目的设计具有应力中断结构的单侧游离端附着体义齿，研究其在功能载荷下的应力传导方式。方法 选择1例个别正常牙合的志愿者，制取其石膏模型并模拟右侧下颌游离端缺失，完成应力中断式附着体义齿的设计和制作。对同一志愿者进行下颌骨牙科锥形束CT扫描，应力中断式附着体义齿进行激光扫描，在计算机中构建三维有限元模型。模拟咬合状态，分析应力中断式附着体义齿的应力传导方式。结果 设计并制作了具有应力中断结构的单侧游离端附着体义齿，构建了三维有限元模型。垂直和侧向载荷下，义齿基托区应力由近中连接体传递至基牙后，沿基牙长轴方向传导，基牙应力分布均匀。结论 本研究设计的应力中断式附着体义齿在修复单侧游离端缺失时可以有效改变义齿基托传递至基牙的应力方向，实现应力中断效应。
Objective To design an attachment-retained unilateral distal-extension removable partial denture with a stress-breaking structure and to analyze the stress conduction mode of it under the functional load. Methods An attachment-retained removable partial denture with a stress breaking structure was designed on the simulated distal-extension absence with a plaster model from a volunteer’s mandibular teeth with individual normal occlusion. After the 3D images of the volunteer’s mandible were obtained by cone beam computed tomography （CBCT） scanning, and the stereo images of the fabricated stress-breaking denture were attained by 3D laser scanning. The data were transmitted into a computer to reconstruct digital 3D models for finite element analysis. Stress conduction of the denture under the functional load was analyzed in simulating human occlusion. Results An attachment-retained unilateral distal-extension removable partial denture with a stress-breaking structure was designed and fabricated. A digital 3D element model of it was also successfully constructed. Under the functional vertical load and lateral load, the stress borne by the denture base was transmitted to the abutments through the mesial connector, which axially loaded on the abutment teeth, and the distribution of the stress on the abutment teeth was much uniform. Conclusion Our designed direct transmission of the stress from the denture base is interrupted by the stressbreaking structure of the attachment-retained denture.
Acta Academiae Medicinae Militaris Tertiae
retained by attachment
unilateral distalextension absence
threedimensional finite element