Abstract:
A dental implant ( 105,137,156 ) has an elongated body ( 100 ) having first and second end portions ( 101,103 ) and having a root on one end portion ( 104,115,116 ) for attaching to a patient&#39;s jawbone to replace the root of a removed tooth. The root portion ( 104,115,116 ) has an anatomically shaped portion between the end portions of the body for fitting into a jawbone opening below the gum tissue of a patient when the root ( 104,115,116 ) is attached to a jawbone. An artificial tooth abutment ( 103,112  &amp;  113 ) is formed on the other end of the elongated body for attaching an artificial tooth thereon of the abutment extending above the gum line of a patient. A method of attaching a dental implant ( 105,137,156 ) includes the steps of extracting a patient&#39;s tooth and selecting the dental implant ( 105,137,156 ) of the apparatus and attaching the dental implant root ( 104,115,116 ) with the jawbone of a patient with the abutment ( 103,112,113 ) extending above the gum tissue of the patient and attaching the artificial tooth to the abutment.

Description:
This is a division of patent application Ser. No. 10/286,490, filed Nov. 1, 2002 now abandoned for a Dental Implant Method and Apparatus . 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to the field of dental implants and in particular to a system of anatomic dental implants, which may be converted to an anatomic facsimile of a natural tooth. The present invention also relates to eliminating the quandary of having to decide if the implant/abutment seam will compromise aesthetics or if the implant/abutment seam will compromise the integrity and long-term of the bone. The present invention also relates to ancillary components and instruments related to the placement and restoration of the anatomic implant. 
   2. Background of the Invention 
   A dental implant is an artificial tooth made of metal with a porcelain coating designed to make it look real. Its most important component is its root, a titanium anchor that is surgically implanted into the jawbone, usually by an oral surgeon or periodontal surgeon. Generally, the anchor is implanted alone, without the tooth. Gradually, during a healing period the bone grows around the implant securing it in place. An abutment is added to the implant for the artificial tooth to sit upon and then a replacement tooth or crown is attached to the metal post. Implants can also be used to anchor bridges and permanent dentures when more than one tooth is missing. 
   The replacement of a patient&#39;s tooth or placement of an anchorage fixture for attaching an overlying fixed or removal prosthesis initially consists of the placement of endosseous anchorage implants to which subsequent attachments might be added. Systems as described by U.S. Pat. No. 3,589,011 to Sneer, U.S. Pat. No. 3,797,113 to Brainin, U.S. Pat. No. 3,979,828 to Taylor, U.S. Pat. No. 4,324,550 to Reuther et al., and U.S. Pat. No. 4,416,679 to Mozsary et al., have proven to be successful for the long term anchorage of the endosseous dental implants to the maxillary and mandibular jawbones. 
   The placement of endosseous dental implants has evolved using 2 surgical approaches. One of these approaches uses a submerged technique where the implant is placed at or below the crest of the bone. The gingiva is closed over the bone and the implant thereby submerging the implant. The other surgical approach involves placement of an implant that extends coronally beyond the alveolar crest where the soft tissue flap is placed around a cover screw extending from the implant body. Once the dental implant has become permanently affixed to the bone by means of the process known as osseointegration, abutment attachments are added to the implant in order to make it suitable for the placement of a prosthetic tooth crown. Those prosthetic teeth crowns are then generally affixed to the abutments by means of fixation screws or by means of permanent cementation. Because the abutment is added to the implant, there is a seam (microgap) between the implant and the abutment. Additionally most implants are manufactured with a polished or smooth machined collar combined with a rough implant body. Studies have shown that the seam (microgap) and the junction of the rough surface and the smooth collar (r/s border) cause crestal bone resorption when placed in close approximation to the crestal bone. Ercoli, U.S. Pat. No. 6,217,333, attempted to address this issue by creating a curved top on the implant so that the seam and the r/s border more closely approximated the saddle-shaped crestal bone. This innovation only partially addressed the issue because the seam (microgap) persisted, though in an altered form; also Ercoli 333 presumed that finite shapes could accommodate the infinite variety of crestal bone shapes. Similarly, Wöhrle, U.S. Pat. Nos. 6,174,167 and 6,283,754 created an implant with a scalloped coating that was designed to remain below, yet follow the crest of bone. Above this scalloped coating there was intended to be a different treatment of the implant surface, such as a machined collar, that was distinctly compatible with the soft tissue. This concept of scalloped exclusion of the collar surface from the subosseous regions because the collar is only compatible with the gum tissue is not in keeping with the technology of the PACE implant, as marketed by Coatoam since 1996 where the surface treatment of the collar is compatible to both bone and tissue attachment. This collar transition does not require a scalloped design because the collar treatment can go below the crest of bone or be above the crest of bone without creating any bone die-back. Additionally there is good gingival attachment to this surface. Also the PACE implant has been marketed since 1996 as being adjustable by the doctor so that the top edge can be scalloped like the pre-fabricated Ercoli 333 design. This ability to adjust the implant provides the property of keeping the treated collar in a subgingival position where it would not retain plaque, plus the property of being able to adjust the implant edge allows for adaptation of the implant when it is surgically placed in the patient&#39;s mouth. This is particularly valuable in maxillary anterior teeth where the crest of bone most often is not actually symmetrically scalloped, but rather is much higher on the facial aspect than it is on the interproximal or palatal aspects of the tooth socket. Both Ercoli 333 and Wöhrle 167 &amp; 754 have symmetrical designs, and the implant edge in Ercoli 333 along with the collar in Wöhrle 167 &amp; 754 can end up in a subosseous position on the palatal aspect when the implants are placed in the maxillary anterior area thereby leading to potential bone die-back in these regions. 
   Because implant abutments are subject to rotational loosening, the dental prosthesis, which is subsequently affixed to the post attachments, is also subject to this unscrewing phenomenon. This can lead to loosening and failure of the dental prosthesis. In order to prevent this phenomenon most implant systems add a non-round interconnection or a Morse taper between the endosseous dental implant and the abutment to prevent rotational movement. In most designs, a screw is then passed through the abutment, affixing it to the body of the implant. This screw generally has a positive seat in some portion of the abutment. Once the screw is tightened with sufficient torque, the abutment is firmly anchored to the dental implant. The coronal extent of the abutment usually has some design feature such as a flat side that ultimately engages the crown prosthesis to provide a non-rotational feature to the cemented crown. In U.S. Pat. No. Des. 401,695 Daftary described a non-round anatomic shape that prevents crown rotation. Rotational forces to the abutment are absorbed at the implant by the non-round component rather than being transmitted directly to the screw itself. These non-round components are generally shaped like a hex, an octagon, a multi-pointed star, or a spline. In each case the seam between the implant and the abutment presents a problem after surgical implant placement because of subsequent bone dieback. 
   Another type of anti-rotational feature on implants is the non-round anatomically shaped implant. This type of implant was described in U.S. Pat. No. 5,246,370 to Coatoam. In this type of system the crown attaches directly down onto the non-round implant body. Since the edge of the head of the implant is a machined non-round anatomical shape the crown cannot rotate. In these systems the anti-rotational feature is the non-round implant shape of the exit profile. With this type of design it is necessary to set the timing of the implant so that the anatomic shape corresponds to the replaced tooth. It is also necessary to keep the edge of the implant in a position above the crest of bone because even though the crown margin finishes on the implant body, that margin may also act as a microgap that can lead to bone loss. In the application of the Coatoam patent 370, the commercially available PACE implant can be altered so that the bevel at the top edge of the implant can be altered by the doctor to accommodate the infinite variety of shapes of the crestal bone. However, whenever the implant was altered it then became essential for the restorative doctor to take direct impressions of the altered dental implant rather than using available impression transfer posts and implant analogs. In U.S. Pat. No. 5,759,034 Daftary proposed a non-round anatomically shaped implant similar to the 370 Coatoam implant but in 034 Daftary there is still an implant/abutment seam between the crest of bone and the margin of the crown. 
   There exists a need for an anatomically shaped dental implant that can be placed so that the crestal bone does not die back as a consequence of an implant/abutment seam. Also there is a need to eliminate this potentially weak implant/abutment seam so that smaller implants can be manufactured without having to enlarge the abutment in order to accommodate anti-rotational components and connectors to the implant. Further, there is a need for an anatomically shaped implant where the edge of the margin of the final crown can be variably and infinitely set by the doctor and the laboratory technician as ultimately determined by the shape of the adjacent crestal bone and the junctional gingival epithelium. 
   SUMMARY OF THE INVENTION 
   The present invention provides a method and a system for placing dental implants in the alveolus of the maxillary or mandibular jawbones. The implant has a distal insertion end that may be rod shaped, screw shaped and/or have fins to assist in retention in the bony alveolus. The implant may be made of biocompatible materials including but not limited to metal, ceramic, glasses or any combination thereof, and potentially having various surface coatings of materials such as titanium beads, titanium plasma spray, hydroxylapatite, or bone growth chemicals or similar coatings to enhance attachment to the bone. The distal end of the implant is inserted into the bone by preparing a hole for the implant. That hole may be made by extraction of a tooth, or a drilled hole in the bone, or a hole made by driving chisels or osteotomes into the bone, and/or alterations of the hole made by round or non-round osteotome devices, drills or chisels. The implants may have a typical rod shape along the entire length, or the implants may have an enlarged anatomically shaped non-round head. The anatomically shaped implants may be inserted partially or fully into extraction sites, or into holes that have had the top portion of the osteotomy site altered and enlarged by free-hand means and associated devices. Such associated devices may be counter-bevel drills, non-round osteotomes, non-round rasps, round rasps, chisels, drill guides or drilling jigs. In some instances the various implants may be inserted into the prepared hole by compression fit. In other instances the implants may be screwed into the bone or affixed by fixed or retractable fins. Bone graft materials, bone growth enhancement chemicals, barrier membranes and/or grids or meshes may be used to enhance bone attachment or build bone around the implants. 
   The proximal end of the implant extends out of the prepared hole in the bone. The proximal ends of the implants have gently rounded, convex amalgamated anatomical abutment bases. The amalgamated abutment base may be partially coated with gold, porcelain, gold-colored titanium nitrite or other substances used to improve aesthetics. The amalgamated abutment may have a bored hole to accommodate various extenders. This bored hole may be non-round, but the actual anatomical shape of the abutment base or Morse taper of the round abutment provides the essential anti-rotational component to the implant. For that reason the shape of this tube-like extension is not critical since any non-round design of this opening may be a redundancy in regard to anti-rotational design. This would also be true of non-round proximal extensions of the abutment base such as hexes, slots, or splines, which might be thought to alter this invention, but would not enhance the design. It is also nonessential that any abutment extender has an indexed shape to prevent crown rotation. The crown is prevented from rotating by direct attachment to the anatomically shaped implant/abutment head. 
   At the bottom of the bore opening there is a threaded extension of the bored opening. This threaded extension can receive a threadedly inserted screw or non-threadedly inserted rod extension. The proximal end can accommodate various fittings that act as posts for a crown and post design or for post and core extenders that will provide added retention to subsequent dental crown prosthesis. This feature facilitates the placement of angled post and core extenders and anatomic coping attachments that are in keeping with dental technology that has been used to restore natural teeth for many years. The doctors&#39; familiarity with these common dental techniques is a meaningful strength of this system. 
   In keeping with the traditional dental procedures of placement of post and core inserts into natural teeth, it is desirable but not essential that the margin of the core portion at the implant body be contained within the confines of the crown itself. However, unlike natural teeth, implants are not subject to decay, so if some portion of the post and core seam extends below the crown margin this would not be an adverse feature unless that core/implant margin extended too close to the crest of bone. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is a representative perspective view of an anatomically shaped dental implant with an amalgamated abutment base. 
       FIG. 2  is a cross-sectional view of  FIG. 1 . 
       FIG. 3  is a cross-sectional, perspective view of one of the possible variations of the implant depicted in  FIG. 2 . 
       FIG. 4  is a perspective view of the head of an implant in accordance with the present invention. 
       FIGS. 5 ,  6 ,  7  are perspective views of various dental instruments that generally relate to the shape of the dental implant in  FIG. 4 . 
       FIG. 8  is an exploded perspective view of stacked components showing a surgical cover screw and an implant in accordance with the present invention. 
       FIG. 9  is an exploded perspective view of stacked components showing a hold-down screw, healing cap, and an implant. 
       FIG. 10  is an exploded perspective view of stacked components showing a plug, a hold-down screw, an impression transfer post, and an implant. 
       FIG. 11  is a representative perspective view of stacked components showing a straight screw-in post and core extender and an implant. 
       FIG. 12  is a representative perspective view of stacked components showing a prosthetic screw, an extension cast-on, an indexing sleeve and an implant. 
       FIG. 13  is a representative perspective view of stacked components showing a castable post and core, an indexing sleeve and an implant. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to the drawings, and particularly  FIG. 1 , a dental implant with a cylindrical body  100 , and an anatomically shaped proximal end  101 , has nearly parallel walls  102 , and has an integrated anatomically shaped abutment base  103  formed as part of the implant and not a separate attachment. Transitional nearly parallel walls  102  between the abutment and the implant adjoin the abutment base to the implant. These walls may have a slight convergence in the coronal direction to facilitate draw of the prosthetic component. This entire assembly is preferably made from titanium or an alloy thereof, and may be cut from one piece of stock material. If the implant body is made of a different material than that of the integrated abutment, the two pieces are permanently fused without any microgap being present after fusion of the parts. This integrated or amalgamated abutment eliminates any abutment/implant seam below the bone or gum tissue. The seam has been implicated in bone die back, so elimination of the seam maximizes health around the implant. The margins of the crown, which will be fabricated in the laboratory will generally finish somewhere on the nearly parallel walls  102 . These parallel walls allow the restorative doctor to variably alter the depth of the margins of the crown relative to the vertical position of the implant within the bone and gum tissue. Owing to the bulk of metal on the facial wall, the doctor may elect to alter the implant with a dental drill and bur to accept a greater bulk of crown material. This places the crown margin in the most ideal subgingival position for aesthetics while assuring that the hermetically sealed crown margin is high enough above the crest of bone to reduce the potential for any bone die back. The implant may have various grooves, threads and/or fins  104 . The implant and portions of the parallel walls may have various coatings such as titanium plasma spray, acid etching, grit blast, hydroxylapatite, ceramics or biological coatings  105  or a combination thereof. The parallel walls, which comprise the collar of the implant may have a various coatings or surface treatments  106  that are different from those on the implant body  105 . The anatomical abutment base  103  and a portion of the parallel walls  102  may be coated with gold, titanium nitride, or ceramics  107 . The top of the amalgamated abutment/implant may have a cylindrical opening  108  to receive various castable or threaded post inserts 
   Referring to  FIGS. 2 and 3 , the anatomical shape of the proximal end of the implant may be ovoid, triangular, rectangular, or circular, in keeping with the general shape of natural teeth. In referring back to the standard view of the implant  FIG. 1  there is a cylindrical opening  108 , which also can be seen in the cross-sectional view of the implant  FIG. 2 . In comparing  FIG. 2  to  FIG. 3  it may be noted that the cylindrical openings  108  and  109  in the two implants may vary in diameter relative to the size of the implants. The cylindrical opening may also step down in diameter  109  as it goes more deeply into the implant. In both sizes of implants there is a threaded opening  110  in  FIGS. 2 and 111  in  FIG. 3  at the distal end of the tube-like opening. In various sizes and shapes of the anatomic implants there are convex and anatomically shaped proximal ends  112  in  FIGS. 2 and 113  in  FIG. 3  with proportionately sized seamless nearly parallel walls  102  in  FIGS. 2 and 114  in  FIG. 3 . The implants may have threads  115  in  FIG. 2  or cylindrical side  116  in  FIG. 3 , and may have vertical grooves  117  and  118  or concentric grooved rings. 
     FIG. 4  is a perspective view of a certain sized dental implant.  FIGS. 5 ,  6 , and  7 , are proportionately sized dental instruments that can be used to place that implant. Though these instruments are not absolutely essential for implant placement, they are helpful in sizing the osteotomy site, selecting the proper sized implant, and assuring proper depth of insertion of the dental implant. Where the implant has a distal shaft  119  of a determined diameter, each of the instruments has a distal shaft  120 , which is just microns smaller in diameter to prevent binding of the instrument in the prepared osteotomy hole. The smooth osteotome  FIG. 5  has a body shape  122  identical in size and dimension to the head of the implant  121  of  FIG. 4 . This smooth anatomic osteotome can be placed in an extraction site or in a prepared osteotomy site to determine the relationship of the implant to the site. In an extraction site for instance, it is desirous for the top edge of the parallel walls of the implant  123  to remain above the crest of bone. If the smooth anatomical osteotome  FIG. 5  is inserted into the extraction site or the prepared site, and the top edge  124  goes below the crest of bone, a larger implant is generally indicated or bone grafting may be necessary. If the top edge  124  is too coronal to the crest of bone, a smaller implant may be desired. It is also possible to reshape the coronal portion of the osteotomy site to set the top edge  124  a little more in an apical direction by applying a gentle blow with a mallet to the end of the instrument shaft  125 . This shaft  125  may be straight or contra-angled. When the osteotomy site is a free-hand creation, or in cases where it might be desirous to increase the anatomical opening of an extraction site, the anatomical rasp  FIG. 6  may be used. As with the smooth anatomical osteotome  FIG. 5 , the anatomical rasp  FIG. 6  has a slightly smaller distal bore  126  than the shaft of the dental implant  117 . However, the anatomical rasp has a body shape  127  that is identical in size and shape to the implant body shape  121 , just like the anatomical osteotome  122 . The distinguishing feature between the anatomical osteotome and the anatomical rasp are ridges  128  that act like cutting teeth when a mallet blow is delivered to the end of the instrument handle  129 . This handle  129  may also be contra-angled. The anatomical rasp  FIG. 6  functions as a bone file to alter the most coronal opening of the osteotomy site. This rasp also has a demarcation edge  130  that corresponds to the top edge of the parallel walls of the implant  123 . This top edge  130  is used as a reference point as the osteotomy site is shaped to receive the implant by repeated blows to the instrument handle  129 . 
   The final shaping of the coronal portion of the osteotomy site might be formed by reinsertion of the anatomic osteotome.  FIG. 5 . A drill guide  FIG. 7  may also be used. The drill guide  FIG. 7 , is similar to the drill guide described in my prior U.S. Pat. No. 5,246,370. This drill guide has a distal bore  131 , and a body shape  132  and a demarcation edge  133  like the other instruments. However, it also has a through bore  134  to accommodate drills, plus it has a multi-angled handle  135  for easier positioning in osteotomy or extraction sites. 
   Referring to  FIG. 8 , there is a surgical setscrew  136  that is threadedly attached to the implant  137  by means of threads  138  at the end of the component. There is a low profile screw head  139  with a hex hole  140 , or slot into which an engagement wrench or screwdriver is inserted. This surgical setscrew has a lip  141  that hermetically seals the top edge of the opening of the implant  142  during any healing phase. Though the implant is anatomically shaped, the components used to seal the implant during surgical healing can be standard cylindrical shapes that can achieve a tight, fluid-free seal. 
     FIG. 9  depicts an anatomically shaped healing cap  143  that is made of a plastic material such as methyl methacrylate or Delron. This healing cap is generally placed on the implant after a period of time that is sufficient to assume that the implant is either integrated or affixed to the bone in a stable fashion. The healing cap has a flange  144  that engages the top ring of the implant  145 , and is threadedly attached to the implant by means of a hold-down screw  146 . This hold-down screw  146  may be similar or identical in design to the surgical setscrew  136 . The hold-down screw has a lip  147  that engages a shoulder  148  in the anatomically shaped healing cap. The threads  149  of the hold down screw pass through the central opening  150  of the healing cap and are threadedly inserted into the implant  151 . As the screw is tightened, the flange  144  of the anatomically shaped healing cap slides down the parallel walls  152  of the implant, thereby retracting the gingiva. Since the anatomic healing cap is made of plastic, the flange  144  can be easily adjusted by means of grinding with an acrylic burr if the flange impinges on attached gingival tissue or bone when the healing cap is threadedly seated onto the implant by means of the hold down screw  146 . 
   In examining  FIG. 9 , there is a bulk of material at the nearly parallel facial wall  145  of the implant. It is possible for the restorative doctor to alter this facial wall if a greater depth of porcelain is desired in this area when the final crown is fabricated. If any alteration is performed, then a direct impression will be taken of the altered implant in the patient&#39;s mouth so that this alteration can be duplicated on a laboratory model that is poured up from the direct impression. 
   In referring to  FIG. 10 , there is a silicone plug  153 , a hold-down screw  154 , an anatomically shaped impression transfer post  155 , and an implant  156 . The hold down screw  154  serves a similar purpose to the hold down screw  146  in  FIG. 9 . This hold down screw also has a lip  157 , which engages a shoulder  158  in the impression transfer post  155 . The plastic impression transfer post has a flange  159 , which engages the parallel walls  160  of the implant  156 . This flange  159  can be adjusted with a burr if it extends too far under the gum tissue thereby impinging on the junctional epithelial attachment or on the bone. After any necessary adjustment is made to the flange of the impression transfer post, it is held tight to the implant by the hold down screw, which is threadedly attached to the implant. The silicone plug  153  may then be inserted into the hole  161  of the impression transfer post so that dental impression material will not flow down into the hole. The doctor then takes an impression. Once the impression is set it is removed from the mouth. The impression transfer post  155  with the silicone plug  153 , and hold down screw  154  are removed from the implant in the patient&#39;s mouth. This impression post apparatus is then threadedly inserted into a facsimile of the implant called an implant analog. This combination of impression transfer post and implant analog is then seated into the impression that was taken of the patient&#39;s mouth. The impression is then poured up using dental stone. Once the poured up impression is set, the impression transfer post is removed from the implant analog. Because the flange extended under the gum tissue, the removal of this component from the impression results in clear access to the parallel walls of the implant analog. It is along these nearly parallel walls that the margin of the crown will be established. The nearly parallel walls provide flexibility in establishing the position of the crown margin. 
     FIG. 11  depicts an abutment extender  162 , as it would be inserted into an implant  163 . Though the Ferrell effect of retention of the crown is primarily accomplished by placement of the crown margin on the parallel walls  164  of the implant/abutment, there are times when the doctor may desire additional crown retention. The abutment extender  162  may be used for this purpose. This extender has a wrench or screwdriver engagement feature  164 , which is used to threadedly insert the threads  166  of the extender into the implant. If the screwdriver slots are ground away during any shortening process of the extender, they can be cut back into the extender with a grinding disk. Machining tolerances of the top shaft  167  of the extender closely approximate those of the internal bore  168  of the implant. This provides lateral strength to the connection. The extender is threadedly inserted into the implant until the lip  169  of the extender seats firmly on the shoulder  170  of the bore opening  171  of the implant. 
   In referring to  FIG. 12  there is seen a prosthetic screw  172 , an extension cast-on  173 , an indexing sleeve  174 , and an implant  175 . This configuration of components has various applications including a screw retained straight extender, a screw retained angled extender, the coping for a screw retained crown, and a screw retained coping for attachment to bars or clips for retention of removable prosthesis. The extension cast-on  173  has a sleeve of ash less plastic  176 , which is affixed to a precious metal base  177 . The plastic sleeve  176  can be cut, ground or altered by the addition of wax or plastic so that it can be shaped at different angles or shapes. Wax or plastic can also be flowed down onto the anatomically shaped fused abutment base  178 , from the base of the extension cast-on  179  so that the changes of angle or shapes of the extension cast-on can be permanently indexed to the implant  175 . This indexing results in one of two possible placements of the altered extension cast-on into the implant, 180 degrees apart. Therefore, there are only two possible insertion positions into the implant, a significant improvement over the six positions of other systems with hex indexing components. Since only one position is correct, it is easier to discern the correct insertion position when the placement is either front wards or backwards in contrast to positions that very only 60 degrees and are hard to discern. To facilitate coverage of the abutment base  178  there is provided an indexing sleeve  174 , made of ash less plastic, which is affixed to the base of the extension cast-on  179  with a little luting plastic or wax. Once the extension cast-on is sufficiently altered and indexed to the implant, it is invested in investment plaster, the ash less plastic is burned out, and the void is cast with precious metal using the lost wax technique. It should be noted that the extension cast-on has features that make it rather flexible. There is a lip  180 , which sits firmly on the shoulder  181  of the bore opening of the implant. If the indexing sleeve  174  is used, then the lip  180  of the extension cast-on is fused to the shoulder  182  of the sleeve. In implant sizes that are large enough, the top bore  183  of the implant may be slightly larger in diameter than the bottom shaft  184  of the prosthetic screw. In those cases an extension sheath  185  is added to the precious metal base  177 . This sheath  185  engages the top bore  183  of the implant, surrounding the shaft  184  of the prosthetic screw. This feature adds strength to the connection and reduces tortional forces on the screw. The entire assembly is threadedly affixed to the implant by means of the prosthetic screw  172 . This prosthetic screw has a slotted top  186  for wrench or screwdriver engagement. If the extension cast-on  173  needs to be shortened, the prosthetic screw can also be shortened. A new screwdriver slot can be readily duplicated at a lower level. The prosthetic screw has a lip  187  that seats positively onto a shoulder  188  in the extension cast-on. The component created by the lost wax casting of the extension cast-on is threadedly attached to the implant by the prosthetic screw until the lip  187  seats positively on the shoulder  188 , forming a firm anti-rotational attachment. 
     FIG. 13  depicts an ash less plastic castable extender  189 , an indexing sleeve  190 , and an implant  191 . The castable extender  189  may be used for cementable straight or angled abutment extenders, or may be used in the fabrication of copings for post &amp; crown applications. The castable extender has a lip  192 , which may seat positively on the shoulder  193  of the bore opening of the implant, or if the indexing sleeve  190  is used, the lip  192  is seated on the shoulder  194  of the indexing sleeve and luted in place. The castable extender  189  has a constricted neck  195  where the extender may be bent when heated so that the angle of the extender may be altered. Once the castable extender is altered by bending at the neck  195  the constriction is filled in with castable wax or plastic. The extender may also be altered in shape or length. Once the angle or concentric shape of the extender is altered, it is then indexed to the implant by use of the indexing sleeve  190  or by flowing wax down onto the non-round abutment base  196 . When either the castable extender  190  or the extension cast-on  174  of  FIG. 12  are incorporated into copings for crowns, the copings will generally be extended down onto the accessible portion of the parallel walls  197  of the implant, thereby establishing the margin of the crown. After the crown or extender is completed in wax and ash less plastic, it is cast with metal using the lost wax technique. This metal casting might then be further altered by the application of porcelain or attachment to other copings or bars connectors. It is then cementedly affixed to the dental implant. The top portion  198  of the extension post has close tolerances to the bore opening of the implant, while the lower portion  199  of the implant has a diameter equal to the minor diameter of the threaded bore of the implant. There are appropriate vents  200 , which allow the cement to flow along side the post and out of the implant at the time of cemented fixation. This relieves hydraulic piston action and allows the component to go fully to seat when it is cementedly affixed to the implant. 
   It should be clear that anatomically shaped dental implants of varied sizes and generally oval, rectangular, triangular, or circular anatomic shapes have been provided, which have integrated abutment base formed thereon. 
   Preferentially, the anatomically shaped dental implants have the greatest diameter of the ovoid shape of the integrated abutment at or near the base of the nearly parallel walls; a position approximating the ideal positional placement of the implant relative to the crest of facial bone in anterior teeth and bicuspids. At this level, the greater dimension of the ovoid anatomic shape ideally will be equal to or greater than 3.25 mm. The minor diameter of the ovoid anatomic shape at this area may be less than 3.25 mm. Larger implants will have greater linear dimensions. Also in the posterior areas of the mouth the implants may be oriented so that the greater dimension of the anatomical shape is in the mesiodistal orientation. 
   The present invention also provides osteotomes, which have instrument tips that are sized and shaped like the heads of the anatomic implants, and bone rasps, which have serrated instrument tips where those instrument tips are the same size and shape of the heads of the anatomic implants. The implants integrated abutments may be coated with various aesthetic components such as ceramics, gold, or titanium nitrite. Those implants with coated integrated abutments may also have the lower edge of the coatings curved coronally from the front/labial portion of the implant to the back/palatal-lingual portion of the implant so that the coatings do not come in direct contact with the bone. 
   Healing collars have internal anatomic openings that can be attached to correspondingly shaped and sized anatomic abutment base. These collars have extension flanges that may intentionally displace gingival tissue for ease of access to the pertinent portion of the implant during the prosthetic treatment phase. Impression transfer posts, which anatomically engage the abutment base and extend onto the parallel walls of the implant provide gingival tissue retraction during the taking of impressions of the dental implant. Extension cast-on posts and castable indexing sleeves may be united to provide copings for crowns or greater extension of the core of integrated abutment base, which are anti-rotational by virtue of their indexed relationship to the anatomically shaped dental implant. 
   It should be clear that the present invention is not to be limited to the forms shown which are to be considered as illustrative rather than restrictive.