Assessment of Fluoride Release and Recharge of Giomer After Recharge With Two Different Topical Fluoride Materials and Two Durations: An In Vitro Study

Aims: The objectives of this study were to determine the fluoride release from a giomer after 24 h, 1 week, and 1 month) and to examine the recharge ability of the giomer after recharge with two different topical fluoride materials and two different durations. Materials and Methods: This is an in vitro study that involved the use of 72 specimens of the tested material; the specimens were divided randomly into three main groups (24 h., 1 week, and 1 month group). Each group consisted of 24 specimens, out of which 12 specimens were recharged with fluoride varnish (six specimens for 12 h and six specimens for 24 h.) and 12 specimens were recharged with APF gel (six specimens for 1 min and six specimens for 4 min). First fluoride release was measured from the tested specimens, and then all of the tested specimens were recharged with different topical fluoride materials with different durations. One-way analysis of variance (ANOVA) and Duncan's multiple range test were used to determine the significant differences among the groups. The statistical results were considered significant at P <= 0.05. Results: The statistical ANOVAs showed there were no statistical significant variations in the mean values of release of all specimens in the 24-h and 1-week group, but there was a highly statistically significance difference in the mean values of release of all specimens in the 1-month group, and after recharge with FV (12 h; 24 h) and APF gel (1 min; 4 min), there was a highly statistically significance difference in the mean values of fluoride release after recharge in the groups (24 h, 1 week, and 1 month). Conclusions: The amount of fluoride released from the giomer was more in the 24-h. group than in other groups. Recharge with APF gel released more fluoride than fluoride varnish. Increasing the time of giomer contact with the recharging material resulted in a greater uptake of fluoride.