Abstract
The objective of this study was to examine whether the recharging of fluoride releasing restorative materials with fluoride affects their strength. Three different types of glass ionomer materials were tested. Disk-shaped specimens were prepared for each material. One hour after mixing or curing, the specimens were immersed in ion exchanged water at 37℃ for up to 21 weeks. Fluoride recharging was done at 3, 6, 9, 12, 15 and 18 weeks after the start of immersion using an acidulated fluoride phosphate gel. The diametral tensile strength of specimens was determined one day after the start of immersion (baseline) and then 3 weeks after recharging. For all materials, the recharged specimens did not show significant differences (p>0.05) in strength after either the first or sixth recharging compared to the specimens without recharging. Under the experimental conditions tested, fluoride recharging of fluoride releasing restorative materials did not appear to deteriorate the strength of the materials.
