N H F Wilson1, F J T Burke2, P A Brunton3, S Creanor4, M T Hosey5, F Mannocci6. 1. King's College London Dental Institute, London, UK. 2. Primary Dental Care Research Group, University of Birmingham School of Dentistry, Birmingham, UK. 3. Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand. 4. Medical Statistics, Plymouth University Peninsula Schools of Medicine & Dentistry, Plymouth, UK. 5. Paediatric Dentistry, King's College London Dental Institute, London, UK. 6. Endodontology, King's College London Dental Institute, London, UK.