Fabrication of Novel Coloured Glass Ionomer Cements

Conventional glass ionomer cements (GIC) are generally produced as tooth-coloured materials. It is possible to produce coloured GIC’s by incorporating transition or rare earth elements into the glass component. The resulting coloured cements have potential applications in the restoration of deciduous teeth, as a temporary filling material, and also as ionomeric bone cements. Objectives: To fabricate a range of coloured glasses and study their ability to form cements. In addition, cement properties including biocompatibility were investigated. Methods: Ionomer glasses with additions of CoCO₃, MnO₂, ErN, Nd₂O₃ or CeO₂ were produced using standard glass-processing routes. Cements were prepared using a standard ratio (1 g of glass powder: 0.2 g of dried polyacrylic acid: 0.3 g of 10% tartaric acid solution). Cement working and setting times were assessed using a Gilmore needle. In vitro biocompatibility was investigated using cultured rat osteosarcoma (ROS 17/2.8) cells and published methods [Hurrell-Gillingham et al, Biomaterials 2003 24 3153- 3160]. Results: All glasses produced showed some degree of colour change. It was possible to fabricate cements from all of the experimental glasses. However, only those made using CoCO₃ or MnO₂ produced a coloured cement. The setting times of these two cements were difficult to assess due to the rapid set (< 20 s). No change in the in vitro biocompatibility was observed following modifications to the parent glass. Conclusion: It was concluded that coloured GICs could be produced without compromising in vitro biocompatibility. However, further modification is required to optimise working and setting time.