eng Science and Education Publishing American Journal of Medical Sciences and Medicine 2327-6657 2020-02-22 8 1 6 10 10.12691/ajmsm-8-1-2 AJMSM2020812 article Amal Abdallah A. Abo-Elmagd Corresponding author: dr.amal.abdallah@qudent.org 1 Assistant professor of Fixed Prosthodontics, college of dentistry Qassim University, Qassim, Al Mulidah, Saudi Arabia. Assistant professor of Fixed Prosthodontics, Faculty of Dental Surgery, Misr for Science & Technology University, October, Egypt http://pubs.sciepub.com/ajmsm/8/1/2/ajmsm-8-1-2.pdf