Dental compactor instrument

Abstract

A dental instrument adapted to be used as a dental compactor for condensing a thermoplastic material in the extirpated root canal of a tooth. The dental compactor instrument is formed with a tapered shank or working portion having at least two helical flutes defining at least two continuous helical shoulders. A helical peripheral land extends between adjacent helical flutes at the periphery of the shank. The shoulders have a neutral rake angle at the periphery of the shank.

What is claimed is: 
     
       1. A dental compactor instrument comprising: a shank terminating at a pilot tip end;   a tapered working portion along at least a portion of the length of said shank;   flute means formed in the working portion of the shank defining at least two continuous helical flutes having helical shoulders at the periphery of said working portion of said shank;   a helical land at the periphery of the working portion of said shank extending between adjacent flutes; and   helical shoulders having a substantially neutral rake angle at the periphery of said working portion of said shank.   
     
     
       2. The dental compactor instrument of claim wherein the width of the lands is over about 0.004 inches. 
     
     
       3. The dental compactor instrument of claim 2, wherein the region of the flute walls defining the neutral rake angle lay substantially on a radius of said working portion of said shank. 
     
     
       4. The dental compactor of claim 2, wherein each of said flutes, in transverse cross-section of said flute, are arcuately concave. 
     
     
       5. The dental compactor instrument of claim 4 wherein the flutes are of variable depth. 
     
     
       6. The dental compactor instrument of claim 1, wherein said flutes are of uniform width and uniform pitch. .Iadd. 
     
     
       7.  A dental compactor instrument comprising a shank terminating at a pilot end and including a working portion extending along at least a portion of the length of the shank adjacent said pilot end;   at least one continuous helical flute formed in said working portion of said shank, with said at least one flute defining a curved concave wall when viewed in transverse cross section and a helical shoulder at the periphery of said working portion which faces generally toward said pilot end of said shank, and with said helical shoulder having a substantially neutral rake angle at the periphery of said working portion of said shank; and   a helical land at the periphery of the working portion of said shank and extending between adjacent flute segments. .Iaddend. .Iadd.   
     
     
       8.  The dental compactor instrument as defined in claim 7 wherein the width of said land is at least about 0.004 inches. .Iaddend. .Iadd.9. The dental compactor instrument as defined in claim 8 wherein said working portion is 
     
     
        tapered toward said pilot end. .Iaddend. .Iadd.10.  The dental compactor instrument as defined in claim 7 wherein said at least one helical flute further defines a pair of helical shoulders which face in generally opposite axial directions, and wherein each of said helical shoulders of said at least one flute has a substantially neutral rake angle at the periphery of said working portion of said shank. .Iaddend. .Iadd.11. The dental compactor instrument as defined in claim 7 wherein said helical land has a width which is equal to at least about 50% of the width of said at least one flute when viewed in longitudinal cross section. .Iaddend.