Abstract: A sintered, shaped long-life dental implant or osseous prosthesis adapted for implantation into a human or animal body with chemical bonding to bone tissue. The implant or prosthesis is the result of sintering of a shaped mass of bioglass particles at or above a temperature softening the bioglass particles to form a bioreactive material having a composition comprising, by weight, 5-14% Na.sub.2 O, 0-12% P.sub.2 O.sub.5, 49-57% SiO.sub.2, and balance, no more than 33% CaO+CaF.sub.2, with the bioreactive material containing 0.5-7% CaF.sub.2. The implant or prosthesis has limited reactivity with bone tissue and a coefficient of expansion less than 10.sup.-5 K.sup.-1 from 0.degree. to 100.degree. C.

Abstract: A method is disclosed for preparing an improved bioreactive material of the glass or partially crystallized glass type for bone prostheses or dental implants, which can be welded to bone tissue by chemical bonding. The material consisting essentially of, by weight, 5 to 14% Na.sub.2 O, 0 to 12% P.sub.2 O.sub.5, 49 to 57% SiO.sub.2, and balance, no more than 33% CaO+CaF.sub.2, the material containing 0.5 to 7% CaF.sub.2, and is prepared by a method comprising the steps of preparing a mixture of powders constituting a precursor of the material made of carbonates, phosphates, silica, oxides and fluorides, melting, homogenizing, casting and cooling the mixture to obtain an intermediate, non-crystallized glass, optionally annealing, and then grinding, either pressing the non-crystallized ground glass obtained cold to shape it, then sintering naturally or under a load after degassing, or sintering under a load directly after degassing, then cooling and optionally polishing or machining.