Dental prosthesis

Abstract

A dental prosthesis formed of a composition comprising a polymeric material, the prosthesis comprising one or more locating formations adapted to receive a dental implant fixture or dental abutment, the or each locating formation comprising a recess comprising a first recess portion formed in the polymeric material of the prosthesis, and a second recess portion provided in a sleeve located in the prosthesis.

1 .- 34 . (canceled) 
     
     
         35 . A dental prosthesis comprising:
 one or more locating formations adapted to receive a dental implant fixture or dental abutment, the one or more locating formations comprising a recess having an inverted frustum-shape, the recess comprising a first recess portion and a second recess portion, wherein the first recess portion is formed in a polymeric material, and   a sleeve including the second recess portion,   wherein the polymeric material comprises a repeat unit of formula (I):   
       
         
           
           
               
               
           
         
         wherein t1 and w1 independently represent 0 or 1 and v1 represents 0, 1 or 2. 
       
     
     
         36 . A dental prosthesis as claimed in  claim 35 , wherein the recess comprises a base and a top, wherein the base is narrower than the top such that a sidewall of said recess tapers towards the base. 
     
     
         37 . A dental prosthesis as claimed in  claim 35 , wherein the recess has an inverted conical frustum shape. 
     
     
         38 . A dental prosthesis as claimed in  claim 35 , wherein the first recess portion and the second recess portion are contiguous. 
     
     
         39 . A dental prosthesis as claimed in  claim 35 , wherein the first recess portion is formed in the polymeric material of the prosthesis by milling. 
     
     
         40 . A dental prosthesis as claimed in  claim 35 , wherein the first recess portion has an upper end and a lower end with a sidewall extending thereinbetween. 
     
     
         41 . A dental prosthesis as claimed in  claim 40 , wherein the sidewall of the first recess portion is a tapered sidewall having a taper angle Φ or wherein the sidewall of the first recess portion is a curved sidewall having a radius of curvature R, and/or wherein the dental prosthesis further comprises a bore formed below and opposing the first recess portion, the bore having a having a diameter greater than the diameter of the lower end of the first recess portion such that an annular undercut region is formed immediately below the lower end of the first recess portion. 
     
     
         42 . A dental prosthesis as claimed in  claim 35 , wherein the sleeve comprises a generally tubular wall and an annular shoulder portion, wherein the inner perimeter of the annular shoulder portion defines the perimeter of the second recess portion. 
     
     
         43 . A dental prosthesis as claimed in  claim 42 , wherein the annular shoulder portion and the hub lie on substantially parallel spaced apart planes which are substantially orthogonal to the generally tubular wall of said sleeve. 
     
     
         44 . A dental prosthesis as claimed in  claim 41 , wherein the sleeve is slidably locatable into the bore formed in the prosthesis below and opposing the first recess portion such that the generally tubular wall of said sleeve is in abutment with the surface of said bore and the annular shoulder portion of said sleeve abuts the annular undercut region immediately below the lower end of the first recess portion. 
     
     
         45 . A dental prosthesis as claimed in  claim 41 , wherein the sleeve comprises means to prevent rotation of the sleeve relative to the prosthesis, wherein the means to prevent rotation of the sleeve relative the prosthesis comprises a key formation on the outer surface of the sleeve wall which is adapted to engage with a complementary key formation provided on or in the bore formed in the prosthesis below and opposing the first recess portion, and wherein the respective key formations comprise one or more complementary flat portions provided on the respective opposing surfaces of the sleeve and bore. 
     
     
         46 . A dental prosthesis as claimed in  claim 35 , wherein the depth of the first recess portion is approximately 1.7 mm. 
     
     
         47 . A dental prosthesis as claimed in  claim 35 , wherein the depth of the second recess portion is approximately 0.6 mm. 
     
     
         48 . A dental prosthesis as claimed in  claim 42 , wherein the diameters of the perimeter of the second recess portion and the lower end of the first recess portion are approximately 2.6 mm. 
     
     
         49 . A dental prosthesis as claimed in  claim 42 , wherein the width of the annular shoulder portion of the sleeve is approximately 0.8 mm and wherein the minimum thickness of the prosthesis surrounding the sleeve adjacent the outer perimeter of the annular shoulder of the sleeve is approximately 0.5 mm, and wherein the thickness of the prosthesis surrounding the sleeve adjacent the outer perimeter of the annular shoulder of the sleeve is at least 0.7 mm. 
     
     
         50 . A dental prosthesis as claimed in  claim 35 , wherein the sleeve is manufactured from titanium or an alloy thereof. 
     
     
         51 . A dental prosthesis as claimed in  claim 42 , wherein the diameter of the perimeter of the second recess portion is substantially equal to the diameter of the lower end of the first recess portion. 
     
     
         52 . A dental prosthesis as claimed in  claim 51 , wherein the second recess portion comprises an annular sidewall surrounding a hub that is internally offset from the shoulder portion, wherein the hub is positioned between said second recess portion and the interior of the sleeve, wherein the annular sidewall of the second recess portion is a tapered sidewall having a taper angle 1 that is substantially the same as a taper angle Φ of a sidewall of the first recessed portion. 
     
     
         53 . A dental prosthesis as claimed in  claim 52 , wherein the annular sidewall of the second recess portion is a curved sidewall having a radius of curvature R that is substantially the same as a radius of curvature R of the sidewall of the first recessed portion. 
     
     
         54 . A dental prosthesis as claimed in  claim 52 , wherein the second recess portion is defined by a chamfer provided on the shoulder portion and around the circumference of an aperture provided though the hub.