NCT07137533

Mandibular Overdentures vs All-on-4 With PEEK

Long-Term Peri-Implant Outcomes of Mandibular Overdentures and All-on-4 Prostheses With PEEK Frameworks

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 40 (estimated)
• Sponsor: Menoufia University · Academic / Other
• Sex: All
• Age: 40 Years – 70 Years
• Healthy volunteers: —

Summary

This study compares long-term peri-implant outcomes between two mandibular full-arch rehabilitation approaches-four-implant-retained overdentures and All-on-4 fixed prostheses-when both are fabricated with polyetheretherketone (PEEK) frameworks. While overdentures and All-on-4 prostheses are widely used, evidence on the clinical performance of PEEK frameworks in these modalities is scarce. By evaluating marginal bone loss and other peri-implant parameters, the research aims to clarify whether prosthetic design influences biological outcomes when using this high-performance polymer.

Detailed description

Mandibular edentulism significantly compromises mastication, speech, and psychosocial well-being. Implant-supported prostheses-particularly four-implant-retained overdentures and the All-on-4 full-arch fixed prosthesis-are well-established solutions for restoring function and quality of life. The overdenture approach provides a removable, cost-effective option with enhanced retention and stability, while the All-on-4 concept offers a fixed, immediately functional solution by placing two anterior straight implants and two posterior tilted implants within the interforaminal region. Long-term success of both treatment modalities is influenced by peri-implant outcomes, especially marginal bone loss (MBL), which reflects the biological stability of the implant-bone interface. MBL can be affected by multiple factors, including loading protocols, implant angulation, prosthetic design, and material properties of the prosthetic framework. Recent advances in materials science have introduced polyetheretherketone (PEEK), a high-performance polymer, as a promising alternative to traditional metallic frameworks such as titanium or cobalt-chromium. PEEK offers mechanical properties that closely mimic bone, excellent biocompatibility, chemical stability, and a lower elastic modulus that may provide beneficial shock absorption, potentially reducing stress on implants and peri-implant bone. When fabricated via CAD/CAM technology, PEEK frameworks achieve high marginal accuracy and favorable fracture resistance, while also being lightweight and comfortable for patients. Despite growing interest in PEEK for dental applications, most clinical research has focused on its use in removable partial dentures or single crowns. Data on its performance in full-arch implant prostheses-whether overdentures or All-on-4 fixed restorations-are scarce. Moreover, few studies have directly compared the peri-implant outcomes of these two rehabilitation strategies when using the same framework material.

Conditions

• Bone Loss in Jaw

Interventions

Type	Name	Description
OTHER	Mandibular Four-Implant-Retained Overdenture (PEEK Framework); Mandibular All-on-4 Fixed Prosthesis (PEEK Framework)	Group I: Four-implant-retained mandibular overdenture with a CAD/CAM-milled PEEK framework and acrylic denture teeth, retained via attachment mechanisms; implants placed in lateral incisor and first premolar sites; delayed loading protocol. Group II: Mandibular All-on-4 fixed prosthesis with a CAD/CAM-milled PEEK framework and acrylic denture teeth; two anterior straight and two posterior tilted implants placed in lateral incisor and first premolar sites; delayed loading protocol.

Timeline

• Start date: 2025-08-01
• Primary completion: 2025-10-01
• Completion: 2025-10-25
• First posted: 2025-08-22
• Last updated: 2025-08-22

Locations

1 site across 1 country: Egypt