Retention loss and wear assessment of three attachment systems for implant retained-mandibular overdentures: An in vitro study
The stud-shaped attachment systems (AS) with different shape designs (ball, cylindrical, conical) and materials (metallic, plastic, or a combination of both) are commonly used to provide better retention and stability in implant-retained mandibular overdentures (IRMO). The purpose of the present stu...
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| Published in: | Journal of the mechanical behavior of biomedical materials Vol. 150; p. 106269 |
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| Main Authors: | , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Netherlands
01-02-2024
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | The stud-shaped attachment systems (AS) with different shape designs (ball, cylindrical, conical) and materials (metallic, plastic, or a combination of both) are commonly used to provide better retention and stability in implant-retained mandibular overdentures (IRMO).
The purpose of the present study was to evaluate and compare the retention loss and the wear (patterns, location, material loss) of three resilient unsplinted AS: a well-established ball attachment system (BAS) and two more recent cylindrical attachment systems (CAS), Locator R-Tx® and Novaloc®.
The implants, their corresponding abutments, the color-coded or position-coded retention devices (RD), the matrix metal housing were incorporated within CAD/CAM resin blocks and cyclically loaded with 19.6 N along the implant axis in a chewing machine to simulate 10,000 insertion-removal cycles (IRC). At cycle 10, 100, 1,000, 5,000, and 10,000, the retention force was measured using a universal testing machine. The wear was qualitatively examined using a binocular magnifier for both systems, and quantitatively assessed from micro-computed tomography acquisitions for CAS. Material loss exceeding 50 μm was considered significant.
The three AS showed different retentive behavior along time. All the Locator R-Tx® RD lost more than 50 % of their retention after 10,000 IRC. The retention of the Ball System slightly varied over time, the final retention loss in B
and B
groups being lower than 25 % of the initial retention. Wear was located at the tip of their gold RD and at the equator area of their ball abutment. For Locator R-Tx®, the more retentive the plastic RD, the greater its wear and retention loss. Only Novaloc® maintained a stable retention with even a slight tendency to increase and showed a negligible wear. Implant abutments of the CAS showed no significant wear.
After 10,000 IRC, corresponding to approximately 5-years clinical use, almost all RD provided retention force over 5 N, which could be sufficient to maintain satisfaction in most of the patients. The retention loss observed most prominently for the Locator R-Tx®, then for the Ball System, seemed to correlate with the wear observed on their RD. The practitioner may expect less RD maintenance with the Novaloc® stable retention overtime. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 1751-6161 1878-0180 1878-0180 |
| DOI: | 10.1016/j.jmbbm.2023.106269 |