Patent Publication Number: US-2005136373-A1

Title: Flexible translucent protective covers used to protect dental appliances from rigid light emitting devices

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      The present application is a divisional application of U.S. patent application Ser. No. 10/423,121 filed Apr. 25, 2003, entitled “Flexible Translucent Protective Covers Used to Protect Dental Appliances from Rigid Light Emitting Devices”, which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      1. The Field of the Invention  
      The present invention relates to the field of dentistry, more particularly to dental light emitting devices used to cure polymerizable adhesive resins.  
      2. The Relevant Technology  
      Light curing devices are employed to polymerize and cure light curable compositions (also referred to herein as adhesives resins) in a variety of industries. Light curing devices include a light source which emits light energy for curing a light curable composition. In the field of dentistry, for instance, light curing devices are often employed to polymerize and cure light curable compositions, such as light curable composites, adhesives, and other polymerizable compositions containing photoinitiators. By way of example, a light curable bonding adhesive is often employed to attach a dental appliance such as a veneer to a dental surface. The adhesive is applied to the surface to be bonded, after which the veneer is placed against the tooth. The light curing device is then directed towards the veneer and actuated for a selected illumination time, emitting light energy into the adhesive. Because veneers are translucent, the light from the curing device passes through the veneer to the light curable adhesive. The light energy polymerizes the adhesive, maintaining the veneer firmly in place.  
      Typical light curing devices include a rigid lens or light guide to direct and collimate light into the area to be treated. To cure the light curable composition and bond the dental appliance to the tooth substrate, the dental light curing device is pushed against the veneer as light energy is emitted to properly seat the appliance to the substrate. The hard touch contact between the rigid lens or light guide and the surface to be treated (e.g. a patient&#39;s tooth or a dental appliance) can cause difficulties. Hard touch contact can result in breaking or cracking of the dental appliance (e.g. a veneer) as it is pressed into place. In addition, it can be difficult for the rigid lens or light guide of the dental curing light device to adapt to irregular tooth or other structure.  
      In view of the foregoing, there is a need to protect dental appliances and or surfaces from rigid surfaces of dental curing lights and lenses that may be attached thereto.  
     BRIEF SUMMARY OF THE INVENTION  
      The present invention is directed to a flexible resilient protective cover used to protect dental appliances from rigid light emitting devices used to light cure a dental adhesive. The protective cover cushions the impact of a rigid light emitting device when placed in contact with a dental substrate, such as patient&#39;s tooth or a dental appliance (e.g., a veneer). The protective cover is transparent or translucent to curing wavelengths emitted from the light emitting device, allowing at least a portion of the curing wavelengths to pass through the cover and into the composition to be cured.  
      The protective cover comprises a base configured to attach to a rigid light emitting device and a flexible translucent body having a first end proximal to the base through which light energy emitted by a light emitting device enters, and a second end distal to the base through which light energy exits. The cover may be integrally attached to a light emitting device, or alternatively may be configured to releasably attach to light emitting device. If attachable, the protective cover may be connected by any mechanical means, for example a snap fit, a friction fit, a threaded coupling, or a bayonet coupling. The protective cover may be used in a variety of restorative procedures, including placement of dental appliances, such as overlays, inlays, veneers and crowns.  
      These and other advantages and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:  
       FIGS. 1-3  illustrate exemplary embodiments of protective covers attached to various light emitting devices;  
       FIGS. 4A-4E  illustrate exemplary surfaces of protective covers according to the invention;  
       FIGS. 5A-5C  illustrate the use of an exemplary protective cover with a suction tip to temporarily hold a dental appliance and then bond it to a substrate surface.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      As used herein, the term “dental appliance” or “appliance” means any dental prosthesis or other appliance such as an overlay, inlay, veneer, crown, or other prosthesis to be bonded to a tooth.  
      As used herein, the term “lens” or “light guide” refers to any object through which light may travel and does not inherently imply any characteristics for focusing or collimating light.  
      As used herein, the term “translucent” refers to the ability of at least some curing light energy to be transmitted through the “translucent” object. It also includes transparent, which allows all or nearly all curing light energy to be transmitted through the object.  
      The term “footprint,” as used herein, is generally made with reference to the cross-sectional shape of light emitted from a light emitting device. The general shape and dimensions of a footprint can generally be identified by placing an object (e.g., a flat object) in front of a light source and observing the area illuminated by the light source.  
      The flexible resilient protective cover provides a soft touch interface for cushioning the impact of the rigid light emitting device when placed in contact with dental substrate, such as a patient&#39;s teeth or a dental appliance. The protective cover includes a base and a flexible translucent body. The base is configured to attach to a rigid light emitting device. The body includes a first and second end. The first end is proximal to the base, and is the end through which light energy emitted by the attached light emitting device enters. The second end, through which light energy exits, is distal to the base.  
      The protective cover may be used with various types of light emitting devices, including dental curing lights, optionally in combination with a fiber optic light guide and/or one of various possible lenses.  FIG. 1  illustrates a flexible protective cover  100  placed on a fiber optic light guide  102  attached to a dental light curing device  104 . Protective cover  100  includes a base  106  and a flexible translucent body  108 . Body  108  includes a first end  110  proximal to base  106  through which light energy emitted by fiber optic light guide  102  enters and second end  112  distal to base  106  through which light energy exits.  
      Base  106  is configured to attach to a light emitting device (e.g. fiber optic light guide  12 ). It may be releasably attachable with a friction fit, a snap fit, a threaded coupling, a bayonet coupling, or any other type of coupling. Alternatively, protective cover  100  may be integrally attached to the fiber optic light guide or other light emitting device, such as with an adhesive, by welding, or with other non-removable coupling.  
      Light energy is generated by light source  114 , which may include a halogen bulb, an incandescent bulb, a fluorescent bulb, a laser source, one or more LEDs or LED arrays, or any other light source. The light energy enters fiber optic light guide  102 , where it is directed towards the protective cover  100 . Light energy enters the flexible protective cover through first end  110 . It passes through the cover  100 , exiting through second end  112 .  
       FIG. 2  illustrates a flexible protective cover  200  placed over a conical lens  202  attached to a dental light curing device  204 , while  FIG. 3  illustrates a flexible protective cover  300  placed over, or integrally part of, a spot curing lens  302  attached to a dental light curing device  304 , e.g., with an intermediate focusing lens  306  interposed between the spot curing lens  302  and the curing light  304 .  
      Although illustrated with a fiber optic light guide, a conical lens, and a spot curing lens ( FIGS. 1-3 ), the flexible protective covers according to the present invention may be used with any light guide or lens, or may be attached directly to a dental light curing device or other light emitting device without a light guide or lens, if desired.  
       FIGS. 4A-4E  illustrate various exemplary flexible protective covers  400 . Each exemplary cover  400  is preferably removably attached to a light emitting device by a friction fit, although other couplings could be used, or the cover could be integrally attached to light emitting device  402 . Each cover  400  is illustrated with a friction fit and is partially removed from light emitting device  402  to better illustrate the friction fit.  
       FIG. 4A  illustrates a protective cover  400  having a cylindrical body  408 . The second end  412  of the protective cover  400  includes a flat surface  416 .  FIG. 4B  illustrates a protective cover  400  that includes a cylindrical body  408  and a second end  412  having a convex surface  416 .  FIG. 4C  illustrates a protective cover  400  that comprises a cylindrical body  408  and a second end  412  having a concave surface  416 .  FIG. 4D  illustrates a protective cover  400  including a cylindrical body  408  that is hollow such that the second end  412  includes a circular rim  416 .  FIG. 4E  illustrates a protective cover  400  comprising a cylindrical body  408  and a second end  412  having a suction tip  416  (e.g., a suction cup). The suction tip  416  can be releasably attached to a dental appliance in order to facilitate placement of the dental appliance onto a substrate surface, such as a tooth. It will be appreciated, however, that any protective cover according to the invention may be modified to temporarily adhere to a dental appliance by means of a sticky material or other temporary adhesive material known in the art.  
      The base and flexible translucent body of the flexible protective covers are preferably formed of a translucent, soft material with a durometer hardness of about 40 to about 100, more preferably about 50 to about 90, and most preferably about 60 to about 80. A preferred material is PELLATHANE, a polyurethane manufactured by Dow Chemical (p/n 2102-70). Although it is preferable to form the protective cover of such a material, it may be formed of any material sufficiently soft to provide a soft touch interface and cushion the impact between the protective cover and the dental appliance. Examples of suitable materials include polyurethane, silicone, flexible polyethylene, rubber, or any other elastomer.  
      Protective covers  400  such as those illustrated in  FIGS. 4A-4E  may have any suitable diameter. Preferably, the cover has a diameter of about 0.1 mm to about 5 mm, more preferably about 0.5 mm to about 4 mm, and most preferably about 1 mm to about 3 mm.  
      In order to illustrate an exemplary method of using the flexible resilient protective cover of the present invention, attention is directed to  FIGS. 5A-5C , which illustrate the use of a light emitting device  502  with a protective cover  400  that includes a suction tip  416 .  FIG. 5A  illustrates a tooth surface  518  being prepared for bonding to a dental appliance  520  ( FIG. 5B ). A light curable composition  522  is applied to the surface to be bonded. It may be applied to the appliance  520 , the tooth  518 , or both.  
       FIG. 5B  illustrates the dental appliance  520  attached to a protective cover  400  connected to a light emitting device by means of a suction tip  416  at an end of the protective cover  400 . The flexible resilient protective cover  400  provides a soft touch interface to cushion the impact of the light emitting device  502  when pressed against the appliance  520  ( FIG. 5C ) during positioning of the appliance  520  against the tooth surface  518 . Once positioned correctly, the dental practitioner uses the light emitting device  502  to cure at least a portion of the light curable composition  522  through the appliance  520 . The suction tip  416  of the flexible protective cover  400  may then be removed from the dental appliance  520 .  
      The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.