Characterisation of Coloured Commercial Glass Ionomer Cements

Glass ionomer cements (GIC) are traditionally tooth-coloured materials. VOCO GmbH (Cuxhaven Germany) has recently introduced a range of coloured GICs for the repair of deciduous teeth. No significant study to date has reported on the properties of these new materials. Objective: The aim of this research was therefore to compare the properties of these novel coloured GICs with traditional tooth coloured materials. Methods: Cements were fabricated in accordance with the manufacturer's instructions. The three coloured cements (pink, green and blue, Ionofil® Colour AC, VOCO GmbH, Germany) were compared to the traditional tooth-coloured cement (Ionofil® Plus AC, VOCO GmbH, Germany). Working and setting times were determined using the Gilmore needle indentation test. Fluoride ion release was measured using an ion selective electrode. Cement radio-opacity was estimated by comparison with an Al step wedge. Finally, the in vitro biocompatibility of the cements was investigated using L929 fibroblasts. Results: All cements had working and setting times within the range indicated by the manufacturer (2 min and 4 min respectively). Very little variation in the handling properties of the cements was noted. The pink and blue cements released significantly more fluoride than the white and green materials. However, the fluoride ion release profiles from all the cements were similar and typical of a GIC. All cements (blue, pink, green and white) displayed similar radio-opacity, however the cements were considerably more opaque than another commercial GIC (ChemFil, Dentsply). Similar in vitro biocompatibility was noted for all materials. Conclusion: The colouring of these GIC's had no major effect on the properties evaluated in this study.