Aim: To compare the distribution of stress formed around an implant and a natural tooth on different zirconia FDP design (implant supported, tooth-implant supported and teeth supported) by 3D finite element analysis. Materials and Methods: A distal extension situation was utilized in this study to evaluate stress distribution around a natural tooth and an implant on three different designs :implant supported, tooth-implant supported and teeth supported zirconia FDPs. The stress values of the three models loaded with oblique forces (300 N) were analyzed using (3D) finite element analysis . Result : The results of this study revealed that the implant presence a highest  influence on the stress concentration in the mandible, while the molar and premolar reflects a low stress concentration. It was noticed that Model 1 has the highest stress concentration more than the other two models this flowed by Model 2 .On the other hand, the less stress concentration noticed around Model 3. Conclusion : Highest stresses was noted around the implant neck on the cortical bone region than those of natural teeth.