Remineralizing calcium-fluoro-aluminosilicate composite resins Calcium- and Fluorine-releasing.

Objectives: innovative materials containing calcium-aluminosilicate particles were designed to confer bioactivity and to give remineralization activity of light-curing composite resins for restorative paediatric dentistry. Methods: four experimental composite resins composed by a calcium-fluoro-aluminosilicate powder (wTC-Ba or FTC-Ba) mixed with an experimental resin (HTP-M) or the commercial flowable composite resin Gradia Direct LoFlo (GC, Japan) were prepared. Powders contained tri- and dicalcium-silicate, tricalcium-aluminate, calcium sulphate, barium sulphate. Sodium fluoride was also included in FTC-Ba. Experimental HTP-M resin consisted of HEMA, TEGDMA, Polyacrylic acid, and photo-activator. Gradia Direct LoFlo and Vitrebond (3M ESPE,Germany) were the controls. The chemical-physical properties were assessed. The pH of soaking water and calcium- and fluorine-releasing (after 3,24 hours and 7,14,28 days) were measured using selective electrodes connected to a meter. The solubility i.e. the percent difference in original mass of round specimens (8 mm diameter and 1.6 mm thick) immersed in 15 ml of deionized water at 37°C (ISO 6876) was evaluated after 24 hours. The water uptake i.e. the percent change in original weight by specimens immersed in 15 ml of deionized water at 37°C (ISO 6876) was assessed at established times (1,6,24 hours). The bioactivity i.e. apatite formation ability was assessed by ESEM-EDX after soaking in simulated body fluid. Results: all the experimental materials release calcium (tab1) and basify the environmental medium (pH 8.2-10). Vitrebond and Gradia showed absence of calcium release. Both experimental Fluoride-containing materials released fluoride more than Vitrebond, p