Complete denture retention. Part I: Physical analysis of the mechanism. Hysteresis of the solid-liquid contact angle.

Analysis of physical forces involved in the mechanism of denture retention clearly shows that the hysteresis of the liquid-solid contact angle governs the viscoelastic response of the system dislodgment. This result is in contradiction to the most commonly admitted view according to which perfect wettability is necessary to obtain good retention and implies the existence of the high advancing contact angle of saliva on a prosthetic material.