나사형 임플란트 고정체의 길이, 직경, 플랫폼 형태에 따른 임플란트와 주위조직의 응력분포 = Influence of Fixture Diameter, Fixture Length, and Platform Shape on the Stress Distribution in and around the Screw Type Implant

다국어 초록 (Multilingual Abstract)

Seven finite element models were constructed in mandible having single screw-type implant fixture connected to the second premolar-shaped superstructure, in order to evaluate how the length, diameter and platform shape of a screw-type fixture influence the stress in the supporting tissue around fixtures. The superstructure were made using UCLA abutment, and connected to the fixture with abutment screw. Each finite element model was varied in terms of length, diameter, and platform shape of the fixture according to the commercial fixture(3i Implant Innovations Inc, Palm Beach Gardens, FL33410, USA) while the superstructure and the mandible with a single fixture placed in it shared no difference in terms of appearance. In each model, 250N of vertical load was placed on the central pit of an occlusal plane and 250N of oblique load placed on the buccal cusp. The stress distribution in the supporting tissue and the other components was analysed using 2-dimensional Finite element analysis and the maximum stress in each reference area was compared.
1. Under lateral loading, the stress was larger in the larger in the abutment/fixture interface, and in the crestal bone, compared to the stress pattern under vertical loading.
2. The amount of stress at the superstructure was similar regardless of the length, diameter and platform shape of a fixture.
3. Around the longer fixture, the stress was decreased at the bone crest and subjacent cancellous bone and increased in the cancellous bone area apical to the fixture.
4. Around the wider fixture, the stress was decreased at the abutment/fixture interface, and the bone crest and increased in the cancellous bone area apical to the fixture.
5. Around the fixture having wider platform, less stress was resulted at the abutnent/fixture interface and the upper part of the cortical bone, compared to the fixture having standard platform.
In short, the stress distribution of the supporting tissue was affected by length, diameter, and platform shape of a fixture, and the fixture which was larger in diameter and length could reduce the stress in the supporting tissues at the bone-fixture interface and bone crest area.