Effect of Simulated Loading on the Locator Attachment System: A Comparison Between the Retentive Values of Locator Attachments With Initially Placed Nylon-Inserts and Replacement Nylon-Inserts: An In-Vitro Study

Abstract

Purpose: This study examined the retentive values of Locator attachments (Zest Anchors, Escondido, CA) with initially placed nylon-inserts, as compared to Locator attachments with replacement nylon-inserts. Materials and Methods: Five test samples simulated implant retained overdentures utilizing Locator attachments. Each attachment was tested with the initially placed pink nylon-insert (Group 1, n=5), and with a replacement nylon-insert (Group 2, n=5). Both groups were tested for 2920 cycles. The results were used to compare Group 1 with Group 2 at three time intervals. A one-way analysis of variance (ANOVA) with a p value of ≤0.05 was considered significant. Results: No significant differences were found between the retentive values of both groups (initial p=0.70, middle p = 0.41, and final p=0.09). The retentive values at the three time intervals were plotted in terms of cycles. A best-fit linear regression showed the rate of degradation. The slope of Group 2 was double that of Group 1. Conclusions: No significant differences in retentive values were found between the attachments with the initial nylon-inserts, and the attachments with replacement nylon-inserts for the time intervals studied. However, the attachments with replacement nylon-inserts lost retention at twice the rate of the attachments with initially placed nylon-inserts.