Prosthetic Complications in Full-arch Screw-retained Implant Restorations Using Monolithic Zirconia Versus Titanium Frameworks: A Randomized Clinical Trial

June 14, 2026 updated by: Ahmad Diab Ahmad ElSayed, Cairo University
The goal of this clinical trial is to to compare the prosthetic complication rate and Oral Health-Related Quality of Life (OHRQoL) between screw-retained monolithic zirconia frameworks and CNC-milled titanium frameworks with zirconia superstructures in completely edentulous patients restored with full-arch implant-supported prostheses over a follow-up period of 12 months.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

12

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Cairo, Egypt, 11553
        • Recruiting
        • Faculty of Dentistry - Cairo University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Aged 18 years or older.
  2. Able to understand the study procedures and provide written informed consent.
  3. In good general health, classified as American Society of Anesthesiologists (ASA) Physical Status Class I or II.
  4. Completely edentulous in the arch to be treated (maxilla and/or mandible).
  5. A candidate for a full-arch, screw-retained implant-supported prosthesis, requiring 4 to 6 implants in the treatment arch.
  6. Sufficient bone volume at planned implant sites to place implants of at least 3.5mm in diameter and 8mm in length.
  7. Adequate crown height space (15-22 mm) for a fixed prosthesis.
  8. A zone of keratinized mucosa at the crest of the ridge measuring at least 2 mm in width.
  9. Opposing arch is fixed full-arch implant-supported prosthesis.
  10. Demonstrates acceptable oral hygiene and the motivation to maintain it.

Exclusion Criteria:

  1. Medical contraindications:

    • Uncontrolled diabetes (HbA1c > 7.0%).
    • History of radiotherapy in the head and neck region.
    • History of intravenous bisphosphonate therapy.
    • Immunosuppressed or immunocompromised status.
    • Any other uncontrolled systemic disease that constitutes a contraindication for oral surgery.
  2. Behavioral Factors:

    • Heavy smoking, defined as consumption of more than 10 cigarettes per day.
    • Presence of parafunctional habits (e.g., bruxism, clenching) as diagnosed by clinical examination.
  3. Local Oral Factors:

    • Active, untreated periodontal disease in any remaining dentition.
    • Presence of acute oral infection or pathology at the intended surgical site.
    • Crown height space less than 15 mm or more than 22 mm.
    • Insufficient keratinized mucosa (< 2 mm width) that cannot be corrected with a simple surgical procedure prior to implant placement.
  4. General:

    • Pregnancy or lactation.
    • Participation in another interventional clinical trial.
    • Perceived inability to comply with the study protocol and follow-up schedule.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Monolithic zirconia framework
The prosthesis is a one-piece, full-arch framework milled from a single, monolithic zirconia blank. It includes the infrastructure, prosthetic teeth, and gingival contours. The prosthesis is screw-retained directly to multi-unit abutments.

Intervention: Screw-Retained Monolithic Zirconia Prosthesis

  • Components: The prosthesis is a one-piece, full-arch framework milled from a single, monolithic zirconia blank. It includes the infrastructure, prosthetic teeth, and gingival contours. The prosthesis is screw-retained directly to multi-unit abutments. The prosthesis is delivered on the day of final insertion and is intended to be a definitive, long-term restoration.
  • Procedure for Tailoring: The prosthesis is fully customized for each participant using a digital workflow:

    1. Digital Impression: An intraoral scan (Medit i700 scanner ) of the multi-unit abutment scan bodies will be performed.
    2. Prosthesis Design: The prosthesis will be digitally designed in the CAD software BlenderforDental .
    3. Fabrication: The design file will be processed in Millbox CAM software and milled from a zirconia blank using a 5-axis milling machine.
Other Names:
  • Screw-Retained Monolithic Zirconia Prosthesis
Active Comparator: CNC-milled titanium framework and zirconia superstructure

The prosthesis consists of two parts: A CNC-milled titanium framework, and a CNC-milled zirconia superstructure that is cemented onto the framework.

The titanium framework is screw-retained directly to multi-unit abutments. The zirconia superstructure is permanently cemented to the framework with resin cement.

The prosthesis consists of two parts: A CNC-milled titanium framework, and a CNC-milled zirconia superstructure that is cemented onto the framework. The titanium framework is screw-retained directly to multi-unit abutments. The zirconia superstructure is permanently cemented to the framework with resin cement.
Other Names:
  • CNC-milled titanium framework

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Prosthetic complications
Time Frame: 1 year
The primary outcome of this study is the incidence of prosthetic complications over 12-month follow-up period. A prosthetic complication is defined as any mechanical or technical issue affecting the prosthesis that requires clinical intervention. This will be assessed through a standardized clinical examination conducted by a calibrated examiner. The outcome for each participant will be recorded as a binary variable (Yes/No).
1 year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Oral Health-Related Quality of Life (OHRQoL)
Time Frame: 1 year
The secondary outcome of this study is the change in Oral Health-Related Quality of Life (OHRQoL) over the 12-month follow-up period. This will be measured using the validated Arabic version of the 5-item Oral Health Impact Profile (OHIP5-Ar) questionnaire (Alhajj et al., 2019). The questionnaire consists of 5 questions, each rated on a Likert scale (e.g., 0 = Never, 1 = Hardly ever, 2 = Occasionally, 3 = Fairly often, 4 = Very often). The total score ranges from 0 to 20, with a higher score indicating a greater negative impact on OHRQoL. The change from baseline to 3, 6 and 12 months will be analyzed.
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 12, 2026

Primary Completion (Estimated)

May 1, 2027

Study Completion (Estimated)

May 1, 2027

Study Registration Dates

First Submitted

June 14, 2026

First Submitted That Met QC Criteria

June 14, 2026

First Posted (Actual)

June 18, 2026

Study Record Updates

Last Update Posted (Actual)

June 18, 2026

Last Update Submitted That Met QC Criteria

June 14, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • 09062026

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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