Effect of Two Different Digital Construction Techniques of Implant-assisted Overdentures

twenty patients received mandibular overdenture constructed by different construction techniques were classified equally and randomly into two groups (n = 10 per group): Group A: received milled mandibular overdenture opposed by maxillary complete denture. Group B: received 3D-printed mandibular overdenture opposed by maxillary acrylic complete denture. peri implant bone loss was assessed by CBCT at baseline (T0), at1 year(T1), at 3 years(T3) and posterior ridge resorption was assessed by CBCT at baseline (T0), at 1 year( T1), at 3 years (T3). By superimposition of pre and post CBCT.

Inclusion criteria

• All patient wearing maxillary conventional denture.
• All patients had temporary mandibular overdenture supported by vertically inserted 4-implant at least six months ago.
• A Cone Beam Computed Tomography (CBCT) done to verify the accurate position and success of the inserted implant.
• They were healthy, free from any systemic diseases relating to bone resorption such as uncontrolled diabetics or osteoporosis. This was achieved through medical history and clinical examination by physician.
• At least 15 mm restorative space must be available (from the mucosa covering the crest of the residual ridge to proposed occlusal plane) to permit construction of all types of tested prosthesis (class I according to Ahuja and Cagna). This was detected by a tentative jaw relation.
• All patients are of angel's class I maxillo-mandibular relationships.

Exclusion criteria

• Patients had head and neck radiotherapy, patients with bleeding disorders or hepatic patients.
• Patients with metabolic disorders as diabetes mellitus, osteoporosis and hepatic disorders that might affect osseointegration.
• Long term immunosuppress and corticosteroid drug therapy.
• Patient with abnormal habits as clenching and bruxism.
• Smoking patient.
• Uncooperative patients.
• Neuromuscular diseases.
• Patient with problems in TMJ.