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Active, Not Recruiting

NCT Number: NCT07250503

Compare the Difference in Occlusal Force Distribution and Denture Retention Using 2 Different Denture Base Materials in Implant Retained Overdenture

The global increase in the aging population has led to a rise in total edentulism, which remains a major public health concern. two-implant-retained mandibular overdentures have been regarded as the standard of care, offering superior retention, stability, comfort, and masticatory efficiency compared to conventional dentures. Among available attachment systems-bar, ball, stud, and magnet-the Equator attachment has gained popularity due to its low vertical profile, suitability for limited inter-occlusal space, and ease of handling.

Assessment of masticatory performance and occlusal balance can be objectively measured using devices such as bite force analyzers and the computerized T-Scan system, which quantifies occlusion and disocclusion times.

Conventional heat-cured polymethyl methacrylate (PMMA) remains the most widely used denture base material; however, it has mechanical and biological limitations. Flexible denture base materials have been introduced to overcome these drawbacks by enhancing adaptation, distributing occlusal loads more evenly, and improving comfort and retention.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Edentulous Alveolar Ridge in Mandible Attachments Complete Edentulism Dental Implant Edentulous Mouth Implant Retained Overdenture Mouth Diseases Mouth, Edentulous Stomatognathic Diseases Tooth Diseases

Age range

60 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Cairo University

Cairo, 4470351, Egypt

About this study

24 Patients will be randomly and equally divided into two treatment groups:

  • Group 1: Each patient in this group will receive conventional maxillary and mandibular complete dentures made of heat-cured acrylic resin PMMA. In the mandible, two implants were inserted in the symphyseal area and retained by equator attachments.
  • Group 2: Patients in this group received the same type of treatment as the patients in group 1, but the mandibular overdentures were made of the flexible acrylic resin "breflex" The present study will be performed to compare the difference in retention, occlusal force distribution, occlusion and disocclusion time, and bite force for implant retained mandibular over denture using PMMA and flexible dentures base materials

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • All patients age must range from 60-70 years old.
  • All patients' ridges should be covered with firm mucosa free from any signs of inflammation or ulceration and exhibit adequate height and width of the residual alveolar ridge.
  • Patients should be free from any metabolic or bone disorder that contraindicate implant installation.
  • All patients must have sufficient inter arch space

Exclusion criteria

  • Patients with oral or systemic diseases.
  • Patients with xerostomia or excessive salivation.
  • Patients with parafunctional habits (bruxism or clenching).
  • Heavy smoker or alcoholic patients.
  • Patients with history of temporo-mandibular dysfunction.
  • Patients with brain disorders or psychiatric disorders

Treatment and study plan

Conventional acrylic resin denture

Procedure

Mandibular complete dentures made of heat-cured acrylic resin (PMMA). In the mandible, two implants were inserted in the symphyseal area and retained by Equator attachments.

Flexible resin denture

Procedure

Mandibular overdentures were made of the flexible acrylic resin breflex, In the mandible, two implants were inserted in the symphyseal area and retained by Equator attachments

Primary outcomes

  1. Occlusal force distribution

    Time frame: Follow up visits were scheduled at denture insertion, 6, and 12 months

    Occlusal force distribution will be measured by T-Scan, The latest version (T-Scan III) provides a dynamic visual evaluation of a patient's occlusion from initial tooth contact to maximum intercuspation. The system records relative force values and allows objective quantitative evaluation of occlusal balance by recording numerical values for occlusion and disocclusion times

Secondary outcomes

  1. Retention of lower denture

    Time frame: Follow up visits were scheduled at denture insertion, 6, and 12 months

    Retention of lower denture will be measured using digital force gauge, Retention will be measured using digital force gauge A digital force meter was used to measure denture resistance to vertical displacement (i.e., retention) by applying a pulling force on a metal hook located in the geometric center of each mandibular conventional denture that was identified on the lower cast at the intersection of three lines bisecting the angles of the triangle, formed by both retromolar pads and the midline. Measurement of mandibular denture retention: The patient was instructed to place his head on chin rest and occlusal plane was set parallel to the floor. Tongue freedom was checked then and three minutes seating time was allowed before taking the measurements. A vertical pulling force was applied using the metallic probe of the digital force-meter that was attached to the hook present at the geometric center of mandibular denture. Average value of six readings was recorded.

  2. occlusion time

    Time frame: Follow up visits were scheduled at denture insertion, 6, and 12 months

    occlusion and disocclusion time will be measured by T-Scan, The latest version (T-Scan III) provides a dynamic visual evaluation of a patient's occlusion from initial tooth contact to maximum intercuspation. The system records relative force values and allows objective quantitative evaluation of occlusal balance by recording numerical values for occlusion times

  3. Biting force

    Time frame: Follow up visits were scheduled at denture insertion, 6, and 12 months

    Biting force will be measured by bite force meter

  4. Disocclusion time

    Time frame: Follow up visits were scheduled at denture insertion, 6, and 12 months

    will be measured by T-Scan, The latest version (T-Scan III) provides a dynamic visual evaluation of a patient's occlusion from initial tooth contact to maximum intercuspation. The system records relative force values and allows objective quantitative evaluation of occlusal balance by recording numerical values for disocclusion times

Sponsors and collaborators

Lead sponsor

Al-Azhar University

Other

Registry information

Official study title

Impact of Wearing Two Different Implant Retained Mandibular Overdentures on Occlusal Force Distribution and Denture Retention (Randomized Clinical Trial)

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Nov 26, 2025
Registry last updated
Nov 26, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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