Passive Fit of Implant-Supported Frameworks: Digital vs Conventional Impressions

August 20, 2026 updated by: Ahmed Hazem Elsayed Helmi, Mansoura University

Passive Fit Evaluation of Full-Arch Implant-supported Frameworks Using Digital and Conventional Impression Techniques: Crossover Study

This randomized crossover clinical trial compares the passivity of fit of complete-arch mandibular implant-supported frameworks fabricated using three impression techniques: a non-calibrated splinted digital scan body system (IO-Connect), a Reverse Scan Body (RSB) digital impression technique, and a conventional splinted open-tray impression technique. Eight completely edentulous patients each receiving four mandibular implants will be included. Passivity of fit will be evaluated clinically using the Sheffield one-screw test and radiographically using intraoral periapical radiographs obtained with the parallel technique.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Full-arch implant-supported fixed prostheses require a high degree of passive fit to avoid mechanical and biological complications. While digital impression workflows are increasingly used as alternatives to conventional splinted impressions, evidence directly comparing their clinical accuracy for complete-arch implant frameworks remains limited, particularly for the IO-Connect non-calibrated splinting system and the Reverse Scan Body technique.

Eight completely edentulous patients with at least four mandibular implants will be enrolled. Using a crossover design, each patient will undergo all three impression techniques: Group I (IO-Connect splinted scan bodies), Group II (Reverse Scan Body technique), and Group III (conventional splinted open-tray impression with polyvinyl siloxane and Type IV stone casts). For each technique, a corresponding implant-supported framework will be fabricated and evaluated for passivity of fit using the Sheffield one-screw test and periapical radiographs taken with a paralleling device to assess microgaps at the implant-framework interface.

Study Type

Interventional

Enrollment (Estimated)

8

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 Contact

Study Locations

  • Egypt
    • Dakahlia Governorate
      • Al Mansurah, Dakahlia Governorate, Egypt
        • Recruiting
        • Faculty of Dentistry, Mansoura University
        • Contact:
        • Principal Investigator:
          • Ahmed Hazem Elsayed Helmi Atwa, BDS

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:

  • Completely edentulous patients requiring full-arch implant-supported fixed prosthesis
  • Age 35-70 years
  • Adequate mandibular bone to place at least four implants without major grafting
  • Ability to undergo digital scanning and radiographic evaluation
  • Signed informed consent

Exclusion Criteria:

  • Systemic conditions affecting healing (uncontrolled diabetes, immunosuppression)
  • History of head/neck radiotherapy or bisphosphonate therapy
  • Active oral infection or severe bruxism
  • Strong gag reflex preventing accurate scanning
  • Poor compliance or unwillingness to attend follow-up visits

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: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Group I: IO-Connect
Patients received complete-arch implant-supported frameworks fabricated using digital impressions obtained with IO-Connect non-calibrated splinted scan bodies.
Procedure: IO-Connect Digital Impression
Digital impression of the mandibular arch obtained using IO-Connect non-calibrated splinted scan bodies to fabricate the implant-supported framework for Group I.
Active Comparator: Group II: Reverse Scan Body
Patients received complete-arch implant-supported frameworks fabricated using digital impressions obtained with the Reverse Scan Body (RSB) technique.
Procedure: Reverse Scan Body Digital Impression
Digital impression obtained using the Reverse Scan Body (RSB) technique, involving extraoral scanning of scan bodies and superimposition with intraoral tissue scans, to fabricate the implant-supported framework for Group II.
Active Comparator: Group III: Conventional Impression
Patients received complete-arch implant-supported frameworks fabricated using a conventional splinted open-tray impression technique.
Procedure: Conventional Splinted Impression
Conventional splinted open-tray impression using polyvinyl siloxane material and Type IV dental stone to fabricate the implant-supported framework for Group III.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Passive Fit Assessed by Sheffield One-Screw Test
Time Frame: The evaluation of passive fit by Sheffield one-screw test will be done 3 months after implant placement (3M-IP), at framework try-in for each of the three impression techniques.
The framework was seated on all implants and a single distal screw was fully tightened; remaining screw sites were examined visually and tactilely for lifting, rocking, or gaps as an indicator of passive fit.
The evaluation of passive fit by Sheffield one-screw test will be done 3 months after implant placement (3M-IP), at framework try-in for each of the three impression techniques.
Passive Fit Assessed by Periapical Radiographs
Time Frame: The evaluation of passive fit by periapical radiographs will be done 3 months after implant placement, at framework try-in for each of the three impression techniques.
Intraoral periapical radiographs were obtained at each implant site using a paralleling device and evaluated for microgaps at the implant-framework interface.
The evaluation of passive fit by periapical radiographs will be done 3 months after implant placement, at framework try-in for each of the three impression techniques.

Collaborators and Investigators

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

Sponsor

Mansoura University

Investigators

  • Study Chair: Fatma A El-Waseef, PhD, Mansoura University

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)

January 25, 2026

Primary Completion (Estimated)

October 25, 2026

Study Completion (Estimated)

January 25, 2027

Study Registration Dates

First Submitted

August 6, 2026

First Submitted That Met QC Criteria

August 20, 2026

First Posted (Actual)

August 21, 2026

Study Record Updates

Last Update Posted (Actual)

August 21, 2026

Last Update Submitted That Met QC Criteria

August 20, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MS.25-12-95

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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.

Subscribe