Objective      To determine the fluoride release and recharge of 4 different types of fluoride-containing pit and fissure sealants in vitro.     Methods      Fuji VⅡ

FujiⅡLC

Fissurit F and Teethmate F-1 were used to investigate fluoride release and recharge. Disk-shaped specimens were prepared from each material. Specimens were stored in a polyethylene test tube containing 5.0 ml ultrapure water. On day 21

specimens were exposed to 1.23% APF gel. Fluoride release was measured using a fluoride-specific ion electrode at days 1 to 7

14

21

22

28

35 and 42 respectively.     Results      The glass-ionomer sealants Fuji VⅡ had the highest fluoride release

and resin-modified glass-ionomer cement FujiⅡLC had the highest fluoride recharge

but Fissurit F had the lowest recharge. The glass-ionomer based sealants had significantly higher fluoride release than the other materials at all times tested (P0.05). Fluoride release of all materials tested was increased following exposure to 1.23% APF gel (P0.05).     Conclusion      In this short-term study of 6 weeks

glass ionomer-based sealants Fuji VⅡ and FujiⅡLC have higher initial fluoride release as well as higher fluoride recharge than other sealants.