1. Biomaterials Department, Faculty of Dentistry, Cairo University, Cairo 12613, Egypt
2. Stem Cells and Tissue Engineering Research Group, Faculty of Dentistry, Cairo University, Cairo 12613, Egypt
3. Oral Biology Department, Faculty of Dentistry, Cairo University, Cairo 12613, Egypt
4. Clinic for Conservative Dentistry and Periodontology, School of Dental Medicine, Christian Albrechts University, 24118 Kiel, Germany
5. Oral Medicine and Periodontology Department, Faculty of Dentistry, Cairo University, Cairo 12613, Egypt