• The Effect Of Locator Abutment Height On The Retentive Values Of Pink Locator Attachments: An In Vitro Study.

      Sia, Priscilla Kia Suan; Masri, Radi, 1975-; 0000-0002-4799-8707 (2015)
      Purpose of this study was to evaluate the effect of different Locator abutment heights on the retention of overdentures. This study was conducted using four sets of edentulous mandible analogs with implants positioned at different depths relative to each other (N=40). Two implant-retained overdenture set-ups with Locator attachments at different vertical levels of 0, 2, 4, 6 mm to each other were tested for changes in peak load-to-dislodgement after simulated chewing of six months. Varying heights of Locator abutments had a significant effect on the retentive values of the pink Locator attachments. The results of ANOVA and Tukey HSD showed that the retention of Groups 0 mm and 2 mm was significantly lower than Group 6 mm. In conclusion, a difference in Locator abutment heights between the two implants did not adversely affect retention, therefore clinicians should choose Locator abutments according to the tissue thickness for implants at different levels.
    • 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

      Greenbaum, Daniel Seth; Masri, Radi, 1975- (2011)
      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.