Fluoride Release Rate Of F-containing Composite Resin-An In Vitro Study And Its Physical Property Testing

Objective: In this study, we observed several composite resins containing different concentrations of fluoride, trying to find a suitable concentration of fluoride in composite resins to prevent caries in base teeth of partial denture restorations and its changes of physical property. Methods: Na2(PO3)F -containing composite resins, respectively 0﹑10%﹑15%﹑20% and 25%(w/w)in concentration were cut into three 1g blocks and immersed in 100ml﹑200ml and 500ml deionized water. These composite resins in 100ml and 200ml solutions were replaced every 1﹑2﹑3﹑6﹑9﹑16 days(every 7 days after that )until two months later, 500ml solution was reserved after 3﹑6﹑9 days every 7 days later until two months,2ml of which were reserved every time. The fluoride release rates of these composite resins were tested by potentiometry. We also observed whether there was harmful effect on the shock strength﹑cross breaking strength under 50 N﹑laborite testing of self-cuting resin after adding fluoride. Results: All composite resins containing different concentrations of fluoride could release F- during the period of 65 days and F- density of theirs were higher than no fluoride added composite resin; the physical property of 25% fluoride containing composite resin has been changed completely. Conclusion: When Na2(PO3)F was mixed in composite resins, it can release fluoride slowly; thermoplastic resina containing 15% F and chemistry hardening resina containing 10% F have high release rates of fluoride; there was no harmful effect on the physical property of 0~20% F-containing composite resin.