Patient Satisfaction and Crestal Bone Changes Around One-piece Zirconia(Zr) and Titanium(Ti) in Implant-Retained Mandibular Overdenture

Inclusion Criteria: * Male patients * The age range of 50 to 60 years old (average of 55). * moderately developed mandibular residual ridges, covered with healthy mucosa, firmly attached to the underling bone and with average mucosal thickness (2-3) mm. * At least 12 mm of vertical bone height in the mandible allowing for placement of a 10 mm implant (2 mm safety distance to inferior alveolar nerve). * Patients were selected with Angle class-I maxillomandibular relationship with sufficient inter-arch space (13-15mm Exclusion Criteria: * Heavy smokers of more than 10 cigarettes a day * Poor oral hygiene. * Patients with temporomandibular joint disorders(TMD), * Patients suffered of xerostomia, * Patients exhibited Para-functional habits, or recent extractions were excluded. * Patients with systemic diseases that might affect bone quality or quantity, or retard healing of the surgical wounds were excluded. * Patients receiving intravenous forms of bisphosphonates. * Patients who have had radiation therapy to the head and neck region. * Patients with existing implants in the jaws * Patients with previous bone grafting in either the maxillary or mandibular jaws.