Fluoride Release and Recharging Ability of Glass Ionomer Cement Incorporating Hydroxyapatite Nanoparticles

Abstract

Aim: The purpose of this study was to evaluate fluoride release and recharging ability of glass ionomer cement incorporating hydroxyapatite nanoparticles. Materials and methods: Hydroxyapatite nanoparticles (NHA) were prepared by wet chemical method, the experimental material powder (GIC-NHA hybrid) was made by combining different weight percent (1%, 5% and 10%) of nano-hydroxyapatite (NHA) powder with GIC powder. Forty disks were prepared and divided into 4 groups, ten specimens from each tested material (n=10), Control group standard GIC, GIC with 1% NHA, GIC with 5% NHA and GIC with 10% NHA. Each specimen was placed in a plastic tube containing 1 ml deionized water, stored at 37°C in an incubator and measurements of fluoride release were determined one day, one week, two week and one month using multi-parameter bench photometer. For evaluation of recharge ability, re-fluoridation of each tested disc was carried on day 30 after measurement of fluoride release and the previous procedures of fluoride release measurements were repeated again. Results: Before and after recharge there was a statistically significant difference in the mean value of fluoride ion release between the control and (1%) groups, as well as a statistically significant difference between the control group and both (5% and 10%) groups, with the highest mean value recorded in (10%) group. Between the different testing intervals used in the study, there was a statistically significant difference where (P<0.001). Conclusion: incorporation of 10% nano-hydroxyapatite particles within glass ionomer cement increased fluoride ion release from GIC and its recharging ability.