Aula, Raz Ali, and Jawad Mohammed Mikaeel. 2022. “Vertical Marginal Gap Evaluation of PEEK and Zirconia Crowns Using Extra-Oral Scanner and CAD/CAM Systems (An Invitro study)”. Erbil Dental Journal (EDJ) 5 (1):37-43. https://doi.org/10.15218/edj.2022.5.