Frictional Retention
Posted on 11/21/2011
Frictional Retention, or the retention created from contact surfaces like guide plates, is an excellent source of retention but often not possible to achieve. This is because guide surfaces must be parallel. Since creating parallel guide plates is difficult and often impossible, frictional retention is not always a reliable source of retention.
In addition to non-parallel guide plates leading to minimal frictional retention, the following two design mistakes will lead to further deterioration of frictional retention:
(1) Blockout of the master cast is excessive
(2) Guide plates are over-relieved
The one situation that does lend itself for use of frictional retention is when abutment teeth are crowned and the proximal and lingual surfaces are paralleled by the lab.
As a result, utilizing frictional retention relies heavily on the lab tech working on the case. If the lab tech is not highly experienced, relying solely on this form of retention can lead to continual retention issues.
*Portions of this post were adapted from the book: Atlas of Removable Partial denture Design by Dr. Russell J. Stratton and Dr. Frank J. Wiebelt published by Quintessence Publishing Co., Inc. in 1988.
In addition to non-parallel guide plates leading to minimal frictional retention, the following two design mistakes will lead to further deterioration of frictional retention:
(1) Blockout of the master cast is excessive
(2) Guide plates are over-relieved
The one situation that does lend itself for use of frictional retention is when abutment teeth are crowned and the proximal and lingual surfaces are paralleled by the lab.
As a result, utilizing frictional retention relies heavily on the lab tech working on the case. If the lab tech is not highly experienced, relying solely on this form of retention can lead to continual retention issues.
*Portions of this post were adapted from the book: Atlas of Removable Partial denture Design by Dr. Russell J. Stratton and Dr. Frank J. Wiebelt published by Quintessence Publishing Co., Inc. in 1988.
