Abstract:
The subject matter of the invention is, in one example, a dental implant having a corpus. an external thread attached on the enossal area of the corpus and a post accommodation formed in the inside of the corpus. Providing a dental implant that can be anchored well in the jaw is achieved by forming a recess on the endostal end of the corpus oriented coaxially to the longitudinal axis of the corpus.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims Priority from German Application No. DE 10 2009 016 920.2-48 filed on 8 Apr. 2009 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a dental implant and, more particularly to a dental implant having a corpus, an external thread attached on the enossal area of the corpus and a post accommodation formed in the inside of the corpus, whereas a recess is formed on the endostal end of the corpus coaxially to the longitudinal axis of the corpus. 
       BACKGROUND 
       [0003]    From WO 2005/065571 A1 a multi-piece dental implant with an external thread is known on the coronal end of which an internal post accommodation is formed. An arched post, if required, can be inserted into this post accommodation onto which a dental prosthesis can be attached. On the outside of said dental implant longitudinal flattenings are defined, in order to prevent twisting of the implanted dental implant, and hence achieve a good and permanent anchoring of the dental implant in the jaw. 
         [0004]    From DE 10 2006 013 456 A1 a single-piece dental implant with an enossal and a coronal area is known which is provided with an external thread. On the enossal area at least a longitudinal, concave recess is formed in order to make twisting of the dental implant more difficult, as soon as bone substance has formed in the cavity thus developed, in order to achieve consequently a good and permanent anchoring of dental implant in the jaw. 
         [0005]    It has turned out, however, that such flattenings or concave recesses have only a minor impact on good and permanent anchoring of the dental implant. 
         [0006]    From WO 2007/073743 A1 a single-piece dental implant is known the interior of which features a through hole. On the endostal end of the corpus, said through hole at first has a cylindrical shape with subsequent conical and cylindrical portions. A plurality of perforations are provided on the circumference of the dental implant which are connected is with the through hole. 
         [0007]    From DE 37 35 378 C2 a metal implant with an anchoring device is known on the endostal end of which a blind hole is provided. Transversely to the blind hole two radially oriented openings are provided connected with the blind hole. Said blind hole is of cylindrical shape. 
         [0008]    From U.S. Pat. No. 5,871,358 A dental implant is known on the endostal end of which a horizontal opening is provided followed by radially projecting openings. 
         [0009]    For all last mentioned dental implants it is necessary to pre-drill a corresponding hole in the jaw before the dental implant is inserted. It is known that this pre-drilling cannot always be made 100% precise. It may happen that the drill is applied obliquely or that weaknesses or defects occur due to a jaw subject to osteoporosis. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a sectional view of a first embodiment of a dental implant described herein. 
           [0011]      FIG. 2  is a sectional view of a second embodiment of a dental implant described herein. 
           [0012]      FIG. 3  is a sectional view of a third embodiment of a dental implant described herein. 
           [0013]      FIG. 4  is a sectional view of a fourth embodiment of a dental implant described herein. 
           [0014]      FIG. 5   a  is a sectional view of a fifth embodiment of a dental implant described herein cut along line Va-Va in  FIG. 5   b.    
           [0015]      FIG. 5   b  is a sectional plan view of the dental implant according to  FIG. 5   a , cut along line Vb-Vb in  FIG. 5   a.    
           [0016]      FIG. 6  is a sectional view of a sixth embodiment of a dental implant described herein. 
           [0017]      FIG. 7  is a sectional view of a seventh embodiment of a dental implant described herein. 
           [0018]      FIG. 8  is a sectional view of an eighth embodiment of a dental implant described herein. 
           [0019]      FIG. 9  is a sectional view of a ninth embodiment of a dental implant described herein. 
           [0020]      FIG. 10  is a sectional of a tenth embodiment of a dental implant described herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    In  FIG. 1 to 8  eight different examples of a multi-piece dental implant an shown with only the implant portion to be inserted into the jaw being illustrated here for reasons of cleamess. This multi-piece dental implant comprises a corpus  10  with an external thread  11  and a post accommodation  12  formed on the coronal end of the corpus  10 . The post accommodation  12  comprises an internal thread  13  for receiving a post provided with an external thread not shown here in detail. 
         [0022]    On the endostal end  14  of the corpus  10  an incision  15  is formed facilitating the screwing in of the dental implant into the jaw. On the endostal end  14  moreover a recess  16  is provided, formed as a through hole extending up to the post accommodation  12  according to  FIGS. 1 ,  3 ,  5   a ,  5   b  and  7 , whereas the recess  16  according to the second, fourth, sixth and eighth example of  FIG. 2 ,  4 ,  6  and  8  is formed as a blind hole. 
         [0023]    In the third, fourth, seventh and eighth example according to  FIGS. 3 ,  4 ,  7  and  8 , the recess  16  in a portion close to the endostal end  14  is conically tapered with a circumferential cutting edge  17  being formed on the endostal end  14 . The external outline of corpus  10  on the endostal end  14  is conically flared as well. 
         [0024]    In the examples five to eight according to  FIGS. 5   a ,  5   b ,  6 ,  7  and  8 , openings  19  are formed radially to a longitudinal axis  18  of the corpus  10  which are formed as a hollow cylinder shaped hole in these examples. In these examples four openings  19  each are provided in a plane which are arranged in an angle of 90° towards each other. Three of said planes are formed with four openings  19  each distributed over the corpus  10 . All these openings  19  either open out into the recess  16  or into the post accommodation  12 . 
         [0025]    In another example (not shown) the opening can also be lead through the corpus in another location. In still another example the openings are not arranged in one plane but are offset from each other in axial direction. 
         [0026]    In the ninth and tenth example shown in  FIGS. 9 and 10 , a single-piece dental implant is illustrated likewise having a corpus  20  and an external thread  21 . In these two examples, an accommodation  22  is formed to the corpus  20  in one piece onto which the actual dental prosthesis is placed later. 
         [0027]    On the endostal end  24  of the corpus  20  a recess  26  is provided which is formed as a blind hole here with the recess  26  extending close to the coronal end of the corpus  20 . On the endostal end  24  the recess  16  is conically tapered whereas the corpus  20  is conically flared so that a cutting edge  27  is formed on the endostal end  24 . 
         [0028]    In the tenth example shown in  FIG. 10  openings  29  are provided in addition formed as a through hole extending radially to the longitudinal axis  28  of the corpus  20 . On the circumference of the corpus  20  four openings  29  are provided equidistantly so that the individual openings  29  are located rectangular to each other. These openings  29  are located in a common plane with two such planes being provided on the entire corpus  20 . 
         [0029]    The recesses  16 ,  26  and the openings  19 ,  29  cause the surface of the corpus  10 ,  20  to be increased so that more bone substance can take root on the corpus. Due to this contact surface increased in such a way the grip or hold in the jaw is improved resulting in an improved osseointegration. 
         [0030]    Due to the formation of a cutting edge  17 ,  27  in combination with the recess  16 ,  26 , the dental implant can be inserted into the jaw without pre-drilling. In this process, the cutting edge  17 ,  27  cuts its way through the jaw with the jaw bone being compressed in this location and received by the recess  16 ,  26 . Due to this compression a certain grip or hold of the dental implant in the corpus occurs already which is even more improved by the increased contact surface. Moreover, the dental implant is maintained well in the jaw also by the external thread  11 ,  21 . 
         [0031]    After the dental implant has grown into the jaw, bone substance exists not only in the recess  16 ,  26  but also in various openings  19 ,  29  so that the dental implant is downright permeated by bone substance resulting in increased osseointegration. 
         [0032]    In view of the foregoing, the examples described herein may provide a dental implant of the type mentioned above, which can well be inserted into the jaw, and which can be anchored permanently in the jaw. The inventions, as defined by the claims appended hereto, provide advantageous developed implementations of these dental implants. 
         [0033]    The example dental implants configured according to this technical teaching offer the advantage that for the inventive dental implant pre-drilling can be omitted because due to the recess formed on the endostal end extending coaxially to the longitudinal axis in connection with the conical tapering of the corpus and the cutting edge formed on the endostal end it is possible to screw said dental implant directly into the jaw. In that case the cutting edge severs the bone at the requested location and the bone thus excised is received by the recess. Due to the conical shaping of the recess, the bone substance is compressed with the result that the dental implant is maintained from the inside by the compressed bone substance and from the outside by the jaw. 
         [0034]    In some examples it has provided advantageous that by omitting pre-drilling the entire surgery associated with implanting the dental implant is simplified so that the stress on the patient is reduced as well. 
         [0035]    The second example dental implants configured according to this second technical teaching it has provided advantageous that by the opening on the dental implant formed radially to the longitudinal axis of the corpus and penetrating the corpus, a cavity is created into which the bone substance can grow. As has already been explained above, the dental implant surface is increased by this cavity so that more bone substance can take root in order to improve osseointegration. 
         [0036]    I some examples, it has proved advantageous that the openings are arranged radially to the longitudinal axis to also prevent the dental implant moving out of the jaw. 
         [0037]    In another example the opening is shaped as a hollow cylinder which facilitates placing of the opening on the prepared dental implant which in this case can occur by simple drilling. 
         [0038]    Advantageously the opening should not be greater than 1 mm so that dental implant stability is not unduly weakened. 
         [0039]    In yet another example the opening is located in the area of the recess and/or in the area of the post accommodation so that bone substance can grow into the recess and into the post accommodation respectively via the opening. This has the advantage that the bone substance can penetrate the dental implant in order to improve osseointegration. 
         [0040]    In still a preferred example, two or more openings are arranged in one plane to the longitudinal axis of the corpus, which are advantageously arranged equidistantly. This has the advantage that the bone substance can grow into the dental implant from different sides in order to anchor the dental implant permanently in the jaw. 
         [0041]    This application makes reference to, incorporates the same herein by reference, and claims all benefits accruing under 35 U.S.C. §119 from an application for patent filed in the Germany Patent Office on Apr. 8, 2009 and there assigned Serial No. DE 10 2009 
         [0042]    Further advantages of the dental implants described herein are apparent. Likewise, the invention lies in each and every novel feature or combination of features mentioned above or described herein after. The embodiments discussed herein are merely exemplary and are not intended to limit the scope of the invention in any matter. Although, certain example apparatus are described herein, other implementations are possible. The scope of coverage of this patent is not limited to the specific examples described herein. On the contrary, this patent covers all apparatus, methods, and articles of manufacture within the scope if the invention.