Abstract:
An arrangement including an instrument for the insertion of a dental implant including a template placeable on a bone or surrounding tissue. The template, or a first sleeve arranged within the template, includes a through-recess, through which the instrument can be guided. The arrangement enables exact alignment and guidance of the instrument and easy handling. A second sleeve that is axially displaceable on the instrument is provided, and axially fixed in a base position through automatically releasable connecting elements with predetermined retaining force such that when the retaining force is exceeded, the connecting elements can be automatically released and the second sleeve can be axially displaced. The instrument, together with the axially fixed second sleeve, can be inserted in the continuous recess and is aligned in the template via the outer surface of the second sleeve, the surface being configured relative to the inner surface of the recess.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to an arrangement for preparing or executing the insertion of an implant, in particular a dental implant. 
     Such an arrangement is known from U.S. Pat. No. 5,320,529 and includes an instrument embodied as a drill and a template by means of which the positioning and insertion of a bore in a bone, in particular the jaw bone, can be determined. The template, which may also be called a splint or is embodied as such or rail, is produced based on data about the bone, in particular the jaw bone, that are generated by means of a computer tomograph (CT), an X-ray device, or another image-producing device in order to be able to plan and define the required position of the implant, taking into account the anatomical, surgical, and also esthetic considerations. The rail is adapted to the individual situation and qualities and includes at least one through-recess for receiving a first sleeve. This first sleeve includes a through-hole through which the instrument embodied as a drill can be passed in order to be able to determine exact positioning or orientation of the bore for the implant. The inner diameter of the through-hole for the aforesaid sleeve is matched to the outer diameter of the drill for adding the bore to the bone. The drill includes an annular collar or stop that can be positioned against the free upper edge of the sleeve in order to thus define the depth of the bore in the bone. In practice there are problems when inserting an implant into the bore added by means of the arrangement, which bore is also called a prepared implant bed, especially in that it is difficult for the operator to control the insertion depth for the implant. 
     Moreover, when the drill is inserted into the sleeve, the drill and/or the interior surface of the sleeve may be damaged, in particular as a result of an imprecise coaxial starting orientation for the drill relative to the through-hole for the sleeve. The inner diameter of the through-hole for the sleeve is at least equal in size to the outer diameter of the drill, which after being inserted into the through-hole in a slide fit can be moved and/or is rotatable therein. If the clearance or difference in diameters between the outer diameter of the drill and the inner diameter of the through-hole is too great, the precise orientation and insertion of the bore is jeopardized. Moreover, there is the risk that as soon as the contact surface of the drill moves into position against the contact surface of the sleeve and the rotation of the drill does not immediately cease, the sleeve will heat up significantly due to the friction losses that occur. Consequently, the fixed seat of the sleeve, in the template that normally comprises plastic, is no longer assured, and there is the risk that the drill will expand the bore just added to the bone and/or will change its orientation in an impermissible manner. 
     Furthermore, known from DE 22 05 314 C3 is an apparatus for infusing liquid means into the bones, which apparatus includes an outer tube, whose end that is to be inserted into the bone tissue has a male thread. The apparatus furthermore includes an inner tube having a pointed tip with openings for the injection and at the opposing end has a cannula. A limiter is provided on the outer sleeve and above the punctured skin can be fixed in a position, a screw being used for fastening. The limiter embodied on the sleeve only enables limiting the apparatus insertion depth into the bone. 
     SUMMARY OF THE INVENTION 
     Proceeding from this point, the underlying object of the invention is to avoid the aforesaid problems and to refine the arrangement such that exact orientation and/or guidance of the instrument, and/or handling when work is being performed with the instrument and/or during insertion of the implant into the prepared implant bed or in particular when the mucous membrane is being punched and/or when the bore is being made in the bone, are attained with great reliability. The arrangement should have a simple structure and in particular the template should be used in combination with different instruments such as punch, drill, thread cutter, and screwing-in tool. The arrangement should have a simple and also functionally reliable structure and/or sound, reliable handling when performing processing steps by means of the instrument. 
     The inventive arrangement is distinguished by a simple structure that is appropriate to its function and in a simple manner and with no problem makes it possible to precisely orient and/or guide and/or position the instrument relative to the bone and/or the mucous membrane present outside on the bone. The instrument can be embodied for different work processes, especially those that involve a punch for preparing the mucous membrane in the area of the implant to be inserted, a drill, a thread cutter for creating a female thread in the implant bed, and furthermore a screwing-in tool. The following explanations, structural features, advantages, and mechanical relationships when embodying the instrument as a drill also apply analogously for instruments embodied in a different manner. It is furthermore established that in the framework of the invention the recess or through-hole provided for the instrument to pass through can be present either directly in the template or indirectly in a first sleeve that is integrated in the template, the recess in the first sleeve also being called a through-hole. Arranged on the instrument is a second sleeve, the outer contour of which is matched to the inner contour of the through-hole, in particular of the first sleeve connected to the template. The instrument is not guided directly in the through-hole of the first sleeve or template, but rather indirectly by means of the second sleeve or sliding sleeve. When the second sleeve is in the basic position, the tip of the instrument preferably projects out of the second sleeve by a pre-determined length, and the instrument thus can initially be inserted into the aforesaid through-hole, even not precisely coaxially, specifically until the end of the second sleeve that faces the tip of the instrument engages in the through-hole. The second sleeve is fixed axially in a basic position on and/or relative to the instrument by means of releasable retaining elements and/or locking elements such that after a pre-specified axial retention force is exceeded the second sleeve is automatically displaceable axially on the instrument, specifically in particular axially away from the free end of the instrument, which then can be inserted into the mucous membrane surrounding the bone and/or into the bone. The retaining and/or locking elements are arranged on the instrument, preferably in an area outside of processing surfaces, such as cutting surfaces of a drill or the like, such processing surfaces being disposed between the tip or the free end of the instrument and the area having the retaining and/or locking element. After the automatic disengagement and/or release of the retaining and/or locking elements of the instrument and the second sleeve, which shall hereinafter also be referred to as a guide sleeve, the latter is axially displaceable on the instrument, in particular to a pre-specified stop. The shaft of the instrument is preferably embodied cylindrical and/or smooth and/or as a guide surface for the sliding sleeve and/or its interior surface, for the purpose of reliably guiding the sliding sleeve after its automatic disengagement, between the area in which the sliding sleeve is disposed in the basic position and the stop. The outer contour of the second sleeve is advantageously embodied essentially cylindrical and/or unthreaded, and thus smooth, as is the interior surface of the through-hole and/or of the first sleeve. 
     Advantageously the interior surface of the first sleeve and the associated exterior surface of the second sleeve have smooth and/or polished surface structures. The inner diameter of the through-hole and/or of the first sleeve is significantly larger than the outer diameter of the instrument that is guided in the second sleeve. The difference in diameter between the interior surface of the first sleeve and the outer diameter of the instrument is essentially equal to twice the wall thickness of the second sleeve. When the instrument is placed into the through-hole of the template or of the first sleeve, due to the aforesaid difference in diameter the risk of damage to the first sleeve is largely precluded. The second sleeve is fixed on the instrument by means of releasable connecting elements. The automatic and/or self-actuating releasable connection is arranged and/or embodied such that when a pre-specified axial force is attained the connection is automatically released and the guide sleeve is then axially displaceable on the instrument. The retaining elements are preferably embodied as locking elements that correspond to one another and are engaged with one another but that also release automatically when the pre-specified retaining force is attained. Moreover, the instrument and the sleeve or guide sleeve are matched to one another such that after the release and/or disengagement of the connection the instrument is guided axially in and/or by means of the sleeve and thus precise handling of the instrument is attained, for instance during further or deeper insertion of a drill into the bone. The instrument is guided precisely, the second sleeve being arrested axially and/or radially with respect to the template, in particular by stops that have been matched to one another, with respect to the template. The second sleeve or displaceable sleeve has a contact surface that is associated with a stop surface of the template or of the first sleeve such that the connecting elements are automatically released or disengaged when the aforesaid surfaces are positioned against them and the aforesaid axial force is effective. 
     The second sleeve is advantageously releasably fixed on the instrument such that before the tip of the instrument reaches the bone the second sleeve is already at least partially inserted into the first sleeve and thus the instrument, for instance the drill, is already reliably oriented with respect to the bone when the drilling of the latter begins. As drilling continues, the second sleeve then moves until its stop is positioned against an associated stop for the first sleeve so that after an axial force has continued its action in the longitudinal direction to the drill bit, the releasable connection of the second sleeve on the drill is automatically disengaged and the drill can now be moved through the second sleeve for further drilling of the bone. Thus functionally reliable and/or axis-parallel and/or coaxial guidance of the instrument is assured. Adding the bore ends as soon as a stop on the drill is positioned against the first sleeve fixed in the template indirectly via the second sleeve, this furthermore defining the insertion depth. It is herein expressly stated that these explanations also apply analogously when a different instrument is used, for instance a punch for the mucous membrane or a thread cutter or a screwing-in tool for the implant. The proposed arrangement is inventively used during the preparation or execution of the insertion of an implant and is furthermore embodied in accordance with the invention for executing a method for preparing or inserting an implant. 
     Refinements and special embodiments of the invention are provided in the subordinate claims and the following description. 
     The invention shall be explained in greater detail in the following using the special exemplary embodiments depicted in the drawings, but this shall not constitute a limitation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective partial cut-away depiction of the arrangement, the instrument being embodied as a drill; 
         FIG. 2  depicts a section of the second displaceable sleeve in an axial plane; 
         FIGS. 3 ,  4  depict the first sleeve in an axial section and in a perspective elevation; 
         FIGS. 5 ,  6  depict the arrangement with the drill in different positions while the bore is being added to the bone; 
         FIGS. 7 ,  8  depict perspective elevations of the drill with the displaceable sleeve; 
         FIGS. 9 ,  10  depict special embodiments of the releasable connection between the second sleeve and the drill; 
         FIG. 11  depicts a first perspective elevation view of a second alternative embodiment of the releasable connection between the second sleeve and the drill; 
         FIG. 12  depicts a second perspective elevation view of the second alternative embodiment of the releasable connection between the second sleeve and the drill; 
         FIG. 13  is a view of a special shaft geometry. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In accordance with  FIG. 1 , the inventive arrangement includes a template  2  in which a first sleeve  4  is arranged and secured against rotation in particular due to a non-round exterior surface. The template  2  and/or the first sleeve  4  contain a through-recess  5 . The template  2  with the preferably integrated first sleeve  4  is placed on a mucous membrane or mucosa  6  that is disposed over a bone  8 , in particular a jaw bone. The lower end  11  of a second sleeve  10  that is arranged on an instrument in the form of a drill  12  is already partially inserted into the first sleeve  4  or the recess  5 . The second sleeve  10  is fixed on the instrument or drill  12  by means of automatically releasable connecting elements  14 ,  16 . The connecting elements  14 ,  16  are inventively embodied as locking elements that are matched to one another and/or that engage in one another and that disengage when a pre-specified axial force is exceeded so that the sleeve  10  subsequently is axially displaced on the instrument, which here is embodied as a drill  12 . The second sleeve  10  has an exterior surface  17  that is matched and/or adapted to the interior surface of the recess  5 . The exterior surface  17  and the aforesaid interior surface of the recess  5  are preferably embodied cylindrically such that the second sleeve  10  is rotatable and/or axially displaceable in the recess  5  with essentially no clearance. 
     For the sake of simplicity, in the following the instrument shall be called a drill  12 ; however, in the framework of the invention the instrument can also be embodied as a punch, thread cutter, or screw-in tool for the implant. The second sleeve  10  is fixed on the drill  12  in a preferred manner such that the second sleeve  10 , as depicted, is at least partially inserted into the first sleeve  4  or the recess  5  before the drill bit  18  reaches the surface  20  of the bone  8 . The bit  18  projects beyond the lower end  11  of the second sleeve or sliding sleeve  10  in its base position by the length  21 . The first releasable connecting element  14  is advantageously embodied as an elastic ring and/or an expandable spring element and is partly arranged in an annular groove in the interior surface of the second sleeve  10 . In its exterior surface, the drill  12  includes the second releasable connecting element  16 , which here is embodied as an annular groove in which engages the correspondingly embodied first connecting element  14  of the second sleeve  10 . The connecting elements  14 ,  16  that correspond to one another are embodied such that when a pre-specifiable axial force in accordance with arrow  22  is exceeded, the releasable connection that the elements  14 ,  16  enable between drill  12  and second sleeve  10  is disengaged. As can be seen, the second sleeve  10  includes a through-hole  23  through which the drill  12  passes. The drill  12 , or its exterior surface  24 , is matched to the second sleeve  10 , or its interior surface  26 , such that the second sleeve  10  is displaceable on the drill  12  after the automatic disengagement of the releasable connecting elements  14 ,  16 . The second sleeve  10  can thus also be called a sliding sleeve that is axially displaceable in the axial direction on the exterior surface of the drill, the drill  12  furthermore being rotatably arranged in the sliding sleeve  10 . It is expressly noted that the drill  12  can preferably also be rotated in the sliding sleeve  10  when the releasable connecting elements  14 ,  16  between the sliding sleeve  10  and the drill  12  have not been disengaged. The sliding sleeve  10  is axially fixed on the drill  12  by means of the releasable connecting elements  14 ,  16 , the rotation of the drill  12  also be enabled in the sliding sleeve  10 . The drill  12  furthermore includes a stop  28  that is embodied here as an annular collar. In the depicted basic position of the sliding sleeve  10 , which position is assured by means of the connecting elements  14 ,  16  there is a pre-specified axial distance between the sliding sleeve  10  and the stop  28 , and this distance defines the insertion depth into the bone  8  for the drill  12  or drill bit  18 . 
     Prior to introducing the drill with the sliding sleeve  10  into the template  2 , an opening  30  was made in the mucous membrane or mucosa  6  by means of an appropriate instrument, for instance a punch tool. The aforesaid punch tool is also embodied and/or adapted to the template  2  and/or its first sleeve  4  such that there is reliable orientation and guidance. The aforesaid punch tool is also a component of the inventive arrangement. It should also be noted that, as indicated by the dot-dash line  31 , the tip  18  of the drill or instrument  12  can initially be engagingly inserted into the first sleeve  4  at an angle until the end  11  of the sliding sleeve  10  is caused to engage with the first sleeve  4  and thus the coaxial orientation of the instrument  12  with the through-hole is achieved. 
     Additionally or alternatively, instead of a closed annular embodiment, the sliding sleeve  10  can have an axial slit such that the sliding sleeve  10  can be laterally moved on and/or clipped to the drill  12 . In this case the sliding sleeve  10  comprises an advantageously resiliently elastic material, especially plastic. Such an embodiment essentially corresponds to the embodiment of the sliding sleeve  10  depicted in cut-away in  FIG. 1 . 
     Moreover, the sliding sleeve  10  can be fixed on the essentially cylindrical drill shaft  32  or in the cutting area  34  or on the drill chuck (not depicted here), the stop  28  naturally being arranged at a different location in the latter case. Furthermore, in the framework of the invention the stop can be embodied as a component of the drill chuck or can be embodied using a corresponding element of the drill device. Regardless of the specific configuration of the releasable connecting elements  14 ,  16  and their spatial arrangement on and/or at the drill and/or their spatial relationship to the drill, what is determinant is that the sliding sleeve  10  is initially fixed or when it is delivered from the plant is fixed or in the basic position is fixed axially in a defined manner on the drill by means of releasable connecting elements and that furthermore after the release or disengagement of the connecting elements a defined axial guidance and/or displacement is made possible that is limited by the stop  28  after a pre-specified displacement path has been traveled. 
       FIG. 2  depicts a section through the sliding sleeve  10 , which includes in its interior surface  26 , preferably its upper end area  38 , an annular groove  40  for receiving some of the first releasable connecting element. The lower end surface  41  of the end area  38  embodied as an annular collar with an expanded diameter, the end surface  41  that faces the tip of the instrument, forms the contact surface of the sliding sleeve  10  on the template and/or of the first sleeve integrated therein. If the lower end surface  41  comes to be positioned against the template and/or the integrated first sleeve and if the axial advancing force continues to be in effect, the connection between the sliding sleeve  10  and the drill or instrument is automatically released and/or released without any additional measures. As the dot-dash line  42  indicates, in the framework of the invention the first releasable connecting element can furthermore be embodied as a conical element, or can include such an element, that cooperates with a correspondingly embodied element of the instrument, especially the drill, this also advantageously providing security against rotation. The cone angle or angles are pre-specified such that there is no conical self-locking, but rather there is the releasable connection. Proceeding from the annular groove  40  to the lower end  11 , the sliding sleeve  10  or its interior surface  26  possesses a uniform inner diameter  43 . It is established that the inventive arrangement includes various sliding sleeves  10 , specifically with different sized inner diameters  43  that are matched to different sized outer diameters of various drills and instruments. Furthermore, in such sliding sleeves the inner diameter of the annular grooves  40  and of the connecting elements arranged therein are correspondingly embodied and/or matched. 
     Furthermore, provided outside on the sliding sleeve  10  is a stop element  44  with which an additional stop element of the first sleeve and/or of the template corresponds such that, as soon as they engaged with one another and/or are positioned against one another, the initially specified rotation is stopped and the sliding sleeve is secured against rotation with respect to the template and/or the first sleeve. Apart from the upper, expanded end area  38 , the sliding sleeve  10  has an outer diameter  46  that is matched to the inner diameter of the first sleeve, and specifically advantageously such that there is a slide fit and/or such that after engaging in the first sleeve the sliding sleeve  10  slides in and out of it easily and/or with no clearance, specifically both axially and rotatingly. It is expressly stated that the sliding sleeves with different inner diameters  43  each have the same outer diameter  46 . Above the annular groove  40  for the connecting element the sliding sleeve  10  has an inner diameter  48  that is preferably specified larger than the inner diameter  43  of the interior surface  26  connecting from the annular groove  40  to the lower end  11 . Thus it is assured in a preferred manner that during and/or after the release of the connection to the instrument the connecting element arranged in the annular groove  40  is not pressed downward into the area of the interior surface  26 , but rather can be partly drawn and/or moved upward into the area with the expanded diameter  48 . As can be seen, the inner diameter of the annular groove  40  is provided larger than the inner diameter  48  of the adjacent area thereabove. 
       FIGS. 3 and 4  provide lateral and perspective elevations, respectively, of the first sleeve  4 . The first sleeve  4  includes a lateral slit  50  that extends at least part of the way down from the upper end face  52 , preferably across the entire axial length, in accordance with the drawing. The first sleeve  4  has an at least partly non-round exterior contour, for instance in the shape of a polygon, so that it can be integrated into the template rotation-fast. Moreover, the template also includes a recess or a slit corresponding to the lateral slit  50  of the sleeve  4  such that the instrument or its tip can be inserted laterally, where necessary on an incline, into the template and/or the first sleeve. Thus, corresponding to the axial length of the slit of the first sleeve  4  and/or of the template, the space requirement is minimized and handling when inserting the instrument is simple, even in constrained spaces, such as for instance oral cavity. Preferably provided in the area of the upper end face  52  is the aforementioned additional stop  54  with which the stop element for the sliding sleeve can be caused to engage or against which it can be positioned. The first sleeve  4  includes interiorly a through-hole having an inner diameter  56  that is matched to the outer diameter of the sliding sleeve and is at least essentially the same size in order to assure certain guidance of the sliding sleeve in the first sleeve. It is stated at this point that in the framework of the invention the first sleeve can be omitted and the instrument can be guided directly in a recess of the template, the configuration of the interior surface of this recess corresponding to the interior surface of the first sleeve. 
       FIGS. 5 and 6  depict additional phases of the insertion of the instrument or drill, the bone not being displayed as it is in  FIG. 1 . In accordance with  FIG. 5 , the drill  12  has been moved toward the template  2  and/or the first sleeve  4  such that the lower end surface  41  of the expanded upper edge area  38  of the sliding sleeve  10  is positioned against the template  2  and/or the first sleeve  4 . If there is further axial movement by the drill  12 , and simultaneous rotational movement thereof, further rotation of the sliding sleeve is prevented by means of the two stop elements that are positioned against one another or engaged with one another, while the rotation of the drill  12  can continue unchanged. As can be seen from  FIG. 6 , the axial movement of the drill is terminated in that the stop or annular collar  28  of the drill  12  comes to be positioned against the upper end face of the sliding sleeve  10 , which is already axially fixed with respect to the template  2  and/or the first sleeve. 
     One alternative embodiment of the instrument  12  as a punch is depicted by a dashed line  57  in  FIG. 5 . This punch  57  is arranged on the shaft  32  at a pre-specified distance beneath the annular groove  40 . The punch  57  is pot-shaped and embodied open in the downward direction toward the mucous membrane  6 . The connecting part of the drill according to  FIG. 5  is not used here. 
     After the connection between the sliding sleeve  10  and the instrument  12  embodied in this manner has been released, the opening  30  is made in the mucous membrane  6  by means of the punch  57 . 
       FIGS. 7 and 8  provide perspective elevations of the instrument  12  embodied as a drill together with the sliding sleeve  10 . The first connecting element  14 , arranged in the retaining or annular groove  40  of the sliding sleeve  10 , is embodied here as a slit spring. The spring ring engages a radially interior surface area in part in the second connecting element of the drill  12 , which element is embodied as an annular groove. If a pre-specified axial force of the drill  12  is exceeded with respect to the sliding sleeve  10 , the spring ring is pressed out of the annular groove or the second connecting element and the connection is thus released. 
       FIGS. 9 and 10  depict partial cut-away perspective elevations of additional exemplary embodiments of the releasable connection, the first connecting element  14  being embodied as a clip spring. Some of the interior surface areas of the clip spring engage in the second connection element  16  of the drill  12 , which element is again embodied as an annular groove. 
       FIGS. 11 and 12  depict another exemplary embodiment for the releasable fixation of the sliding sleeve  10 , depicted on the shaft  32  of the drill. The shaft  32  includes for the sliding sleeve  10  both a usefully annular guide cam  58  and the second connecting element  16 , which is embodied as a retaining groove. Since the retaining groove  16  has a longer axial longitudinal extension than the first connecting element  14  or spring element, the sliding sleeve is axially displaceable to a certain degree with respect to the drill  12 , even when the connection has not been disengaged. Due to the guide cam or cams  58  it is assured that the sliding sleeve  10  moves easily on the drill  12  in a particularly useful manner. 
     Finally,  FIG. 13  depicts a view of a specific geometry of the drill shaft  32 . The second connecting element  12 , which is embodied here as an annular groove, is arranged between the usefully cylindrical shaft  32  and the cutting area  34 .