하악 대구치 결손 부위에 있어서 임플랜트의 직경과 개수의 차이에 따른 유한요소 응력분석

Abstract

To reduce the risk of implant failure in the mandibular posterior edentulous region, wide implant is suggested. But not all patients have the enough edentulous region to install the wide implant. The purpose of this study was to compare the amount and distribution of stress around the implant fixtures placed in the mandibular molar region, when using the standard three implant with using the wide two implant. Two finite element model was designed on the mandibular molar region. One was designed with the parallel placement of wide two implant fixtures (4.8 mm diameter x 10 mm length, SSII, Osstem corp.), and the other was designed with the parallel placement of standard three implant fixtures. (4.1 mm diameter x 10 mm length, SSII, Osstem corp.) This study simulated that 200N were applied to the central fossa in a axial direction, and 200N was applied to the buccal cusp tip in a 30° outward oblique direction. Von Mises stress values were recorded and compared in the supporting bone, fixture, and abutment. The following results have been made based on this study : 1. Stress distribution was more effective in the wide two implants model. 2. The highest stress concentration occurred at the cervical region of the implant fixture 3. Stress concentrated on the cortical bone rather than lamellar bone. 4. In case of vertical loading condition, stress concentrated on the loaded fixture, but in oblique loading condition, stress concentrated not only on the loaded fixture but also on the unloaded fixtures. The results from numerical analysis concluded that wide two implant were more effective than standard three implant in the edentulous molar region.