Abstract:
A device having pliable walls is provided for placement in the mouth of a patent to serve, in one manner, as a matrix barrier with walls of the device bearing upon opposed tooth surfaces. An inlet permits inflation of the device, as by a dental syringe, of the installed device. A valve closes under air pressure to seal the inlet which may also be closed by a fused inlet segment.

Description:
BACKGROUND OF THE INVENTION 
     The present invention concerns generally an inflatable device primarily for placement intermediate adjacent teeth preparatory to the insertion of filling material. 
     Matrix barriers as used in dentistry include a metal band and a screw down tensioning device and have been in use for many years for confining filling or matrix material. Installation of conventional matrix barriers is time consuming and renders the patient&#39;s gum or lip subject to being pinched upon tightening of the screw mechanism. Further, wedges may be required to enhance engagement of the matrix band with the tooth being filled to provide the necessary sealing effect. At completion of use, the conventional matrix band or retainer is removed from the tooth by unscrewing of the mechanism which must be subsequently autoclaved. The metal matrix band is dispensed with after use. Accordingly, retention of matrix material in a prepared tooth entails a considerable effort and time in installation and removal, is costly and may subject the patient to a pinched gum or lip. Further, it is often necessary to utilize a dental wedge along with a matrix band to achieve desired band-to-tooth securement resulting in further discomfort to the patient. 
     SUMMARY OF THE PRESENT INVENTION 
     The present invention is directed toward the provision of an inflatable dental device primarily for installation between adjacent teeth to serve as a retainer to confine matrix material at the prepared location in a tooth. Additional uses of the inflatable device may encompass securing of a dam in place in the mouth or to retain facial tissue away from a work site. 
     The present device is of pliable material with a fused or heat sealed perimeter defining an air chamber which, upon inflation, biases outermost wall surfaces of the device into engagement with interproximal tooth surfaces. The device, when used as a matrix barrier, is readily insertable between adjacent teeth in view of a thin cross section consisting of plies of synthetic material in sheet form fused at their perimeters. An inlet receives a pressurized flow during inflation of the barrier with closure means maintaining the barrier in an inflated state. A valve may be utilized or the neck may be heat sealed upon inflation. Subsequent to use, the device is readily removed upon deflation as by puncturing of same. Inflation of the barrier may be by use of a three way dental syringe as adequate air pressure is available in most dental facilities. 
     Important objectives of the present dental device include use as an inflatable barrier which may be readily placed between teeth and subsequently inflated to provide a seal against composite filing material subsequently deposited in the tooth; the provision of an inflated matrix barrier for contact with the edges of the cavo surface of a tooth being restored to reduce trimming or touch-up efforts of the deposited material upon barrier removal; the provision of a readily usable matrix barrier utilizing readily available air pressure which ultimately permits barrier removal simply by puncturing of the disposable barrier; the provision of a matrix barrier of the single use or throw away type to reduce autoclaving efforts; the provision of an inflatable device for securing a rubber dam in place in the mouth or as a retraction device for the tongue or cheek retention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a perspective view of the present dental device operatively disposed between adjacent teeth as a matrix barrier; 
     FIG. 2 is an end elevational view taken from the left hand side of the barrier of FIG. 1 partially inflated for illustrative purposes; 
     FIG. 3 is an exploded view of the device; 
     FIG. 4 is a vertical sectional view of the device taken along line  4 — 4  of FIG. 1; 
     FIG. 5 is an enlarged plan view of a device fragment and inlet extending therethrough; 
     FIG. 6 is a plan view of a modified inlet component; and 
     FIG. 7 is a plan view of still another form of inlet. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With continuing attention to the drawing wherein applied reference numerals indicate parts similarly hereinafter identified, the reference numeral  1  indicates generally the present device disposed between adjacent teeth  2  and  3  of a dental patient. A matrix receiving site  3 A has been formed in tooth  3 . Device outer walls at  4  and  5  are disposed for biased contact with interproximal tooth surfaces upon inflation of the device. Outer walls  4  and  5  each have a companion wall as at  6  and  7 . Wall marginal areas at  4 A- 6 A and  5 A- 7 A are joined as by fusing. An inner pair of walls at  8  and  9  are similarly joined at their outer marginal areas at  8 A and  9 A. Accordingly, chambers at  10 ,  11  and  12  are provided with communication therebetween as follows. 
     Walls  6  and  8  and  7  and  9  have fused inner areas at  6 B,  8 B and at  7 B,  9 B respectively which define corresponding openings  14 - 15  in the walls for the passage of a pressurized medium between the wall defined chambers. 
     While multiple sets of walls are above noted, in some instances a single set of walls may be adequate with the chamber defined thereby in direct communication with an inlet as later described. 
     Suitable material for the walls may be very thin nylon sheets each having a polyethylene layer enabling joining of the above mentioned areas by heat a combination found in metallic coated, non-latex balloon construction. Surface coatings at  17  in place on outer walls  4  and  5  serve to reflect light wave energy for curing of composite matrices. 
     For charging the device with a pressurized fluid an inlet, generally at  20 , is provided. As best shown in FIG. 5, the inlet is formed from two elongate plies  21 - 22 , heat sealed together along their corresponding sides or edges  21 A- 22 A to form a passageway  23  terminating at an outlet end  24  interiorly in center chamber  11 . To maintain passageway  23  open during heat sealing of the inlet plies, a heat resistant strip  25  extends from an air inlet opening  26 , between ply  22  and the strip, and along passageway  23  to a point beyond where inlet  20  intersects fused margins  8 A and  9 A of walls  8  and  9  defining centrally disposed chamber  11 . U.S. Pat. No. 4,917,646 is incorporated herein by reference and discloses a self-sealing valve in conjunction with balloon construction. 
     In FIG. 6, a modified inlet generally at  30  is shown having plies  31 - 32  fused along their corresponding edges  31 A- 32 A providing a passageway  36  and which fuse with fused edges  8 A- 9 A of the inner pair of walls  8  and  9  and provide an outlet  33  in communication with central chamber  11 . An inlet opening at  34  receives the nozzle  35  of a three-way dental syringe for purposes of inflation. Inlet  30  may rely on a folded or flap valve at  37  folded at  38  and closed by chamber pressure bearing upon the plies  31 - 32  to urge a free end of the valve at  37  to close against the plies. A heat resistant strip at  39  prevents fusing of plies  31 - 32  during fusing of marginal areas  8 A- 9 A of the device. 
     In FIG. 7 a further modified inlet is shown generally at  40 . Inlet plies are at  41 - 42  having marginal edges  41 A- 42 A fused to define a passageway  43 . A slit  44  in ply  41  permits insertion of syringe nozzle  35  for inflation of chamber  11  defined by walls  8  and  9 . 
     Upon inflation of the device, a heat source with heated, biased members pinches plies  41  and  42  together resulting in fusing and in closure of passageway  43  at an area indicated at  47 . 
     The present device is approximately one inch by one-half inch excluding the inlet, for use in the mouth of an adult and of somewhat lesser size for a younger person. Inflation of the device will require a source of air pressure in the range of 20 psi -40 psi. 
     The device is flat prior to inflation with the combined layers or walls of nylon material of a cross section permitting insertion between teeth prior to inflation and after tooth preparation. If simultaneously used to hold or stabilize a rubber dam, the device will be placed prior to tooth preparation. The dental auxiliary may, if necessary, maintain the device in place during inflation as by a three-way syringe. The device will expand to its fully inflated shape to retain its position. The use of reflective coating  17  on the surface proximate the prepared area of the tooth will assist in proper curing of the composite materials by reflection of high-intensity curing light. 
     With the device in the proper position, the composite materials are deposited, manipulated and cured as usual per the clinician&#39;s chosen protocol. The seal achieved at the edges of the preparation (the cavosurface) minimizes trimming or touch-up. When completed, the device is punctured with a sharp instrument and withdrawn from between. the teeth. The final steps, verification and adjustment of the bite, polishing and a final sealer are then completed as usual. 
     While I have shown but a few embodiments of the invention, it will be apparent to those skilled in the art that the invention may be embodied still otherwise without departing from the spirit and scope of the claimed invention.