CAJ | 학술논문

目的：确定下颌前磨牙牙体长轴和釉牙骨质界，建立三维有限元分析模型，研究牙槽骨吸收程度对下颌前磨牙牙周膜承受应力的影响。方法：选择离体下颌前磨牙，通过micro-CT扫描重建牙齿三维图像、通过锥形拟合法确定牙体长轴、手工划定釉牙骨质界，将牙根十等分、划分单元格、设定模型力学性质、设定加载，建立下颌前磨牙的三维有限元模型。加载力值100N；加载方向为与牙体长轴平行、与牙体长轴成45°、与牙体长轴垂直；加载位置位于牙体长轴与牙合面相交的点。分析不同牙槽骨吸收程度、不同加载方向下牙周膜所受的最大Von Mises应力值。结果：结合牙体长轴、釉牙骨质界的概念，建立了三维有限元分析模型。随着牙槽骨吸收程度的增加，下颌前磨牙牙周膜的Von Mises应力最大值显著增高。在与牙体长轴平行的加载力作用下，牙槽骨吸收达到50%时下颌前磨牙牙周膜承受的最大应力为牙槽骨无吸收时的2倍；在与牙体长轴垂直或与牙体长轴成45°的加载力作用下，下颌前磨牙牙槽骨吸收30%时牙周膜最大应力值达到牙槽骨无吸收时的2倍。结论：在建立三维有限元分析模型时结合牙体长轴、釉牙骨质界的概念，有利于规范和统一加载方向、模拟不同牙槽骨吸收量。对于下颌前磨牙牙周膜应力分析结果表明，当牙槽骨吸收至30%时将会对牙周组织造成损伤。
목적：학정하합전마아아체장축화유아골질계，건립삼유유한원분석모형，연구아조골흡수정도대하합전마아아주막승수응력적영향。방법：선택리체하합전마아，통과micro-CT소묘중건아치삼유도상、통과추형의합법학정아체장축、수공화정유아골질계，장아근십등분、화분단원격、설정모형역학성질、설정가재，건립하합전마아적삼유유한원모형。가재력치100N；가재방향위여아체장축평행、여아체장축성45°、여아체장축수직；가재위치위우아체장축여아합면상교적점。분석불동아조골흡수정도、불동가재방향하아주막소수적최대Von Mises응력치。결과：결합아체장축、유아골질계적개념，건립료삼유유한원분석모형。수착아조골흡수정도적증가，하합전마아아주막적Von Mises응력최대치현저증고。재여아체장축평행적가재력작용하，아조골흡수체도50%시하합전마아아주막승수적최대응력위아조골무흡수시적2배；재여아체장축수직혹여아체장축성45°적가재력작용하，하합전마아아조골흡수30%시아주막최대응력치체도아조골무흡수시적2배。결론：재건립삼유유한원분석모형시결합아체장축、유아골질계적개념，유리우규범화통일가재방향、모의불동아조골흡수량。대우하합전마아아주막응력분석결과표명，당아조골흡수지30%시장회대아주조직조성손상。
Objective:To establish three dimensional finite element analysis models based on tooth long axis, and to investigate the effects of alveolar bone loss on stress distribution of periodontal ligament of mandibular premolar.Methods:A sound extracted mandibular premolar was selected. Finite-analysis modeling procedures included micro-CT scanning, the digital tooth modeling, determining the long axis and the cemento-enamel junction, dividing the root into ten equal sections, and establishing the stress analysis model. The loading force was 100N, and the loading directions were either parallel, perpendicular, or 45 degrees to the tooth long axis. The values of maximum Von Mises stress were calculated.Results:Three dimensional finite element analysis models were established based on tooth long axis and the cemento-enamel junction. The values of maximum Von Mises stress increased along with the ratio of alveolar bone loss. When the forces were applied parallel to the long axis of the tooth,the maximum Von Mises stress of periodontal ligament in 50% alveolar bone loss is two times higher than normal teeth without bone loss. When the forces were applied perpendicular, or 45 degrees to the long axis of the tooth, the maximum Von Mises stress of periodontal ligament in 30% alveolar bone loss was two times higher than normal teeth without bone loss.Conclusion:For mandibular premolars, the alveolar bone loss up to 30% will cause damage to the periodontal tissues.