Radiographic and Clinical Evaluations of Mandibular Implant-Supported Overdentures Supported by Conventional and Zirconia CAD/CAM Bars: A Randomized Clinical Trial

Inclusion Criteria: * • Patients age range was between 50-60 years old. * Only male patients were selected to participate in this study. * All patients were apparently free from any systemic or debilitating diseases that might affect bone metabolism or delay post-operative healing. * Patients were free from any temporo-mandibular joint disorders. * Patients were free from any neuromuscular or bony disorders, and medically free from any neurologic disorder affecting the neuro-muscular system. * Patients' residual alveolar ridges were covered with firm, healthy mucosa, free from any signs of inflammation, ulceration, or flabby tissue. * Mandibular edentulous alveolar ridge areas had sufficient width and height of alveolar bone. * Patients exhibited Angle Class I maxillo-mandibular relationship and sufficient inter-arch space. * Patients had good oral hygiene. * A period of at least six months up to one year had elapsed from the last extraction. Exclusion Criteria: * • Patients with systemic diseases that might affect bone quality, contribute to bone resorption, increase surgical risk, or delay/complicate post-operative healing. * Patients with parafunctional habits such as bruxism, clenching, or grinding. * Patients with residual ridge covered by inflamed, ulcerated, or flabby mucosa. * Patients with inadequate inter-arch space. * Patients with abnormal tongue behavior and/or size. * Patients with xerostomia or excessive salivation. * Heavy sm…