RPI卡环的改良设计

描述了改良ＲＰＩ卡环的设计，并与传统的ＰＲＩ卡环相比较，改良ＲＰＩ卡固位尖端只需进入基牙颊面最远的较小倒凹则可获得听固位，而且更美观，同时也符合远中游离鞍基围绕近中Ｈｅ支托转下沉中，Ｉ杆固位尖端与基牙脱离接触原则。因此发言奶卡环可小或避免伟给基牙持力，量种适用远中淳离端可摘局部义齿的新型止环设计。

The Modified RPI Clasp Design

The modified RPI clasp was described and compared with the conventional RPI clasp in the article. The modified RPI clasp could provide adequate retention with the minimum undercut of the most distal part of abutment tooth and gain good esthetical effect. The I bar tip would disengage from the tooth and reduce or avoid torsional forces transmitted to the abutment tooth when rotation of distal extension base occured around the mesio occlusal rest. Therefore, it is a new type of clasp design for the distal extension removable partial dentures.