[The mechanical behavior and biocompatibility of different modern ideas of partial fixed free-end saddle dentures]

This research is aimed to check the mechanical holding and the biocompatibility at various conceptions of removable partial dentures with free saddles, constituted from satellite alloys. As a matter of fact, the duality of the supporting surface in this kind of dental prosthesis sets biological problems, that one must try to sort out in the best way. It consists of three in vitro experimentations to point out the type or the types of framework answering in the best way to biomechanical and biological requirements. The very same equipment has been used on that three experimentations adapting it to the needs. It's "a machine to overdrive", imagined into the building of "L'Ecole supérieure d'Aéronautique de Toulouse"; this machine is made of an electric engine with an axis of rotation, of two speed reducers giving a motion, of one turn by second, of a knee-joint converting a rotary motion to an alternating motion, of a lever-arm enclosing supporting the weights, of a needle with a foam point which secure the saddles or the strategic zones, of two supporting mandibular and maxillary framework resin patterns, and on the areas representing the osteo-mucosa support capped uniformly with a compressible silicone material of on millimetre thick, of one dynamometer and of an accurate comparator to check the strength used, and the displacement tested zones. The first part consists in testing the amplitude of the saddle displacement and the mobilization of strategic joining areas from various frameworks used. So we can infer the impact on the mucosa during the function. That is why six types of frameworks have been achieved in Wironit satellite alloy showing mechanical qualities admitted to be excellent and to be subject to very accurate experiment conditions with 30 Kz strength (Lundeen and Gibbs, 1982). The results are interpreted through the reading of histograms which X-AXIS represent the points where motions have been located and the Y-AXIS represent the motion at 1/100th millimetre. It allows to show the existence more or less important of the saddle displacement which is not far from the mucosa one and constitute therefore on the biological view point a favourable component but also the existence of tensions in level of some strategic zones which let foresee, for same, a risk of weariness.(ABSTRACT TRUNCATED AT 400 WORDS)