1. Department of Periodontology, Faculty of Dentistry, Ziauddin University, Karachi, Pakistan;
2. Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia;
3. Faculty of Dentistry, Ziauddin University, Karachi, Pakistan;
4. Department of Periodontics and Community Dentistry, King Saud University, Riyadh, Saudi Arabia;
5. Department of General Dentistry, Eastman Institute for Oral Health, University of Rochester, Rochester, NY, USA