Berg T, Caputo A A
Section of Removable Prosthodontics, University of California, School of Dentistry, Los Angeles.
J Prosthet Dent. 1993 Sep;70(3):245-50. doi: 10.1016/0022-3913(93)90059-w.
An in vitro study that used photoelastic models compared stress distribution characteristics of three maxillary, bilateral, distal-extension removable partial denture designs when the abutments were subjected to a progressive loss of periodontal support. One design used I-bar retention, a second design used a semiprecision, spring-loaded plunger attachment, and a third design used the ERA attachment. Both attachment designs were tested with and without splinted abutments. The ERA design was also tested with and without supporting rests and included light and heavy retention elements. Periodontal support loss up to 35%, a 60/40 crown-to-root ratio, resulted in increased stress concentrations. The ERA design with supporting rests, light retention elements, and splinted abutments compared very favorably with the I-bar retained design on nonsplinted abutments.
一项使用光弹性模型的体外研究，比较了三种上颌双侧远中游离可摘局部义齿设计在基牙牙周支持逐渐丧失时的应力分布特征。一种设计采用I型杆固位，第二种设计采用半精密弹簧加载栓体附着体，第三种设计采用ERA附着体。两种附着体设计均在基牙有无夹板固定的情况下进行测试。ERA设计还在有无支持支托的情况下进行测试，并包括轻、重固位元件。牙周支持丧失高达35%（冠根比为60/40）导致应力集中增加。带有支持支托、轻固位元件和夹板固定基牙的ERA设计与非夹板固定基牙的I型杆固位设计相比具有很大优势。
