Fluoride containing bioactive glass composite for orthodontic adhesives - ion release properties

- Novel fluoride containing BAG-resin adhesive has a sustainable long term release of F, Ca and PO4.
- The new adhesive reacts selectively in low pH environment to maintain the pH of the solution.
- The new adhesive reacts selectively in low pH environment to release Ca and PO4 ions.
- The novel BAG-resin has the potential to prevent demineralisation and promote remineralisation.

ObjectiveDental materials that release calcium, phosphate and fluoride ions could prevent demineralisation and/or enhance remineralisation of enamel. The objective was to develop a novel bioactive glass (BAG) resin and investigate pH changes and ion release in 3 immersion media.MethodsQuench melt derived BAG (35.25% SiO2, 6% Na2O, 43% CaO, 5.75% P2O5, and 10% CaF2) was incorporated into a resin (42.25% BisEMA, 55% TEGDMA, 0.25% DMAEM, 0.5% camphorquinone and 2% 4-Meta), with a filler load of 80% by weight. Ninety composite disks for each BAG loading of 80%, 60%, 50%, 40%, 20%, and 0% were made and each disk was immersed in 10 ml of either tris buffer (TB), or artificial saliva at pH = 7 (AS7) or pH = 4 (AS4), n = 30 for each solution. Three disks of each loading were taken from each of the solutions, at ten time points (6 h-6 months), for measurement of pH, fluoride, calcium and phosphate.ResultsThe BAG adhesive raised the pH in all the solutions, release Ca, PO4 and F ions especially in AS4. The rise in pH and the release of Ca and F are directly related to the BAG loading and the time of immersion. The pH and the ion releases were maintained and continued over 6 months.SignificanceUnlike glass ionomer resins, favourable ions F, Ca and PO4 releases were maintained over a long time period especially in acidic condition for this novel BAG-resin composite. This indicates the resin has the potential to prevent formation and progression of early caries lesions.