Physical Factors in the Retention of Dentures

By Dr.Swathi Pai on Wednesday, January 7, 2009 with 0 comments

None of the physical factors for retention can be totally explained. However, they all commonly and intricately participate at the moment of dislodgment. Retention is enhanced by he elasticity of the mucous membranes of the basal seat area and by a good border seal which keeps space between denture and mucosa as small as possible.

Physical factors that influence retention:

  1. adhesion (the bond between mucosa membranes and the denture) and cohesion (the molecular bond between saliva or water) were claimed negligible.

  2. Negative atmospheric pressure under the denture was not valid because of imperfect seal and the presence of saliva.

  3. The authors claimed capillary action was the most important. The narrower the space between the denture and mucosa, the more retention occurs.

  4. Viscosity of saliva was responsible for initial retention; as quality over time increases, retention decreases. It also helps prevent dislodgment of the denture.

The Model: Biting or sucking forces deform elastic tissue under the denture which when deformed allows for capillary action retention. As tissues return to natural state and saliva increases, retention begins to fail. It is necessary for a denture, from time to time, to be pushed back against (deform) the mucosa membrane to maintain retention.

Category: Prosthodontics Notes



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