Initial retention force of three attachment systems for implant retained-mandibular overdentures: An in vitro study.

Abstract

To evaluate and compare the initial retention force of three resilient unsplinted attachment systems for implant-retained mandibular overdentures: two cylindrical attachment systems (Locator R-Tx® and Novaloc®), and one ball attachment system (Ball System). and methods. For each attachment system, initial retention is measured as the average of the maximal dislodging forces during 10 insertion-removal cycles. For the Ball System, 3 activation degrees of the matrix are included whereas 4 and 6 color-coded retention devices for the Locator R-Tx® and the Novaloc®, respectively, represent the complete regular retention devices panel. For each retention device or activation degree, 8 samples are tested. The initial retention range is similar between the Ball System (7.7 ±3.4 N - 19.9 ±4.6 N) and the Novaloc® (2.0 ±0.5 N - 18.9 ±1.4 N) and broader for the Locator R-Tx® (3.3 ±5.0 N - 60.2 ±6.0 N). In each attachment system, the initial retention of each retention device is significantly different from the others, except for the two most retentive Novaloc® ones. Retention devices were also classified according to their initial retention (low, medium, and maximum). In each retention group, the Novaloc® and the Ball System provided similar retention values lower than the Locator R-Tx®. Most of the retention devices tested provided an initial retention force of over 5 N for all three attachment systems. The Locator R-Tx® had the most comprehensive range, and the Novaloc® seemed to provide the most reproducible values, unlike the Ball System due to the activation required by the operator. This article is protected by copyright. All rights reserved.