Abstract: A fluoride-containing bioactive glass composition suitable for bulk implant prosthetic devices and coatings for prosthetic devices, the bioactive glass compositions selected from glass formulations containing, by mole 46.1% SiO.sub.2, 2.6% P.sub.2 O.sub.5, 26.9% CaO and 24.4% Na.sub.2 O and glass formulations containing, by mole, 52.1% SiO.sub.2, 23.8% CaO, 21.5% Na.sub.2 O, 2.6% P.sub.2 O.sub.5 wherein, respectively, 30 to 50 molar percent and 40 to 60 molar percent of the CaO is substituted with CaF.sub.2. These fluoride-containing bioactive glass materials demonstrate high resistance to demineralization in physiological fluids as well as extensive apatite formation which shows a predominance of crystalline apatite of mixed phase character.

Abstract: A middle ear prosthesis is constructed of a bio-active bio-compatible glass. The prosthesis includes a substantially disc-like base member, one base surface of which is adapted to bond to the tympanic membrane, and a substantially cylindrical stem member projecting from the other base surface. The axis of the stem member is offset from the center of the base member and perpendicular to the base surface.