We propose to study a range of novel fluorine-containing bioactive glasses with potential applications in dentistry and orthopaedics. At present little is known about the atomic structure of these materials and how it impacts the macroscopic properties. This proposal aims to undertake neutron diffraction studies on these glasses as part of a wider series of structural studies. In order to model and predict the behaviour of these materials and optimise dissolution and selective ion release it is important to understand the connections between the glass composition, its atomic structure and relevant macroscopic properties such as glass degradation and apatite formation in solution. We therefore propose to undertake a detailed study of these materials using a combination of neutron and X-ray diffraction and molecular dynamics modelling.