DENTAL IMPLANT WITH PROGRESSIVE THREAD

Abstract

A dental implant includes a screw body and screw threads. The screw body has an apical end and a coronal end. Screw threads include a primary thread and a secondary thread, which overlap in at least a portion of the screw thread. Thread depth progressively increases from the coronal end to the apical end. The coronal end may contain any suitable secondary characteristics, such as machined threads, grooves, micro-threads, or any other characteristics favorable to successful outcomes with dental implant treatment. A method of making such a dental implant is also disclosed.

Claims

1. A dental implant having an apical end and a coronal end, the dental implant comprising: a screw body; and at least one screw thread defining a root and a crest, the at least one screw thread comprising a primary thread configuration and a secondary thread configuration along at least a portion of the screw thread, the primary thread configuration and the secondary thread configuration overlapping on at least a portion of the screw thread such that along the overlapping portion of the screw thread the secondary thread configuration extends from the root to an intermediate position between the root and crest, and the primary thread configuration extends from the intermediate position to the crest; wherein the at least one screw thread becomes progressively deeper from the coronal end to the apical end.

2. The dental implant of claim 1, wherein the at least one screw thread is a multi-lead thread.

3. The dental implant of claim 1, wherein the at least one screw thread is a single lead thread.

4. The dental implant of claim 1, wherein the at least one screw thread has a thread pitch of about 0.6 mm.

5. The dental implant of claim 1, wherein the primary thread configuration defines an included angle of about 60°.

6. The dental implant of claim 1, wherein the secondary thread configuration defines an included angle of about 30°.

7. The dental implant of claim 1, wherein the at least one screw thread is V-shaped.

8. The dental implant of claim 1, wherein the at least one screw thread comprises a first portion situated near the coronal end, a second portion situated near the apical end, and a third portion situated between the first portion and the second portion.

9. The dental implant of claim 8, wherein the primary thread configuration and the secondary thread configuration overlap in the first portion, the second portion, and the third portion.

10. The dental implant of claim 8, wherein the primary thread configuration and the secondary thread configuration overlap in the third portion and the second portion only.

11. The dental implant of claim 8, wherein the primary thread configuration and the secondary thread configuration overlap in the third portion only.

12. A method of making a dental implant having an apical end and a coronal end, the method comprising: providing a cylindrical or conical feedstock; applying at least one first cut path to set a lower limit of a depth that increases from the coronal end to the apical end; and applying at least one second cut path along at least a portion of the first cut path to set an upper limit of the depth.

13. The method of claim 12, wherein the method comprises applying two first cut paths and two second cut paths.

14. The method of claim 12, wherein the method comprises applying three first cut paths and three second cut paths.

15. A method of making a dental implant having an apical end and a coronal end, the method comprising: providing a cylindrical or conical feedstock; applying at least one first cut path to set a upper limit of a depth that increases from the coronal end to the apical end; and applying at least one second cut path along at least a portion of the first cut path to set an lower limit of the depth.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below serve to explain various aspects of the invention.

[0013] FIG. 1 is a schematic view of a typical V-thread.

[0014] FIG. 2 is a schematic view of a typical buttress thread.

[0015] FIG. 3 is a schematic view of a typical reverse buttress thread.

[0016] FIG. 4 is a schematic view of a typical square-shaped thread.

[0017] FIG. 5 is a diagrammatic side view of a conventional V-shape threaded dental implant.

[0018] FIG. 6 is a diagrammatic side view of a tapered implant screw with progressive threading.

[0019] FIG. 7 is a schematic view of a pre-threaded implant screw.

[0020] FIG. 8 is a schematic view of a progressively threaded implant screw with V-threads in which the cutting process has destroyed the crest of the threads adjacent to an apical end of the screw.

[0021] FIG. 9 is a diagrammatic side view of one embodiment of the dental implant with V-threads and progressive threading.

[0022] FIG. 10 is a diagrammatic side view of a second embodiment of the dental implant with V-threads and progressive threading.

[0023] FIG. 11 is a diagrammatic side view of a third embodiment of the dental implant with V-threads and progressive threading.

[0024] FIG. 12 is a diagrammatic side view of a fourth embodiment of the dental implant with V-threads and progressive threading.

[0025] FIG. 13 is a schematic diagram of a method of making a dental implant with V-threads and progressive threading.

[0026] FIG. 13A is an enlarged view of the circled region of FIG. 13.

[0027] FIG. 14 is a schematic view of a progressively threaded implant screw with V-threads in accordance with the invention.

[0028] FIG. 14A is an enlarge view of the circled region of FIG. 14.

[0029] FIG. 15 is a schematic diagram of an alternative method of making a dental implant with V-threads and progressive threading.

[0030] FIG. 15A is an enlarged view of the circled region of FIG. 15.

DETAILED DESCRIPTION

[0031] Although the invention will be described next in connection with certain embodiments, the invention is not limited to practice in any one specific type of dental implant. The description of the embodiments of the invention is intended to cover all alternatives, modifications, and equivalent arrangements as may be included within the spirit and scope of the invention as defined by the appended claims. In particular, those skilled in the art will recognize that the components of the embodiments of the invention described herein could be arranged in multiple different ways.

[0032] With reference to FIG. 9, a dental implant 10 is shown with screw body 12 and screw threads 14. The screw body 12 has an apical end 16 and a coronal end 18. Screw threads 14 include primary thread 20 and secondary thread 22. Thread depth progressively increases from the coronal end 18 to the apical end 16, as the diameter of the screw body 12 tapers from the coronal end 18 to the apical end 16. Coronal end 18 may contain any suitable secondary characteristics, such as machined threads, grooves, micro-threads, or any other characteristics favorable to successful outcomes with dental implant treatment. No secondary characteristics are shown in FIG. 9, but one of ordinary skill in the art is capable of selecting the appropriate coronal end features for the particular application.

[0033] The dental implant may be made from any suitable material. For instance, the dental implant may be made of titanium, the metallic element from group 4 of the periodic table, or a titanium alloy. The human body tolerates sufficiently-pure titanium well, which pure titanium does not cause allergic or foreign body reactions. Indeed, titanium forms a molecular bond with bone in a manner unlike most other materials. Therefore, osseointegration of these implants may be viewed as the formation of molecular bonds between the jaw bone of the patient and the titanium implant. Thus, with greater osseointegration, the connection between the bone and the implant is stronger.

[0034] Dental implant 10 may be of any desired length from coronal end 18 to apical end 16. For instance, the length of the dental implant 10 may range from about 3 mm to about 18 mm. This length may be about 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, or any fractional portion thereof. In certain embodiments, the length of the dental implant 10 may be about 6 mm, 8 mm, 10 mm, 11.5 mm, 13 mm, or 16 mm.

[0035] Dental implant 10 may be of any desired diameter. For instance, this diameter may range from about 3 mm to about 7 mm. This diameter may be about 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, or any fractional portion thereof.

[0036] The included angle of the primary thread 20 may be any suitable thread angle. For instance, the included angle of the primary thread 20 may range between about 45° and about 75°, between about 50° and about 70°, or between about 55° and about 65°. In one embodiment, the included angle of the primary thread 20 may be about 60°. The included angle of the secondary thread 22 is generally less than the included angle of the primary thread 20. For instance, the included angle of the secondary thread 22 may range from between about 15° and about 60°, between about 20° and about 50°, or between about 25° and 35°. In one embodiment, the included angle of the secondary thread may be about 30°.

[0037] The thread pitch of the dental implant of the present invention is not particularly limited. For instance, the thread pitch may range from about 0.2 mm to about 2 mm, from about 0.5 mm to about 1.5 mm, or from about 0.6 mm to about 1 mm. In certain embodiments, the thread pitch may be about 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1.0 mm. A common thread pitch used in the industry is 0.6 mm. The thread pitch may be relatively uniform throughout the threaded portion of the dental screw or may be variable.

[0038] The arrangement of the primary thread 20 and secondary thread 22 on screw body 12 is not particularly limited. FIGS. 9-12 provide exemplary embodiments of the dental implant 10. In FIGS. 9 and 10, the primary thread 20 is present near the coronal end 18 of the dental implant 10. Then, a portion of the primary thread 20 is present in the midsection 24 and near the apical end 16 along with the progressively deeper secondary thread 22, which is also present in the midsection 24 and near the apical end 16 of the dental implant 10. A difference between FIGS. 9 and 10 is that the screw body 12 is tapered in FIG. 9 and straight in FIG. 10, although both show a progressive thread.

[0039] Turning now to FIG. 11, just as in FIGS. 9 and 10, the primary thread 20 is present near the coronal end 18 and the progressively deeper secondary thread 22 is present in the midsection 24 with the primary thread 20, but in this embodiment, only secondary thread 22 is present near the apical end 16, not the primary thread 20.

[0040] Alternatively, as shown in FIG. 12, the primary thread 20 may be coupled with the secondary thread 22 throughout the threaded body 26. The coronal end 18 and apical end 16 both include the primary thread 20 and the secondary thread 22.

[0041] The dental implant of the invention may have single lead threads or multiple lead threads. In the embodiments shown in FIGS. 9-12, the threads are double lead threads, meaning there are two starts for the primary thread 20. Similarly, the secondary thread 22 may be single lead or multiple lead.

[0042] The dental implants of the present invention may be manufactured analogously to the process described above as to FIGS. 7 and 8. In FIGS. 13-14A, first cut path 28 creates intermediate threads 30, the upper limit 36 of which is determined by the major diameter of the stock material, and the lower limit 33 establishes an intermediate root. The upper limit defines the crest of the final thread. Second cut path 34 completes the formation of screw threads 14, setting the pitch P2 and the lower limit 31 of the depth ranging from D3 to D4. The distance between lower limit 33 of first cut path 28 and lower limit 32 of second cut path 34 increases from the coronal end 18 to the apical end 16. As best shown in FIG. 14, the two cut paths 28, 34 create primary thread 20 and secondary thread 22. FIGS. 13A and 14A provide an enlarged view of a portion of the thread. During manufacture of the embodiment shown in FIGS. 13-14A, intersection point 38 between cut paths 28 and 34 also represents the interface between primary thread 20 and secondary thread 22, and the lower limit 31 of the depth is formed solely from second cut path 34.

[0043] Cut paths 28 and 34 may be applied in either order. Thus, as shown in FIGS. 15 and 15A, where like labels refer to like features, first cut path 28 could set lower limit 31, followed by second cut path 34 setting the upper limit 36. Furthermore, in the case of multiple lead threads, multiple first cut paths 28 and second cut paths 34 may be applied.

[0044] The implants are placed using conventional methods. First, the dental practitioner accesses the jawbone of an anesthetized patient by using either a scalpel to create flaps from the gum tissue or a circular tissue punch with a diameter slightly larger than that of the planned implant. Next, a pilot hole is created in the bone tissue using a series of drills of increasing diameter. The dental practitioner may then create threads in the newly formed bore hole matching those of the planned implant using a screw tap, if applicable. The implant is placed into the void using a dental driver with an appropriate adapter or a hand wrench, such as a torque wrench. Finally the surgical site is closed or a healing/temporary abutment is assembled onto the implant to remain during the osseointegration process.

[0045] The deeper progressive threads of the invention allow for the use of undersized step-down drills. Thus, the implant experiences better apical bone engagement while preventing excessive bone condensation near the apical tip of the implant.

[0046] While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be from such details without departing from the scope of the general inventive concept.