1. Substitutive Dental Sciences Department, College of Dentistry, Taibah University, Al Madinah 41311, Saudi Arabia
2. Prosthodontics Department, College of Dentistry, Ibb University, Ibb 70270, Yemen
3. Removable Prosthodontics Department, Future University, Cairo 11835, Egypt
4. Removable Prosthodontics, Faculty of Dental Medicine, Al-Azhar University, Cairo 11884, Egypt