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.
Claims
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): ##STR00002## 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.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0085] In the accompanying drawings:
[0086] FIG. 1 is a schematic drawing showing an exemplary prior art dental prosthesis comprising a plurality of locating formations;
[0087] FIG. 2 is a detailed plan view of a locating formation of an exemplary prior art dental prosthesis;
[0088] FIG. 3a is a schematic cross-section of the locating formation of FIG. 2;
[0089] FIG. 3b is a schematic cross-section of the locating formation of FIG. 2 shown with a dental abutment in location;
[0090] FIG. 4 is a perspective cross-section of a locating formation in accordance with the invention shown with a sleeve in position;
[0091] FIG. 5 is a cross-section elevation of the locating formation of FIG. 4 but shown with the sleeve absent;
[0092] FIG. 6 is a cross-section elevation of the locating formation of FIG. 4 shown with a sleeve;
[0093] FIG. 7 is a cross-section elevation of the locating formation of FIG. 4 shown with a sleeve and exemplary dental abutment or implant feature in location;
[0094] FIG. 8 is a perspective view of an exemplary sleeve in accordance with the invention;
[0095] FIG. 9 is a dimensioned cross-section elevation of an exemplary locating formation in accordance with the invention;
[0096] FIGS. 10a, 10b and 10c show exemplary dental prostheses comprising locating formations in accordance with the invention;
[0097] FIGS. 11a, 12a and 13a are perspective cross-sections of exemplary locating formations in accordance with the invention having domed shapes; and;
[0098] FIGS. 11b, 12b and 13b are cross-section elevations of the locating formations of FIGS. 11a, 12a and 13a, respectively.
[0099] FIG. 14 is a cross-section of an exemplary locating formation in accordance with the invention adapted for connection directly to an implant head of a Straumann® dental implant system.
[0100] FIGS. 15a and 15b are cross-sections of an exemplary locating formation in accordance with the invention adapted for connection directly to an implant head of a
[0101] Nobel Biocare® dental implant.
DETAILED DESCRIPTION
[0102] With reference to FIG. 1 there is shown an exemplary dental prosthesis 1 comprising a plurality of locating formations 2 adapted for mounting the prosthesis to a dental implant fixture or feature (not shown) affixed to a patient's jaw, or to an intermediate dental abutment that is attached to the free end of a dental implant fixture (not shown) affixed to a patient's jaw.
[0103] With reference to FIGS. 2, 3a and 3b, a known type of locating formation 2 in a dental prosthesis 1 is formed having a tapered recess 3 that is separated from a substantially cylindrical bore 4 (FIGS. 3a and 3b) by a radially inwardly extending flange 5 (FIG. 3a). The tapered recess 3 is shaped to accommodate and engage a dental abutment or an abutment multi-unit or a dental implant feature 60 as shown schematically in FIG. 3b. An aperture 5A (FIG. 3a) defined by flange 5 permits the shank of a screw 6 (FIG. 3b) to extend through the locating formation 2 via bore 4 in order to screw threadedly engage with a dental abutment or dental implant feature 60 as shown in FIG. 3b. As screw 6 is tightened, the screw head engages the inwardly extending flange 5 thereby drawing the prosthesis 1 into tighter engagement with the dental abutment or dental implant feature 60 thereby affixing the prosthesis firmly to the patient's jaw. In FIG. 3b a gap is shown between the dental abutment or dental implant feature 60 and the tapered recess 3 of the locating formation 2 however it will be appreciated that the dental abutment and the tapered recess features contact in use.
[0104] Such dental prostheses are commonly machined from a block of material, for example a ceramic or polymeric block, by computed aided milling, with the specific geometry of the prostheses and their respective locating formations in dependence upon data collated using digital technology and in relation to the intended recipients of said prostheses.
[0105] With reference to FIGS. 10a, 10b and 10c there is shown as series of dental prostheses 10 each comprising a plurality of locating formations 20 in accordance with the invention.
[0106] Prostheses 10 in accordance with the invention are preferably polymeric prostheses having a composition consisting of polyetheretherketone (PEEK) polymer, preferably, PEEK-OPTIMA™ of melt viscosity (MV) 0.45 kNsm.sup.−2 , simply referred to hereinafter as PEEK. Preferably still, the PEEK polymeric prostheses are formed from a JUVORA™ Dental Disc made from said PEEK-OPTIMA™.
[0107] FIGS. 4-7, 9 and 11a to 15 each show a cross-section of a segment of a PEEK dental prosthesis 10 in accordance with the invention at the region of a locating formation 20.
[0108] With reference to FIGS. 4, 11a, 12a, 13a, 14 and 15, locating formations 20 comprise a recess 30 adapted to receive a dental abutment, abutment multi-unit, or a dental implant fixture.
[0109] As shown in FIGS. 4, 6, 11a, 11b, 12a, 12b, 13a, 13b and 14, recess 30 comprises a first recess portion 13 formed in the PEEK material of the prosthesis 10, and a second recess portion 43 formed in a sleeve 40 locatable in the prosthesis.
[0110] In the examples of FIGS. 4-7 and 9, recess 30 is shown having an inverted conical frustum shape.
[0111] In the examples of FIGS. 11a to 13b, recess 30 is shown having a domed shape. In FIGS. 12a to 13b the recess has a spherical dome-shape.
[0112] In the example of FIG. 14, recess 30 is shown having a substantially cylindrical first recess portion 13 and a tapered second recess portion 43 defined by a chamfer 48 around the circumference of an aperture provided though a hub 44 which separates said second recess 43 portion from the interior 45 of the sleeve as described below.
[0113] With reference to FIG. 4, when taken as a whole, each recess 30 comprises base 31 and a top 32, wherein the base is narrower than the top such that the sidewall 33 of said recess tapers towards the base 31.
[0114] In the example shown in FIG. 5, the first recess portion 13 is a tapered recess. The first recess 13 is formed in the PEEK material of the prosthesis, for example by computed aided milling or other suitable means. The first recess portion has an upper end and a lower end with a tapered sidewall 33A thereinbetween. The lower end of first recess portion 13 has a diameter D1. The tapered sidewall 33A has taper angle Φ (not shown). A bore 14 having a diameter greater than D1 is formed in the prosthesis 10 below and opposing first recess portion 13 such that an annular undercut 15 region is formed immediately below said lower end of the first recess portion. Thus the bore 14 is in communication with the first recess portion 13.
[0115] In the examples shown in FIGS. 4-7 and 9, recess 30 is shown as an inverted conical frustum-shaped recess having a tapered sidewall 33, however it will be appreciated that the recess may be any other suitable inverted frustum-shaped recess and may therefore comprise a plurality of sidewalls.
[0116] With reference to FIGS. 4, 6 and 8, sleeve 40 comprises a generally tubular wall 41 and an annular shoulder portion 42 having an inner and an outer perimeter, wherein the inner perimeter of the shoulder portion 42 defines the perimeter of a recess portion 43. In FIGS. 4-8 recess portion 43 is shown having a tapered sidewall 33B surrounding an internally offset hub 44 which separates said recess portion 43 from the substantially cylindrical interior 45 of the sleeve. Recess portion 43 is thus the second recess portion of recess 30 in use.
[0117] The diameter D2 (FIG. 8) of the perimeter of recess portion 43 at its junction with the shoulder portion 42 is substantially the same as diameter D1 (FIG. 5) of the lower end of first recess portion 13 formed in the prosthesis.
[0118] The shoulder portion 42 and hub 44 of sleeve 40 lie on substantially parallel spaced apart planes which are substantially orthogonal to the wall 41.
[0119] The tapered sidewall 33B has a taper angle Φ (not shown) which is substantially equal to the taper angle Φ of tapered sidewall 33A. Thus the first recess portion 13 and the second recess portion 43 are contiguous.
[0120] Sleeve 40 is preferably manufactured from titanium or an alloy thereof, however other suitable materials or alloys may be used, for example, but not limited to Cobalt Chromium (Co-Cr), stainless steel, etc.
[0121] When sleeve 40 is fully inserted within bore 14 formed in the prosthesis as shown in FIG. 6, the tubular wall 41 of sleeve 40 is in slidable abutment with the surface of bore 14 and annular shoulder portion 42 of sleeve 40 abuts annular undercut region 15 immediately below the first recess portion 13.
[0122] As shown by way of example in FIG. 8, sleeve 40 is provided with a key formation 41a in order to prevent rotation of the sleeve relative the prosthesis. In FIG. 8 the illustrated key comprises a flat surface on the exterior of sidewall 41 of the sleeve which is adapted to engage with a complementary flat surface provided on bore 14 (not shown) however it will be appreciated that any suitable key arrangement may be employed, for example, but not limited to, ribs, ridges, notches and corresponding grooves, indentations, etc.
[0123] As described above with reference to FIGS. 5 and 8, the respective diameters D1 and D2 of first recess 13 and second recess 43 are substantially the same, and the taper angles D of the respective tapered sidewalls 33A and 33B of recesses 13 and 43 are also substantially equal. Thus when sleeve 40 is located within bore 14 as described above and as shown in FIGS. 4 and 6, the first and second recess portions 13 and 43 are brought into mutual communication and their respective sidewalls 33A and 33B define a continuous tapered sidewall 33 of recess 30. Thus a dental abutment, abutment multi-unit or dental implant fixture 60 located within the locating formation as shown in FIG. 7 will be fully supported along its interface with recess 30. As a result of the presence of sleeve 40 at the interface between the PEEK prosthesis 10 and dental implant fixture 60, the locating formation of the present invention provides increased stability and strength to the connection between said prosthesis and dental implant fixture.
[0124] As shown in FIG. 7, when a dental abutment or an abutment multi-unit 60 is located within recess 30, the surface of hub 44 proximate sidewall 33B of recess portion 43 of sleeve 40 abuts the terminal end of said dental abutment or abutment multi-unit.
[0125] As shown in FIG. 7, an aperture 46 (see FIGS. 6 and 8) provided though hub 44 permits the shank of a screw 6, inserted via the interior 45 of the sleeve to extend through said sleeve 40 and into recess 30 of locating formation 20 to screw threadedly engage with the dental abutment 60. As screw 6 is tightened, the screw head engages the reverse side of hub 44 thereby drawing the prosthesis 10 into tighter abutment with the dental abutment 60 thereby affixing the prosthesis firmly to the patient's jaw.
[0126] Referring to FIG. 9, exemplary dimensions of a locating formation having an inverted conical frustum shape and comprising a titanium sleeve in accordance with the invention are shown. It will be appreciated that these exemplary dimensions apply also to titanium sleeves formed having a dome-shaped recess therein. In the example shown, the depth of the first recess portion 13 (i.e. formed in the polymer of the prosthesis) is approximately 1.7 mm; the depth of the second recess portion (i.e. formed in the sleeve) is approximately 0.6 mm (thus the depth of recess 30 is approximately 2.3 mm); the diameter D2 of the second recess portion 43 at its junction with the annular shoulder portion 42 is approximately 2.6 mm (thus the diameter D1 of the lower end of first recess portion 13 is also approximately 2.6 mm); the width of annular shoulder portion 42 is approximately 0.8 mm; the diameter of the sleeve is 4.2 mm.
[0127] Ideally the minimum thickness of the PEEK prosthesis surrounding the sleeve 40 at it its closest point to the sleeve wall (i.e. perpendicularly adjacent the outer perimeter of annular shoulder 42) is 0.5 mm.
[0128] Preferably, the thickness of the PEEK prosthesis surrounding the sleeve at it its closest point to the outer diameter of the sleeve wall sleeve 40 at it its closest point to the sleeve wall (i.e. perpendicularly adjacent the outer perimeter of annular shoulder 42) is at least 0.7 mm.
[0129] With reference to FIGS. 11a-13b a recess 20 having a dome-shape is shown. Other than the specific shape of the recess defined by its first 13 and second 43 portions, the structure, function and form of a dome-shaped recess and associated reinforcing sleeve 40 is substantially the same as that described in respect of the examples above.
[0130] In the example shown in FIGS. 11a and 11b, the first recess portion 13 (formed in the PEEK material of the prosthesis) and the second recess portion 43 (formed in sleeve 40 locatable in the prosthesis) have curved sidewalls 33 A and 33B which are contiguous such that they define a continuous curved sidewall 33 of recess 30. In the example recess 30 has a substantially flat base 31.
[0131] In the example shown in FIGS. 12a and 12b, the recess 20 is a spherical dome shape wherein the first recess portion 13 (formed in the PEEK material of the prosthesis) and the second recess portion 43 (formed in reinforcing sleeve 40) each have the shape of a spherical segment. Thus recess 20 has contiguous curved sidewalls 33 A and 33B and a substantially flat base 31. The first 13 and second 43 recess portions have the same spherical radius R such that they are contiguous.
[0132] In the example shown in FIGS. 13a and 13b, first recess portion 13 (formed in the PEEK material of the prosthesis) has the shape of a spherical segment while the second recess portion 13 (i.e. formed in the reinforcing sleeve) has the shape of a spherical cap. The first 13 and second 43 recess portions have the same spherical radius R such that they are contiguous, however recess 30 is absent a flat base.
[0133] In the example shown in FIG. 14, which is adapted for direct connection to an implant head of a Straumann® dental implant system, the first recess portion 13 (formed in the PEEK material of the prosthesis) is substantially cylindrical. The second recess portion 43 is formed in sleeve 40 and is defined by a chamfer 48 provided on shoulder portion 42 and around the circumference of aperture 46 provided though hub 44 which separates said second recess portion 43 from the interior 45 of the sleeve. A second chamfer 49 is provided around the hub 44 adjacent the cylindrical interior 45 of the sleeve. An annular trough 51 formed around the cylindrical wall of the first recess portion 13 at a lower end of said first recess portion is adapted to engage flush with a corresponding feature of a Straumann® dental implant design, and on an external emergence profile to fit with the gum line in use.
[0134] In the example of FIG. 14, recess 30 is shown having a substantially cylindrical first recess portion 13 and a tapered second recess portion 43 defined by a chamfer 48 around the circumference of an aperture provided though a hub 44 which separates said second recess 43 portion from the interior 45 of the sleeve as described below.
[0135] With reference to FIGS. 15a and 15b, in an aspect of the invention there is provided a reinforcing sleeve for location in a bore 4 formed in dental prosthesis, the reinforcing sleeve 40 comprising a generally tubular wall 41 and having a hub 44 at one end and an open bore 50 at an opposing end. The hub 44 is provided with an aperture 46. Aperture 46 has a diameter that is less than the diameter of the opposing open bore 50. The reinforcing sleeve 40 is insertable into the bore 4 formed in the prosthesis 10 such that the hub 44 abuts the underside of a flange 5 formed in said prosthesis, the flange being located intermediate the bore 4 and a recess 13. When located in the prosthesis in this way, aperture 46 aligns with an aperture 5A defined by flange 5A such that the shank of a screw (not shown) inserted into the prosthesis via the interior 45 of the reinforcing sleeve 40 can extend through said sleeve 40 and into the recess 13 formed in the prosthesis 10 in order to screw threadedly engage the head of a dental implant (not shown) located in recess 13. As the screw (not shown) is tightened, the screw head will engage the underside of the hub 44 thereby drawing the prosthesis 10 into tighter engagement with the dental implant head. Such a reinforcing sleeve is particularly suited for use with Nobel Biocare® dental implant systems.
[0136] Reinforcement of the connection between a dental implant fixture and a prosthesis 10 by the use of a locating formation 20 comprising a reinforcing sleeve 40 in accordance with the invention enables a wider range of torque forces can be applied to the screw used to secure the prosthesis 10 to the implant feature 60.
[0137] This is because the sleeve 40 provides an interface between the screw and the polymeric prosthesis 10 such that the screw does not directly impinge or contact the polymeric prosthesis, but rather the screw head engages the reverse side of the hub 44 of the sleeve.
[0138] Thus higher torque forces can be applied than otherwise would be possible without the presence of such a sleeve 40. Accordingly, the sleeve provides increased stability and wider user flexibility when torqueing the prosthesis 10 to a dental implant feature 60.
[0139] The sleeve 40 allows for a more precise fit between the polymeric prosthesis and the implant interface improving the passivity of the system. Accordingly, the sleeve 40 allows for a greater degree of passivity seating when torqueing the prosthesis 10 to a dental implant feature 60.
[0140] Sleeves 40 also permit the use of screws having small or conical heads to secure a prosthesis 10 to an implant feature 60. Thus the invention permits the use of a wider range of dental implant systems, in particular dental implant features adapted to use abutment screws carrying conical and small screw heads.
[0141] Advantageously, the small size of the sleeve (approximately 4.2 mm diameter) mitigates its impact on the overall dimensions of a polymeric prosthesis adapted to receive such a sleeve. Thus prostheses in accordance with the invention achieve maximum stability with minimal dimensional change required to said prostheses.
