Introduction: This study was performed to evaluate the effects of two different implant supported removable partial denture designs restoring mandibular Kennedy class II on the supporting bone and periodontium. Materials and Methods: Fifteen patients were selected to receive implants at the first molar area. Then patients were divided into 2 groups according to the partial denture design. The first group received unilateral denture without cross arch stabilization. The second group received bilateral denture with cross arch stabilization. Results: The results showed that although both designs were successful, there was a significant difference between the two designs regarding crestal bone loss.Conclusion It could be concluded that unilateral implant assisted removable partial denture is not recommended as it may increase the stresses on the implant. However, long term studies are needed to better justify the efficacy of this treatment modality.