Introduction of an interproximal mineralisation model to measure remineralisation caused by novel formulations containing calcium silicate, sodium phosphate salts and fluoride

OBJECTIVES: To introduce a new interproximal mineralisation model and to investigate the effectiveness of novel toothpaste and dual phase gel formulations to remineralise acid softened enamel in a simulated interproximal environment.

METHODS: Specimens were positioned opposite each other with an approximately 100 μm space between enamel surfaces to simulate an interproximal environment. Target specimens were demineralised in 1% (w/v) citric acid, pH3.75. Specimens were daily immersed in artificial saliva (AS) for 1h, treated with formulations, re-immersed in AS for 6h, re-treated and re-immersed in AS for a further 1h. Study 1 evaluated prototype calcium silicate/phosphate fluoride toothpaste formulations. Study 2 evaluated novel calcium silicate/phosphate fluoride toothpaste and dual phase gel formulations. Both studies contained fluoridated and non-fluoridated controls. The surface microhardness of each target enamel block was measured following demineralisation and following days three, seven and fourteen for study one and after days one, three and seven for study two.

RESULTS: This new mineralisation model was able to show increased remineralisation from calcium silicate/phosphate fluoride prototype formulations over fluoridated formulations alone, after three and seven days of treatment. Using this new model, the combined application of novel calcium silicate/phosphate fluoride toothpaste and novel calcium silicate/phosphate fluoride dual phase gel showed the greatest amount of remineralisation, which was significantly greater than sodium fluoride and non-fluoride controls.

CONCLUSIONS: Employing a new interproximal mineralisation model successfully determined the remineralisation potential of novel calcium silicate/phosphate fluoride oral healthcare formulations.

CLINICAL SIGNIFICANCE: Modifying a mineralisation model to include specimens positioned in an interproximal environment allows us to better understand the remineralisation potential of oral healthcare products. It is important to minimise mineral loss at interproximal sites as the enamel within these areas is thinner than the rest of the crown.