: In this thesis, influence of abutment angulation and material composition on stresses transferred to implants and their surrounding bones is studied. 15 virtual models were designed: 3 fixed partial dentures with two parallel implants in sites 45 and 47 on which straight abutments were fixed, and 3 fixed partial dentures with two implants in sites 45 and 47, where the anterior implant was fixed straightly and the posterior implant with 15 and 20 degrees mesial angulation, with 15 and 20 degrees abutment. There were 5 types of materials: full zirconia, zirconia coping veneered with lithium di-silicate ceramic, zirconia coping veneered with glass ceramic , porcelain fused to base metal and porcelain fused to nobel metal. Simulations and Analysis were performed with Abaqus 6.13 software. 450 N static force was applied straightly along the longitudinal axis of the anterior implant in a tripod and the stress distributions were examined based on the restoration materials and abutment angulations of the models in the 3 sites of cortical, cancellous bone and implants.The amount of stress on the cortical, cancellous bones, and the implant was similar in all the 5 materials used. In all cases, the amount of stress exerted on the cancellous bone were less than the amount of stress on the cortical bone. In fixed partial dentures with angled implants and abutments in posterior region, more stresses were exerted on the bone and other implants, and less on angled implants. - Keywords: Angled abutment, Dental implant, Fixed dental prosthesis