RPI System for success in Mandibular Distal Extension RPD , RPI Systems in RPD The RPI system is a combination of occlusal rest (R) distal guide plate (P) and gingivally approaching I bar clasp (I) used primarily with mandibular distal extension saddles. The minor connector carrying the mesial rest contacts the mesiolingual surface of the abutment tooth and, together with the distal plate, acts as a reciprocal for the tip of the retentive clasp which is positioned on or anterior to the midpoint of the buccal surface of the tooth. The distal guide plate is positioned at the gingival end of a guide surface prepared on the distal aspect of the tooth. Positions of caption Metal Framework of RPI System The RPI system is designed to allow vertical rotation of a distal extension saddle into the denture-bearing mucosa under occlusal loading without damaging the supporting structures of the abutment tooth. As the saddle is pressed into the denture-bearing mucosa, the denture rotates about a point close to the mesial rest. Both the distal guide plate and the I bar move in the directions indicated and disengage from the tooth surface. Potentially harmful torque is thus avoided. When trying in the metal framework, it is advisable to check that it is able to rotate about the abutment tooth in the intended fashion. If this is found not to be the case, the framework should be carefully adjusted to allow this rotation. A distal extension saddle should not be rigidly attached to the abutment tooth by a combination of stiff clasp and long guide plates. If these are incorporated the occlusal loads falling on the saddle, which is in effect a long cantilever arm, are likely to result in the RPD acting like extraction forceps, with consequent damage to the supporting structures of the tooth. Movement of RPI system The effect , http://bit.ly/YgXwdE

RPI System for success in Mandibular Distal Extension RPD , RPI Systems in RPD The RPI system is a combination of occlusal rest (R) distal guide plate (P) and gingivally approaching I bar clasp (I) used primarily with mandibular distal extension saddles. The minor connector carrying the mesial rest contacts the mesiolingual surface of the abutment tooth and, together with the distal plate, acts as a reciprocal for the tip of the retentive clasp which is positioned on or anterior to the midpoint of the buccal surface of the tooth. The distal guide plate is positioned at the gingival end of a guide surface prepared on the distal aspect of the tooth. Positions of caption Metal Framework of RPI System The RPI system is designed to allow vertical rotation of a distal extension saddle into the denture-bearing mucosa under occlusal loading without damaging the supporting structures of the abutment tooth. As the saddle is pressed into the denture-bearing mucosa, the denture rotates about a point close to the mesial rest. Both the distal guide plate and the I bar move in the directions indicated and disengage from the tooth surface. Potentially harmful torque is thus avoided. When trying in the metal framework, it is advisable to check that it is able to rotate about the abutment tooth in the intended fashion. If this is found not to be the case, the framework should be carefully adjusted to allow this rotation. A distal extension saddle should not be rigidly attached to the abutment tooth by a combination of stiff clasp and long guide plates. If these are incorporated the occlusal loads falling on the saddle, which is in effect a long cantilever arm, are likely to result in the RPD acting like extraction forceps, with consequent damage to the supporting structures of the tooth. Movement of RPI system The effect , http://bit.ly/YgXwdE , via كل يوم معلومة من طب الأسنان http://www.facebook.com/photo.php?fbid=450282495054690&set=a.448867895196150.1073741861.157162584366684&type=1