Mandibular Overdentures Retained by Four Locator Attachments Versus Four-Implant Bar Attachments
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Four Locator Attachments, Four Bar Attachment System.
- Who it may be relevant to
- Registry conditions: Bone Loss. Basic parameters: 40 years — 70 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Egypt
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Residual Ridge Changes in Mandibular Overdentures Retained by Four Locator Attachments Versus Four-Implant Bar Attachments: A 10-Year Retrospective Study
Overview
This 10-year retrospective study investigates residual ridge changes in edentulous patients treated with mandibular overdentures (ODs) retained by either four Locator attachments or a four-implant bar system. Although two-implant ODs are well established, four-implant configurations may offer enhanced stability and function. Locator and bar attachments are commonly used, but their long-term effects on bone resorption patterns-especially posterior mandibular and anterior maxillary resorption-remain unclear. By standardizing implant positions, this study aims to directly compare the two systems to help guide clinicians in selecting the most effective attachment type for long-term success.
Detailed description
Implant-supported mandibular overdentures (ODs) have become the preferred treatment for edentulous patients, particularly after the endorsement of this approach by the McGill and York consensus statements. Although the use of two implants is well established, emerging research supports the use of four implants to enhance denture stability, improve masticatory function, and better maintain the surrounding oral structures.
Among the available attachment systems, Locator and bar-retained attachments are the most frequently utilized, each offering specific benefits. Locator attachments are known for their simplicity, affordability, and ease of maintenance. In contrast, bar-retained systems provide more rigid splinting between implants and more even stress distribution. These systems differ biomechanically, especially regarding their impact on bone resorption in the posterior mandible, which plays a vital role in denture retention and function.
While some research has compared different attachment types, few studies have standardized implant number and position. Moreover, there is a lack of long-term comparative studies assessing four-implant mandibular ODs using both Locator and bar attachments. Critical outcomes such as posterior mandibular ridge resorption (PMandRR), marginal bone loss (MBL), and anterior maxillary ridge resorption (AMaxRR) must be examined to evaluate the long-term effectiveness and biomechanical performance of these attachment systems.
Interventions
- Other Four Locator Attachments, Four Bar Attachment System
This study retrospectively evaluated two types of implant-retained mandibular overdenture attachment systems placed in edentulous patients over a 10-year period. All patients received four dental implants placed in the interforaminal region (lateral incisor and first premolar areas). In the Locator group, each implant was restored with an individual Locator attachment, allowing for independent retention and easier hygiene access. In the Bar group, the four implants were splinted together with
Primary outcome measures
- Marginal Bone Loss (MBL) [Time frame: 10 years]
Eligibility criteria
Inclusion criteria
- Completely edentulous mandible and maxilla for at least 12 months.
- Four interforaminal dental implants placed in the lateral incisor and first premolar regions.
- Opposing maxillary complete denture constructed using a muco-compressive impression technique, with maximum denture base extension and lingualized occlusion.
- Mandibular bone height between 15-25 mm at the symphysis region as measured on panoramic radiograph.
- Minimum 10-year follow-up with adequate radiographic documentation.
Exclusion criteria
- Systemic diseases affecting bone metabolism.
- Parafunctional habits (e.g., bruxism).
- Smokers of more than 10 cigarettes/day or those with alcohol abuse.
- Patients with implant failures, missing follow-up data, or implants placed outside the interforaminal region.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Study design
- Observational model
- Cohort
Study locations
Egypt · 1 center
- Faculty of Dentistry — Al Mansurah
Identifiers
NCT: NCT07093853 · ADMNF-00925