Evaluating Crestal Bone Height In Implant Retained Mandibular Overdenture Using Cad/Cam Milled Cobalt Chromium Bar Versus Zirconia Bar

Abstract

This study was conducted to evaluate and compare the marginal bone height around bar attachment in implant retained mandibular overdenture. Sixteen Completely edentulous patients were selected for this study, from the outpatient clinic, Prosthetic Department, Faculty of Oral and Dental Medicine, Ain shams University. Patients were rehabilitated by mucosa supported maxillary complete denture and implant retained mandibular overdenture. Standard clinical and laboratory techniques were followed for denture construction for all patients. Patients participating in this study were randomly divided into two equal groups: Group A: Patients of this group received two mandibular interforaminal implants and an overdenture retained by a CAD/CAM milled Zirconia bar attachment. Group B: Patients of this group received two mandibular interforaminal implants and an overdenture retained by a CAD/CAM milled Cobalt Chromium bar attachment. Surgical installation of the implant was performed under strict aseptic conditions. After three months post-operatively bars were cemented to abutments and dentures were delivered to patients. Follow-up visits were scheduled at the time of denture insertion, three, six, nine and twelve months after insertion for inspection of the prosthesis and radiographic evaluation of the peri-implant supporting structures. Marginal bone height changes around the implants were evaluated by the cone beam computed tomography.