In vitro comparison of change in retentive force values of three different attachment systems for two implant-supported overdentures

Background: In edentulous patients, a complete denture has traditionally been the recommended course of care. However, obtaining positive outcomes can be very difficult, particularly when the mandibular arch exhibits severe alveolar ridge resorption. Since Branemark first proposed the idea of osseointegration, implant-supported overdentures have developed into a common form of treatment for people who are missing all of their teeth. There are numerous attachments with various designs available. The objective of this study was to evaluate and compare the change in retentive force of three different attachment systems: ball, locator and Hader bar and clip attachment for two implant-supported overdentures at baseline, 3 months, 6 months and 1 year duration. Methods: Three types of attachments were used: ball, locator, and Harder bar. All the group consisted of 6 samples. Overdenture models were then designed to be dislodged by using a universal testing machine. The retentive values were evaluated at baseline, 3 months, 6 months and 1 year duration which was synchronized at baseline, 270 cycles, 540 cycles and 1,080 cycles considering insertion and removal activities done by the patient three times a day. Results: Group III (bar attachments) showed the highest retentive values for all cycles, followed by Group II (locator attachments) whereas, Group I (ball attachments) showed least retentive values (P<0.001). Conclusions: Even though all the attachment systems showed loss of retentive values from baseline to the corresponding cycles, bar attachments were having better retention followed by locator attachments and ball attachments.