Nadhum, N. . S., & Al-Khafaji, A. . H. (2014). The effect of in office bleaching on surface roughness and micro-hardness of newly developed composite materials (In vitro study). Journal of Baghdad College of Dentistry, 26(2), 24-29. https://jbcd.uobaghdad.edu.iq/index.php/jbcd/article/view/445