Preliminary study of factors affecting the fluoride release from glass-ionomer cements.

A study has been made on the release of fluoride from three glass-ionomer cements. The effect of the maturity of cements at the time of immersion and powder/liquid ratio were examined. It was found that fluoride release from immature cements was dependent on cement and powder/liquid ratio and that the effect was permanent. The effect of cement type and powder/liquid ratio lessened as cements were allowed to mature prior to immersion. It appears that fluoride release was dependent on the strength and maturity of the cement matrix and not fluoride content. It was concluded that the rate of fluoride release would depend largely on clinical factors rather than cement type.