Investigation of the pull-off forces for implant-supported overdentures with two resilient attachment systems

Here we evaluated the retention of two implant-supported overdenture attachment systems - Locator and CM-LOC - on edentulous mandibular models. We compared the retention force between these systems based on implant number and position, addressing complications like loss of retention and ease of denture removal. Implants were placed in various configurations (two, three or four implants) and two attachment systems were tested using different retention inserts. Locator system generally provided higher pull-off forces than the CM-LOC system, especially with the red and transparent inserts. However, the CM-LOC system showed less complications, such as loss of retention element. In terms of axial and non-axial pull-off tests, Locator system performed better than the CM-LOC system, particularly in the non-axial direction, which closely reflects real-life conditions. The results showed that implant angulation and choice of attachment system were critical factors influencing resulting retention forces. Overall, the study concluded that while the Locator system achieved high retention forces, the CM-LOC system had less complications and might be a better option for patients with difficulties in denture removal.