An in vitro study of non‐axial forces upon the retention of an O‐ring attachment

Abstract

Within the limitations of this study, it was concluded that O-rings for implant/attachments perpendicular to the occlusal plane were adequately retentive over the first year and that the retentive capacity of O-ring was affected by implant inclinations despite the proposed positioners.

Retentive Properties of O‐Ring and Locator Attachments for Implant‐Retained Maxillary Overdentures: An In Vitro Study

“…The difference in implant number could explain the greater retention noted with O‐rings in this study. The increased retention loss of O‐ring attachment over a simulated time period of 6 months was similar to the findings of another study conducted on two‐implant overdentures with different angulations. The authors found a 16.6% retention loss of O‐ring attachments after simulation of 6 months when the implants were placed parallel to each other.…”

“…In this study, the initial retention during vertical dislodgement of O‐rings (27.3 N) was higher than initial retention obtained with two implants inserted in acrylic resin blocks (8.4 to 18.4 N) or in a mandibular acrylic resin model (13 to 15 N) . Ohya et al found a 7.3 N initial retention force of palateless maxillary overdentures retained to two implants with ball attachment and resilient material (polyvinylsiloxane and silicone dioxide).…”

“…As a result, the O‐ring is compressed into position, which may prematurely damage and wear the ring . The deformation, friction, or degeneration in the O‐ring neck during the test increases rubber hardness and increases retentive ring diameter . Therefore, in clinical studies, some authors have pointed to the need for O‐ring replacement within 5 or 6 months .…”

Attachment systems for implant overdenture: influence of implant inclination on retentive and lateral forces

“…Moreover, the measurement of the retention force was performed in a universal testing machine without saliva. This could increase the friction between the patrices and matrices of the attachments, which would increase the retentive force (Botega et al 2004; Rodrigues et al 2009). Hence, further studies are needed to evaluate the effects of the maximum retentive force and lateral force to the implant under clinical conditions.…”

Use of an Implant O-Ring Attachment for the Tooth Supported Mandibular Overdenture: A Clinical Report

“…There are however, some disadvantages such as the gradual loss of retention due to the wear of O-rings, and the need for periodic replacement. Rodrigues et al25 conducted a study to evaluate the retention force of an O-ring attachment system at different inclinations to the ideal path of insertion. They concluded that O-ring studs perpendicular to the occlusal plane were adequately retentive over the first year and that the retentive capacity of the O-ring was affected by stud inclinations.…”