Title: 0235 - In-vitro Retention Changes of Novel Implant Overdenture Aattachments


Sabrina Maniewicz (Presenter)
University Clinics of Dental Medicine, University of Geneva

Isabelle Badoud, University Hospitals of Geneva
François Herrmann, University Hospitals of Geneva
Najla Chebib, University Clinics of Dental Medicine, University of Geneva
Patrick Ammann, University Hospitals of Geneva
Martin Schimmel, University of Bern
Frauke Müller, University Clinics of Dental Medicine, University of Geneva
Murali Srinivasan, University Clinics of Dental Medicine, University of Geneva


Objectives: This in-vitro study aimed to compare the effect of cyclic dislodging and implant inclination on the retentive force of three novel un-splinted attachments.

Methods: Experimental models simulating a mandibular two-implant overdenture situation, with implants positioned with different inter-implant angular discrepancies were fabricated (Groups: 1=0°; 2=20°; 3=40°; 4=60°; attachments: Novaloc®, LOCATOR R-Tx®, and CM LOC®; for angulations of 60°: Novaloc® 15° and CM LOC® FLEX). All models underwent wet-testing and were subjected to 10’000 cycles of insertion and removal in a universal testing machine. The mean retentive forces were calculated for cycles #10, #100, #1’000, #5’000 and #10’000. ANOVA and mixed-effects regression models were applied for statistical analyses (α<0.05).

Results: The ANOVA tests revealed a significant overall effect of cyclic dislodging on the retentive force of the pooled attachments (p=0.0066). With parallel implants, LOCATOR R-Tx® did not lose retention before 10’000 cycles, but angulations of 40° or higher led to lower retentive forces (0° vs 40° cycle #5’000: p=0.032, cycle #10’000: p=0.056; 0° vs 60° cycle #100: p=0.019, > cycle #1’000: p<0.001). The CM LOC® attachments did not lose retention before 10’000 cycles for all angulations (cycle #10’000 all angles: p<0.001). Retention forces seen in angulated implant configurations were from the beginning lower than in parallel implants, but consistent. In contrast, Novaloc® attachments demonstrated an increasing retention until 1’000 cycles, which subsequently diminished and reached its initial retention at 10’000 cycles. Novaloc® demonstrated no effect of implant angulation, except for 60° after 10’000 cycles (p=0.019).

Conclusions: This study confirmed that all tested attachments changed retention over time and functioned even in extreme inter-implant angulations. However, their retentive behaviors under the same testing conditions were diverse and should be verified in a clinical context.

Student Presenter

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE