Abstract:
A method for isolating a work object to achieve a predetermined operational objective, the method including the steps of encapsulating at least a portion of the work object in a housing in a work position so as to establish a zone of isolation relative to the portion of the work object; releasibly interconnecting the housing and the portion of the work object so as selectively to maintain said zone of isolation for a period of time sufficient to achieve the predetermined operational objective; and occluding an area proximate to the housing to resist incursion into the area during the period of time. An apparatus for isolating a work object, the apparatus including a housing having an interior dimensioned to permit the housing to be disposed in a work position with the work object received in the interior of the housing; and means for retaining the housing in the work position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    Not Applicable.  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not Applicable.  
         BACKGROUND OF THE INVENTION  
         [0003]    1. Field of the Invention  
           [0004]    The present invention relates to a method and apparatus for isolating a work object and, more particularly, to such a method and apparatus which are operable with particular utility in surgical and other medical techniques and particularly those involving osseointegration.  
           [0005]    2. Description of the Prior Art  
           [0006]    A variety of surgical procedures have long been employed to restore, or reinforce, the physiological integrity of living creatures, and particularly of human beings. While the earliest such surgical techniques focused on the restoration of, for example, the human skeletal structure, the same basic techniques have application to a wide variety of surgical and other medical applications with significant beneficial effect.  
           [0007]    It is known, for example, to use the technique of osseointegration to unite bone fragments for the purpose of restoring an arm, leg or other skeletal structure. This technique has been employed with beneficial effect in a wide variety of applications including, more recently, in the establishment of dental implants. For example, the Lazzara, et al. U.S. Pat. Nos. 4,846,683 and 4,850,870 disclose, respectively, prosthodontic restoration techniques which employ osseointegration to achieve attachment of the individual dental implants. These patents are merely representative of a wide variety of techniques, both patented and otherwise in usage, which permit the implacement of dental appliances at locations and with a permanency not heretofore achieved using prior art surgical techniques.  
           [0008]    It is apparent, however, that the use of such surgical techniques, whether for dental surgery or other surgical or medical purposes, presents difficulties which may not only interfere with the long term success of the technique, but may also cause unwarranted pain and other discomfort for the patient during the recovery period. More specifically, in the case of dental implant surgery, a condition develops because of the passage of time required for the osseointegration to be achieved. It is inherent in this surgical technique that a period of several months is required for the implant to join with the bone structure by the very process of osseointegration. It is also necessary to provide sufficient time for the dental restoration to be prepared by a dental laboratory. During this period of time, other physiological development occurs which may interfere, or complicate, the subsequent surgical procedures. The discomfort and pain of the patient experienced during these surgical procedures is well known and the long term success of the surgical procedure may be compromised. More specifically, the gum tissue proximate to the location in which the dental implant is undergoing osseointegration, and thereafter before the permanent dental appliance is installed, continues to grow and occludes the site of the implant. The natural tendency is for such gum tissues invade and to overlay the site of the implant during this period of time. After osseointegration has taken place, a solid abutment is attached to the implant. The dental appliance is subsequently attached to the abutment. It is required that the incursion of gum tissue be displaced from the location of the implant to permit the solid abutment and subsequently the dental appliance to be permanently affixed to the location. Typically, the removal of such gum tissue requires that the gum tissue be incised and extracted from the site to expose the implant and the area required for the abutment and dental appliance to be installed. This surgical procedure, of course, causes discomfort and pain to the patient as well as presenting the opportunity for infection and other medical complications which may significantly interfere with the overall success of the surgical procedure.  
           [0009]    Therefore, it has long been known that it would be desirable to have a method and apparatus for isolating a work object which have particular utility in the practice of surgical and other medical procedures employing the technique of osseointegration; which operate to ensure that the negative consequences experienced with the use of such surgical techniques are minimized; which have particular utility in the surgical techniques employed in the use of osseointegration in the establishment of dental implants; which operate to secure the surgical area over the lengthy period required for osseointegration to take place and subsequent surgical procedures to be performed; which are fully compatible with surgical techniques presently employed in osseointegration, whether dental or for other specific purposes; and which are otherwise fully capable of achieving their respective operational objectives.  
         BRIEF SUMMARY OF THE INVENTION  
         [0010]    Therefore, it is an object of the present invention to provide an improved method and apparatus for isolating a work object.  
           [0011]    Another object is to provide such a method and apparatus which are adapted to usage in surgical and other medical techniques wherein the surgical area must conventionally be restored to a predefined condition in order for subsequent surgical, or other medical procedures, to be preformed.  
           [0012]    Another object is to provide such a method and apparatus which are particularly well suited to usage in all surgical techniques in which osseointegration is employed thereby requiring the passage of time to achieve integration between the medical appliance and the bone structure.  
           [0013]    Another object is to provide such a method and apparatus which are uniquely well suited to usage in such surgical techniques where the passage of time results in the incursion of tissue into the surgical area conventionally requiring removal, or displacement, in order to permit subsequent surgical procedures to be performed.  
           [0014]    Another object is to provide such a method and apparatus which possess the ability to preserve a surgical area over a lengthy period of time for the subsequent performance of restorative techniques, surgical techniques, or other medical procedures, in the surgical area while reducing to an absolute minimum the susceptibility of the surgical area to infection, or other medical incapacity.  
           [0015]    Another object is to provide such a method and apparatus which significantly enhance both the comfort of the patient and the likelihood of complete success in the performance of surgical producers.  
           [0016]    Another object is to provide such a method and apparatus which are fully compatible with conventional surgical and medical procedures and devices.  
           [0017]    Another object is to provide such a method and apparatus which require little specialized training so as to permit their adoption expeditiously and at minimal cost.  
           [0018]    Further objects and advantages are to provide improved elements and arrangements thereof in an apparatus for the purpose described which is dependable, economical, durable and fully effective in accomplishing its intended purposes.  
           [0019]    These and other objects and advantages are achieved, in the preferred embodiment of the present invention, in a method for isolating a work object to achieve a predetermined operational objective, the method including the steps of: encapsulating at least a portion of the work object in a housing in a work position so as to establish a zone of isolation relative to the portion of the work object; and occluding an area proximate to the housing to resist incursion into the area during a predetermined period of time.  
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0020]    [0020]FIG. 1 is a fragmentary side elevation of the lower jaw, or mandible, of a patient representing a typical operative environment within which the method and apparatus of the present invention can be employed.  
         [0021]    [0021]FIG. 2 is a somewhat enlarged fragmentary vertical section of a work position depicted in FIG. 1 with the apparatus of the present invention installed in accordance with the method of the present invention and shown in larger than actual size.  
         [0022]    [0022]FIG. 3 is a somewhat reduced fragmentary vertical section showing the work position of FIG. 2 and depicting a subsequent step in the practice of the method of the present invention, producing a dental impression using an impression tray.  
         [0023]    [0023]FIG. 4 is a fragmentary vertical section of the work position shown in FIGS. 2 and 3 and showing the apparatus of the present invention and a temporary dental appliance employed in accordance with a subsequent step in the practice of the method of the present invention.  
         [0024]    [0024]FIG. 5 is a somewhat enlarged fragmentary vertical section of the impression tray shown in FIG. 3 and employed in a subsequent step in the practice of the method of the present invention employing, additionally, an implant analog.  
         [0025]    [0025]FIG. 6 is a fragmentary vertical section of the implant analog depicted in FIG. 5 and employed in an inverted attitude for purposes of the practice of a subsequent step in the method of the present invention.  
         [0026]    [0026]FIG. 7 is a somewhat enlarged fragmentary vertical section of the work position depicted in FIGS. 2, 3 and  4  showing a permanent crown mounted on the dental implant in accordance with a subsequent step in the practice of the method of the present invention.  
         [0027]    [0027]FIG. 8 is a somewhat enlarged, fragmentary perspective view of the embodiment of the apparatus of the present invention depicted in FIGS. 2 and 3.  
         [0028]    [0028]FIG. 9 is a side elevation of a second embodiment of the apparatus of the present invention depicted in FIG. 4.  
         [0029]    [0029]FIG. 10 is a somewhat enlarged side elevation of the implant analog depicted in FIGS. 5 and 6.  
         [0030]    [0030]FIG. 11 is a somewhat further enlarged fragmentary vertical section taken from a position indicated by line  11 - 11  in FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]    Referring more particularly to the drawings, the apparatus of the present invention is generally indicated by the numeral  10  in FIG. 2.  
         [0032]    The method and apparatus of the present invention are adapted for usage in a wide variety of environments and are particularly well suited to usage in surgical and other medical procedures such as where osseointegration is employed to reconstruct bone structure, tissue and the like in living organisms and, most particularly, human beings. In such surgical environments of usage, typically the restoration is accomplished through the use of pins, screws or other fastening devices which are implanted in predetermined locations and allowed to knit in those positions by the integration of the living bone matter and tissue with the implant. Such osseointegration requires typically several months to be achieved and must be accomplished for any subsequent surgical procedures can be performed.  
         [0033]    In the illustrative environment hereof the method and apparatus of the present invention are employed with dental implant procedures such as, for example, of the type developed by Institut Straumann A. G. of Switzerland, Implant Innovations, Inc. and of other types such as shown and described in the prior art patents made of record in this case.  
         [0034]    In the illustrative environment shown herein, the mouth of a patient is shown fragmentarily in FIG. 1 and generally indicated by the numeral  20  therein. As shown therein, the lower jaw of the mouth of the patient is generally indicated by the numeral  21  and may be viewed as having a proximal portion  22  and lateral extremities  23 . The lower jaw has an upper portion  24 .  
         [0035]    More specifically, the lower jaw  21  has a lower jawbone, or mandible,  30 , with an upper surface  31 , as shown in FIG. 2. The lower jawbone is encased in gum tissue  32  which, for purposes of describing the method and apparatus of the present invention may be viewed as having an exterior surface  33  and an interior surface  34  contiguous with the lower jawbone.  
         [0036]    For purposes of illustrative convenience, as shown in FIG. 1, lower front teeth, or incisors, are generally indicated by the numeral  40  and a lower back tooth, or molar, by the numeral  41 . Between the lower front teeth and the lower back tooth, a first work position, second work position and third work position are generally indicated by the numerals  42 ,  43  and  44 , respectively.  
         [0037]    A work object or dental implant is generally indicated by the numeral  50  in the several views. For purposes of illustrative convenience, it will be understood that the dental implant  50  shown in FIGS. 2, 3,  4  and  7  is the dental implant shown in the first work position  42  in FIG. 1. The dental implant  50  has a lower or base portion  51  which, in accordance with prevailing surgical procedures has been screw-thread ably inserted in the lower jawbone  30  in the first work position  42 . The base portion has a distal end portion  52  and an externally screw threaded portion  53 . The base portion has a proximal end portion  54  having a flat upper surface  55  which, at the time of the surgical implanting procedure, is disposed in coplanar relation to the upper surface  31  of the lower jawbone  30 . It will be understood that an externally screw threaded bore extends into the flat upper surface  55  of the base portion and extends axially of the base portion a predetermined distance.  
         [0038]    The dental implant  50  has an upper, or abutment portion, generally indicated by the numeral  61  and having a distal end portion  62 . The abutment portion has a tapered upper portion  63  having a substantially conical outer surface  64 . The abutment portion has a flat lower surface  65 . As can be visualized in FIG. 2, the abutment portion  61  and base portion  51  can be separated from each other, as will hereinafter be described, along a plane defined by the upper surface  55  of the base portion and lower surface  65  of the abutment portion.  
         [0039]    Returning again to the structure of the base portion  51  of the dental implant  50 , the proximal end portion  54  has an annular collar or shoulder  66  extending thereabout. The annular shoulder may be viewed as having a lower divergent surface  67  and an upper convergent surface  68 . The lower divergent surface and upper convergent surface are separated by an annulus or annular ridge  69  which extends about the annular shoulder defining a plane right-annularly related to the longitudinal axis of the dental implant and concentric thereto.  
         [0040]    A groove  80  is formed in the outer surface  64  of the tapered upper portion  63  of the abutment portion  61  extending therealong to a terminal surface  81  defining a plane right-angularly related to the longitudinal axis of the dental implant  50 .  
         [0041]    The apparatus  10  employed in the practice of the method of the present invention is shown herein in two embodiments shown respectively in FIGS. 8 and 9. For illustrative convenience, the two embodiments of the invention are described herein together.  
         [0042]    The apparatus  10  of the two embodiments has a body portion or housing  100  which can be fabricated of any suitable material. In the preferred embodiment, the housing is constructed of a thermal injected plastic material such as Bayer  348 ABS medical grade plastic which is molded in the configuration hereinafter described. In this regard it will be understood that the housing, as shown in the drawings hereof, is larger than actual size for purposes of more clearly disclosing the structure thereof.  
         [0043]    The housing  100  may be viewed as having a distal portion  101  and an opposite proximal portion  102 . The housing has an outer surface  103  and encloses an interior chamber  104  defined by an interior surface  105 . As best shown in FIG. 4, the interior surface  105  is configured so as preferably to conform to the outer surface  64  of the abutment portion  61  of the dental implant  50  in fitted relation. The housing has a lower annulus  106  and an upper end wall  107 .  
         [0044]    The interior surface  105  of the housing  100  has a terminal surface  120 . A convergent surface  121  extends upwardly to communicate with the terminal surface  120 . As shown in FIG. 9, a ridge portion  122  is formed in the convergent surface  121  and dimensioned and so configured as to mate with the groove  80  of the abutment portion  61  of the dental implant  50 . The interior surface  105  has an interior annulus  123  at the lower end of the convergent surface  121  and outwardly from which is extended in interior shoulder surface  124 . A sloped interior annular surface  125  extends downwardly and outwardly therefrom to an interior annulus  126 . The interior annulus  126  has an interior annular surface  127  shown best in FIG. 11. The interior annular surface is sloped in downwardly converging relation so as to permit the lower annulus  106  to be snap fitted on the annular ridge  69  of the annular shoulder  66  of the base portion  51  of the dental implant  50 .  
         [0045]    The housing  100  has an annular shoulder  140  which is of thickened proportions so as to occupy a predetermined amount of space, as can best be visualized in FIGS. 8 and 9. The annular shoulder has a sloped annular surface  141  and a beveled upper surface  142 . As can be visualized in FIGS. 2, 3 and  4 , the configuration and dimensions of the annular shoulder  140  are, in the preferred embodiments, such as to occupy sufficient space to prevent the gum tissue  32  from incursion into the area bounding the annular shoulder  66  of the base portion  51  of the dental implant  50 , as will hereinafter be described in greater detail. A wide variety of other embodiments can be employed in the method and apparatus of the present invention.  
         [0046]    As previously noted, two embodiments of the apparatus  10  of the present invention are depicted in the drawings, those being in FIGS. 8 and 9. In the embodiment shown in FIG. 8, the housing  100  has a grasping portion  143  mounted on and integral with the upper end wall  107  of the housing  100 . The grasping portion has multiple prongs  144 , in this example three prongs, extending outwardly from the longitudinal axis of the housing  100 , as best shown in FIG. 8.  
         [0047]    The method of the present invention employs an implant analog generally indicated by the numeral  160  in FIGS. 5, 6 and  10 . The implant analog has a base portion  161  extending to a distal end portion  162  and having four rib portions  163  disposed at 90 degrees relative to each other. Each of the rib portions has a pair of arcuate recesses  164 . An annular collar or shoulder  166  extends upwardly from the rib portions  163  and includes a lower divergent surface  167  and an upper convergent surface  168  separated from each other by an annulus or ridge  169 . It will be seen that the annular shoulder  166  is so dimensioned and configured as to be identical to the annular shoulder  66  of the dental implant  50 .  
         [0048]    The implant analog  160  has an abutment portion  180  extending to a terminal surface  181  and having a groove  182  so configured and dimensioned as to conform to the ridge portion  122  of the convergent surface  121  of the interior surface  105  of the apparatus  10  and thus to the groove  80  of the dental implant  50 .  
         [0049]    For illustrative convenience in describing the method of the present invention and the use of the apparatus  10  hereof, reference is had in several of the views of the drawings to other elements to illustrate the environment of usage of the method and apparatus of the present invention. Thus, in FIG. 3 an impression tray  200  is fragmentarily shown therein defining an interior  201  containing mold material  202 . The outer surface of the mold material or, in other words, the impression made thereby is indicated at  203  and, if desired, an adhesive layer coating the apparatus  10  of the present invention can be employed which is generally indicated by the numeral  204 .  
         [0050]    Referring more particularly to FIG. 4, a temporary dental appliance or crown is generally indicated by the numeral  210  into which a passage or interior  211  extends dimensioned to fit the outer surface  103  of the housing  100  of the apparatus  10 . As shown in FIG. 4, an adhesive layer is generally indicated by the numeral  212 .  
         [0051]    Referring more particularly to FIG. 5, dental stone is generally indicated by the numeral  220 . The surface of the dental stone providing the impression model is indicated by numeral  221 .  
         [0052]    Referring then finally to FIG. 7, a permanent dental appliance or crown is generally indicated by the numeral  230 . A passage or interior  231  extends into the permanent crown and is dimensioned to conform to the outer surface  64  of the abutment portion  61  of the dental implant  50 . An adhesive layer  232  attaches the permanent crown on the outer surface  64 . As shown therein, the outer surface of the permanent crown is indicated by the numeral  233 . The surface of the gum tissue  32  about the permanent crown is indicated by the numeral  234 .  
       Operation  
       [0053]    The operation of the described embodiments of the subject invention and the method hereof are believed to be clearly apparent and are briefly described hereinafter.  
         [0054]    In the method of the present invention, one or more dental implants  50  are installed in the upper and/or lower jawbone of the patient using otherwise conventional surgical or medical techniques. For illustrative convenience, and as previously described, the dental implant  50  occupying first work position  42 , as shown in FIG. 1, will be assumed to be the site described. It will be understood, however, that the method of the present invention can be employed on one or more other work positions by varying the procedures accordingly.  
         [0055]    Again, using conventional surgical procedures, the dental implant  50  occupying the first work position  42  is permitted to osseointegrate with the lower jawbone  30  for a period of several months. When this condition has been achieved, the dental implant is ready to receive occlusal load and be restored by conventional dental means. The cover screw, not shown, which covers the entrance into the dental implant  50  is removed and the internal aspect is irrigated with an antimicrobial solution. The soft gum tissues and their integrity and position in relation to the collar of the dental implant are evaluated along with the interocclusal space between the dental implant or collar or shoulder and the opposing dentition.  
         [0056]    An appropriate height for the abutment portion  61  of the dental implant  50  is selected such as, for example, 4.0 millimeters, 5.5 millimeters, or 7.0 millimeters. The selected abutment portion is inserted into the internal aspect of the dental implant base portion  51  and screwed in a clockwise direction into place using an appropriate carrier device, not shown. The abutment portion  61  is tightened to 35 Ncm of pressure using a torque wrench moved in a clockwise direction. The abutment portion  61  and the annular collar or shoulder  66  of the base portion  51  are then isolated and dried.  
         [0057]    The apparatus  10  of the present invention is then positioned in covering relation to the abutment portion  61  and pressed downwardly until the lower annulus  106  snaps into place in fitted engagement with the annular ridge  69  of the annular collar  66  of the base portion  51 , as shown in FIGS. 2 and 11.  
         [0058]    Subsequently, the apparatus  10  is coated with a suitable adhesive and is roughened on the surface thereof to produce undercuts and grooves permitting retention in dental impression material. The prongs  144  also operate to retain the apparatus  10  in the dental impression material. Either or both of the undercuts and grooves on the one hand and/or the prongs on the other can be employed for this purpose.  
         [0059]    Referring to FIG. 3, the impression tray  200  containing dental impression material  202  in the interior  201  thereof is positioned in the patient&#39;s mouth  20  to make a mold of the apparatus  10 , the adjacent teeth, the adjacent soft tissues and the opposing dentition. After an appropriate period of setting and hardening time, the impression tray is removed from the patient&#39;s mouth containing a mold of the teeth and removing the apparatus  10  from the dental implant  50  as shown in FIG. 3.  
         [0060]    Referring next to FIG. 4, a second apparatus  10  preferably of the form shown in FIG. 9, is trimmed to match the height of the abutment portion  61  and is snap fitted into the position shown in FIG. 4 again engaging the annular ridge  69  of the base portion  51 . The second apparatus  10  is used as a base for construction of the dental temporary restoration lined with dental acrylic and/or a temporary cement material. The temporary dental appliance or crown  210  is then mounted on the second apparatus  10 , as shown in FIG. 4. It will be seen that the annular shoulder  140  of the apparatus  10  operates to occlude the area bounding the annular shoulder  66  of base portion  51  so as to prevent the gum tissue  32  from growing into or otherwise occupying the area.  
         [0061]    In the meantime, the impression mold  203  is sent to a dental laboratory for fabrication of the dental restoration which will be mounted on the dental implant  50 . During this procedure, the implant analog  160  is inserted into the interior chamber  104  of the housing  100  of the apparatus  10 , as shown in FIG. 5. Sufficient pressure is exerted to cause the implant analog to snap into place with the lower annulus  106  of the housing  100  snapping over the annular ridge  169  of the annular shoulder  166  of the implant analog  160 .  
         [0062]    Then, using conventional laboratory techniques, dental laboratory gypsum stone is mixed and poured into the impression  203  to reproduce a mold of the patient&#39;s mouth and implant suprastructure. After a period of setting time, the dental stone hardens and the impression tray is separated therefrom retaining the apparatus  10  of the present invention in the mold material  202  and leaving the implant analog  160  in the resulting dental stone  220  as best shown in FIG. 6.  
         [0063]    At this time, a third apparatus  10  of the present invention is trimmed to match the height of the implant analog in the dental stone  220  and inserted onto the abutment portion  180  of the implant analog until it snaps into place as previously described. This third apparatus  10  of the present invention is used as a waxing base for the construction of the dental restoration. Wax is applied directly onto the third apparatus  10  and carved to simulate the final tooth morphology, sprued, invested in dental bum-out investment and cast with metal alloys using the wax bum-out casting technique. The final restoration is polished, coated with porcelain or other suitable material and prepared for final installation in the patient&#39;s mouth.  
         [0064]    The resulting permanent crown  230 , as described in the illustrative example shown in FIG. 7, is ready for installation. The second apparatus  10  and temporary crown  210  are removed from the dental implant  50  from the position shown in FIG. 4. The area is irrigated with an antimicrobial solution. The soft tissues and their integrity and position in relation to the collar of the implant are also evaluated. The final restoration is seated on the abutment portion  61  of the dental implant  50  and the interproximal contact areas and occlusal contacts are adjusted to the desired fit. The adjusted permanent crown  230  is removed, the dental implant  50  is isolated and dried. The permanent crown  230  is filled with dental cement and then seated directly on the abutment portion  61  of the dental implant  50 . The cement is permitted to set for several minutes, excess cement is removed from the annular shoulder  66  of the base portion  51  and the area is irrigated once again with antimicrobial solution. Subsequently a dental radiograph is taken to confirm seating of the restoration and removal of the excess cement.  
         [0065]    Therefore, the method and apparatus for isolating a work object of the present invention having particular utility in the practice of surgical procedures employing the technique of osseointegration; operate to ensure that the negative consequences experienced with the use of such surgical techniques are minimized; have particular utility in the surgical techniques employed in the use of osseointegration in the establishment of dental implants; operate to secure the surgical area over the lengthy period required for osseointegration to take place; are fully capable with surgical techniques presently employed in osseointegration in all surgical procedures, whether dental or for other specific purposes; and are otherwise fully capable of achieving their operational objectives.  
         [0066]    Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention which is not to be limited to the illustrative details disclosed.