PEEK vs Metal Bar Attachments

Patient Satisfaction After Prosthetic Rehabilitation of Mandibular Single Denture With Two Implants Using Different Attachments: A Randomized Clinical Trial

This study is being conducted to compare two types of bar attachments used to support lower dentures in patients who have lost all their lower teeth. Many people who wear a single lower denture experience problems with stability, chewing, and comfort. Placing two implants in the lower jaw and attaching the denture to a bar can greatly improve how well the denture stays in place.

Traditionally, these bars have been made from metal. While effective, metal bars can place higher stress on the bone around the implants, which may lead to more bone loss over time. A newer material, PEEK (polyetheretherketone), is lighter and has flexibility closer to natural bone. This may reduce stress on the implants and help protect the surrounding bone.

In this randomized clinical trial, patients are assigned to receive either a PEEK bar or a metal bar to retain their lower denture. All participants receive two implants placed in the canine region of the lower jaw, followed by a bar-retained overdenture after healing.

The study follows patients for 12 months and measures:

Marginal bone loss: how much bone is lost around each implant, assessed through radiographs.

Patient satisfaction: how comfortable and functional the denture feels, including stability, chewing, speech, hygiene, and overall handling.

Early results show that both types of bars support the denture well, but implants connected to PEEK bars tend to show less bone loss after several months compared to those connected to metal bars. Patient satisfaction is high in both groups, with slightly higher scores reported by patients using PEEK bars, although not significantly different.

This study may help dentists choose the best bar material to improve long-term implant health and denture comfort.

Study Overview

• Status: Completed
• Conditions: Edentulism in Lower Jaw
• Intervention / Treatment: Device: PEEK Bar Attachment; Device: Metal Bar Attachment

Detailed Description

This randomized, parallel-group clinical trial evaluates the clinical performance of CAD/CAM-fabricated PEEK bars compared with traditional metal bars for retaining mandibular single overdentures supported by two implants. The study includes 20 fully edentulous mandibular patients aged 40-70 years who report functional difficulties with a single lower denture.

All participants undergo placement of two dental implants in the mandibular canine regions using a two-stage surgical protocol. After osseointegration, patients are randomly assigned to one of two groups:

PEEK bar group: overdentures retained using a digitally designed and milled PEEK bar.

Metal bar group: overdentures retained using a conventional metal alloy bar.

The scientific rationale for evaluating PEEK is based on its lower elastic modulus, which may allow more favorable stress distribution to peri-implant bone compared with the higher stiffness of metal bars. This biomechanical difference may influence implant survival, marginal bone remodeling, and perceived comfort.

Clinical outcomes are assessed at insertion and at 3, 6, 9, and 12 months. Marginal bone loss is measured radiographically using standardized periapical images. Patient-reported satisfaction is captured using a validated Visual Analogue Scale across major functional domains.

The statistical approach uses Aligned Rank Transform ANOVA due to non-normal data distribution, with Tukey post-hoc testing for pairwise comparison.

This trial contributes new data on material selection for bar attachments in implant-retained mandibular overdentures. The findings suggest that PEEK bars may offer biomechanical advantages by reducing bone loss while maintaining patient satisfaction comparable to metal bars. Further long-term studies with larger sample sizes are recommended to validate these results and support broader clinical adoption.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Banī Suwayf, Egypt
    • Nahda University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 40 to 70 years
• Mandibular single complete denture with complaints of poor retention or stability
• Adequate bone volume in the mandibular canine regions to receive two dental implants without the need for bone grafting
• Good general health allowing dental implant surgery
• Willingness to participate and comply with study procedures and follow-up visits
• Signed written informed consent

Exclusion Criteria:

• Presence of uncontrolled systemic diseases (e.g., uncontrolled diabetes mellitus)
• History of head and neck radiotherapy
• Metabolic bone diseases or conditions affecting bone healing
• Current smokers or tobacco users
• Poor oral hygiene or inability to maintain oral hygiene
• Active oral infections or untreated periodontal disease
• Bruxism or severe parafunctional habits
• Previous implant placement in the mandible
• Pregnant or lactating women

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PEEK Bar Attachment Group; Participants receive two dental implants placed in the mandibular canine regions. After osseointegration, the mandibular overdenture is retained using a CAD/CAM-fabricated polyetheretherketone (PEEK) bar attachment. Clinical and patient-reported outcomes are evaluated over a 12-month follow-up period.	Device: PEEK Bar Attachment; A CAD/CAM-fabricated polyetheretherketone (PEEK) bar used to retain a mandibular implant-supported overdenture on two implants placed in the canine regions of the mandible.
Active Comparator: Metal Bar Attachment Group; Participants receive two dental implants placed in the mandibular canine regions. After osseointegration, the mandibular overdenture is retained using a conventional metal alloy bar attachment. Clinical and patient-reported outcomes are evaluated over a 12-month follow-up period.	Device: Metal Bar Attachment; A conventional metal alloy bar used to retain a mandibular implant-supported overdenture on two implants placed in the canine regions of the mandible.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient Satisfaction With Mandibular Implant-Retained Overdentures	Description: Patient satisfaction will be evaluated using a Visual Analogue Scale (VAS). Participants will rate comfort, chewing efficiency, denture stability, speech, hygiene, ease of handling, and overall satisfaction. Scores will be recorded on a numerical scale and compared between intervention groups over the follow-up period.	Baseline (at overdenture insertion), and at 3, 6, 9, and 12 months post-insertion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Marginal Bone Loss Around Dental Implants	Description: Marginal bone loss around the two mandibular implants will be assessed radiographically using standardized periapical radiographs. Measurements will be recorded as the vertical distance (in millimeters) from the implant shoulder to the first bone-to-implant contact on the mesial and distal aspects of each implant. Mean bone loss per implant will be calculated and compared between the PEEK bar and metal bar attachment groups.	Baseline (at overdenture insertion), and at 3, 6, 9, and 12 months post-insertion

Collaborators and Investigators

• Sponsor: Sherif Aly Sadek

Publications and helpful links

General Publications

• Tada, S., Stegaroiu, R., Kitamura, E., Miyakawa, O., & Kusakari, H. (2003). Influence of implant design on stress around implants. Journal of Prosthetic Dentistry, 90(2), 164-170.
• Schwitalla A, Muller WD. PEEK dental implants: a review of the literature. J Oral Implantol. 2013 Dec;39(6):743-9. doi: 10.1563/AAID-JOI-D-11-00002. Epub 2011 Sep 9.
• Skalak R. Biomechanical considerations in osseointegrated prostheses. J Prosthet Dent. 1983 Jun;49(6):843-8. doi: 10.1016/0022-3913(83)90361-x.
• Feine JS, Carlsson GE, Awad MA, Chehade A, Duncan WJ, Gizani S, Head T, Lund JP, MacEntee M, Mericske-Stern R, Mojon P, Morais J, Naert I, Payne AG, Penrod J, Stoker GT Jr, Tawse-Smith A, Taylor TD, Thomason JM, Thomson WM, Wismeijer D. The McGill Consensus Statement on Overdentures. Montreal, Quebec, Canada. May 24-25, 2002. Int J Prosthodont. 2002 Jul-Aug;15(4):413-4. No abstract available.
• Burns DR. Mandibular implant overdenture treatment: consensus and controversy. J Prosthodont. 2000 Mar;9(1):37-46. doi: 10.1111/j.1532-849x.2000.00037.x.

Study record dates

Study Major Dates

• Study Start (Actual): May 5, 2024
• Primary Completion (Actual): October 10, 2025
• Study Completion (Actual): November 10, 2025

Study Registration Dates

• First Submitted: December 19, 2025
• First Submitted That Met QC Criteria: December 23, 2025
• First Posted (Estimated): January 7, 2026

Study Record Updates

• Last Update Posted (Actual): January 9, 2026
• Last Update Submitted That Met QC Criteria: January 7, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Patient Satisfaction; Marginal Bone Loss; Edentulous Mandible; Mandibular Implant Overdenture; PEEK Bar Attachment; Metal Bar Attachment
• Additional Relevant MeSH Terms: Behavior; Treatment Adherence and Compliance; Health Behavior; Patient Satisfaction
• Other Study ID Numbers: 02-02-23

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No