1. Department of Prosthetic Dental Sciences; College of Dentistry; King Saud University; Riyadh Saudi Arabia
2. Dental Health Department; College of Applied Medical Sciences; King Saud University; Riyadh Saudi Arabia
3. Department of Periodontology; School of Dental Medicine; Stony Brook University; Stony Brook NY USA
4. Department of Oral Surgery and Implant Dentistry; Johann Wolfgang University; Frankfurt Germany
5. Department of General Dentistry; Eastman Institute for Oral Health; University of Rochester; Rochester NY USA