**2. Materials and Methods**

#### *2.1. Study Setting and Ethical Approval*

This study was conducted at the Department of Operative Dentistry in collaboration with the Institute of Biomedical Sciences, Dow University of Health Sciences, Karachi from July 2017 to December 2018 after obtaining ethical approval (IRB-862/DUHS/Approval/2017/50) from Institutional Review Board, Dow University of Health Sciences. All the recommendations of the Helsinki Declaration and its later amendments were strictly followed.
