釉牙本质界潜行性破坏对牙颈部硬组织应力分布的影响

Effects of undermining damage of enamelo-dentinal junction on stress distribution of sclerous tissues of dental cervix

背景:对釉牙本质界缺损的下颌前磨牙进行有限元接触分析,为楔状缺损的预防及咬合治疗提供生物力学依据。目的:分析釉牙本质界潜行性破坏对牙颈部硬组织应力分布的影响。方法:在下颌前磨牙沿釉牙本质界建立三角形缺损设计楔状缺损模型,模拟紧咬和咀嚼运动中牙的受力情况,对下颌前磨牙颈部硬组织进行非线性接触分析。结果与结论:模拟紧咬和咀嚼运动中牙的受力情况,釉牙本质界缺损的下颌前磨牙缺损区均存在明显应力集中。随着缺损高度的增加,应力值增大,应力集中程度也增加。可见釉牙本质界破坏改变了缺损区牙颈部的应力分布,临床上楔状缺损应及时充填治疗。

BACKGROUND：Finite element contact analysis was performed in premolars of lower mandible with enamelo-dentinal junction defects, which provided biomechanical evidence for the prevention of wedge-shaped defect and occlusion treatment. OBJECTIVE：To analyze the effects of undermining damage of the enamelo-dentinal junction on the stress distribution of sclerous tissues of dental cervix. METHODS：Triangle defects were established and models of wedge-shaped defect were designed in mandibular premolar along the enamelo-dentinal junction. The stresses during tightly biting and masticatory movement were simulated. Nonlinear contact analysis was conducted in sclerous tissues of mandibular premolar in the buccal cervical region. RESULTS AND CONCLUSION：By simulating the stresses during tightly biting and masticatory movement, the stresses were concentrated in the defected regions of mandibular premolar at the enamelo-dentinal junction. With the defect length increased in size, the stress value and the magnitude of the stress field both increased. These indicated that the destruction of enamelo-dentinal junction altered stress distribution in the buccal cervical region. In the clinic, wedge-shaped defect should be fil ed promptly.