1. Department of Oral Function and Prosthetic Dentistry; Radboud University Medical Centre; Nijmegen The Netherlands
2. Periodontal Research Group; College of Medical and Dental Sciences; Dental School; University of Birmingham; Birmingham UK
3. Department of Special Care Dentistry; Birmingham Dental Hospital and School of Dentistry; Birmingham UK
4. Department of Restorative Dentistry; Birmingham Dental Hospital and School of Dentistry; Birmingham UK