Abstract:
A method for performing an inferior lift in the sinus includes preparing an initial opening in the bone that is drilled to a depth just prior to reaching a sinus floor. Using a sonic drilling device, a final portion of the sinus floor is removed until a schneiderian membrane is reached. A bone graft is inserted into the opening, lift said schneiderian membrane. After ossification of the bone graft, an implant is inserted into the opening and graft.

Description:
RELATED APPLICATION  
       [0001]    This application claims the benefit of priority of U.S. patent application Nos. 61/349,545, filed on May 28, 2010 and 61/364,461 filed on Jul. 15, 2010, the entirety of which are incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    In the area of dental/periodontology implants, inferior lift technique has been used successfully for many years. In certain cases, the bone thickness in the region where the implant is to be inserted is not of ideal depth. The inferior lift technique involves drilling the bone to the floor of the sinus then breaking the floor of the sinus using osteotomes and exposing the schneiderian membrane. The membrane is then elevated and a bone graft is inserted into the opening. This bone graft eventually ossifies and provides a better thickness to properly support the dental implant. 
         [0003]    However, there are at least two drawbacks associated with the present inferior lift technique. First, patients undergoing this procedure always describe it as an uncomfortable process due to the necessary tapping of the osteotomes against the bones involved. For example, even with proper anesthesia, an osteotome is still used to break the floor of the sinus to expose the schneiderian membrane. This tapping reverberates throughout the bone (and neighboring bones) and is uncomfortable. 
         [0004]    Additionally, when using osteotomes, the repeated tapping on the sinus floor is somewhat imprecise and thus carries risk of rupturing the schneiderian membrane. If the schneiderian membrane is ruptured it can cause infection and otherwise delay the bone graft/lift procedure. 
       OBJECTS AND SUMMARY 
       [0005]    The present technique minimizes or avoids the above described drawbacks by preparing the opening and breaking the floor of the sinus using a new combination of drill/cutting implements and technique for using the same, thus exposing the schneiderian membrane without the use of osteotomes. The membrane can then be elevated after using this technique and bone is plugged in without any of the uncomfortable tapping on the sinus and with a greatly reduced risk of rupturing the schneiderian membrane. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0006]    The present invention can be best understood through the fallowing description and accompanying drawings, wherein: 
           [0007]      FIG. 1  is an image of the dental implant region, in accordance with one embodiment; 
           [0008]      FIG. 2  is an image of a step of the process for drilling through the bone to the sinus floor, in accordance with one embodiment; 
           [0009]      FIG. 3  is another image of a step of the process for drilling through the bone to the sinus floor, in accordance with one embodiment; 
           [0010]      FIG. 4  is an image of a step of the process for widening of the graft opening, in accordance with one embodiment; 
           [0011]      FIGS. 5-6  is an image of an intermediate stage of the drilling process in the graft opening, with  FIG. 6  showing an axial view of the opening; 
           [0012]      FIG. 7  is an image of a step of the process for widening of the graft opening, in accordance with one embodiment; 
           [0013]      FIG. 8  is another image of a step of the process for widening of the graft opening, in accordance with one embodiment; 
           [0014]      FIG. 9  is an image of a step of the process for inserting the bone graft, in accordance with one embodiment; and 
           [0015]      FIG. 10  is an image showing the completed graft with the implant therein, in accordance with one embodiment. 
       
    
    
     DETAILED DESCRIPTION  
       [0016]    The following is an exemplary description of the implant procedure described in accordance with the accompanying  FIGS. 1-10 . 
         [0017]      FIG. 1  shows generally the tooth area that undergoes an inferior lift procedure and receives a bone graft. In this figure, bone area  12  receives the intended bone graft. Open area  14  represents the sinus cavity. Hard floor  16  is the bottom portion of bone area  10  that borders the schneiderian membrane  18  which forms the bottom of sinus cavity  14 . 
         [0018]    In a first step in the inferior lift procedure as shown in  FIG. 2 , the process begins by drilling the initial opening into the bone using a standard dental drill bit  20  of the appropriate size. Typically, drill bit  20  would be approximately 2.0 mm in diameter in accordance with the typical implant sizes, discussed in more detail below. Such a procedure mirrors the prior art procedure. Because of the nature of drill bit  20  and the available precision when using ft, the drill depth must be estimated to be short of the sinus floor. Drill bit  20  cannot be used to expose all the way to the schneiderian membrane  18  without significant risk of breaking or rupturing the membrane because it cannot be used in such a manner to have its depth controlled with precision (e.g. via tactile feedback in the user&#39;s hand). In one example, using a pilot twist drill, drill bit  20  is used for creating the opening through the majority of the bone, except for approximately the final 1 mm below maxillary sinus cavity (representing the approximate thickness of sinus floor  16  and schneiderian membrane  18 ). 
         [0019]    In the prior art, the same bit may be used in multiple iterations until the hole in bone  12  is wide enough and then an osteotome is used to complete the break of sinus floor  16 , since such an implement can be used with more precision than the initial drill bit  20  pictured in  FIG. 2 . However, as outlined above, the use of the osteotomes to complete the break of sinus floor  16  is painful for the patient. 
         [0020]    In the present arrangement, as shown in  FIG. 3 , instead of using an osteotome to complete the break of sinus floor  16 , a sonic drilling implement  30  is used to complete the break of sinus floor  16 . Sonic drilling devices, such as sonic drilling device  30 , utilize variable modulation ultrasonic vibrations that are activated only when its cutting tip  32  is n contact with the bone tissue to be cut. 
         [0021]    An exemplary sonic drilling implement  30  may be a sonic bone drill as disclosed in U.S. Patent Application No. 2009/0023118, assigned to Piezosurgery, the entirety of which is incorporated by reference. 
         [0022]    Such “drilling devices” are advantageous because they provide a significantly more precise cutting ability on bone tissue while simultaneously providing better assurance that nearby soft tissue is not damaged since such sonic cutting tips, such as tip  12 , lose their cutting capacity when contacting soft tissue (the soft tissue absorbs the sound vibrations). 
         [0023]    In this context, using sonic drilling implement  30  with tip  32 , having a diameter substantially corresponding to the initial drill bit  20  (e.g. 2.0 mm), implement  30  is used to remove the remaining 1 mm of bone (sinus floor  16  is a the final portion of bone before schneiderian membrane  18  SM). 
         [0024]    In one arrangement, tip  32  of sonic drilling implement  30  may be a specific tip  32  for such inferior lift procedure. It is noted that, in general, sonic cutting tips have an active cutting region and other non-cutting regions as well, In the present  FIG. 3 , region  32 A represents the active region of tip  32  and region  32 B represents the non-cutting portion of tip  32 . 
         [0025]    The portion  32 B of tip  32  that is not active does not act to cut the neighboring bone  12  which it contacts. The only bone that is cut by tip  32  is bone that is kept in pressing contact with tip  32  via active region  32 A. As shown in  FIG. 3 , active region  32 A of the cutting tip  32  is very small and directionally only active in the forward (front) tip direction so that the only portion of bone being cut is the final 1 mm of sinus floor/bone  16 . 
         [0026]    As shown in  FIG. 4 , Once the initial opening is made through bone  12  and completed through sinus floor  16 , a different widening sonic tip  40  may be used to widen the initial opening to the desired width (i.e. with respect to the size of the desired implant). In this widening tip  40 , the active area  40 A is not only a front active area, but also a side active area (360°) to allow bone  12  to be drilled laterally. In this step the main portion of bone  12  is drilled using lateral motion exposing a greater part of sinus floor  16  until a circular opening  50  is made to its full size with only a small donut shaped area  52  of sinus floor  16  remaining. As a result, there is a small opening to membrane  18  in the center of a larger hole through bone  12  with circular or doughnut shaped ring  52  of the final 1 mm of sinus floor/bone  16 . This is shown in  FIGS. 5  (in cut-away) and  6  (axial view). 
         [0027]    It is noted that each of the various bone grafts/implants that may be used have different shapes (eg, cylindrical, conical, etc . . . ). In the next step, as shown in  FIGS. 7-8 , final ring  52  of sinus floor  16  bone (the doughnut shape) is removed, using a sonic cutting tip  60 , preferably a specially configured tip  60 , where the active area  60 A only cuts in the forward direction and only slightly along the sides of the front of tip  60 . Unlike tips  30  and  40 , cutting tip  60  is dimensioned with an active area  60 A such that in operation there is no accidental bone removal along the sides of the main opening in the main portion of bone  12 , which could make hole too large to accept the desired implant. Using this sonic tip  60 , the desired shape of the removal of the final 1 mm of sinus floor/bone  16  can be achieved, again without the use of osteotomes and likewise without damage to schneiderian membrane  18 . 
         [0028]    In one embodiment, the size of tip  60  is dimensioned in diameter to be slightly smaller than the size of the size/diameter of the intended implant, discussed below as implant  74 , so as not to inadvertently overly widen the opening which could result in a loose fit for the implant. For example, if the implant is 3.7 mm, the diameter of tip  60  may be 3.4 mm for eliminating ring  52  of sinus floor  16 . Alternatively, if the implant is 4.1 mm tip  60  may be or a 3.8 mm, or if the implant is 4.7 mm then tip  60  may be 4.2 mm in diameter. 
         [0029]    Once the above drilling procedures are complete, as shown in  FIG. 9 , a bone graft  70  is pressed into the opening using an osteotome  72  or other pressing device, lifting the floor of schneiderian membrane  18  of the sinus. It is noted that the usage of an osteotome in this respect is not the same as the use of osteotomes for breaking sinus floor  16  as in prior arrangements. Here the osteotome is being used only after the creation of the opening as per the above steps, primarily as a pressing device. 
         [0030]    As shown in the final  FIG. 10 , once the opening/bone graft  70  has had a sufficient amount of time for the graft to ossify, the implant  74  may be screwed/inserted into place. 
         [0031]    While only certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes or equivalents will now occur to those skilled in the art. It is therefore, to be understood that this application is intended to cover all such modifications and changes that fall within the true spirit of the invention.