Retention in complete denture Definition That quality inherent

Retention in complete denture

Definition That quality inherent in the prosthesis which resist the force of gravity , adhesiveness of food , and the forces associated with the opening of the jaw.

The factors that affect retention Anatomical factors Physiological factors. Physical factors Mechanical factors Muscular factors

The various anatomical factors Size of the denture bearing area Quality of the denture-bearing area

Physiological factors Saliva-viscosity of saliva determines retention. Thick ropy saliva-loss of retention Very thin watery saliva also lead to compromised retention

Physical factors Adhesion Cohesion Inter facial surface tension Capillary attraction Atmospheric pressure

Adhesion The physical attraction of unlike molecules to one another

Cohesion The physical attraction of like molecules for each other

Inter facial surfacial tension The tension or resistance to separation possesssed by the film of liquid between two well-adapted surfaces

Capillary attraction That quality or state , because of surface tension causes elevation or depression of the surface of a liquid that is in contact with the a solid

Atmospheric pressure

Mechanical factors Undercuts Retentive springs Magnetic forces Denture adhesives Suction chambers suction discs

Muscular factors Neutral zone Definition – It is defined as the zone in which the forces of the tongue directed outwards are neutralized by the forces of the lips and cheeks directed inwards. Also called the zone of equilibrium.