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심한 골흡수가 있는 하악에서 임플란트지지-보철치료에 대한 삼차원 유한요소 분석을 이용한 생체역학적 분석
Get PDF학위논문(석사)--서울대학교 대학원 :치의학대학원 치의과학과,2019. 8. Kwon, Ho-Beom.1. 목 적
이 연구의 목적은 협측 골흡수가 동반된 하악 부분 무치악 모형에서 협측 캔틸레버가 있는 보철물의 생체역학적 움직임을 평가하고, 여러 보철물 설계 디자인을 비교하는 것이었다.
2. 방 법
환자의 CT 영상을 기반으로 총 3개의 유한요소 모형을 제작하였다. 유한요소 모형은 제2소구치와 제1대구치가 결손된 하악 구치부에 임플란트가 식립되고 제1소구치와 제2대구치가 포함된 모형이었다. 첫 번째 모형(CP2)은 골 양에 기반하여 2개의 임플란트가 식립된 모형이었고 보철물에 협측 캔틸레버가 존재하였다. 두 번째 모형(BP2)은 보철물을 기준으로 식립된 2개의 임플란트가 포함되었다. 세 번째 모형(BP3)은 보철물을 기준으로 식립된 3개의 임플란트가 포함된 모형이었다. 모든 모형에서 466.4N의 전하중이 지대주나사에 가해졌다. 저작력을 가정한 하중이 교합면에 75도로 가해졌다. 피질골, 해면골 및 임플란트 구성요소에서 최대등가응력이 관찰되었다.
3. 결 과
캔틸레버 모형이 다른 디자인 만큼 우수한 응력 분포를 나타내었다. 최대등가응력은 모형 CP2와 모형 BP3에서는 제1소구치 지대주에, 모형 BP2 에서는 대구치지대주에 집중되었다. 피질골에서 최대 등가 응력은 주로 임플란트 경부 주위에 집중되었으며 CP2에서 293 MPa, BP2 에서 348 MPa, 그리고 BP3 에서 791 MPa 이었다. 해면골에서는 CP2를 제외하고 모두 소구치 부위 임플란트의 첨부에 최대등가응력이 집중되었고, CP2에서는 응력이 임플란트 경부 주변에 집중되었다. 해면골에서의 최대등가응력은 CP2 에서 26 MPa, BP2 에서 348 MPa, BP3에서 791 MPa 이었다. 최대등가응력의 최대값은 CP2 와 BP2에서 유의미한 차이가 없었다.
4. 결 론
골흡수가 심한 부분 무치악 하악에서 골의 양을 기반으로 임플란트를 식립했을 때 보철물을 기준으로 식립하는 방법 만큼 좋은 결과를 보여주었다. 캔틸레버 보철물이 있는 모형에서는 보철물에서 가장 큰 최대등가응력이 관찰되었다. 골에서는 캔틸레버 보철물이 있는 모형에서 가장 작은 최대응가응력이 관찰되었다.1. Purpose
The purpose of this study was to evaluate the biomechanical behavior of a buccal cantilever and to compare it with other prosthetic designs to determine the best design in terms of stress distribution within the bone of a buccally resorbed partially edentulous mandible.
2. Material and methods
Based on patient computed tomography (CT) scan data, three finite element models were created. Each model composed of the severely resorbed mandible, the first premolar, the second molar and the implants that replaced the second premolar and the first molar. The first model had two implants placed based on bone quantity creating a buccal cantilever (CP2). The second model had two prosthetic-driven implants (BP2). The third model had three prosthetic-driven implants (BP3). In all models preload of 466.4 N on the abutment screw was applied. A load simulating chewing cycle was applied at seventy-five degrees to the occlusal surfaces of the prostheses. The maximum load magnitude was 262 N. The maximum von Mises stresses were demonstrated and compared in cortical and cancellous bone as well as the implant components.
3. Results
The results showed that the cantilever model exhibited better stress distribution compared to the other models. The overall maximum von Mises stress in each model was concentrated on the premolar abutment for CP2 (1036 MPa), on the molar screw for BP2 (982 MPa) and on the premolar abutment for BP3 (922 MPa). In the cortical bone, the maximum von Mises stress was around the neck of the implants with values as follows: 293 MPa in CP2, 348 MPa in BP2 and 791 MPa in BP3. For the cancellous bone von Mises stress was concentrated at the apex of the premolar implants for BP2 and BP3. For CP2 the maximum von Mises stress was around the implant neck. The recorded values were 26 MPa in CP2, 348 MPa in BP2 and 791 MPa in BP3. Von Mises stress peaks in the implants components did not exhibit significant difference.
4. Conclusion
Considering the severely resorbed partially edentulous posterior mandible, placing implants based on the available bone quantity is more desirable than prosthetic-driven implant placement in terms of biomechanical behavior. The cantilever model created the highest maximum von Mises stress among the three models with regard to the prosthesis. However, when considering the bone, the cantilever model recorded the lowest maximum von Mises stress.Ⅰ. INTRODUCTION, page 1
Ⅱ. MATERIAL AND METHODS, page 7
Ⅲ. RESULT, page 11
Ⅳ. DISCUSSION, page 12
V. CONCLUSION, page 18
REFERENCES, page 19
TABLES, page 27
FIGURES, page 30
국문초록, page 40Maste
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