Mandibular overdentures versus All-on-4 fixed prostheses with PEEK frameworks

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

Observational Menoufia University · NCT07137533

This study tries to see if PEEK-framework four-implant overdentures or PEEK All‑on‑4 fixed prostheses lead to less marginal bone loss around implants in people with a completely toothless lower jaw.

Quick facts

Study typeObservational
Enrollment40 (estimated)
Ages40 Years to 70 Years
SexAll
SponsorMenoufia University Academic / other
Locations1 site (Shibīn al Kawm, Menoufia)
Trial IDNCT07137533 on ClinicalTrials.gov

What this trial studies

This observational comparison examines long-term peri-implant outcomes between four-implant-retained overdentures and the All‑on‑4 fixed prosthesis when both use CAD/CAM-milled PEEK frameworks. Eligible patients have a completely edentulous mandible and were treated with implants placed in the lateral incisor and first premolar regions, using a delayed loading protocol. The primary outcome is marginal bone level change measured on standardized periapical radiographs with a minimum follow-up of four years, alongside other peri-implant parameters. All treatments included were performed and followed by the same surgical and prosthodontic team to reduce operator-related variability.

Who should consider this trial

Good fit: Ideal candidates are adults aged 40 or older with a completely edentulous mandible for at least six months who received either a four-implant PEEK-retained overdenture or an All‑on‑4 PEEK fixed prosthesis fabricated via CAD/CAM and have at least four years of standardized radiographic follow-up.

Not a fit: Patients with uncontrolled systemic conditions affecting bone healing, prior head and neck radiotherapy, active periodontal or peri‑implant infection, bisphosphonate therapy, or lacking the required standardized radiographs/follow-up are unlikely to receive benefit or be included.

Why it matters

Potential benefit: If PEEK frameworks reduce stress on implants, this could help preserve peri-implant bone and improve long-term implant stability and prosthesis survival for edentulous mandibles.

How similar studies have performed: Existing data on PEEK frameworks are limited—laboratory studies and short-term clinical reports show promising mechanical and biocompatibility properties, but long-term comparative clinical evidence is scarce.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

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.

Exclusion Criteria:

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.

Where this trial is running

Shibīn al Kawm, Menoufia

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Bone Loss in Jaw
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.