Patent ID: 6027012
Filing Date: 2000-02-22
Classification: A61C

Abstract:
A method for making metal frameworks for dental protheses:of the type comprising metallic cops, optionally coated with resin or ceramic material, designed to be anchored in the mouth directly onto the stump of the tooth or teeth to be restored, contiguous or independent,optionally coupled by also metal intermediate members;using for the embodiment of said cops directly on the master mould, generally of plaster, obtained from the patient maxilla or mandibular cast, i.e. without having to pass through a duplicate in refractory material, first a thin metal sheet forming operation on the stump model of the tooth to be restored and then sintering and/or melting operation of precious, semiprecious and non-precious metal powder, coating said metal sheet, through the effect of a suitable heat supply;using metallic powders having different melting points in order to weld among they the particles having a high melting point with the particles with a lower melting point; wherein said method consists in:(a) directly coating the stump of the master model corresponding to the tooth to be restored, with a film of binding substance which has the property on one hand to keep the metal sheet secured against said stump when forming it and on the other hand to volatilize under the effect of a suitable heat supply so that it allows the metal sheet bearing the metallic powder onto to be taken apart from said stump before the cop proper forming operation under the effect of the suitable heat supply;(b) using, to coat said stump model, in turn coated with said binding substance film, a metal sheet the melting point of which is higher than the melting point of the metal particles of the metal powder designed to melt during cop forming operation under the effect of the suitable heat supply and which has the property not to form, at forming temperature of said cop, an eutectic mixture with one or several of the metal constituents of said metal powder;(c) using, to coat said metal sheet formed on said stump model, a metal powder of which one part of the metal particles has the property to melt at the temperature of transforming the cop proper so that on one hand to weld between them the other portion of the metal particles which did not melt at said temperature and on the other hand to weld the overlying cop which is being formed onto the underlying cop constituted by the metal sheet formed on said model of stump;(d) to submit then the assembly constituted by the metal sheet, coated with metal powder to the action of the suitable heat supply so that a monolithic composed cop is obtained constituted by the coat of overlying metal powder integral with the underlying metallic sheet.