Purpose: The aim of this study was to analyze stress distribution on four different implant designs and four different qualities of cortical bone surrounding the implant crest modules using three-dimensional finite element analysis. Materials and Methods: Four different implant designs of the same diameter and length (3.75 × 11.5 mm) were used. Rhinoceros 4.0 3D modeling software was used for preparing the four types of bone quality (D1, D2, D3, and D4). Mandibular second premolar crowns were constructed as prosthetic superstructures of the implants, and a total force of 300 N was vertically applied to the crowns. Stress distribution on dental implants and cortical bone of D1, D2, D3, and D4 bone quality was evaluated. Results: Among all of the implants, the maximum von Mises stress value on cortical bone surrounding the neck region of the implants was found in D4 bone quality, while the minimum stress was detected in D1 bone quality. The stress distribution on the threads of dental implants exhibited the most homogenous distribution in D1 bone quality, while higher von Mises stress values were observed in the apical blade segment of the implants in D3 and D4 bone quality. Conclusion: It was found that the maximum stress of cortical bone surrounding the implant crest module decreased as the bone density increased. The microthreads on the implant crest module might cause an increase in stress to cortical bone surrounding the neck region of implants. Keywords: bone quality, dental implant design, stress distribution