Clinical Performance of Mandibular All-on-4 Modified Polyetheretherketone Treatment Approach Versus Conventional Metal Framework and Hybrid Prostheses: a Randomized Clinical Trial

The objectives of this randomized clinical trial are to 1) compare clinical performance of the two different treatment concepts during the follow up period of up to 3 years concerning prosthesis survival and success, 2) to assess the implants survival and success rates after 3 years, 3) to assess the accuracy of two surgical guides for full-arch implant surgery, 4) to assess the anticipated and actual pain following implant surgery, and 5) to assess patient satisfaction and quality of life will be assessed.

The study will be conducted according to the guidelines of the CONSORT statement for reporting randomized clinical. The study will be conducted at the College of Dental Medicine, University of Sharjah, United Arab Emirates.

Population and sample Study patients will be recruited from an existing pool of edentate adults referred for treatment to the College of Dental Medicine, University of Sharjah, United Arab Emirates. The patients will not be charged any treatment costs as part of this study. The target population will comprise patients requiring treatment for edentulous arches. Eligible patients for the implant phase of the study will be evaluated through a clinical assessment, panoramic radiograph, and cone-beam computed tomography (CBCT) exam. All study patients will be provided with a patient information sheet and provided written consent to take part in the study.

Conventional upper and lower denture constructions In the first phase of treatment, new maxillary and mandibular complete dentures with acceptable function and esthetics will be made and deliver to the patients. The conventional maxillary and mandibular complete denture constructions will follow the established methods which are primary impression with compound impression material, secondary impression with zinc oxide eugenol, jaw relation, try-in, issue and recall. The satisfactory mandibular complete denture will be converted into provisional all-on-4 mandibular prostheses immediately after implants placement.

Implant treatment planning The implant surgery planning will be performed using CBCT images of the anterior mandible obtained with a limited Field of View and standard protocols for minimizing radiation exposure. Implant placement planning and construction of surgical guides will be accomplished using available software and 3D printing machine. Implant placement will be fully guided surgery. The accuracy of two surgical guides will be assessed (milled and 3D-printed) by obtaining another CBCT after 3 months. The pre- and post-treatment scans will be superimposed and evaluated using Geomagic Control software.