FLUORIDE RELEASE FROM GLASS-IONOMER AND COMPOMER RESTORATIVE MATERIALS - 6-MONTH DATA

Objectives. To investigate the daily fluoride release of two glass ion omers (Ketac-Fil and ChemFil Superior) and two compomers (Compoglass a nd Dyract Restorative) over 6 months. Methods. A pilot study evaluated the rime taken for sample solutions to equilibrate to establish an ap propriate time period for sample solution storage between fluoride ion measurements. In the main study storage water replacement and fluorid e ion determination was made daily using a specific ion electrode, TIS AB buffer and standard solutions for calibration. Results. Equilibrati on of fluoride concentration in aqueous solution occurred in under 48 h for all materials. Total fluoride released (mu g mm(-2)) after 6 mon ths by Ketac-Fil (30.6, s.d. 4.9) was significantly greater than ChemF il Superior (12.7, s.d. 2.5), Compoglass (10.4, s.d. 1.0) end Dyract R estorative (7.7, s.d. 1.7) (P<0.05). Daily fluoride release at 24 h an d 10 days was significantly higher for the glass ionomers than the com pomers (P<0.05). After 40 days the daily fluoride release (mu g mm(-2) ) from ChemFil Superior (0.05, s.d. 0.01) was not significantly differ ent from Compoglass (0.04, s.d. 0.01) and Dyract Restorative (0.03, s. d. 0.00) (P>0.05). Daily fluoride release from Ketac-Fil remains signi ficantly higher than the compomers at 3 and 6 months (P<0.05). Conclus ions. Specimens stored in water equilibrate rapidly, suggesting the ra te at which storage water is changed may alter the relative fluoride r elease rates of materials. This important fact is often overlooked. Fl uoride release from the glass ionomers is initially higher than for th e compomers. Fluoride release from glass ionomers falls rapidly to app roach levels released by compomers. Compomers produce no initial burst of fluoride and levels of release remain relatively constant. (C) 199 8 Elsevier Science Ltd. All rights reserved.