Mill blank library and computer-implemented method for efficient selection of blanks to satisfy given criteria

Abstract

The present invention relates generally to mill blank constructions to facilitate the manufacture of dental restorations. A given mill blank is formed in a shape (i.e. with a given geometry) that has been predetermined to reduce material waste when the mill blank is machined into the final part. A set of two or more blanks each having such characteristics comprise a smart blank “library.” In one embodiment, a smart blank library includes a sufficient number of unique blanks such that, when the geometry of the designed restoration is known, the smart blank with a highest yield can be selected for use in milling the restoration. The “yield” of a given smart blank represents the amount of material of the smart blank that is actually used in the final restoration. Automated processes for smart blank inventory management and smart blank selection are also described.

1 . A method of assembling blanks for use in manufacturing dental restorations, comprising: 
 given a set of blanks, selecting an assemblage of the blanks that satisfy a given criterion, wherein at least first and second of the blanks in the assemblage comprise a body adapted to be shaped by material removal, the body of the first blank having a geometry that differs from the body of the second blank by other than scaling; and    using that assemblage to manufacture dental restorations.    
   
   
       2 . The method as described in  claim 1  wherein the given criterion is that an average yield per blank in the assemblage is maximized.  
   
   
       3 . The method as described in  claim 1  wherein the given criterion is that a weighted average of the blank yields in the assemblage is maximized.  
   
   
       4 . The method as described in  claim 1  wherein the given criterion balances an average yield per blank with a given productivity factor.  
   
   
       5 . The method as described in  claim 1  wherein the given criterion balances an average yield per blank with a given cost factor.  
   
   
       6 . The method as described in  claim 1  wherein the given criterion balances among a set of yield, productivity, cost and tooth distribution factors.  
   
   
       7 . The method as described in  claim 1  further including the step of maintaining the assemblage over a given time period.  
   
   
       8 . An assemblage, comprising: 
 a plurality of mill blanks, at least first and second of the mill blanks in the plurality each comprising a body adapted to be shaped by material removal;    wherein the body of the first blank has a geometry that differs from the body of the second blank by other than scaling.    
   
   
       9 . The assemblage as described in  claim 8  wherein each blank includes a holder to enable the blank to be maintained within a shaping apparatus.  
   
   
       10 . The assemblage as described in  claim 8  wherein at least one of the blanks is formed of a precious metal or precious metal alloy.  
   
   
       11 . The assemblage as described in  claim 8  wherein at least one of the blanks is formed of a semi-precious metal or semi-precious metal alloy.  
   
   
       12 . The assemblage as described in  claim 8  wherein at least one of the blanks is formed of a ceramic.  
   
   
       13 . The assemblage as described in  claim 8  wherein the body of at least one of the blanks has at most one symmetric plane.  
   
   
       14 . A method of producing dental items, comprising: 
 maintaining an assemblage of “m” mill blanks, the assemblage comprising at least first and second mill blanks each comprising a body adapted to be shaped by material removal, wherein the body of the first blank has a geometry that differs from the body of the second blank by other than scaling;    for a given restoration R being designed, selecting a subset {B 1 , B 2 , . . . B n ) of “n” blanks, where n≦m, such that each of the blanks of the subset contain the restoration R; and    selecting a given one of the blanks of the subset for use in producing the restoration.    
   
   
       15 . The method of  claim 14  wherein the given one of the blanks that is selected has the smallest volume.  
   
   
       16 . The method of  claim 14  wherein the given one of the blanks that is selected has a given yield.  
   
   
       17 . The method of  claim 14  wherein the body of at least one of the mill blanks in the assemblage has at most one symmetric plane.  
   
   
       18 . The method of  claim 14  wherein the dental item is prepared by milling the selected blank.  
   
   
       19 . The method as described in  claim 18  wherein the selected blank is milled using a computer-assisted milling machine.