Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 15 4 2018 08 19 259 265 EN Hakimeh Siadat Professor, Dental Research Center, Dentistry Research Institute, Department of Prosthodontics, Tehran University of Medical Sciences, School of Dentistry, Tehran, Iran Amir Reza Rokn Professor, Dental Implant Research Center, Dentistry Research Institute, Department of Periodontics, Tehran University of Medical Sciences, School of Dentistry, Tehran, Iran Elaheh Beyabanaki Assistant Professor, Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2018 01 31 2018 04 17 Typically, full arch reconstruction of edentulous ridges requires five to 10 dental implants; however, some patients demanding fixed implant-supported prostheses are not able to medically or economically afford complex bone grafts and/or a greater number of implants. These situations could pivot the treatment plan toward the All-on-4 protocol. Nevertheless, due to less implant support in this treatment option, mechanical and biological complications might arise. This article describes the treatment of a fully edentulous patient with two types of fixed implant-supported prostheses on four dental implants along with the following complications https://fid.tums.ac.ir/index.php/fid/article/view/2386 https://fid.tums.ac.ir/index.php/fid/article/download/2386/1016