1. Eng.A.B. Growth Factors and Bone Regeneration Research Centre, King Saud University, Riyadh, Saudi Arabia,
2. Department of Semiology and Clinic, School of Dentistry, Federal University of Pelotas, Rua Gonçalves Chaves, Brazil
3. Dental Clinic, Cambridge, UK
4. Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
5. Division of Periodontology, University of Connecticut, Farmington, Connecticut, USA