Bone Loss in JawNCT07137533
Mandibular Overdentures vs All-on-4 With PEEK
An observational study of Bone Loss in Jaw, run by Menoufia University at 1 site in Egypt.
Trial 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. Read more about this study
- Who is it for?
- Ages 40 to 70 years
- Conditions the study is for
- Bone Loss in Jaw
- What is being tested?
- Mandibular Four-Implant-Retained Overdenture (PEEK Framework); Mandibular All-on-4 Fixed Prosthesis (PEEK Framework)
- How many people
- 40 participants
- Where
- 1 siteEgypt
- Study dates
- 1 Aug 2025to 25 Oct 2025
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 to 70 years
- All sexes
- Adult, Older adult
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.
Who may be able to join
- 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).
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- 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.
Who cannot join
- 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.
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- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Egypt1 site, 1 recruiting
- Recruiting
Faculty of Dentistry
Shibīn al Kawm, Menoufia
Mohammed A. El-Sawy, PhD, 00201061314522, Dr_sawy@windowslive.com
About this study
Official title: Long-Term Peri-Implant Outcomes of Mandibular Overdentures and All-on-4 Prostheses With PEEK Frameworks
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.
Read the 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
- Being tested
- Mandibular Four-Implant-Retained Overdenture (PEEK Framework); Mandibular All-on-4 Fixed Prosthesis (PEEK Framework)
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
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.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: 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. Receives: Other: Mandibular Four-Implant-Retained Overdenture (PEEK Framework); Mandibular All-on-4 Fixed Prosthesis (PEEK Framework) |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: 5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Aug 2025
- Study start1 Aug 2025
- Primary completion1 Oct 2025 (estimated)
- Study completion25 Oct 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bone Loss in JawStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Menoufia University
- Sponsor type
- University, hospital or other
- Collaborators
- Mansoura University
- Responsible party
- Principal investigator, Mohammed El-Sawy, Menoufia University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07137533
- Sponsor's protocol ID
- ADMNF-00625
- Status last verified
- Aug 2025
- First submitted
- 15 Aug 2025
- Last updated
- 22 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Up on resonable request from the corresponding author
Study at a glance
From the registry record, last updated by the sponsor on 22 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Long-Term Peri-Implant Outcomes of Mandibular Overdentures and All-on-4 Prostheses With PEEK Frameworks
- ClinicalTrials.gov ID
- NCT07137533
- Acronym / sponsor ID
- ADMNF-00625
- Conditions
- Bone Loss in Jaw
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Menoufia UniversityUniversity, hospital or other
- Collaborators
- Mansoura University
- Study start
- 1 Aug 2025 (actual)
- Primary completion
- 1 Oct 2025 (estimated)
- Study completion
- 25 Oct 2025 (estimated)
- First posted
- 22 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group A - Overdenture Group | – | Other: Mandibular Four-Implant-Retained Overdenture (PEEK Framework); Mandibular All-on-4 Fixed Prosthesis (PEEK Framework)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. |
| Group B - Fixed Prosthesis Group | – | Other: Mandibular Four-Implant-Retained Overdenture (PEEK Framework); Mandibular All-on-4 Fixed Prosthesis (PEEK Framework)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. |
Who may qualify
- Ages
- 40 to 70 years
- Sex
- All
- Age groups
- Adult, Older adult
- 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.
Key inclusion criteria (11 listed)
- Adults aged ≥40 years.
- Completely edentulous mandible for at least 6 months prior to implant placement.
- 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).
Key exclusion criteria (10 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 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. | Other | Group A - Overdenture Group, Group B - Fixed Prosthesis Group |
Primary outcome
Marginal Bone Loss (MBL) per implant (mm)
Time frame: 5 years
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
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Aug 2025.
- Individual participant dataSharing planned: No. Up on resonable request from the corresponding author
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Bone Loss in Jaw, run by Menoufia University at 1 site in Egypt.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 11 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 22 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Egypt. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Mohammed A. El-Sawy, PhD (00201061314522, Dr_sawy@windowslive.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Marginal Bone Loss (MBL) per implant (mm) (time frame: 5 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Aug 2025.