[Stress breaking saddle framework or stress breaking framework. 1. Principles]

The treatment success of a removable partial denture is conditioned by the respect of the base structures, tooth abutments and hard and soft tissues. In order to achieve this goal, the prosthesis should be in accordance with the following fundamentals: tissue duality (STEIGER diagram); visco-elastic behaviour of the mucous membrane (TURK, KYDD, DALY, PICTON WILLS); JORES, LERICHE and POLICARD principles. The proposed prosthetic solution, the stress breaker framework allows the disconnexion between the saddle and the framework as well as between the different saddles. The originality of the concept is due to the particular design of the framework, which permits the disconnexion of the saddle. Due to its principle, the displacement of the saddle takes place only when mastication forces are applied on the prosthetic teeth. These movements stimulate the bony tissues. The clinical construction of a stress breaker framework can be adapted to all types of edentation, as well as to sub-total dentures. The clinical results shown that, after twelve years of experience, the stress breaker framework allows the preservation of the abutments as well as the conservation of osseo-mucous tissues (no need of rebase). Several experimental research investigations have been carried out. Work on trial banks have revealed that, compared with the semi-rigid framework, the stress breaker framework lays less stress on the abutment and provides a better base surface beneath the saddle. Other studies have dealt notably with the displacement of the saddle as well as with fatigue tests of the prosthetic system. These studies have led to the development of specific preformed systems.