Occlusal Adjustment Time and Volume for Single Unit Fixed Prosthesis Fabricated With Different Virtual Mounting

March 18, 2026 updated by: Aly Ayman Mohamed El-Kady, Cairo University

Intraoral Occlusal Adjustment Time and Volume Required for Single Unit Fixed Prosthesis Fabricated With Different Virtual Articulator Mounting Methods (a Randomized Controlled Clinical Trial)

Regardless of the fabrication workflow occlusal adjustments seem to be inevitable during delivery of indirect fabrication of the restoration. This has been attributed to snowballing of discrepancies due to multiple procedures for information transfer between the clinician and the laboratory. Current digital workflows minimize these discrepancies due to digital acquisition technology which eliminates drawbacks from physical materials which would alter the dimensions and morphology of the final restoration. Utilizing 3D face scanning technology is by far the least invasive and the least time consuming of available virtual facebow techniques and thus it's utilization could offer the benefit of saving time during occlusal adjustment and enhanced strength of the restoration by not subjecting it to the heat generation and subsequent crack initiation which occurs during occlusal adjustment. This study aims to compare the effect of a face scan to alignment of the maxillary cast on the volume and time of occlusal adjustment compared to conventional articulator digitization to align the maxillary cast.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This study will be carried out on participants enrolled at the outpatient fixed prosthodontics clinic, Faculty of Dentistry, Cairo University.

Digital face scanning technology has made it possible to align the maxillary cast in a virtual articulator to represent a more accurate relationship to the terminal hinge axis of the patient than average positioning on a virtual Bonwill triangle. This would be reflected on the occlusal design of the restoration and subsequently on the amount of adjustment needed to the occlusal surface of the restoration during delivery. Decreasing the amount and time of occlusal adjustment would result in a decrease in chair time, increase in the longevity of the restoration and enhanced esthetics of the restoration.

Conventional alignment and mounting of casts to simulate the patients' dynamic occlusions remains the gold standard to which newer digital cast alignment and relation technology is to be compared. Thus the selection of the articulator scan as the comparator was made

Participants' Timeline

Clinical Visit 1 Preoperative records Clinical examination, Radiographic examination, Assessment of inclusion, Informed consent, Intraoral photographs, Primary impression (irreversible hydrocolloid) for diagnostic cast fabrication.

Clinical Visit 2 Facebow record, Articulator mounting, Face Scan, Foundation restoration for participant tooth built to full contour.

Clinical Visit 3 Preparation, Impression, Provisionalisation,

Allocation Impartial third party randomly allocates jaw relation methods to participants and informs laboratory technician of allocation results.

Single unit fixed prosthesis will be fabricated as per allocation results

Clinical Visit 4 Checking and verification of restoration ensuring

  1. Proximal contour and contact.
  2. Marginal integrity
  3. Facial and lingual contours.
  4. Surface finish.
  5. Color and shade.

Impression prior to occlusal adjustment, Occlusal adjustment, Timing occlusal adjustment procedure, Impression after occlusal adjustment, Cementation.

Study Type

Interventional

Enrollment (Actual)

33

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

  • Egypt
      • Giza, Egypt
        • Faculty of Dentistry, Cairo University

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

21 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Be aged 21-70 years old, be able to read and sign the informed consent document.
  • Psychologically and physically able to withstand conventional dental procedures.

  • Participants with molars indicated for full coverage restorations

    1. Large carious lesions
    2. Teeth restored with large restorations
    3. Endodontically treated teeth
  • Accept to undergo face scanning and articulator mounting procedures
  • Have no active periodontal or pulpal diseases, have teeth with clinically acceptable restorations.
  • Able to attend punctually for preplanned visits and evaluation.

Exclusion Criteria:

  • Participants with active resistant periodontal diseases.
  • Participants with poor oral hygiene, high caries risk and uncooperative participants.
  • Pregnant women.
  • Participants in the growth stage with partially erupted teeth.
  • Psychiatric problems or unrealistic expectations.
  • Lack of opposing dentition in the area of interest.
  • Restored occlusal surface opposing the planned restoration.
  • The presence of a removable or fixed orthodontic appliance.
  • Signs of bruxism or clenching

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: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Digitized Mounted Articulator Scan

Conventional articulator facebow mounting will be digitized using extraoral digital 3d scanner and used to position the maxillary cast on the virtual articulator.

This positioning will be utilized during design of the occlusal surface of the restoration.
Procedure: Digitized Mounted Articulator Scan
Conventional articulator facebow mounting will be digitized using extraoral digital 3d scanner and used to position the maxillary cast on the virtual articulator. This positioning will be utilized during design of the occlusal surface of the restoration.
Experimental: Average Positioning on Virtual Bonwill Triangle

Virtual Bonwill triangle will be used to position the maxillary cast on the virtual articulator.

This positioning will be utilized during design of the occlusal surface of the restoration.
Procedure: Average Positioning on Virtual Bonwill Triangle

Virtual Bonwill triangle will be used to position the maxillary cast on the virtual articulator.

This positioning will be utilized during design of the occlusal surface of the restoration.
Experimental: Digital Face Scan

Digital face scan will be used to position the maxillary cast on the virtual articulator.

This positioning will be utilized during design of the occlusal surface of the restoration.
Procedure: Digital Face Scan

Digital face scan will be used to position the maxillary cast on the virtual articulator.

This positioning will be utilized during design of the occlusal surface of the restoration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical Occlusal Adjustment Time
Time Frame: Immediately after verification of restoration acceptability but prior to occlusal adjustment. Time will be measured until occlusal contacts of the crown have been harmonized during the delivery clinical visit.
Time taken to harmonize occlusal contacts with participants masticatory function during delivery of the crown.Measured in minutes and seconds.
Immediately after verification of restoration acceptability but prior to occlusal adjustment. Time will be measured until occlusal contacts of the crown have been harmonized during the delivery clinical visit.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Volume of Occlusal Adjustment
Time Frame: Before and immediately after the occlusal adjustment. Volume before occlusal adjustment - volume after occlusal adjustment of the of the crown = volume difference
Amount of material removed from occlusal surface of restoration to harmonize occlusal contacts during delivery of the crown with participants masticatory function.
Before and immediately after the occlusal adjustment. Volume before occlusal adjustment - volume after occlusal adjustment of the of the crown = volume difference

Collaborators and Investigators

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

Sponsor

Cairo University

Investigators

  • Principal Investigator: Aly AM El-Kady, MSc, Fixed Prosthodontics Department, Misr International University
  • Study Chair: Shereen A Ameen, Prof. Dr., Fixed Prosthodontics Department, Cairo University
  • Study Director: Rasha NM Sami, Prof. Dr., Fixed Prosthodontics Department, Cairo 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 1, 2022

Primary Completion (Actual)

June 1, 2022

Study Completion (Actual)

July 27, 2022

Study Registration Dates

First Submitted

June 28, 2022

First Submitted That Met QC Criteria

July 20, 2022

First Posted (Actual)

July 22, 2022

Study Record Updates

Last Update Posted (Actual)

March 20, 2026

Last Update Submitted That Met QC Criteria

March 18, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • KADY0001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Only outcomes will be shared. Participants' personal information will be stored in a password protected folder.

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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