This study was conducted to evaluate the effect of three different occlusal schemes on both alveolar bone height and density surrounding Implants supporting complete mandibular over dentures. Thirty male completely edentulous patients were selected from the out patent clinic of prosthodontic department, Faculty of oral and Dental Medicine, Cairo University; the patients were divided into three equal groups (ten patients each) as follows:Group I: Patients received Implant – supported over dentures with their occlusal scheme set according to bilateral fully balanced occlusion. Group II: Patients received Implant – supported over dentures with their occlusal scheme set according to lingualized occlusion.Group III: Patients received Implant – supported overdenture with their occlusal scheme set according to monoplane occlusion. Complete maxillary denture and Implant – Supported mandibular over denture were made for each patient following the selected occlusal scheme. Two Implants were placed In the Interforaminal region of the mandible (each one was placed in the canine area). The placement of implants were made according to the protocol of two surgical stages, So after three months from the first surgery the implants were exposed for fixation of healing abutment that were altered to be dome- shaped permanent abutments.