[Adhesion, contribution to full denture retention: experimental research on resin surface energy]

The authors propose a study of the surface energy of dental resins. The two liquids measure method, by means of water and alkanes enables to determine the dispersive and polar components of this energy and therefore to understand what types of bindings may be altered in the process of various physical or chemical treatments of the surface of the material. Treatment by alcoholic potash, or immersion of the resin in water, increase the polar component of surface energy by inducing a re-orientation of polymer molecules along the interface between P.M.M.A. and water. This improvement is not reversible. It reaches its maximum towards the eighth day of immersion in water. It cannot be obtained in saliva, a feebly polar medium. After a temporary increase towards the third day, the dispersive component of surface energy falls back approximately to its initial value. This treated resin can no longer be considered as a low energy solid. All comparative experimentation on the surface energy of prosthetic materials ought to be made on resin treated by water immersion.