Fluoride Release and Uptake Capability of Glass-ionomer Cements and Compomers Used as Dental Restorative Materials

Dental caries and secondary caries are the most common problems in dentistry. Many studies provided evidence for the anticariogenic effect of fluorides. The incidence of secondary caries is decreased in teeth restored with fluoride releasing materials. The purpose of the present in vitro study is to evaluate the fluoride release and uptake capability of two glass-ionomer cements and two compomers. A total number of 60 specimens were prepared according to the manufacturer s instructions using silicone molds. The specimens were transferred in plastic containers containing artificial saliva (pH=7), incubated at 37 C for 24 h and divided in three subgroups: control group, varnish treated group and dentifrice treated group. The fluoride ion content was measured on five times during a period of 30 days using an Orion 720A fluoride meter with 9609 BN fluoride ion electrode. The self-curing glass-ionomer cement released the highest amounts of fluoride ions at the beginning and after the one month study period. The samples of the four materials tested in the varnish treated groups showed significant differences compared to their control groups on the second day. Dentifrice treated groups did not show significant differences compared to their control groups, except values measured after 30 days. Application of fluoride varnish produced an increase of fluoride release for the first 24 h in case of all materials. However, results suggest that the use of fluoridated dentifrice would be more effective in caries prevention due to their fluoride uptake capability.