1. Dental Research Center, Dentistry Institue, Restorative Dentistry Department, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
2. Oral Microbiology Laboratory, Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
3. Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
4. Department of Maxillofacial Surgery, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
5. Department of Prosthodontics, Islamic Azad University Dental Branch of Medical sciences, Dental School, Tehran, Iran