Effect of Digital Versus Static Jaw Relation Record on Crestal Bone Changes Around Implants Supporting Maxillary Single Overdenture

* Conventional single upper denture will be made for all patients. * Occlusal adjustment of lower teeth for all patients by T-scan using the single upper conventional denture. * The single maxillary denture will be duplicated with radiopaque markers and CBCT will be used to determine the exact positions of the implants. Surgical procedures 1. Surgery will be done under local anesthesia. 2. Drilling will be carried out under copious sterile irrigation. 3. four implants will be inserted in canines and second premolar area in the maxilla. After 3-4 months of implants placement, patients will be equally and randomly divided into 2 groups. Each group contains seven patients: Digital group: For this group, implant supported maxillary overdenture will be constructed using electronic facebow to record maxillo-mandibular relation. Static group: For this group, implant supported maxillary overdenture will be constructed using the conventional jaw relation method. Post insertion: * Clinical evaluation for any signs of inflammation is made. * Further occlusal refining of lower teeth by T-scan is done with final overdenture. Method of evaluation: Radiographic evaluation for crestal bone height around implants using direct digital periapical paralleling cone technique. All data of radiographic evaluation were collected and tabulated then statistically analyzed using SPSS software.