Shibuya T
Bull Tokyo Med Dent Univ. 1975 Sep;22(3):221-34.
This experiment was designed to investigate and evaluate the characteristic behavior of mandibular free-end saddle removable partial denture using various retainers. The abutment tooth displacement and saddle movement were measured while a known vertical force was applied on the saddle. Fifteen different types of free-end saddle dentures were tested, using four various types of prefabricated attachments. Strain-measuring devices were used to measure the extent of abutment tooth displacement and saddle movement. The findings were as follows: 1) The force transmitted to the abutment tooth and the residual ridge were affected by (a) the selection of direct retainers, (b) splinting of abutment teeth, and use of indirect retainers, and (c) the variation in size and shape of the occlusal table on the saddle. 2) The influences by direct retainers a) With use of a resilient joint, the stress was heavily loaded on the residual ridge directly under the direction of force. b) With the joint incorporating the vertical rock-preventing device, a heavy proportion of lateral force was transmitted to the abutment tooth. 3) Both the lateral stress on the abutment tooth and movement of the saddle were reduced more effectively by use of indirect retainers than by splinting of abutment teeth. 4) By reduction of the occlusal area in bucco-lingual dimension, the denture saddle was better stabilized and the lateral stress on the abutment tooth was reduced effectively.
本实验旨在研究和评估使用各种固位体的下颌游离端鞍基可摘局部义齿的特征性行为。在向鞍基施加已知垂直力时，测量基牙位移和鞍基移动情况。使用四种不同类型的预制附着体，对十五种不同类型的游离端鞍基义齿进行了测试。使用应变测量装置测量基牙位移和鞍基移动的程度。结果如下：1）传递至基牙和剩余牙槽嵴的力受以下因素影响：（a）直接固位体的选择；（b）基牙的夹板固定及间接固位体的使用；（c）鞍基咬合面大小和形状的变化。2）直接固位体的影响：a）使用弹性连接体时，应力在力的方向正下方的剩余牙槽嵴上大量加载。b）连接体带有垂直防翘装置时，很大一部分侧向力传递至基牙。3）使用间接固位体比基牙夹板固定更有效地减少了基牙上的侧向应力和鞍基移动。4）通过减小颊舌向咬合面积，义齿鞍基得到更好的稳定，基牙上的侧向应力也有效降低。
