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

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: Complete Edentulism
• Intervention / Treatment: Other: Monolithic Zirconia Prosthesis; Other: CNC-milled titanium framework and zirconia superstructure

• Study Type: Interventional
• Enrollment (Estimated): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Cairo, Egypt, 11553
    • Recruiting
    • Faculty of Dentistry - Cairo University
    • Contact: Faculty of Dentistry - Cairo University; Phone Number: 0020223642705; Email: dentmail@dentistry.cu.edu.eg

Participation Criteria

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

How is the study designed?

Design Details

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

Number of Arms

2

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.	Other: Monolithic Zirconia Prosthesis; 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:Digital Impression: An intraoral scan (Medit i700 scanner ) of the multi-unit abutment scan bodies will be performed.Prosthesis Design: The prosthesis will be digitally designed in the CAD software BlenderforDental .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.	Other: 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.; Other Names: CNC-milled titanium framework

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prosthetic complications	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)	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

• Sponsor: Cairo University

Study record dates

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