior of fluoride release from sound and demineralized enamel with APF solution applied at 25 °C and 50°C was compared. ResultsApplication of APF to enamel at 50 °C showed a significantly greater degree of F− release up to 18 h than the 25 °C group in sound specimens and up to 48 h in demineralized specimens. Moreover, longer-lasting and greater amounts of F− release were observed in demineralized specimens versus sound specimens. The profiles of changes in hardness over time in vitro and in situ showed that the hardness was significantly greater in the 50 °C group than in the 25 °C and control groups at all measurement points and the mean value of the hardness recovery in the 25 °C and 50 °C groups was observed by 2 weeks, although a significant increase was only noted from baseline to 1 week in the 25 °C group. Overall, the recovery of hardness was inadequate, compared to the original enamel. ConclusionIn conclusion, application of the warmed APF solution to the demineralized enamel lesion showed potential to increase the fluoride release and enhance the rate of remineralization than that at 25 °C.
Read full abstract