Method for the electrophoretic coating of dental substrates

Abstract

The coating of dental substrates, such as the stumps of a working model or implants including ceramics, e.g. alumina, by means of electrophoresis results, especially because of the production of gas, in products unfit for use. It is therefore the aim of the invention to provide a coating method that allows for a high-quality coating of dental substrates in the shortest time possible, irrespective of the material constitution of the substrate. According to the inventive method, the substrate (stump 2 ) is fixated in an insulating mass ( 3 ) in a vertical holder ( 1 ). The substrate is coated with a separating agent and a hygroscopic layer and a further layer is applied thereon by shortly dipping the stump into the slip ( 6 ). The current used for electrophoresis is supplied via the layer ( 7 ) so formed. The inventive method, when used for non-conducting substrates, requires no silver enamel or the like. The method can also be used for conducting substrates, e.g. titanium implants, as the current flows only via the layer ( 7 ).

1 . A method for coating of dental substrates with a ceramic by electrophoresis in an aqueous slip, characterized by 
 a. fixing the substrate ( 2 ;  12 ) in a vertically moving holder ( 1 ;  11 ) in an insulating mass ( 3 ;  13 ),    b. coating the substrate ( 2 ;  12 ) with a separation agent    c. applying a hygroscopic salt layer onto the separation agent    d. dipping the region so coated into the slip and    e. pulling out the substrate from the slip far enough so that during subsequent application of a voltage only the part of the substrate to be coated with the ceramic is situated in the slip.    
   
   
       2 . A method according to  claim 1 , characterized by supplying current to the substrate via a tongue ( 4 ).  
   
   
       3 . A method according to  claim 1 , characterized by supplying current to the substrate via the applied layer, the layer being in contact with holder ( 11 ).  
   
   
       4 . A method according to  claim 1 , wherein the substrate is a stump ( 2 ) made of gypsum.  
   
   
       5 . A method according to  claim 1 , wherein the substrate is an implant abutment made of titanium or ceramic.  
   
   
       6 . A method according to  claim 1 , wherein the salt layer contains sodium chloride.  
   
   
       7 . A method according to  claim 1 , wherein surfactants are added to the salt layer.  
   
   
       8 . A method according to  claim 1 , wherein dentin or a cutting mass is applied to a metallic or ceramic substrate.  
   
   
       9 . A method according to  claim 1 , wherein the separation agent is coated with solids of the slip.  
   
   
       10 . A method according to  claim 1  and further comprising coating a stump ( 2 ) of a working model or an implant abutment ( 12 ) with alumina or zirconia during the subsequent application of the voltage.