活动义齿的组成及覆盖义齿.ppt

components of the partial denture;A typical removable, extension partial denture will generally have these components: one or more bases; one or more major connectors; several minor connectors; two or more direct retainers; one or more indirect retainers; varying number of resin or porcelain teeth or resin teeth with cast occlusal surfaces to replace those missing. Where the direct retainer is of the clasp type, it will usually include an occlusal rest, a reciprocal clasp arm and a retentive clasp arm. 一个典型的伸展性可摘局部义齿通常有这些部分组成：一个或多个基托；一个或多个大连接体；几个小连接体；两个或多个直接固位体；一个或多个间接固位体；不定数目的树脂或全瓷牙，或带有金属合面的树脂牙来替代缺失牙。直接固位体是卡环，它通常包括合支托，卡环的对抗臂和固位臂。;The base;The extension base also stimulates those structures covered by it, thus encouraging tissue tonus. Given the stability achieved through maximum coverage, the base aids in lessening the twisting and/or tilting forces inherent in an extension partial denture, thus minimizing the stress load which reaches the abutment teeth. 延伸的基托也可以刺激其覆盖的组织，从而维持组织的健康。假如通过最大化的覆盖面积可以获得义齿的稳定，基托辅助减轻延伸性局部义齿本身扭转或倾斜的力量，从而减少对基牙产生的应力。;The connectors 连接体;In whichever form that convenience or anatomic conditions may dictate, however, the functions of the major connector remain the same. It unifies the various component parts of the partial denture. 无论是哪种情况，方便性或解剖情况都要考虑，但是大连体的功能都是相同的。它将局部义齿的各个组成部分连成一体。 ;If the major connector is rigid, it will be capable of transmitting stress loads effectively and, by his distribution, it lessens the concentration of stresses at certain areas in the dental arch. Also, the principle of leverage may be utilized to decrease torque stresses on the abutments, by having the terminal of a rigid major connector anchored as remotely as possible from the “free-end”. 如果大连接体是刚性的，它可以有效的传递应力，通过大连接体的分布，它可以减少牙弓某些区域应力的集中。另外，可以利用杠杆原理，通过末端的硬性的大连接体连接到离游离端尽可能远来减???对基牙的扭转应力。 ;The minor connectors 小连接体 This unit usually occurs in multiple. These parts perform the important functions of unifying the various components of the appliance, thus making p