Mandibular Overdentures vs All-on-4 With PEEK

NCT07137533 | Recruiting

• 1 other identifier: ADMNF-00625
• Study Type: observational
• Target: 40
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Bone Loss in Jaw

Outcome Measures

Primary Outcomes (1)

• Marginal Bone Loss (MBL) per implant (mm)

  Definition: Change in crestal bone level on the mesial and distal aspects of each implant from baseline to last follow-up. Baseline: Prosthesis delivery (insertion) radiograph. Follow-up window: Minimum 48 months post-insertion (target range ≈ 4-9 years, depending on patient record length). Measurement method: Standardized periapical radiographs using a paralleling technique

  5 years

Study Arms (2)

Group A - Overdenture Group

Patients in this group received four parallel implants placed in the interforaminal region-two in the lateral incisor sites and two in the first premolar sites. The implants supported a removable overdenture retained by a CAD/CAM-fabricated PEEK framework. The overdentures were designed for improved retention, stability, and load distribution, with acrylic resin denture teeth.

Other: Mandibular Four-Implant-Retained Overdenture (PEEK Framework); Mandibular All-on-4 Fixed Prosthesis (PEEK Framework)

Group B - Fixed Prosthesis Group

Patients in this group received four implants according to the All-on-4 protocol-two anterior straight implants in the lateral incisor region and two posterior tilted implants in the first premolar region. The implants supported a screw-retained full-arch fixed prosthesis with a CAD/CAM-fabricated PEEK framework and acrylic resin denture teeth. The design aimed to optimize anteroposterior spread and reduce cantilever length while providing a fixed restoration.

Other: Mandibular Four-Implant-Retained Overdenture (PEEK Framework); Mandibular All-on-4 Fixed Prosthesis (PEEK Framework)

Interventions

Mandibular Four-Implant-Retained Overdenture (PEEK Framework); Mandibular All-on-4 Fixed Prosthesis (PEEK Framework) OTHER

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.

Group A - Overdenture Group; Group B - Fixed Prosthesis Group

Eligibility Criteria

• Age: 40 Years - 70 Years
• Sex: all
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population consisted of adult patients with completely edentulous mandibles who underwent full-arch implant-supported rehabilitation between 2015 and 2018 at two private dental clinics. Eligible patients had been restored with either a four-implant-retained mandibular overdenture or an All-on-4 mandibular fixed prosthesis, both fabricated with CAD/CAM-milled polyetheretherketone (PEEK) frameworks and acrylic denture teeth. All implants were placed in the inter foraminal region, following a delayed loading protocol.

You may qualify if:

• Adults aged ≥40 years.
• Completely edentulous mandible for at least 6 months prior to implant placement.
• Treated with either:
• Four-implant-retained mandibular overdenture with a PEEK framework, or
• Mandibular All-on-4 fixed prosthesis with a PEEK framework.
• All implants placed in the lateral incisor and first premolar regions (per respective protocol).
• Restorations fabricated via CAD/CAM-milled PEEK framework with acrylic denture teeth.
• Prosthesis delivered with a delayed loading protocol.
• Minimum clinical and radiographic follow-up of 4 years.
• Availability of standardized baseline and follow-up periapical radiographs for marginal bone level assessment.
• Treated by the same surgical and prosthodontic team.

You may not qualify if:

• History of uncontrolled systemic diseases that could affect bone healing (e.g., uncontrolled diabetes, osteoporosis under bisphosphonate therapy).
• History of head and neck radiotherapy.
• Active periodontal or peri-implant infection at the time of implant placement.
• Insufficient bone volume in the interforaminal region requiring grafting beyond minor augmentation.
• Heavy smoking habit (\>10 cigarettes/day) at the time of treatment.
• Parafunctional habits (e.g., severe bruxism or clenching) documented in patient records.
• Use of medications known to affect bone metabolism (e.g., high-dose corticosteroids, antiresorptive drugs).
• Pregnancy at the time of implant placement.
• Incomplete clinical or radiographic records.
• Follow-up period of less than 4 years.

Sponsors & Collaborators

• Menoufia University: lead
• Mansoura University: collaborator

Study Sites (1)

Faculty of Dentistry

Shibīn al Kawm, Menoufia, Egypt

RECRUITING

Central Study Contacts

Mohammed A. El-Sawy, PhD

CONTACT

00201061314522; Dr_sawy@windowslive.com

Mohammed T. Khater, PhD

CONTACT

00201003854552; MohamedKhaterdentalsmile1234@gmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Dr

Study Record Dates

• First Submitted: August 15, 2025
• First Posted: August 22, 2025
• Study Start: August 1, 2025
• Primary Completion: October 1, 2025
• Study Completion: October 25, 2025
• Last Updated: August 22, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)