1. Department of Periodontics, Dental College of Georgia, Augusta University, Augusta, Georgia, United States
2. Department of Endodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
3. Department of Endodontics, Faculty of Dentistry, The British University in Egypt, Cairo, Egypt
4. Department of Endodontics, Faculty of Dentistry, Misr International University, Cairo, Egypt