In order to resolve enamel demineralization around orthodontic bracket, fluoride-releasing materials, glass ionomer cements and fluoride-containing resin, were introduced in orthodontic department. There were many studies about their fluoride release, but their results were controversial.
The purpose of this study was to clarify the pattern and amounts of fluoride release from glass ionomer cements and a fluoride-containing resin during 70 days in vitro.
Disc shaped specimens were prepared and immersed in polyethylene tube containing 2m1 distilled deionized water. The daily amounts of the fluoride released from each specimens were measured after experiment 1 day, 3 days. 7 days, 14 days, 42 days and 70 days. They were measured by fluoride-specific electrode combined pH/ Ion meter.
The following results were as follow,
1. Fluorides released from fluoride-containing resin during 1 day were significantly less than those from glass ionomer cements.
2. On experiment 70 days, mean daily amounts of fluoride released from Miracle-Mix®were 3.4,ag/cd, those from Fuji GC fl® were 2.7tg/cnr?, those from Orthobond® were 2.3,ag/ca, those from Fuji GC LC®were 1.4fg/cn and those from fluoride-containing resin, Heliomolar®, were 0.lug/en´.
3. There were no significant differences in daily amounts of fluoride released from between self-curing glass ionomer cements and light-curing glass ionomer cements. Amounts of released fluoride vi -led among commercially available products.
4. In all experimental materials, amounts of released fluoride decreased rapidly until experimental 3 days and then decreased slowly until 14 days and more slowly until 70 days.
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