Abstract:
A dental clamp for supporting a flexible sheet around a tooth during a dental operation has a resilient member connecting oppositely disposed jaws. The resilient member biases the jaws toward each other. A plurality of resilient fingers extend toward each other from each jaw.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 60/244,936 filed Nov. 1, 2000. 
    
    
     BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The invention relates to a dental clamp and, more particularly, to a clamp for use with a rubber dam when it is desirable to isolate one or more teeth being treated. 
     2. Description of the Related Art 
     Certain dental operations, such as root canals, are performed with a flexible sheet, such as a rubber dam retained around the tooth, or in some cases several teeth, undergoing treatment. The dam isolates one or more teeth from the rest of the interior of the patient&#39;s mouth and serves two functions. One, it prevents ingestion by the patient of medicine or other substances associated with the operation and, two, it inhibits the introduction of bacteria and other contaminants from the mouth into the operating theater around the tooth during the procedure. The dam comprises a flexible membrane retained in a frame. While the frame is placed outside the mouth, the membrane is flexible enough to extend inwardly of the patient&#39;s mouth. In the case of a single treated tooth, a hole is punched in the membrane to accommodate the tooth and the dam is inserted over the tooth so that it is the only tooth exposed through the hole. A similar procedure is employed if more than one tooth is to be isolated. 
     A dental clamp is typically used to retain the rubber dam in proper position around the tooth. Dental clamps include a pair of laterally opposed jaws that are spring-biased to grip the tooth immediately above the gum line. The clamp typically attaches to the dam at the hole for positioning the dam around the tooth. The clamp is applied by spreading the jaws with a special forceps, positioning the clamp around the tooth, and carefully releasing the jaws when the clamp has been properly placed. The edges of the jaws may include serrations to facilitate gripping of the tooth or it may include a soft bumper to avoid damage to the surrounding gums. 
     FIG. 1 shows one embodiment of a tooth clamp according to the prior art. The tooth clamp comprises a resilient arcuate spring A which is attached at each end to jaws B. The jaws B are laterally opposed and define an intervening space C. The inwardly directed edge D of each jaw B is curved and may include serrations. The shape of the edge D is intended to correspond roughly with the arc of a tooth along the gum line. 
     Each jaw B is provided with an aperture F for insertion of a forceps, which is used to spread the jaws B apart for placement of the clamp around the tooth. Tabs E extend laterally from the outside edges of the jaws B. The tabs E are inserted into a hole in a rubber dam G to spread the hole open. 
     One of the problems with known clamps is that the spring force, and thus the force required to open the clamp, is very high, making the placement of the clamp on a tooth difficult. Also, such force may cause the device to bite into the gums if the placement is improper, or if the device is urged downwardly by the shape of the tooth. In addition, the clamp may slide off the tooth during a procedure, thus disrupting the treatment and permitting the introduction of contaminating substances to the operating theater. 
     SUMMARY OF INVENTION 
     These problems are solved by the present improvement in a dental clamp of the type for clamping a tooth and supporting a flexible sheet during a dental operation. Such a clamp typically has a resilient member connecting oppositely disposed jaws and biasing the jaws toward each other. Each jaw comprises a plate having an outward edge for engaging the flexible sheet and an inward edge that together with the opposing inward edge define a space between the jaws. The improvement lies in a plurality of resilient fingers extending from the inward edge of each plate and toward the oppositely disposed plate. 
     Preferably, the resilient fingers are arranged in a rank on each jaw. In one aspect of the invention, the resilient fingers extend slightly away from the resilient member. In another aspect of the invention, each finger has a crimp to facilitate resiliency. Preferably, the ends of the fingers are arranged to define a curve roughly approximating the curvature of a tooth. The jaws can each incorporate an additional tab to further engage and hold the flexible sheet. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     In the drawings: 
     FIG. 1 is a perspective view of a tooth clamp according to the prior art; 
     FIG. 2 is a perspective view from the underside of a tooth clamp according to the invention; 
     FIG. 3 is a front elevational view of the tooth clamp shown in FIG. 2; and 
     FIG. 4 is a perspective view of a tooth clamp according to the invention inserted into a hole in a rubber dam for placement around a tooth. 
    
    
     DETAILED DESCRIPTION 
     An embodiment of the invention is illustrated in FIG. 2, where a dental clamp  10  according to the invention comprises a resilient arcuate bridge  12  connecting a pair of opposing jaws  14 . The bridge  12  is configured to extend over the teeth when the clamp  10  has been properly installed. The jaws  14  define a space  16  therebetween. Each jaw  14  comprises a plate  18  with an aperture  20  therethrough, a dam tab  22 , and resilient fingers  24 . 
     The apertures  20  accommodate in a conventional manner a rubber dam forceps (not shown) for spreading the jaws  14  apart in order to install the clamp  10  around a tooth (not shown). The plate  18  extends forward in a generally lateral direction from the end of the bridge  12 . The outward edge  19  of the plate  18  terminates in a generally laterally disposed dam engaging wing  26 . The inward edge  21  of each plate  18  defines the space  16 . Referring to FIG. 3, the wing  26  is bent slightly downwardly from the top of the plate  18 . The dam tab  22  extends forwardly from the plate  18  and comprises a first segment  28  essentially coplanar with the plate  18 , a second segment  30  orthogonal to the first segment  28 , and a tongue  32  orthogonal to the second segment  30 . 
     The resilient fingers  24  extend laterally from the inward edge  21  of the plate  18  into the space  16  and toward the oppositely disposed plate. Referring again to FIG. 3, the fingers  24  are formed with a crimp  38  comprising a first segment  40 , an elbow  42 , and a second segment  44 . The ends  34  of the fingers  24  are bent in a slightly downward position relative to the top of the plate  18  so that the corner  46  contacts the tooth. The ends  34  of the fingers  24  define a curve  36  corresponding generally to the arc of a tooth along the gum line. In the preferred embodiment, at least two and no more than nine fingers are utilized depending upon the type of tooth (e.g., molar, bicuspid) to be clamped. 
     Referring now to FIG. 4, as with a conventional dental clamp, a rubber dam  48  is attached to the clamp  10  by stretching the edges of a hole  50  over the wings  26 . Additionally, the dam tab  22  is inserted into the hole  50  to further spread the edges of the hole  50  apart and increase the size of the hole formed by the hole  50 . Using conventional rubber dam forceps (not shown), the clamp  10  is placed over the selected tooth (not shown), thereby positioning the rubber dam  48  in place. The fingers  24  contact the periphery of the tooth at the corners  46  and deform individually to distribute the contact force exerted by the jaws  14  uniformly along the tooth. The slightly downward orientation of the finger ends  34  resists slippage of the clamp  10  upward and off the tooth. 
     While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.