EFFECTS OF OVERDENTURE RETENTION ON THE AXIAL LOAD OF IMPLANT IN THE MANDIBULAR IMPLANT-SUPPORTED OVERDENTURE

하악 임플란트지지 오버덴춰에서 바 어태치먼트의 유지력이 임플란트의 축력에 미치는 영향

Three linear strain gauges (KFR-02N-120-C1-23, Kyowa, Japan) were placed around the abutment of implant future and the maximum axial loads on the mandibular implants supporting over dentures were registered in experimental model when the overdenture was removed. The overdenture attachments used in this study were Round bar Hader bar, Dolder bar with and with out spacer. The retention of bar attachment was measured using universal testing machine while being con-trolled by Activating set and Deactivator except in case of the Hader bar. Simultaneously strains were recorded with the strain smart program in strain P-6000 series (Measurement group, Raleigh, USA). The maximum axial load was calculated and compared with each other. The results were as follows: 1. The amount and the timing of the maximum axial loads were different between the right and left implant in all attachment systems. 2. The retention of bar attachment except Hader bar could be adjusted but the controllability was different among the attachment systems. 3. The more the axial load, the higher the retention with Hader bar and Dolder bar without spacer. but the tendency of increase was not shown with round bar and Dolder bar with spacer.