Hussein Albu_Saabar, Shaymaa Rahim , General Directorate of Education in Najaf Hussein Al–Mousawi, Alia , Department of pathological analysis techniques, University of Alkafeel Hussein Neamah, Bent alhuda , Department of pathological analysis techniques, University of Alkafeel Hussian, Suzan Saadi Hwang, Chol-Jun , Department of Dental Caries and Oral Medicine Research, Faculty of Dentistry, Pyongyang University of Medical Sciences, Pyongyang, Democratic People’s Republic of Korea. Hyon, Kyong Hui , Agency for Testing of Biological Products, Food and Drug Administration, Ministry of Public Health, Democratic People’s Republic of Korea. Hyon, Sun Jong , Department of Dental Implant, RyuGyong Dental Hospital, Pyongyang, Democratic People’s Republic of Korea.