Caroline Gorin

Purpose 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). Materials 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, three activation degrees of the matrix are included versus four and six color‐coded retention devices for the Locator R‐Tx® and the Novaloc®, respectively, to represent the complete regular retention devices panel. For each retention device or activation degree, eight samples are tested. Results 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®. Conclusion 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.