EFFECT OF GLASS-IONOMER MANIPULATION ON EARLY FLUORIDE RELEASE

Purpose: To determine the amount of fluoride released from several gla ss ionomer products [Fuji Cap II, Fuji Ionomer Type II, Ketac-Silver, Chelon-Silver, and Miracle Mix (hand-mixed and encapsulated)], and to compare them between triturated (5, 10, 15 seconds) encapsulated and h and-mixed glass ionomers. Materials and Methods: The amount of fluorid e released at 1, 2, 3, 7, 14, 21 and 28 days after the start of immers ion in deionized-distilled water at 37 degrees C was determined with a fluoride ion selective electrode. Rates of fluoride release and cumul ative amounts of fluoride release were calculated. Results: Each glass ionomer released the greatest amount of fluoride during the first 24- hour period. Although there was some variation between products, gener ally the hand-mixed specimens released significantly (P < 0.05) less f luoride than those prepared by mechanical trituration (10 and 15 secon ds). The cumulative amounts of fluoride released from the mechanically triturated glass ionomers were significantly (P < 0.05) greater than the amounts released from the hand-mixed glass ionomers. No significan t differences in the cumulative amounts of fluoride released from trit urated materials were found among the different trituration times.