Effect of Geometric Modifications of Implant Scan Bodies

Effect of Geometric Modifications of Implant Scan Bodies Compared to Conventional Transfer Techniques on Passivity of Mandibular All on Four Restorations

The aim of this clinical study will be the effect of geometric modifications of implant scan bodies compared to conventional transfer techniques on passivity of all on four mandibular restorations

Study Overview

• Status: Completed
• Conditions: Prosthesis Durability
• Intervention / Treatment: Device: Implant supported hybrid prosthesis

Detailed Description

The aim of this study will be the effect of geometric modifications of implant scan bodies compared to conventional transfer techniques on passivity of all on four mandibular restorations.

Evaluation method:

The trueness of the final impression and the passivity of the final prosthesis will be evaluated by two methods:

Invitro evaluation For each patient in every group, the standard tessellation language (STL) files of scanned impressions will be superimposed on the reference file to determine the 3D surface, linear, and angular position analysis.

The STL files for both frameworks will be superimposed on the reference file to determine the passivity.

In vivo (Clinical) evaluation Radiographic evaluation using long cone parallel technique will be done for the framework after 6 month (T6) after one year (T12), and after 18 month (T18) from insertion.

• Study Type: Interventional
• Enrollment (Actual): 18
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Mansoura, Egypt, 35516
    • Mansoura University ,Faculty of dentistry

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 1. All selected patients will have four implants placed in the mandibular interforaminal region according to all -on -four concept.

  2. All selected patients have a healthy mucosa and with no clinical complications.

  3. All patients are cooperative and approve the proposed treatment protocol.

Exclusion Criteria:

• 1. Patients who reject to participate in the study. 2. Patients who need implant placement as a result of previous implant failure.

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
Active Comparator: • Group I (control group); Final impression will be done by conventional one-step impression technique. For the same patient, another final impression using unmodified scan bodies will be done by direct intraoral scan technique.	Device: Implant supported hybrid prosthesis; For each patient, implant supported mandibular hybrid prosthesis will be fabricated digitally. Frameworks will be tried in patient's mouth, scanned intraorally by intraoral scanner (IOS).
Active Comparator: • Group II (Test Group); Final impression will be done by conventional one-step impression technique. For the same patient another final impression using subtractive modified scan bodies will be done by direct intraoral scan technique	Device: Implant supported hybrid prosthesis; For each patient, implant supported mandibular hybrid prosthesis will be fabricated digitally. Frameworks will be tried in patient's mouth, scanned intraorally by intraoral scanner (IOS).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
passivity of the prosthesis	Radiographic evaluation using long cone parallel technique will be done for the framework	one year
trueness of final impressions	For each patient in every group, the standard tessellation language (STL) files of scanned impressions will be superimposed on the reference file to determine the 3D surface, linear, and angular position analysis	one year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
patient satisfaction	patient satisfaction will be evaluated using Visual analogue scale questionnaire	one year

Collaborators and Investigators

• Sponsor: Mansoura University

Study record dates

Study Major Dates

• Study Start (Actual): March 20, 2023
• Primary Completion (Actual): May 7, 2024
• Study Completion (Actual): February 16, 2025

Study Registration Dates

• First Submitted: September 4, 2023
• First Submitted That Met QC Criteria: September 13, 2023
• First Posted (Actual): September 15, 2023

Study Record Updates

• Last Update Posted (Actual): August 14, 2025
• Last Update Submitted That Met QC Criteria: August 10, 2025
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Postoperative Complications; Pathologic Processes; Prosthesis Failure
• Other Study ID Numbers: M0203023RP

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