RPD Framework - Retention: An Introduction
Posted on 11/17/2011
Retention and the retainers that provide it, is an important but often misunderstood aspect of partial denture design. While it may seem logical that a framework with strong retention is ideal, in fact, many frameworks with few retentive elements are the most successful in the long term. This is because excessive retention often dislodges abutment teeth or causing permanent change to clasps. Ideal retention will prevent the RPD from reasonable dislodging, but not one that would prevent dislodging completely.
To fully understand this concept, we must define the term retention: Retention is resistance to dislodgement of the prosthesis in an occlusal direction*. Since our only goal is to avoid occlusal dislodgement, any retentive elements that prevent other forms of dislodging will often cause more negative outcomes than positive.
In fact, many long term RPD wearing patients show incredible neuromuscular control and adaptability to frameworks that often provide little direct retention. As such, it will be our goal in the posts discussing retention to offer guidelines that will achieve occlusal dislodgement, but provide for long term positive outcomes for the patient.
*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. Pages 45-46.
To fully understand this concept, we must define the term retention: Retention is resistance to dislodgement of the prosthesis in an occlusal direction*. Since our only goal is to avoid occlusal dislodgement, any retentive elements that prevent other forms of dislodging will often cause more negative outcomes than positive.
In fact, many long term RPD wearing patients show incredible neuromuscular control and adaptability to frameworks that often provide little direct retention. As such, it will be our goal in the posts discussing retention to offer guidelines that will achieve occlusal dislodgement, but provide for long term positive outcomes for the patient.
*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. Pages 45-46.
