1. Dental Biomaterials Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt
2. Dental Biomaterials Department, Faculty of Dentistry, Horus University, New Damietta, Dumyat al Jadida, Egypt
3. Spectroscopy Department, Physics Division, National Research Center, Dokki Cairo, Giza, Egypt
4. Basic Oral and Medical Sciences Department, College of Dentistry, Qassim University, Buraydah, Saudi Arabia