1. Department of Periodontics and Community Dentistry, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia
2. Department of Restorative Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia
3. College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia