The present invention relates generally to the field of dentistry. More particularly, the present invention relates to threaded dental implants.
Typical threaded dental implants, such as those shown in
Material jam in bones can lead to stress concentrations and potentially bone fractures. A bone fracture can cause an otherwise successful threaded dental implant procedure to be considered a failure. As a result, current threaded dental implants have a high percentage failure rate. Furthermore, threaded dental implants having steep thread flank angles generate high side wall pressure and radial stress, generate high heat during installation, do not provide for sufficient thread surface area, and, in some cases, exhibit poor joint stability.
Consequently, it would be beneficial to have a threaded dental implant that minimized stress concentrations so as to minimize bone fractures. Furthermore, it would be beneficial to have a threaded dental implant that generated lower side wall pressure and radial stress, generated less heat during installation, provides for sufficient thread surface area, and exhibits superior joint stability.
A threaded dental implant according to the present invention includes threads having a relatively shallow flank angle. In one embodiment the flank angle is between approximately 20 and 30 degrees. In another embodiment, the flank angle transitions from approximately 30 degrees to approximately 20 degrees
A threaded dental implant includes a shaft having first and second ends. In one embodiment the shaft is essentially a solid cylinder having an exterior surface that defines a relatively constant first diameter. In such an embodiment, threads extend radially from the first diameter of the shaft in a helical pattern between the first and second ends of the shaft. Between the threads, the first diameter of the shaft defines a helical root of the threads.
Some embodiments of the present invention include a relatively substantial transition section between the threads and the shaft. In some embodiments, the combination of the relatively shallow flank angles of the threads and the relatively substantial transition sections between the threads and the shaft provides smaller thread roots than are provided by traditional threads. This leads to increased flank engagement, and optimized bone flow. Additionally, in some embodiments, the helix angle of the thread has also been optimized to allow for more thread engagement per length of implant.
The foregoing and other objects are intended to be illustrative of the invention and are not meant in a limiting sense. Many possible embodiments of the invention may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of invention may be employed without reference to other features and subcombinations. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention and various features thereof.
A preferred embodiment of the invention, illustrative of the best mode in which the applicant has contemplated applying the principles, is set forth in the following description and is shown in the drawings and is particularly and distinctly pointed out and set forth in the appended claims.
As required, a detailed embodiment of the present invention is disclosed herein; however, it is to be understood that the disclosed embodiment is merely exemplary of the principles of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Referring now to the invention in more detail, a threaded dental implant 10 includes a shaft 20 having first 22 and second 24 ends. (
The threads 30 include a proximal end 32 coupled to the shaft 20 and a distal end 34 opposed to the proximal end 32 of the threads. In some embodiments, a first flank 36, and an opposed second flank 38 extend from the distal end 34 of the threads 30 towards the proximal end 32 of the threads, thereby defining a flank angle. In some embodiments, the flank angle is between approximately 20 and 30 degrees. In other embodiments, the flank angle transitions from approximately 30 degrees near the distal end 34 of the threads 30 to approximately 20 degrees nearer the proximal end 32 of the threads 30.
The distal end 34 of the threads 30 defines a major diameter of the threads 30 while the exterior surface 26 of the shaft 20 defines a minor diameter of the threads 30. A thread pitch of the threads 30 is defined as the axial distance between one major diameter of the threads 30 and the next major diameter of the threads 30.
As shown in
Also shown in
In some embodiments, each thread flange 50 defines a transition point 56 at which the flank angle transitions from a first angle 56A to a second angle 56B. In some such embodiments, the first angle is approximately 30 degrees and the second angle is approximately 20 degrees. This reduces the radial stress and eliminates bone cracking by reducing sidewall bone pressure and allows for smooth flow of bone material inward with minimal outward stresses Transition areas 70 further assist with the flowing of bone material into the root of the thread. It will be appreciated that in various embodiments, alternative values of the first angle 56A and second angle 56B will be utilized. In some such embodiments the first angle 56A is between 29 and 31 degrees, and the second angle 56B is between 19 and 21 degrees. In other embodiments, still other angle values are utilized, and the differentiation between the first angle 56A and second angle 56B will vary, so long as the angle transitions from a greater value of the first angle 56A to a lesser value of the second angle 56B.
In some embodiments a small helix angle and/or a unique cored recess 40 allows for natural flow of bone material during and after installation. In some such embodiments, the helix angle is approximately between five (5) and seven (7) degrees.
In some embodiments, each thread flange 50 defines a transition radius (not shown) rather than a transition point 56. In such embodiments, the flank of the thread includes an arc or rounded feature transitioning from a first flank angle into a second flank angle. In some such embodiments, the lack of sharp angles at the transition radius allows for even more smooth bone flow.
In other embodiments, the outline of each thread flange 50, from its distal end 54 to its proximal end 52, is completely rounded or curved such that there are no transition points at all. For instance, in some embodiments, the transition between the flanks 36, 38 and the transition areas 70, 72, 74 defines a transition radius rather than a transition point. In some such embodiments, the transition between the transition areas 70 and the flat areas 60 also defines a transition radius.
The chart below shows the preferred thread pitch to diameter.
The construction details of the invention as shown in
In use, the threaded dental implant 10 is at least partially positioned below a gum-line of a patient such that the threads 30 are at least partially in communication with a jawbone so as to secure the threaded dental implant 10 to the jawbone. In some embodiments, the threaded dental implant 10 includes an abutment 12 coupled to the first end 22 of the shaft 20 and extending away from the jaw bone so as to enable securing another dental device, such as a crown, to the abutment 12.
The multi-angled thread profile and cored recess allow for improved bone flow to provide maximum bone to implant engagement, the arc or approximately 30 degree angle which backs off into a 20 degree angle allows unimpeded flow of bone material, the larger surface area enabling superior bone healing, less heat build up during installation and less radial stress and side wall pressure providing for superior implant stability and allows for thinner bone substrate necessary to achieve implant stability, an increased number of threads are engaged in the bone when compared to conventional implant thread higher mechanical strength and improved serviceability. The almost flat pitch allows more threads to engage in bone areas with porosity, pockets or voids. The thread allows for a high clamp load at smaller contact pressure by the increased flank engagement. The lower pressure allows for faster healing, less patient discomfort and a more stable implant.
Other various advantages of the inventive concept include, but are not necessarily limited to:
offering higher clamp load at smaller contact pressure by means of high flank engagement;
the thread design provides for reduction of fastener length and/or diameter as well as improved tensile and torsional stress;
lower drive torque and less material displacement allowing for less radial stress;
high strip to drive torque ratios;
greatly reduced bone expansion and cracking; and
greater pullout strength.
While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.
Number | Name | Date | Kind |
---|---|---|---|
3466748 | Christensen | Sep 1969 | A |
4406623 | Grafelmann et al. | Sep 1983 | A |
4468200 | Münch | Aug 1984 | A |
4746294 | Colombo et al. | May 1988 | A |
4863383 | Grafelmann | Sep 1989 | A |
5000686 | Lazzara et al. | Mar 1991 | A |
5088926 | Lang | Feb 1992 | A |
5338197 | Kwan | Aug 1994 | A |
5435723 | O'Brien | Jul 1995 | A |
5527183 | O'Brien | Jun 1996 | A |
5620323 | Bressman | Apr 1997 | A |
5642996 | Mochida et al. | Jul 1997 | A |
5964768 | Huebner | Oct 1999 | A |
5967783 | Ura | Oct 1999 | A |
6036491 | Hansson | Mar 2000 | A |
6149432 | Shaw et al. | Nov 2000 | A |
6315564 | Levisman | Nov 2001 | B1 |
6468277 | Justin et al. | Oct 2002 | B1 |
6997711 | Miller | Feb 2006 | B2 |
7806693 | Hurson | Oct 2010 | B2 |
8066511 | Wöhrle et al. | Nov 2011 | B2 |
20050095550 | Kim et al. | May 2005 | A1 |
20060204930 | Sul | Sep 2006 | A1 |
20070218425 | Gatti | Sep 2007 | A1 |
20080254411 | Bondar | Oct 2008 | A1 |
20080274440 | Smith | Nov 2008 | A1 |
20080286720 | Reed | Nov 2008 | A1 |
20090142732 | Kahdemann | Jun 2009 | A1 |
20100009316 | Hurson | Jan 2010 | A1 |
20100055644 | Arni | Mar 2010 | A1 |
20100316970 | Shih et al. | Dec 2010 | A1 |
20110195380 | Giorno | Aug 2011 | A1 |
20110200969 | Schroering | Aug 2011 | A1 |
20110300510 | Heo | Dec 2011 | A1 |
20120231419 | Park | Sep 2012 | A1 |
20120257945 | Phua | Oct 2012 | A1 |
Number | Date | Country |
---|---|---|
10 2008 063 397 | Jul 2010 | DE |
10 2009 050 049 | Apr 2011 | DE |
10 2011 101 253 | Aug 2012 | DE |
Entry |
---|
Semblex Delta PT Screw PDF (Sep. 16, 2008). |
Semblex Corporation-Delta PT Sep. 17, 2008. |
Semblex Delta PT Screw PDF (Sep. 16, 2008); “Semblex”. |
https://www.semblex.com/files/DeltaPT-Semblex.pdf (Accessed Apr. 24, 2015). |
Number | Date | Country | |
---|---|---|---|
20160206406 A1 | Jul 2016 | US |