Eliason C M
J Prosthet Dent. 1983 Jan;49(1):25-7. doi: 10.1016/0022-3913(83)90232-9.
The RPA design has been discussed as an alternative to the RPI design. With its mesial rest and special retentive arm design, it gives essentially the same kind of tooth release that the RPI clasp provides. In addition, there are some advantages over the RPI design. The circumferential-type retentive arm is easier to grasp for removal of the prosthesis. The clasp is simple in design with few variations among patients and thus can be easily and consistently fabricated by dental laboratories. But most important, the circumferential retentive arm avoids the tissue problems around abutment teeth and allows the RPA clasp to be used in many situations where the RPI clasp is contraindicated.
RPA设计已被作为RPI设计的替代方案进行讨论。凭借其近中支托和特殊的固位臂设计,它能提供与RPI卡环基本相同的牙齿脱位效果。此外,与RPI设计相比还有一些优势。环形固位臂更容易抓持以便取下修复体。该卡环设计简单,不同患者之间差异很小,因此牙科实验室能够轻松且一致地制作。但最重要的是,环形固位臂避免了基牙周围的组织问题,使得RPA卡环能够用于许多RPI卡环禁忌使用的情况。