Comparison of Non-Calibrated Splinting Bodies and T-Marker for Complete-Arch Implant Scanning

Accuracy of Complete-Arch Implant Scans Obtained Using Non-Calibrated Splinting Bodies and a Mobile Phone-Based Photogrammetry System (T-Marker): A Randomized Crossover Clinical Trial

This randomized crossover clinical trial aims to compare the accuracy and scanning efficiency of two digital techniques for recording implant positions in completely edentulous patients receiving implant-supported full-arch prostheses. Each participant will undergo digital impressions using both a non-calibrated splinting scan body system (IoConnect) with an intraoral scanner and a mobile phone-based photogrammetry system (T-Marker). The order of the two scanning methods will be randomized.

The primary outcome is the accuracy (trueness) of implant position recording, assessed by comparing each digital impression with a verified reference model. Secondary outcomes include the time required to complete each digital impression. The findings of this study may help determine whether these digital workflows provide accurate and efficient alternatives for complete-arch implant impressions, thereby supporting clinical decision-making in implant prosthodontics.

Study Overview

• Status: Recruiting
• Conditions: Edentulism; Edentulism Complete
• Intervention / Treatment: Device: Non-Calibrated Splinting Scan Body System (IoConnect); Device: Mobile Phone-Based Photogrammetry System (T-Marker)

Detailed Description

Detailed Description

Accurate recording of implant positions is essential for the fabrication of passively fitting implant-supported full-arch prostheses. Although intraoral scanners have demonstrated acceptable accuracy for single implants and short-span restorations, complete-arch implant scanning remains challenging because of the absence of stable anatomical landmarks, long interimplant distances, and cumulative image stitching errors. To overcome these limitations, several digital impression techniques have been developed, including splinted implant scan body systems and photogrammetry-based workflows.

Recently, non-calibrated splinting scan body systems have been introduced to improve the stability of implant scan bodies during intraoral scanning without requiring scanner-specific calibration. In parallel, mobile phone-based photogrammetry systems have emerged as simplified and more accessible alternatives for capturing implant positions. However, clinical evidence directly comparing these technologies is limited.

This prospective randomized crossover clinical trial will compare the accuracy and scanning efficiency of a non-calibrated splinting scan body workflow (IoConnect) with a mobile phone-based photogrammetry system (T-Marker) for complete-arch implant impressions. Twenty-four completely edentulous patients rehabilitated with four implant-supported multiunit abutments will undergo digital impressions using both techniques. The order of the scanning procedures will be randomized using a computer-generated randomization sequence, allowing each participant to serve as their own control.

A verified conventional splinted impression and master cast will be fabricated for each participant and digitized with a high-accuracy laboratory scanner to generate the reference dataset. Digital impressions obtained with both workflows will be compared with the reference model using three-dimensional metrology software. Trueness will be evaluated by measuring linear and angular deviations of implant positions after standardized replacement of the scan bodies with their corresponding CAD library files and construction of an identical virtual implant-supported bar for all datasets.

The primary objective is to compare the trueness of implant position acquisition between the two digital workflows. The secondary objective is to compare the effective chairside scanning time required for implant position acquisition. The results of this study are expected to provide clinical evidence regarding the accuracy and efficiency of these emerging digital workflows and to support evidence-based selection of digital impression techniques for complete-arch implant rehabilitation.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Mohammed A. Elsawy, PhD; Phone Number: 00201061314522; Email: mohamed.elsawy@dent.menofia.edu.eg

Study Locations

• Egypt
  • Shibin Alkom
    • Shibīn al Kawm, Shibin Alkom, Egypt, 2266166
      • Recruiting
      • Mohammed Elsawy
      • Contact: Mohammed Algharissi, PhD; Email: mohamed.elsawy@dent.menofia.edu.eg

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria

• Adults aged 18 years or older.
• Completely edentulous maxilla rehabilitated with four well-integrated implants connected to multiunit abutments.
• Patients presenting with a screw-retained interim implant-supported prosthesis or requiring a definitive implant-supported prosthesis.
• Adequate implant osseointegration with no clinical signs of implant failure.
• Ability to understand the study procedures and provide written informed consent.

Exclusion Criteria

• Fewer than four implants supporting the maxillary prosthesis.
• Implants located outside the maxillary arch.
• Failed implants or implants exhibiting mobility.
• Active peri-implant infection or suppuration.
• Inability to tolerate intraoral scanning or comply with study procedures.
• Refusal or inability to provide written informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental: IoConnect → T-Marker; Participants first undergo complete-arch digital implant impressions using the non-calibrated splinting workflow (IoConnect), followed by the mobile phone-based photogrammetry workflow (T-Marker).	Device: Non-Calibrated Splinting Scan Body System (IoConnect); A non-calibrated splinting scan body system used with an intraoral scanner to record complete-arch implant positions. The workflow uses splinted scan bodies that are digitally merged with the soft-tissue scan to generate the definitive implant impression.; Other Names: IoConnect Flags; True Abutment; Medit i700; Device: Mobile Phone-Based Photogrammetry System (T-Marker); A smartphone-based photogrammetry system used to capture complete-arch implant positions through optical markers attached to multiunit abutments. The system generates a digital implant position dataset for prosthetic workflow and accuracy assessment.; Other Names: T-Marker; TruAbutment T-Marker; iPhone 15 Pro Max
Experimental: Experimental: T-Marker → IoConnect; Participants first undergo complete-arch digital implant impressions using the mobile phone-based photogrammetry workflow (T-Marker), followed by the non-calibrated splinting workflow (IoConnect).	Device: Non-Calibrated Splinting Scan Body System (IoConnect); A non-calibrated splinting scan body system used with an intraoral scanner to record complete-arch implant positions. The workflow uses splinted scan bodies that are digitally merged with the soft-tissue scan to generate the definitive implant impression.; Other Names: IoConnect Flags; True Abutment; Medit i700; Device: Mobile Phone-Based Photogrammetry System (T-Marker); A smartphone-based photogrammetry system used to capture complete-arch implant positions through optical markers attached to multiunit abutments. The system generates a digital implant position dataset for prosthetic workflow and accuracy assessment.; Other Names: T-Marker; TruAbutment T-Marker; iPhone 15 Pro Max

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Trueness of Complete-Arch Implant Position Recording	Trueness will be assessed by comparing each experimental digital implant impression with a verified reference dataset generated from a conventional splinted impression. Three-dimensional analysis will be performed using reverse-engineering software to calculate the linear (µm) and angular (degrees) deviations of implant positions. Lower deviation values indicate greater trueness.	Immediately after completion of each digital impression (during the 1 day study visit).
Angular Deviation of Complete-Arch Implant Position Recording	Angular trueness will be assessed by comparing each experimental digital implant impression with a verified reference dataset. Three-dimensional analysis will be performed using reverse-engineering software to calculate the angular deviation (degrees) of implant axes. Lower values indicate greater trueness.	Immediately after completion of each digital impression (during the 1 day study visit).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effective Chairside Scanning Time	Time required to capture and register implant positions using each digital impression workflow, measured in seconds. Only the implant position acquisition phase will be included; soft-tissue scanning, STL export, and data processing will be excluded.	Immediately after completion of each digital impression (during the 1 day study visit).

Collaborators and Investigators

• Sponsor: Menoufia University
• Investigators: Principal Investigator: Mohammed Elsawy, PhD, Menoufia University

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): January 1, 2027

Study Registration Dates

• First Submitted: July 18, 2026
• First Submitted That Met QC Criteria: July 22, 2026
• First Posted (Actual): July 23, 2026

Study Record Updates

• Last Update Posted (Actual): July 23, 2026
• Last Update Submitted That Met QC Criteria: July 22, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: ADMNF0426

Drug and device information, study documents

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