1. Department of Periodontics and Community Dentistry; College of Dentistry; King Saud University; Riyadh Saudi Arabia
2. Department of Dental Health; College of Applied Medical Sciences; King Saud University; Riyadh Saudi Arabia
3. Department of Oral Pathology and Microbiology; Faculty of Dental Sciences; M.S. Ramaiah University of Applied Sciences; Bangalore Karnataka India
4. School of Dentistry; University of Queensland; Brisbane Qld Australia