Patent Publication Number: US-2006014119-A1

Title: Powered surgical instrument

Description:
BACKGROUND  
      A tooth may need to be extracted from the mouth for a variety of reasons. For example, in some situations it may be desirable to extract a tooth that is decayed, damaged or loose. Other times, teeth may be extracted for ‘orthodontic’ reasons, such as to provide room for other teeth, enable other teeth to grow, etc.  
      In its most basic form, a tooth includes a crown, which is the upper, visible portion of the tooth, and a root structure, which is hidden from view in the boney substructure of alveolar bone comprising the socket. A tooth is secured in place by a combination of factors, including the structural relationship between the root structure and the alveolar bone of the gums and the periodontal ligaments connecting the tooth root structure to the alveolar bone.  
      Depending on the type of extraction, removal of a tooth may require the skills of dentists, oral surgeons or similar professionals. As used herein, such professionals are referred to as dental professionals. It should be appreciated that the term dental professional should be read broadly to include any individual trained or skilled to extract teeth from a human or animal.  
      When a tooth includes a sufficient amount of sturdy crown to enable a dental professional to grip the tooth, the tooth may be removed by rocking the tooth until it is released from the socket. The rocking motion accomplishes at least two purposes. First, the rocking motion expands the alveolar bone in the region circumscribing the tooth socket. This rocking motion changes the structural relationship between the tooth root structure and the alveolar bone. Prior to rocking the tooth, the root structure and the alveolus are associated such that the alveolar bone provides a substantial amount of the retentive force on the tooth. The rocking motion compresses the alveolar bone surrounding the root structure, expanding the tooth socket away from the root structure.  
      Additionally, the rocking motion stretches the periodontal ligaments that extend from the root structure to the alveolar bone. The stretching of the ligaments may break some or all of the periodontal ligaments from the bone. In other cases, the periodontal ligaments may be stretched, but still intact, after completing the rocking motion to expand the tooth socket. In these cases, the dental professional may be able to break the tooth free from the ligaments by pulling on the tooth.  
      While the rocking technique allows a dental professional to remove a tooth, the procedure is not ideal. The procedure typically requires the dental professional to exert a great deal of force on the tooth to compress the alveolar bone. Additionally, the limited space in the mouth in which the dental professional must complete this rocking technique complicates the procedure. Furthermore, in some circumstances, the rocking motion can be applied with too much force damaging the crown of the tooth before the socket is sufficiently expanded or resulting in damage or breaks in the alveolar bone. If the crown is sufficiently damaged, the tooth may need to be treated as a surgical extraction to accomplish the removal. A surgical extraction traditionally required the removal of bone utilizing a rotary instrument or chisel. Further, broken alveolar bone may complicate the installation of a dental implant immediately after extraction, sometimes requiring bone grafts and subsequent implant placement at a later date.  
      The rocking procedure briefly described above may be difficult to perform when there is little or no crown for the dental professional to grip. For example, in some patients, the crown may be sufficiently deteriorated, or not sufficiently extended above the alveolar bone to enable a dental professional to grip the crown. In these cases, specialized tools may be used to remove bone to allow gripping of the remaining tooth structure. For example, a drill may be used to drill into the alveolar bone in the space surrounding the tooth being removed to expose more of the tooth. Drilling the bone may result in undesired bone removal. In some cases, the drilled out bone material must then be replaced with graft material and the patient must wait for the damaged alveolar bone to heal. For example, when a patient is to receive a dental implant, the patient may have to return after the tooth socket has healed to receive the implant. The pain and potential complications associated with the bone graft procedure and the delay in installation of the implant may be undesirable for both the patient and the dental professional.  
      Some dental professionals use manual periotomes during extraction of a tooth. Manual periotomes may be configured with a shaped tip disposed at an end of a shaft. In use, the tip may be placed at the base of the crown adjacent the periodontal ligament space. The dental professional then applies force on the shaft to force the tip into the periodontal space. A great amount of force may be required to use the manual periotome and the dental professional&#39;s hand and arm may be fatigued by the process.  
      As described above, a variety of special tools and techniques have been developed to improve tooth extraction. Such tools may be specialized for single purpose use. For example, in a tooth extraction and implantation procedure, separate instruments may be required to extract the tooth, collect the bone graft material, prepare the implant site and install the implant. This variety of tools may require the dental professional to be familiar with and own multiple different instruments. More than just inconvenient, the use of several different instruments may be expensive for the dental professional.  
     SUMMARY  
      A powered surgical instrument is provided. In some embodiments, the powered surgical instrument includes a housing having a proximal end and a distal end, wherein the distal end is configured to receive an expander adapted to expand the tooth socket. The instrument further may include a user-adjustable actuator disposed within the housing configured to move the expander from a first position to a second position, where the second position is linearly offset from the first position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of an embodiment of a powered surgical instrument of the present disclosure.  
       FIG. 2  is a cross-sectional view along line  2 - 2  schematically illustrating some components of the embodiment shown in  FIG. 1 .  
       FIG. 3  is a perspective view of another embodiment of a powered surgical instrument of the present disclosure.  
       FIG. 4  is a cross-sectional view along line  4 - 4  schematically illustrating some components of the embodiment shown in  FIG. 3 .  
       FIG. 5  is a perspective view of another embodiment of a powered surgical instrument of the present disclosure.  
       FIG. 6  is a schematic view of a surgical instrument according to another aspect of the present disclosure.  
       FIG. 7  is a cross-sectional view of the expander in  FIG. 5 .  
       FIG. 8  is a schematic illustration of a dental implant site preparation device according to an embodiment of the disclosure.  
       FIG. 9  is a cross-sectional view of an alternative dental implant site preparation device that may be used in cooperation with a powered surgical instrument of the present disclosure.  
       FIG. 10  is a perspective view of another dental implant site preparation device that may be used in cooperation with a powered surgical instrument of the present disclosure.  
       FIG. 11  is a perspective view of one embodiment of a powered surgical instrument of the present disclosure.  
       FIG. 12  is a cross-sectional view of the embodiment shown in  FIG. 11 . 
    
    
     DETAILED DESCRIPTION  
       FIG. 1  illustrates, somewhat schematically, a perspective view of a powered surgical instrument according to one embodiment of the present disclosure. It should be appreciated that the powered surgical instrument described below may be used in any suitable dental or medical application, including, for example, extraction of teeth and dental implant procedures. Further, such powered surgical instrument may be used in both human medical and dental applications as well as veterinary medical and dental applications.  
      It should be noted that the drawings depict a plurality of embodiments for the powered surgical instrument and that reference characters may refer to corresponding elements throughout multiple views. Similarly, the drawings are intended to illustrate exemplary embodiments that depict a variety of elements and subelements. It is within the scope of the disclosure that these elements and subelements may be selectively embodied in devices according to the present invention alone or in combination with one or more other elements and/or subelements, regardless of whether the particular selected element, subelement, or combination thereof is specifically illustrated in the figures. For example, the powered surgical instrument disclosed herein may include any of the described and/or illustrated actuation controls, actuators, power supplies, tips, etc., regardless of the particular combination shown in a specific figure.  
      As shown in  FIG. 1 , powered surgical instrument  10  may include a housing  12 . Housing  12  may be configured as a cylindrical body as shown or it may have other suitable configurations. It should be noted that a portion of housing  12  may be contoured to be comfortably held in the hand of a dental professional. For example, the housing may be ergonomically designed to substantially correspond to a user&#39;s grip. Additionally, housing  12  may be provided with gripping features or padding to increase the dental professional&#39;s comfort and ability to grip the housing. Although not described in detail herein, it should be recognized that housing  12  may include additional features to increase its functionality or its cooperation with other dental instruments and apparatus, such as holders, chargers, power supplies, etc.  
      Housing  12  may include a proximal end  14  and a distal end  16 . Distal end  16  may be configured to receive an expander  18 . In some embodiments, distal end  16  may be configured to selectively receive one of a plurality of tools configured to perform one or more surgical functions. Expander  18 , as well as, the plurality of selectively receivable tools will be described in more detail below.  
      Powered surgical instrument  10  may also include a receiver  20  within housing  12  adapted to selectively receive an expander. In some embodiments, receiver  20  may be adapted to receive one or more of a variety of tools of different dimensions and configurations. A locking mechanism may be incorporated in distal end  16  of housing  12  or into receiver  20  to accommodate receipt and securement of the various tools to the instrument. For example, and not by limitation, housing  12  or receiver  20  may include a locking mechanism similar to the adjustable chuck customarily used on power drills in the hardware industry. Additionally, distal end  16  or receiver  20  may include other clamping mechanisms that will be recognized as suitable for securing differently-sized tools.  
      With reference to  FIG. 2 , powered surgical instrument  10  may include an actuator  22  disposed within housing  12 . As used herein, the term “actuator” includes a device that causes movement in another component of the surgical instrument, such as expander  18  or other tool secured by receiver  20  or distal end  16 . The movement caused by the actuator may be linear in one direction or it may be linear in a reciprocating, back and forth motion. When actuator  22  causes reciprocating movement, actuator  22  may be referred to as a “reciprocator.” It should be understood that powered surgical instrument  10  may include an actuator  22  configured to move expander  18  in a forward linear motion, such as from a first position to a second position offset from the first position, such as indicated by forward directional arrow  32  in  FIG. 2 . Alternatively, actuator  22  may be adapted to move expander  18  in a reverse linear motion, such as indicated by reverse directional arrow  34 . Thus, the expander may be driven away from the housing  12 , toward housing  12  or in both directions. In some embodiments, actuator  22  may be configured to allow a user to select the direction of linear motion, forward  32 , reverse  34  or both. In other embodiments, actuator  22  may be configured to alternatingly move expander  22  in both the forward direction and the reverse direction.  
      Actuator  22  may be any suitable linear driving device. For example, actuator  22  may be a solenoid actuator, a pneumatic actuator, a mechanical actuator, or other actuator capable of causing linear motion.  FIG. 2  illustrates a solenoid actuator  26 , which may include a solenoid coil  28  and a plunger  30  configured to slidingly engage the coil. In an exemplary embodiment, solenoid actuator  26  may be configured to move plunger  30  in the forward direction, shown by arrow  32 , and allow the force of the dental professional pushing instrument  10  to move plunger  30  in the reverse direction, shown by arrow  34 . Alternatively, solenoid actuator  26  may be adapted to move plunger  30  in the reverse direction or in reciprocating forward and reverse directions.  
      Solenoid actuator  26  may be configured to reciprocatingly move plunger  30  in the forward direction  32  and the reverse direction  34 . Such a configuration may be achieved by using a biasing member to drive the plunger in the reverse direction. Any suitable biasing mechanism may be used, including, but not limited to, a spring, a bumper, such as a gasket, a reversal of the polarity of the solenoid coil, or by other means. In the embodiment illustrated in  FIG. 2 , a rubber gasket  33  is illustrated forward of plunger  30 . Rubber gasket  33  may be configured to rebound plunger  30  in the reverse direction preparing it for subsequent movement in the forward direction by actuator  22 .  
      In some embodiments, a bi-directional solenoid may be incorporated within the housing. The bi-directional solenoid may decrease the fatigue experienced by a dental professional and may allow for increased functionality of the instrument. In an embodiment of surgical instrument  10  where the solenoid is bi-directional, solenoid actuator  26  may be operatively coupled to expander  18  such that the reverse motion of plunger  30  also pulls expander  18  in the reverse direction  34 .  
      Actuator  22  may be configured to linearly drive expander  18  to enable a dental professional to more easily remove a tooth or perform other surgical functions. For example, expander  18  may be configured to be positioned along the periodontal ligament space. In some embodiments, expander  18  may be sized such that it is slightly larger than the periodontal ligament space.  
      As the actuator moves expander  18  linearly, the alveolar bone surrounding the tooth socket is compressed or compacted, thus expanding the socket along the periodontal ligament space. Expander  18  is thus adapted to expand the tooth socket. The linear driving motion of the powered surgical instrument operates with sufficient force to compress the bone surrounding the tooth socket. As a byproduct of the compression of the bone surrounding the tooth socket, the periodontal ligaments may be severed or otherwise broken. Once the bone is sufficiently compressed and the socket is sufficiently expanded, the tooth may be gripped and removed. The linear motion of the powered surgical instrument facilitates the expansion of the tooth socket while minimizing the fatigue which would occur if such a procedure was attempted manually.  
      With reference to  FIGS. 1 and 2 , surgical instrument  10  may also include a power supply. The power supply may be external to housing  12 , such as an electrical connection between surgical instrument  10  and a standard alternating circuit power supply. Alternatively, the power supply may be disposed within housing  12 . In such an embodiment, the power supply may include batteries, either rechargeable or non-rechargeable.  
      Surgical instrument  10  may also include a power control  38 . Regardless of how power is supplied to surgical instrument  10 , power control  38  may be configured to allow the dental professional to turn the instrument on or off. Surgical instrument  10  may be considered to be “on” when power is flowing from power supply  36  to another component of powered surgical instrument  10 , such as actuator  22 . Power control  38  may be disposed on housing  12  as shown in  FIGS. 1 and 2 . Alternatively, power control  38  may be disposed external to housing  12 , such as on an external control box or other component.  
      Surgical instrument  10  may also include an actuation or reciprocation control  40 . Actuation control  40  may be disposed on or within housing  12  or it may be external to housing  12 , such as on an external control box, as will be seen in other embodiments described below. It should be understood that actuation control  40  is in communication with actuator  22 . Actuation control  40  may be configured to enable a user, such as the dental professional, to selectively adjust one or more properties of the actuator or other operational element of the surgical instrument  10 .  
      Actuation control  40  may include a variety of user interfaces and controls, including analog systems and/or digital systems. Actuation control  40  may be a mechanical controller and/or an electronic controller. For example, in  FIGS. 1 and 2 , surgical instrument  10  is shown with an electronic controller  42 . Electronic controller  42  may include one or more LED displays (or other type of electronic display), one or more user input devices, such as touch pads, sliders, or dials, and one or more digital processors to convert the user input into electronic signals.  
      It should be appreciated that actuation control  40  may include other control systems, including, but not limited to, analog systems incorporating dials and electrical circuitry rather than digital processing, combinations of analog and digital systems, etc. For example, actuation control  40  may include a combination of digital and analog systems working cooperatively to enable a user to selectively control or adjust the linear motion as generated by actuator  22 . Examples of these and other alternative embodiments will be better understood with reference to the description below.  
      Actuation control  40 , in whatever embodiment it is implemented, may be configured to adjust the linear motion induced by actuator  22 . For example, actuation control  40  may control one or more of the following characteristics or other like characteristic: the frequency of the linear motion, the intensity of the linear motion, the stroke-length of the linear motion, or some other characteristic of the motion. With continued reference to the embodiment shown in  FIG. 1 , it should be understood that expander  18  will move at a given speed (frequency), will travel a certain distance in each direction with each motion (stroke-length), and will travel with a certain force conveyed by actuator  22  (intensity). Other characteristics that may be controlled by actuation control  40  may include such things as modifying one or more of these characteristics over time to create actuation or reciprocation patterns. As one example of an actuation pattern, a user may prefer a lower frequency, intensity, or stroke-length at the beginning of the procedure to ensure proper placement of the instrument and prefer a higher frequency, intensity, or stroke-length after the expansion is underway and the expander is at least partially maintained in the proper placement by the surrounding tooth and bone.  
      As an illustration of the use of actuation control  40  to enable a user to selectively control characteristics of the motion generated by actuator  22 , the following examples are provided.  
      In some embodiments, actuation control  40  may allow a user to select the frequency at which actuator  22  drives expander  18 . In some embodiments, the range of selectable frequencies may range from about 0 Hz to about 40.0 kHz, or anywhere there between. In some embodiments, the upper frequency limit may be 20 kHz, 10 kHz, or 1.0 kHz. Embodiments with a narrower range of selectable frequencies may also be configured. For example, in some embodiments, the selectable range of frequencies may span from about 0 Hz to about 100 Hz. In still other embodiments, the selectable range may span from about 0 Hz to about 60 Hz. Actuation control  40  may be configured to allow a user to select a desired frequency in the range. Alternatively, actuation control  40  may be indexed so that a user can select from a collection of predetermined frequencies within the range.  
      Additionally, actuation control  40  may allow a user to select the intensity at which actuator  22  drives expander  18 . In some embodiments, the actuator may drive the expander with up to about 1.5 pounds of force. A user may be able to select an intensity ranging from 0 pounds-force to about 1.5 pounds-force. Alternatively, actuation control  40  may provide an index of selectable intensities within this range. In other embodiments, actuator  22  may drive expander  18  with a lower maximum force, such as 0.75 pounds-force or 1.0 pounds-force.  
      In some embodiments, actuation control  40  may enable a user to select the stroke-length that actuator  22  provides expander  18 . As described above, in the embodiments where a solenoid actuator is used, actuation control  40  may adjust the stroke-length by modifying the extent to which plunger  30  is driven in the forward direction (represented by arrow  32 ), by modifying the amount of rebound force provided by a biasing force, or by adjusting the position of the solenoid actuator  26  within housing  12 . In some embodiments, the user may be able to select a stroke-length ranging from about 0.01 mm to about 1.0 mm or anywhere there between. In other embodiments, the stroke-length may be selectable within a range from about 0.01 mm to about 0.5 mm.  
      Referring back to the figures, in some embodiments, housing  12  may be configured with an operational control  39 . Operational control  39  may be disposed on housing  12  to provide additional control and convenience to the dental professional performing the surgical procedure. For example, operational control may be configured to temporarily halt the motion of expander  18  without requiring the dental professional to modify other settings or reach for other controls. The operational control may be configured to cooperate with a portion of actuator  22  or with a portion of expander  18  or both. It should be appreciated that in some embodiments, operational control  39  may cooperate with power control  38  or with actuation control  40 . Although shown at the distal end  16  of housing  12 , operational control  39  may be disposed on any suitable location on the housing of the instrument or accessible component of the instrument.  
      Referring now to  FIGS. 3 and 4 , an alternative embodiment of a powered surgical instrument is illustrated in a somewhat schematic perspective view. As described above, components of this embodiment may be interchangeable with the earlier and later described embodiments and are not limited to the combinations as illustrated in the exemplary figures.  
      As in  FIGS. 1 and 2 , the powered surgical instrument  110  of  FIGS. 3 and 4  includes a housing  112  with a proximal end  114  and a distal end  116 . Distal end  116  may be configured to receive an expander  118 . Surgical instrument  110  may also include a receiver  120  as described above. It will be noticed in  FIG. 3  that expander  118  has a slightly different configuration than expander  18  of  FIG. 1 . The differences will be discussed in greater detail below.  
      The embodiment shown in  FIGS. 3 and 4  also includes an actuator  122  to move expander  118 . Like in the embodiment shown in  FIGS. 1 and 2 , actuator  122  may be configured to move expander  118  in a linear motion. However, actuator  122  of the embodiment illustrated in  FIGS. 3 and 4  is a pneumatic actuator  126  as opposed to solenoid actuator  26  of  FIGS. 1 and 2 . Pneumatic actuator  126  may include one or more pneumatic devices, represented schematically at  128 , capable of pneumatically moving plunger  130  to move expander  118  in a linear motion. As with solenoid actuator  26 , pneumatic actuator  126  may be configured to drive plunger  130  in the forward direction, shown by arrow  132 , in the reverse direction, shown by arrow  134 , or in both the forward and the reverse directions, either selectively or alternatingly.  
      Surgical instrument  110  incorporating pneumatic actuator  126  may also include a compressed air supply  144  in communication with pneumatic actuator  126 . Compressed air supply  144  may supply a stream of compressed air to an actuation control  140 . For example, as shown in  FIG. 3 , actuation control  140  may have an air input  146  and an air output  148 . Alternatively, compressed air supply  144  may provide compressed air directly to housing  112  and pneumatic actuator  126 . In some embodiments, pneumatic actuator  126  or actuation control  140  may be configured with a plurality of valves, channels, and other components adapted to allow a user to selectively control the linear motion provided by the actuator, such as forward only, reverse only, or reciprocating motion.  
      Air from compressed air supply  144  may be directed into instrument  110 . For example, as shown in  FIG. 4 , pneumatic actuator  126  may include a housing air inlet  154 , an air feed  150  and an air vent  152 . Housing  112  may also include an air vent  156 . In some embodiments, actuation control  140  will control the air supply to pneumatic actuator  126  to cause plunger  130  to drive expander  118  in a linear motion. Alternatively, a steady stream of compressed air may be provided to pneumatic actuator  126  and the pneumatic actuator may control the movement of plunger  130 .  
      As shown in  FIG. 3 , actuation control  140  may include one or more controls to allow a user to selectively adjust the linear motion as described above. For example, in the illustrated embodiments, actuation control  140  may include user-maneuverable dials that may be selectively adjusted during a procedure. Similar to the embodiments shown in  FIGS. 1 and 2 , actuation control  140  may be used to selectively control the frequency of actuation, the intensity of actuation, or the stroke-length, as well as other characteristics. Actuation control  140  may be part of a separate control box  158  or, in some embodiments, one or more of the controls may be disposed on housing  112 . Additionally, compressed air supply  144  may be a separate component as shown in  FIG. 3  or it may be incorporated into control box  158 .  
      When powered surgical instrument  110  is pneumatically driven as in  FIGS. 3 and 4 , the power supply and power control may be different than the power supply and power control described in connection with the embodiment illustrated in  FIGS. 1 and 2 . For example, there may be several power controls that cooperate to determine when pneumatic actuator  126  actually moves or drives expander  118 . For example, in some embodiments, there may be a power control on compressed air supply  144 ; a power control on control box  158 ; a power control associated with actuation control  140 ; a power control on housing  112 ; a power control associated with pneumatic actuator  126 ; a power control associated with more than one of these components, etc. One or more power controls may cooperate to control when actuator  122  moves expander  118  in a linear motion. Additionally, one or more of these power controls may be configured as an operational control  139  (as discussed above in regards to operational control  39 ) to temporarily secure expander  118  in a fixed location while not interfering with the operation of the remaining components.  
       FIG. 5  illustrates another embodiment of the powered surgical instrument of the present disclosure. Powered surgical instrument  210  may include the features discussed above in connection with instrument  10  and/or instrument  110 . In  FIG. 5 , both actuation control  240  and power source  236  are external to housing  210 . Further, actuation control  240  is shown as a digital readout, but it should be appreciated that the dials of  FIG. 3  or other like controls may be used without departing from the scope of the disclosure.  
       FIG. 5  further illustrates an embodiment wherein powered surgical instrument  210  includes a pressure sensitive device, such as foot pedal  260 . The pressure sensitive device may be a foot pedal as shown, but may also include other pressure sensitive devices, such as a touch pad disposed on housing  212 . In some embodiments, foot pedal  260  may cooperate with actuation control  240  to allow a user additional control over the linear motion during the surgery or procedure. In this way, pressure sensitive device  260  is similar to operational control  39 ,  139 . However, in addition to the start/stop functions of operational control  39 , foot pedal  260  may be adapted to allow a user to variably control one or more characteristics, such as frequency, intensity, etc.  
      For example, foot pedal  260  may be configured to allow a user to adjust the frequency of the motion by applying more or less pressure. In some embodiments, powered surgical instrument may be provided with more than one pressure sensitive device, such as a foot pedal and a touch pad. The pressure sensitive device that may be a component of powered surgical instrument  210  may be adapted to cooperate with actuation control  240  to allow adjustment up to set maximum. For example, when foot pedal  260  is used to adjust the frequency of linear motion, actuation control  240  may be adapted to allow a user to set a maximum frequency and foot pedal  260  may be configured to allow the user to vary the frequency between 0 Hz and the maximum frequency set on actuation control  240 .  
       FIGS. 6-10  illustrate an embodiment of powered surgical instrument adapted to prepare a tooth socket for a dental implant. As in the embodiments described above, the surgical instrument of  FIG. 6  may include a housing  312 . Housing  312  may include a receiver (indicated generally at  320 ) configured to selectively receive a dental implant site preparation device  318 . The actuator (as indicated by general arrow  322 ) may be any suitable actuator configured to drive the dental implant site preparation device  318  linearly.  
       FIG. 6  illustrates a dental implant site preparation device  318  somewhat schematically. It should be understood that the expander described above is an example of a dental implant site preparation device  318  and that the above description of surgical instruments, actuators, and expander motion also may describe the surgical instrument of  FIG. 6  and dental implant site preparation device  318 .  
      The procedure for installing a dental implant often begins with extraction of the natural tooth to make way for the implant. However, the natural tooth socket is generally not naturally prepared to receive a dental implant. For example, the alveolar bone material around the tooth socket may not be able to securely hold the implant or the tooth socket may not be properly shaped to receive the implant.  
      Exemplary steps for preparing a dental implant site are summarized in box  370  of  FIG. 6 . For example, such steps may include, but are not limited to, removing or extracting a resident tooth, expanding the tooth socket, collecting bone graft material, compacting bone graft material into the tooth socket and forming the tooth socket to the proper shape. Additionally, when bone graft material is utilized, the dental professional may treat the placement area to facilitate proper healing. For example, the bone graft placement area may be covered with a protective membrane that is secured to the surrounding bone using bone tacks.  
      As illustrated in  FIG. 6 , a powered surgical instrument may be used to prepare a dental implant site by selectively securing a dental implant site preparation device  318  to housing  312 . One exemplary dental implant site preparation device may include an osteotome. The osteotome as an implant site preparation device may be used in soft bone to form the site by compressing the bone laterally, causing a denser bone to implant interface, rather than removing valuable bone from the surgical site. A variety of additional site preparation devices may be used in cooperation with the disclosed powered surgical instrument, some of which include an expander  372 , a harvester  374 , a compacter  376 , and a shaper  378 . It should be understood that a single site preparation device may be configured to perform more than one function, such as compaction of bone material and shaping of the tooth socket.  
      Expander  372  may be used to extract the tooth from the tooth socket, as discussed above. For example, expander  372  may be configured to have a width slightly larger than the width of the periodontal ligament space. When expander  372  is slightly larger than the periodontal ligament space, the linear motion of the expander compresses or compacts the alveolar bone surrounding the tooth socket expanding the socket. Additionally, as the socket expands and expander  372  is moved further into the periodontal ligament space, expander  372  may be adapted to cut or sever the periodontal ligaments. Embodiments of expander  372  are illustrated in  FIGS. 1, 3 , and  5  as expander  18 ,  118 , and  218  respectively. Expander  372  may be adapted to have a relatively flat distal end as shown in  FIG. 1 .  
      Alternatively, expander  372  may have a contoured distal end as shown in  FIGS. 3 and 5 . A cross-section of the contoured distal end is illustrated in  FIG. 7 , which is a cross-sectional view of expander  218  in  FIG. 5 . Contoured expander  218  may be adapted to substantially correspond with the contours of an average tooth. Contoured expander  218  may be formed in a u-shaped configuration having a bottom portion  262  and a pair of raised portions  264   a ,  264   b.    
      Additionally, expander  372  may be configured with a bayonet tip as shown in  FIG. 5 . It should be understood that some embodiments of the implant site preparation device include one or more bends in the shaft. Such bends in the shaft may be similar to those shown in  FIG. 5  or may include other bends and configurations of the shaft to enable the dental professional to better access the surgical site.  
      It should be understood that expander  372  may include a variety of devices configured to facilitate removal of a tooth and/or preparation of a tooth socket for a dental implant. Expander  372  is adapted to expand the periodontal ligament space and may be configured to have width at the distal end greater than the width of the periodontal ligament space. On average, the periodontal ligament space ranges from 0.25 mm to 0.4 mm. Expanders  372  of the present disclosure may have a width at the distal end ranging from about 0.25 mm to about 0.75 mm.  
      With continued reference to  FIG. 6 , the powered surgical tool disclosed herein also may be used with a harvester. Harvester  374  may be used to collect bone fragment material. An exemplary harvester is illustrated in  FIG. 8  and includes a shaft  382  having a distal end  384  and a proximal end  386 . Harvester  374  may also include one or more scrapers  388  disposed adjacent to distal end  384 . In use, harvester  374  may be used to collect bone fragment material by placing scrapers  388  in contact with a surface of a bone  
      Harvester  374  may be received within the powered surgical instrument described herein such that the harvester is driven in a collection direction (e.g. toward the housing) to coincide with the configuration of scrapers  388 . However, harvester  374  may also be used in cooperation with a surgical instrument configured to drive in a forward direction if scrapers  388  were configured accordingly. The driven motion of harvester  374  coinciding with the configuration of scrapers  388  allows the harvester to collect bone graft material with less effort and fatigue for the dental professional.  
      A compacter  376  may also be received within the disclosed powered surgical tool. Compacter  376  may be configured to perform one or more functions. For example, compacter  376  may be configured to pack bone graft material into a tooth socket. Additionally, compacter  376  may be configured to compress bone material surrounding the tooth socket to increase the density of the bone to implant interface to better receive an implant. As mentioned above, an empty tooth socket is not generally naturally prepared for receipt of an implant. Bone graft material is often used to provide the dental professional with material to form a more preferred implant site. The graft material may be compacted into place, such as by repeated impacts from compacter  376 .  
      A shaper  378  may also be received within powered surgical tool  318 . Shaper  378  of  FIG. 6  may include a set of site shaping devices  390  illustrated in  FIG. 9 . A set of site shaping devices  390  may include one or more shapers  392 ,  394 ,  396 . Each shaper  392 ,  394 ,  396  may be configured to perform one or more functions similar to those of compacter  376 . For example, site-shaping devices  390  may be configured to pack bone graft material into a tooth socket. Additionally, site-shaping devices may be configured to compress bone material surrounding the tooth socket to densify the bone to implant interface. As shown, the shapers have a rounded distal end but the distal end may be configured to meet particular needs or desires of patients or dental professionals. For example, the shapers may be tapered to form the site into the proper shape for receiving the dental implant. The difference between shaper  378  and compacter  376  will be better understood with reference to the following discussion.  
      Once the graft material is compacted into the socket or when graft material is not used, it may still be desirable to shape the tooth socket. A natural tooth socket may be oblong or elliptical and many dental implants are circular. Accordingly, dental implant site preparation may include forming the tooth socket to correspond with the dental implant. For example, bone graft material may be compacted into a socket leaving a socket opening that may be smaller than required to receive the implant. A hole the size of the implant may be drilled into the graft material but the edges of the hole may not be dense enough or stable enough to secure an implant.  
      A compression and expansion process may be used to form the tooth socket for receiving an implant and to increase the density of socket. In such a process, a hole smaller than the diameter of the implant may be drilled to start the forming process. For example, the dental implant may have a diameter of 5.0 millimeters and a 2.0 millimeter hole may be drilled in the filled-in tooth socket. Subsequently, a 3.5 mm diameter shaper  392  may be driven into the 2 mm hole. Each of the shapers  392 ,  394 ,  396  may have a tapered distal end to allow the larger compactor to start into the hole prepared by the smaller compacter. The impact of the larger diameter shaper into the hole compresses the bone graft material outwardly, densifying the bone and forming the implant site. Shaper  392  may be driven by powered surgical instrument in a forward direction or in reciprocating motion to reduce the fatigue on the dental professional. Shaper  392  will form a 3.5 mm hole in the filled-in tooth socket. Shaper  394  may then be driven into the filled-in tooth socket by the surgical instrument. Shaper  394  may have a 4.3 mm diameter and may compress the bone enlarging the tooth socket to 4.3 mm in diameter. This process of expanding a hole in the filled-in tooth socket may continue until the hole reaches the desired diameter. For example, shaper  396  may have a diameter of 5.0 mm to prepare a dental implant site for a 5.0 mm diameter implant.  
      Another dental implant site preparation device  318  is illustrated in  FIG. 10 . Tack driver  350  may be adapted to drive tacks into bone surrounding a bone-graft placement area. For example, typically, once bone graft material is placed in the implant site from a collection area, the placement area needs to heal. As discussed above, a dental professional may place a protective membrane over the placement area to allow the bone to grow back (rather than being displaced by faster growing soft tissue). The protective membrane may be secured to the bone with bone tacks.  
      Tack driver  350  may facilitate the securement of the protective material through the repetitive linear motion of the powered surgical instrument disclosed herein. Tack driver  350  may be configured to have a blunt head  352  as shown in  FIG. 10 . Blunt head  352  may have a flat surface or it may be configured with a slight concavity  354  as illustrated. Blunt head  352  may also be configured with a plurality of flanges  356  within concavity  354 . A tack may be positioned within concavity  354  on blunt head  352 . Flanges  356  may secure the tack. The powered surgical instrument may then be positioned to drive the tack into place. Once the bone tack is started into the bone, the flanges will release the tack and the actuator will continue to smoothly drive the tack into the bone.  
       FIGS. 11 and 12  illustrate an alternative embodiment of a powered surgical instrument. It should be understood that the instrument shown in  FIGS. 11 and 12  are exemplary only and may be combined with one or more of the features and aspects described above.  FIG. 11  illustrates a perspective view of powered surgical instrument  410  according to the present disclosure. As shown in  FIG. 11 , powered surgical instrument  410  includes a housing  412 , a proximal end  414 , a distal end  416 , and a receiver  420 .  
       FIG. 12  illustrates a cross-sectional view of the embodiment illustrated in  FIG. 11 . As seen in  FIG. 12 , powered surgical instrument  410  includes a housing  412 , a proximal end  414 , a distal end  416 , and a receiver  420 . Within the housing  412 , powered surgical instrument  410  is illustrated as including an actuator  422  operatively associated with receiver  420  to move dental implant site preparation devices that may be received therein. Actuator  422  is illustrated as a solenoid actuator  426 , including a solenoid coil  428  and a plunger  430 . Additionally, actuator  422  is shown including biasing member  433  to drive the reverse linear motion of plunger  430 . In the embodiment of  FIG. 12 , biasing member  433  includes one or more springs.  
      Although the present disclosure includes specific embodiments, specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various elements, features, functions, and/or properties disclosed herein. The following claims particularly point out certain combinations and subcombinations regarded as novel and nonobvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.  
      Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment and such features, structures and/or characteristics may be included in various combinations with features, structures and/or characteristics of other embodiments.  
      In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.