Abstract:
A protective barrier that can be removably fitted over a dental instrument to protect against the transfer of contaminants from one dental patient to another via the dental instrument. The protective barrier, when in use will generally replicate the ergonomic features found on the outer surface of the dental instrument. The barrier is constructed from two mating half portions that include interior chambers and are adapted for placement over and in proximate contact with at least a portion of the outer surface of a dental instrument. The interior chambers of each half portion uniquely contain a yieldably deformable cushion-like elastomer such as polyurethane foam.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to protective barriers. More particularly, the invention relates to protective barriers for use with dental instruments and like devices to prevent the spread of contaminants. 
   It has long been recognized in the dental industry that after an infectious agent from one patient contaminates a dental instrument, the instrument has the potential to spread the contaminants to the next patient unless special care is taken to replace the instrument or properly sterilize it. As a general rule, replacing the instrument parts which are vulnerable to contamination is prohibitively expensive and sterilizing the parts by autoclaving is time consuming. While attempts have been made in the past to sterilize the instrument parts by spraying the parts with a disinfectant, experience has shown that such an approach is inadequate to effectively remove all contaminants. 
   2. Discussion of the Prior Art 
   In the past, various attempts have been made to provide protective plastic sheaths of various configurations for covering hand held dental tools. For example, U.S. Pat. No. 5,921,776, issued to Heilbrunn, discloses a barrier device that includes a disposable sheath, which can be positioned to shroud the instrument without encumbering its functionality. The device further includes a disposable probe which is integrally formed with the sheath and which is attached to the instrument along with the sheath. 
   In a similar vein, U.S. Pat. No. 4,907,968 issued to Eisner, et al., discloses a yieldably deformable shield or prophylactic, which exhibits sufficient deformability to adapt to any of a variety of angular or curved shapes of the nozzle of a dental syringe. 
   U.S. Pat. No. 6,350,124, issued to Wade discloses a dental system comprising a hand piece having a housing and including a bur and air and water outlets for performing dental operations in an oral operating field; an inner cover separate from the housing having a shape substantially conforming to a shape of the hand piece for enclosing the hand piece and including a first aperture for receiving the bur and a second aperture for passing air and water from the air and water outlets of the hand piece; and an outer cover having a shape substantially conforming to a shape of the inner cover for enclosing the inner cover and including a first aperture for receiving the bur and a second aperture for passing air and water passed from the inner cover to the operating field. 
   A common drawback of the prior art barrier devices resides in the fact that the dental instrument is more difficult to grip and to manipulate after the barrier device has been interconnected with the dental instrument. This is generally because the ergonomics provided on the dental instrument are covered and masked by the barrier device. Another drawback of the prior art barrier devices concerns the difficulty in initially attaching the barrier device securely to the dental instrument and then the removal of the barrier device from the dental instrument following completion of the dental procedure. 
   It is the drawbacks of the prior art devices as set forth in the preceding paragraph that the protective barrier of the present invention seeks to overcome. As will be better understood from the discussion that follows, the protective barrier device of the present invention is very easy to connect and disconnect from dental instruments and like devices and uniquely replicates the ergonomic features found in the instrument. In one form of the invention the protective barrier device is fabricated from a moldable plastic that can be sterilized through use of appropriate antimicrobial liquids. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a unique protective barrier assemblage that can be removably fitted over a device to protect against the transfer of contaminants from one device to another. 
   Another object of the invention is to provide a protective barrier as described in the preceding paragraph which is of a novel design that enables the user to positively grip the device, as for example, a dental instrument during the conduct of dental procedures. 
   Another object of the invention is to provide a protective barrier assemblage of the aforementioned character which includes an inner sleeve and a spaced-apart outer sleeve which is connected to and cooperates with the inner sleeve to define a pair of hingably interconnected half portions, each of which has an elongated interior chamber filled with a yieldably deformable cushion material, such as a resilient, foamed polyurethane. 
   Another object of the invention is to provide a protective barrier assemblage as described in the preceding paragraph in which the surfaces of the inner sleeve of the protective barrier generally replicate the ergonomic features found on the outer surface of the dental instrument. 
   Another object of the invention is to provide a protective barrier of the class described in which the inner and outer sleeves are constructed from a moldable plastic that can be sterilized by soaking the protective barrier assemblage in an antimicrobial liquid. 
   Another object of the invention is to provide a protective barrier of the character described in the preceding paragraphs that is lightweight, durable and easy-to-use. 
   Another object of the invention is to provide a protective barrier that can be inexpensively fabricated in quantity using well-known plastic molding techniques. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a generally perspective view of a prior art device with which the protective barrier of the invention can be used. 
       FIG. 2  is a plan view of the inner surface of the first, or inner sleeve of the protective barrier apparatus of one form of the invention. 
       FIG. 3  is a plan view of the outer surface of the first, or inner sleeve of the protective barrier apparatus of one form of the invention. 
       FIG. 4  is a generally perspective view of the assembled protective barrier of one form of the invention, partly broken away to show internal construction. 
       FIG. 5  is a generally perspective exploded view of the protective barrier shown in  FIG. 4 . 
       FIG. 6  is a cross-sectional view taken along line  6 — 6  of  FIG. 5 . 
       FIG. 7  is an enlarged fragmentary view of the area designated as  7 — 7  in  FIG. 6 . 
       FIG. 8  is a cross-sectional view taken along lines  8 — 8  of  FIG. 5 . 
       FIG. 9  is an enlarged fragmentary view of the area designated as  9 — 9  in  FIG. 8 . 
       FIG. 10  is a cross-sectional view similar to  FIG. 8  but showing the two half portions of the protective barrier moved into an open position. 
       FIG. 11  is an enlarged fragmentary perspective view of the lower portion of the second, or outer sleeve of the protective barrier assemblage shown in  FIG. 5 . 
   

   DESCRIPTION OF THE INVENTION 
   Referring to the drawings and particularly to  FIG. 1 , one type of prior art dental instrument “DI” of the type with which the protective barrier device of the present invention can be used is there shown. It is to be understood that the type of dental instrument shown in  FIG. 1  is merely exemplary of the many different types of dental instruments with which the barrier device of the present invention can be used. 
   Turning to  FIGS. 2 through 8 , one form of protective barrier device of the present invention is there shown for use in connection with a dental instrument “DI” of the character shown in  FIG. 1 . This protective barrier assemblage of the invention, which is generally designated by the numeral  14  ( FIG. 4 ), is designed for placement over and in proximate contact with the outer surface of the handle portion of the dental instrument. However, it is to be understood that the protective barrier assemblage could also be constructed for placement over and in proximate contact with all or part of the dental instrument or in proximate contact with other types of hand-held instruments. 
   In the present embodiment of the invention the protective barrier assemblage  14  comprises a first substantially rigid inner plastic sleeve  16  having inner and outer surfaces  18   a  and  18   b  ( FIGS. 2 and 3 ) which generally replicate at least a portion of the outer surface of the dental instrument “DI”. As best seen in  FIGS. 3 and 8 , inner sleeve  16  also has a spaced-apart, outer surface  20 . 
   A second, yieldably deformable, relatively thin plastic film outer sleeve  22  ( FIG. 5 ) is connected to and cooperates with the first inner sleeve  16  to define a pair of the hingably interconnected half portions  24   a  and  24   b  ( FIG. 8 ), each of which has an elongated interior chamber  26 . Disposed within each elongated interior chamber  26  is a yieldably deformable cushion material  30 . Yieldably deformable cushion material  30  can comprise various types of resilient foamed elastomer of a character well known to those skilled in the art. However, for present purposes, the yieldably deformable cushion material  30  preferably comprises a resilient foamed polyurethane. The resilient foamed elastomer, such as foamed polyurethane, can readily be molded to shape or cut to shape to fit within each elongated interior chamber  26 . 
   Sleeves  16  and  22  can be of various thicknesses, but preferably have a thickness of between about 0.020 and about 0.1 inch. Construction of sleeve  16  is preferably accomplished by injection molding of a moldable plastic using an injection mold in which both sides of the mold cavity substantially replicate the outer surface of the dental instrument. In this regard, it is to be understood that the mold cavity is constructed so that the internal dimensions of sleeve  16  are slightly larger than the external dimension of the outer surfaces of the dental instrument. In this way some clearance is provided between of the protective barrier and the dental instrument. 
   Referring particularly to  FIG. 8 , it can be seen that second sleeve  22  comprises a first segment  32  having a first margin  32   a  and a second segment  34  having a first margin  34   a . In the present form of the invention, first margin  32   a  of first segment  32  is connected to first margin  34   a  of second segment  34  by a living hinge  38  (see also  FIG. 10 ) so that the two halves of the barrier assembly can be moved from the closed position shown in  FIG. 8  to the open, dental instrument receiving position shown in  FIG. 10 . 
   First segment  32  of second sleeve  22  also has a second margin  32   b  and second segment  34  of second sleeve  22  also has a second margin  34   b . As illustrated in  FIGS. 8 and 9 , second margin  32   b  of first segment  32  is connected to second margin  34   b  of second segment  34  by connector means for releasably interconnecting together the first and second segments. The connector means of the present form of the invention comprises a conventional type of zipper, or “zip-lock” type arrangement. More particularly, as best seen in  FIG. 9 , second margins  32   b  and  34   b  have mating, strategically configured interlocking portions  36  and  38  respectively which can be interconnected and disconnected by a slider assembly  40  of conventional design which comprises a part of the connector means of the invention. 
   As indicated in  FIGS. 4 ,  5  and  8 , slider assembly  40  is disposed for movement along the second margins of the first and second segments  32  and  34  of the second sleeve  22  in a manner to engage and disengage the mating interlocking portions  36  and  38 . When the interlocking portions are interconnected by sliding the slider assembly downwardly of the assemblage as indicated by the arrows  43  in  FIG. 5 , the two halves of the barrier assembly are moved into the closed configuration shown in  FIG. 8  to encase the handle portion of the dental instrument. Conversely, when the slider assembly is moved upwardly of the assemblage, the two halves of the assembly can be pivoted about the living hinge into the position shown in  FIG. 10  so that the assemblage can be conveniently removed from the dental instrument. As illustrated in  FIG. 7 , a conventional zipper type end-stop  45  is interconnected with segment  32  of outer sleeve  22 . 
   In using the barrier assembly of the present invention, the connector means are manipulated so as to permit the barrier assembly to be moved into the open configuration shown in  FIG. 10 . In this configuration, the handle portion of the dental instrument can be inserted into the open assembly as indicated by the dotted lines in  FIG. 10 . Once the handle of the dental instrument is in position within the barrier assembly, the two halves of the assembly can be closed and the connector means can be used to secure the assembly about the handle of the dental instrument. 
   With the barrier assembly in the closed configuration, when the caregiver grips the barrier assembly, the thin outer flexible sleeve portion  22  of the assembly will tend readily to conform to the caregiver&#39;s hand and fingers and will impart a deforming pressure to the yieldably deformable, cushion-like foam  30 . The consistency of the foam  30  is such that it will readily conform to the shape of the deformed outer flexible sleeve portion and at the same time will also conform to the shape of the inner surface of the inner sleeve of the assembly which replicates the outer surface of the handle of the dental instrument. The net effect of this deformation of the outer sleeve  22  and the yieldably deformable, cushion like foam  30  permits the caregiver to securely grip the dental instrument and to provide substantially the same feel to the caregiver as would be experienced as a result of directly gripping the handle of the dental instrument itself. More particularly, because the ergonomic features provided on the dental instrument are replicated on the inner sleeve of the protective barrier and the cushion foam  30 , upon being compressed, will closely conform to the outer surface of the inner sleeve, the caregiver can securely grip the protective barrier and readily manipulate it in the same manner as the dental instrument could be manipulated without the addition of the protective barrier. As indicated in  FIG. 11  the lower extremity of sleeve  22  is provided with vent means here shown as a plurality of circumferentially-spaced vent openings  22   v  for permitting equalization of air pressure with the barrier assembly. 
   Upon the completion of the dental procedure, the connector means can be manipulated to once again permit the two halves of the barrier assembly to be moved into the open position shown in  FIG. 10  of the drawings. In this position the dental instrument can be conveniently removed from the barrier assembly and the barrier assembly can either be discarded, or alternatively sterilized in an appropriate antimicrobial liquid. 
   Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following documents.