1. Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia;
2. Department of Periodontics and Community Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia;
3. Department of General Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia;
4. Department of Mechanical Engineering, Capital College, Pennsylvania State University, Pennsylvania, PA, USA