WO1992006646A1 - Forceps with inserts for removing dental prosthetics - Google Patents

Abstract

A pair of dental forceps (10), whether configured for anterior, premolar or molar teeth, includes a pair of cushioning and gripping inserts (34) removably mounted in depressions (32) disposed in opposed jaws (18, 20) of the pair of forceps. The depressions (32) are configured to correspond with the respective labial (232) and lingual (234) surfaces of the associated tooth (230). The pair of inserts (34) conformingly grippingly and frictionally retain a respective dental prosthetic device, such as a crown, to be removed without imposing stress concentrations sufficient to mar or damage the dental prosthetic device. The jaws may be formed as tips (200) removably attached to a pair of forceps (150).

Description

FORCEPS WITH INSERTS FOR REMOVING DENTAL PROSTHETICS

Background of the Invention

1. Field of the Invention

The present invention relates to dental implements and, more particularly, to forceps for removing dental prosthetic devices.

2. Description of the Prior Art

Dental forceps, particularly configured for use upon the anterior, premolar or molar teeth have been available for years for purposes of extracting a tooth. These forceps have jaws particularly angled and of a length to facilitate grasping a particular tooth. During tooth extraction, it is very important that a firm grip of the tooth be achieved and it is of no consequence if the enamel of the tooth cracks or if the tooth is otherwise damaged. The forceps used for extracting teeth have been developed over a period of many decades to provide an effective combination of rripping a tooth and ease of manipulation of the gripped tooth to effect the extraction process. Primarily, the developmental work has been directed to the length and angulation of the gripping jaws.

To remove a crown for purposes of reattaching it more securely to develop a better seal or for adjustment purposes, it is very important that the crown not be aesthetically damaged or physically distorted. To use a conventional pair of extraction forceps for this purpose presents a real problem for the following reasons. The jaws of the forceps may damage the surface of the crown even though a good firm grip is established. If the forceps are only lightly squeezed to avoid damage to the crown, the jaws may slip from the crown and cause injury to the patient or damage to other teeth or restorations. For these reasons, many dentists use their fingers, and particularly their fingernails, to grasp the cervical ridge of the crown to dislodge and extract the crown. Since not all dentists have sufficient power in their fingers for this purpose, crown removal is a problem. Similarly, not all dentists have sufficiently robust fingernails to withstand the forces imposed without bending and causing substantial pain to the dentist. A potential problem of fungal infection also exists.

Various devices have been developed over the years to attempt to solve the above enumerated problems. In the 1920s, a clamp forceps was developed which cooperated with a detachably attached rubber dam to minimize damage to a crown while retaining sufficient gripping and extracting force.

Regrettably, this device was difficult and awkward to use as a practical matter. Some time later, a pair of forceps was developed which included a pair of opposed curved surfaces lined with resilient material for gripping a crown. These forceps were very difficult to use for all teeth due to the different requirements of grip and manipulation imposed by the placement of each tooth within the mouth.

A yet further device was developed which is of a plier like configuration having one jaw of the pair of jaws oriented to contact and bear against the proximal edge of the crown while the second jaw was penetrably inserted through a passageway cut in the top of the crown to bear against the underlying tooth. In situations where the underlying tooth is little more than a post, this device is ineffective. Moreover, the requirement for a passageway through the cusp of the crown necessitated repair and reconstruction of the crown prior to remounting.

Summary of the nvention

A pair of extraction forceps and associated jaws are configured to correspond with the tooth supporting a crown, bridge or other dental prosthetic to be removed. Removable inserts are disposed in the jaws for gripping with sufficient force to permit removal of the dental prosthetic while preventing damage or disfigurement to the surface and structure of the dental prosthetic. The replaceability of the inserts permits autoclaving or other sterilizing procedures of the forceps and the inserts may be disposable after one use. The forceps may include fixed or detachably attachable differently angled jaws selected to correspond with the tooth supporting the crown, bridge or dental prosthetic to be removed. Moreover, the forceps with inserts are readily useable for extracting bridges and other dental prosthetic devices which may need adjustment, repair or reconstruction without causing damage during such extraction.

It is therefore a primary object of the present invention to provide a pair of forceps for grasping and removing a dental prosthetic device without damaging it.

Another object of the present invention is to provide resilient conformable inserts for the jaws of a pair of forceps to grasp and remove a crown. Yet another object of the present invention is to provide an extraction tool for extracting premolar and anterior crowns.

Still another object of the present invention is to provide a selection of jaw elements interchangeably replaceable upon the jaws of a pair of dental forceps for grasping and extracting a dental prosthetic device.

A further object of the present invention is to provide removable inserts for use with dental forceps to extract dental prosthetic devices.

A still further object of the present invention is to provide a method for extracting a dental prosthetic device without damaging the device during extraction.

A yet further object of the present invention is to provide a method for firmly grasping but not damaging a dental crown to be removed.

These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.

Brief Description of the Drawings

The present invention will be described with greater clarity and specificity with reference to the following drawings, in which:

Figure 1 is a partial plan view of a pair of forceps adapted for removing a dental crown and bridge;

Figure 2 is a side view of the pair of forceps shown in Figure 1; Figure 3 illustrates a variant of the jaw configuration of the forceps shown in Figure 2;

Figure 4 illustrates a depression disposed in one of the jaws of the pair of forceps;

Figure 5 is an exploded view illustrating the shape and placement of an insert within the depression in a jaw of a pair of forceps;

Figure 6 illustrates a boot usable with each jaw of the pair of forceps; Figures 7a and 7b depict the force vectors acting upon the crown;

Figure 8 illustrates a prior art crown engaging device;

Figures 9a and 9b depict the force vectors attendant the device shown in Figure 8;

Figure 10 illustrates a perspective view of a pair of forceps adapted for removing premolar and anterior dental crowns;

Figure 11 illustrates a side view of the forceps shown in Figure 10;

Figure 12 illustrates a jaw of the forceps shown in Figures 10 and 11;

Figure 13 is a cross sectional view taken along lines 13-13, as shown in Figure 12; Figure 14 is a partial cross sectional view of the jaws of the forceps shown in Figure 10;

Figure 15 illustrates a removable insert;

Figure 16 illustrates a pair of forceps having female fittings for receiving a pair of jaws; Figure 17 illustrates a side view of the pair of forceps;

Figure 18 and 19 illustrate adaptations of the forceps shown in Figures 16 and 17;

Figure 20 illustrates an end view of the fittings attached to a variant of the forceps shown in Figures 16 and 17;

Figure 21 illustrates a tip and mating insert usable with each of the fittings shown in Figure 20;

Figure 22 illustrates a cross section of the tip and insert;

Figure 23 illustrates a device for securing the tip to the fitting of the forceps;

Figures 24a and 24b illustrate representative side and rear elevational views of premolar and anterior crowns mounted upon a tooth;

Figure 25 illustrates a cross sectional view of a representative forceps jaw;

Figures 26a, 26b and 26c illustrate cross sectional views of the jaws segment illustrated in Figure 25; and

Figures 27a and 27b illustrate modifications to a representative jaw for accommodating cervical ridge anomalies.

Description of the Preferred Embodiment

To assist a dentist in extracting teeth, numerous extraction forceps have been developed for groups of teeth which represent similar or related accessibility, direction of extraction and manipulation impediments. These forceps can generally be categorized as being suitable for anterior, premolar or molar teeth. It is to be understood that further gradations also exist. For tooth extraction purposes, jaws of a pair of forceps may be of surgical steel or similar material which permits a very firm rigid grip of a tooth to be extracted. Various composite plastic materials can also be used. Whether the act of gripping and manipulating the tooth during extraction results in damage to the tooth enamel or the structure of the tooth is generally not of significance.

When a crown is to be removed in the event the seal for the crown has been compromised or the crown needs to be repaired or adjusted, it is important to prevent . damage to the crown during the act of removal. Were such damage to occur, reconstruction or replacement of the crown would result in substantial expense which should be avoided. Because of the fragility of crowns, a dentist often must rely upon the strength of his fingers to effect removal since implements for this purpose and which implements have a low probability of causing damage to the crown do not exist. All dentists do not have sufficient strength in their fingers to effect removal of a crown. Furthermore, the space or volume available within the oral cavity to manually grip a crown may be a limiting factor of the ease with which a crown can be manually removed. Since dental forceps have been developed to facilitate the grasp of any of a patient's teeth, and as a crown usually has the same dimensions and configuration as the formerly existing complete tooth, the use of a pair of forceps intended for extraction of such tooth would vastly ease removal of the crown.

As shown in plan view in Figure 1, a generalized pair of forceps 10 includes handles 12,14 pivotally attached to one another by pivot means 16. Jaws 18,20 associated with handles 12,14, respectively, may extend generally planar with the handles or may be slightly bent, as shown in side view in Figure 2 of substantially bent as shown in side view in Figure 3. The degree of bend of jaws 18,20 primarily dictates the type of tooth with which the pair of forceps is to be used. Referring to Figure 4, there is illustrated a jaw 30, which jaw may be commensurate with one of jaw 18,20. The jaw has been formed with a depression 32 disposed in the working surface of the jaw. As shown in Figure 5, an insert 34 includes a body portion 36 configured to mate with and be received within depression 32. To assist in removably installing the insert, a tang 38 may extend rearwardly. This tang is penetrably insertable into passageway 40 of the jaw to protrude therefrom. Upon grasping the protruding tang, insert 34 can be pulled, as well as pushed, into seated engagement with depression 32. Face 42 of the insert may extend peripherally beyond perimeter 44 of depression 32 to define a shoulder 46. The shoulder would rest upon and be supported by the surface of jaw 30 extending about perimeter 44.

Moreover, face 42 is displaced from the surface of jaw 30 to the extent of the thickness of layer 48 adjacent body 36. Such displacement of the face will tend to preclude physical contact between jaw 30 and the crown to be removed whereby damage to the crown due to pressure exerted by the hard surface of jaw 30 would be precluded. Insert 34 can be relatively easily removed from the supporting jaw by simply grasping the overhanging portion of layer 48 extending beyond the surface of the jaw and pulling the insert out of depression 32. Thereafter, the forceps may be autoclaved or otherwise sterilized without concern for damage to the insert. The pair of inserts usable with each pair of jaws may be rendered sterile by conventional techniques and packaged accordingly prior to use. It is contemplated that each pair of inserts would be disposable.

Preferably, insert 34 is of resilient flexible material, such as a rubber composition or a plastic composition, which is suitable for molding or other fabrication. Sufficient resistance to compressibility must be present to prevent the pressures exerted by a pair of jaws 30 (corresponding with each of jaws 18 and 20) from coming into contact with the crown to be removed. Furthermore, the product of the force vector times the frictional coefficient between the surfaces (insert/crown) prevents slippage without the application of sufficient compressive forces, which forces might collapse or otherwise damage the crown upon disengagement from the underlying and supporting tooth.

Referring to Figure 6, there is illustrated a variant 60. This variant includes a sleeve 62 which may be slipped upon one of the jaws 30 (corresponding with each of jaws 18 and 20) . A similar sleeve would be slipped upon the opposing jaw. The sleeve includes a bulbous element 64 of sufficient size to occupy cavity 32 of the sleeved jaw. That is, sufficient material must be present to essentially fill the cavity and prevent collapse of the sleeve adjacent the depression during manipulation of a crown.

In operation, the pair of forceps are manipulated to locate opposed bulbous elements 64 attendant the respective jaws adjacent the crown to be removed. Upon applying pressure to the crown, the bulbous elements will resiliently grip the crown and permit manipulation of the crown to effect its removal without damage to the surface of the crown or its underlying structure.

The use of sleeve 60, rather than insert 34, has an advantage in positioning stability. That is, insert 34 relies upon the support provided by the walls of depression 32 to retain the insert in place despite the disruptive forces that may occur during manipulation of the crown. Sleeve 60, on the other hand, can be configured to very tightly encircle the supporting jaw and thereby create frictional resistance against relative movement between the sleeve and the sleeved jaw. The physical engagement of bulbous element 64 with depression 32 in the jaw serves in the manner of a locking element to prevent rotation of the sleeve about its axis. It also serves in the manner of a locking element to inhibit axial translation of the sleeve.

Figure 7a is a top view illustrating force vectors 66 imposed by insert 34 horizontally along the surface of the crow to be grasped. These vectors are essentially of equal length (equal force) due to the curved nature of the insert as dictated by the supporting depression and further modified by the configuration of the insert to conform with the actual surface of the crown. Similarly, Figure 7b is a side view illustrating force vectors 68 imposed by insert 34 vertically along the surface of the crow to be grasped. These vectors are essentially of equal length (equal force) due to the curved nature of the insert as dictated by the supporting depression and further modified by the configuration of the insert to conform with the actual surface of the crown. The forces imposed are therefore uniform and little likelihood of distortion of the crown would exist.

Referring to Figure 8, there is illustrated a prior art device having a pair of jaws 70,72 secured to a pliers type of device. Each of these jaws includes a cylindrical segment 74,76 of rigid material, such as stainless steel, faced with a resilient facing 78,80, respectively. The resilient facing provides a cushioning effect to a crown to be grasped. Because cylindrical segments 74,76 are generalized in terms of curvature, the forces imposed upon the crown to be removed are of greatest magnitude at the center of curvature. These forces are shown in top view in Figure 9a and in side view in Figure 9b with decreasing forces applied toward the opposed extremities. This is depicted by central vector 82 and lateral vector pair 84,86 and 88,90. Thus, deformation of the crown to be removed is highly likely and such deformation may cause cracking or other damage to the porcelain of the crown and the underlying structure. It may be noted that the curvature of each of cylindrical segments 74,76 is about a single axis; there is no teaching for providing curvature about a second axis to produce a dished segment.

As shown in plan view in Figure 10 and in Figure 11, a pair of forceps 100, which forceps are of a configuration generally used for premolar and anterior teeth. The pair of forceps includes handles 102,104 pivotally attached to one another by pivot means 106. Jaws 108,110 associated with handles 102,104, respectively, extend generally perpendicular to the respective handles. The degree of bend of jaws 108,110 with respect to handles 102,104 primarily dictates the type of tooth with which the pair of forceps is to be used.

Referring to Figures 12 and 13, there is illustrated a jaw 120, which may be commensurate with one of jaws 108,110, formed with a depression 122 disposed in the working surface of the jaw. As shown in Figures 14 and 15, an insert 124 includes a body portion 126 configured to mate with and be received within depression 122. To assist in removably installing the insert, a tang 128 may extend rearwardly. This tang is penetrably insertable into passageway 130 to protrude therefrom. Upon grasping the protruding tang, insert 124 can be pulled, as well as pushed, into seated engagement with depression 122. Face 132 of the insert serves as the working surface for gripping contact with the crown to be extracted. The face of one or both of the inserts may extend peripherally beyond perimeter 134 of depression 122, as shown in Figure 14. The extended part of the insert would rest upon and be supported by the surface of jaw 120 surrounding perimeter 134. Preferably, face 132 of the insert is displaced from the adjacent surface of,jaw 120. Such displacement of the face will tend to preclude physical contact between jaw 130 and the crown to be removed whereby damage to the crown due to pressure exerted by the hard surface of the jaw would be precluded.

Jaw 136 and insert 138 disposed in depression 140 are in opposed relationship to but correspond with jaw 120 and insert 124 disposed in depression 122 in structure and function.

Inserts 124 and 138 can be relatively easily removed from the respective supporting jaw by simply grasping the insert body and pulling the insert out of the respective depression. Thereafter, the pair of forceps may be autoclaved or otherwise sterilized without concern for damage to the insert. The pair of inserts usable with each pair of jaws may be rendered sterile by conventional techniques and packaged accordingly prior to use. It is contemplated that each pair of inserts would be disposable.

Preferably, inserts 124 and 138 are of resilient flexible material, such as a rubber composition or a plastic composition, which is suitable for molding or other fabrication. Sufficient resistance to compressibility must be present to prevent the pressures exerted by pair of jaws 120,136 from coming into contact with the crown to be removed. Furthermore, the inserts must exert sufficient friction upon the surface of the crown to prevent slippage without the application of sufficient compressive forces which might collapse or otherwise damage the crown upon disengagement from the underlying supporting tooth.

The configuration of each of the depressions (122,140) in jaws 120,136 and inserts 124,138 is preferably commensurate with the surface of the crown to be grasped by the respective jaw/insert, i.e. each depression corresponds to the basic lingual/labial impression of the surface to be engaged. Such correspondence will tend to distribute uniform forces along the contacted crown surface (both vertically and horizontally) to minimize the likelihood of damage or deformation to the crown surface. Moreover, a greater effective gripping area of essentially uniformly applied forces will result and extraction of the crown will be eased.

As shown in Figures 16 and 17, a pair of forceps 150 includes handles 152,154 pivotally attached to one another by pivot means 156. Jaws 158,160 associated with handles 152,154, respectively, may extend generally planar with the handles or may be slightly bent, as shown in side view in Figure 18 or substantially bent as shown in side view in Figure 19. Female fittings 155,157 are disposed at the ends of each of jaws 158 and 160, respectively. Each of these fittings includes a cavity 162,164 defined by a cylinder 166,168 extending from the respective jaw 158,160. A pair of opposed slots 170,172 and 174,176 is formed in diametrically opposed sections of cylinders 166,168, respectively. As shown in Figure 17, the cylinders extend perpendicularly to the major axis of the respective jaws.

Figures 18 and 19 illustrate variant orientations of the fittings to assist the dentist in extracting particular anterior, pre molar or molar dental prosthetic devices. For example, the fittings (178), shown in

Figure 18, are oriented at an angle of approximately 45° with respect to the major axis of jaws 180,182. Fittings (184), shown in Figure 19, are oriented in general alignment with the major axis of jaws 186,188. To accommodate overlap of jaws 158,160, as shown in Figure 20, fittings 166,168 may be of different length to place their respective ends in a common plane. The degree of angular orientation of the fittings primarily dictates the type of tooth (dental prosthetic) with which the pair of forceps is to be used.

Referring to Figure 21 there is illustrated a representative jaw 190 (like jaws 158,160) having a fitting 192 extending perpendicularly therefrom. The fitting includes a cavity 194 formed in a cylindrical element 196 of the fitting. A pair of diametrically opposed slots, of which slot 198 is shown, are in communication with cavity 194. A tip 200 includes a scoop 202 having a generally elongated recess 204 formed therein. Depression 204 has the geometric cavity contour of the labial/buccal or lingual surface relating to the crown to be removed. A support element 206 extends from one end of the scoop. It includes a cylindrical member 208 configured for penetrable engagement with cavity 194. A groove 210 circumscribes cylindrical member 208. Upon insertion of cylindrical member 208 into cavity 194, groove 210 is coincident with the slots (198) in fitting 192. A clip 212 is configured to penetrate the opposed slots in the fitting and partially engage groove 210. The engagement between clip 212 and groove 210 will create an interfering fit to preclude withdrawal of cylindrical member 208 from within cavity 194. By having the groove cylindrical, tip 200 may rotate about the axis of cylindrical member 208 in response to forces imposed. An insert 214 is configured to mate with and nest within depression 204. It also includes a tang 216 for penetrable insertion into passageway 218, which passageway may be coincident with the longitudinal axis of the tip. As particularly illustrated in Figure 22, insert 214 includes a face 220, which face extends above, or is displaced from perimeter 222 of tip 202.

The displacement of face 220 of insert 214 will tend to preclude physical contact between tip 200 and the crown or other dental prosthetic to be removed whereby damage due to pressure exerted by the hard surface of tip 200 would be precluded.

Insert 214 can be relatively easily removed from the supporting tip by simply grasping the extending portion and pulling the insert out of depression 204.

Thereafter, the pair of forceps and tips may be autoclaved or otherwise sterilized without concern for damage to the insert. It is contemplated that each pair of inserts would be used only one time and would be disposable.

Preferably, insert 214 is of resilient flexible material, such as a rubber composition or a plastic composition, which is suitable for molding or other fabrication. Sufficient resistance to compressibility must be present to prevent the pressures exerted pair of tips (200) from coming into contact with the dental prosthetic to be removed. Furthermore, the insert must exert sufficient friction upon the surface of the dental prosthetic, such as a crown, to prevent slippage without the application of sufficient compressive forces which might collapse or otherwise damage the crown upon disengagement from the underlying supporting tooth.

Under certain circumstances, it may be preferable to inhibit rotation of tip 200 about its longitudinal axis. By substituting a pair of opposed indentations (of which indentation 224 is shown) for groove 210 (Figure 21) and by incorporating an essentially rigid clip 226 for clip 212, rotation of the tip will be inhibited due to the resulting interference between clip 226 and indentations 224.

The configuration of each of the depressions 204 in tips 200 and inserts 214 is preferably commensurate with the surface of the dental prosthetic to be grasped by the respective tip/insert. Such correspondence will tend to distribute uniform forces along the contacted dental prosthetic to minimize the likelihood of damage or deformation. Moreover, a greater effective gripping area of essentially uniformly applied forces will result and extraction of the dental prosthetic will be eased.

A representative tooth mounted premolar and anterior crown 230 is illustrated in Figures 24a and 24b. Outward surface 232 is generally referred to as the labial surface while inward surface 234 is generally referred to as the lingual surface. These are the two surfaces contacted by the jaws of the forceps during extraction. Furthermore, it is generally sixty percent of these surfaces which is gripped. This portion of the lingual surface is identified by lines 236,238 (the cavity rim associated with radius R5 (Figure 25) . To promote and ensure a non slipping grip, the depressions in the forceps jaws preferably conform with the various curvatures depicted by designations Rl, R2, R3, R4 and R5 in the cervical, mid and incisal portions of the crown. Figure 25 illustrates a cross section of a typical depression 240 formed in a jaw 242. The depression illustrated is representative of the curvature of the lingual surface 234, it being understood that the curvature of the depression in the jaw used in conjunction with the labial surface 232 would be commensurately configured. More particularly, the curvature or radius at each of locations Rl, R2, R3, R4 and R5 would be specifically contoured to the mating curvature of the crown. That is, Rl would be equivalent to the lower lingual profile, R2 would be equivalent to the upper lingual profile, R3 would be equivalent to the cavity sidewall, R4 would be equivalent to the tooth gum line in the cervical area and R5 would be equivalent to the curvature of the rim of the depression commensurate with the contact area of the lingual surface extending longitudinally along the tooth generally proximate lines 236,238 (see Figure 24b). Referring jointly to Figures 26a, 26b and 26c, further views of depression 240 in jaw 242 are illustrated. Terminal end 244 includes a curved edge 246 conforming in general to the curvature attendant Rl of crown 230. A dished section 248 is configured to receivingly mate with the bulbous like cervical lingual surface of crown 230. The remaining curvatures and contours of depression 240 generally conform to the profiles contained in the tooth surfaces within lines 236,238 (Figure 24b). The jaw (or tip 200) depicted in Figures 25, 26a, 26b and 26c may include a passageway 248 for penetrably receiving a tang extending from the approximate center bottom of the insert (as discussed above) . This tang assists in installing the insert by pushing the tang into the passageway and pulling on the protruding tang until the insert becomes seated. Simultaneous pushing on the insert will assist the seating of the insert. Preferably, the insert extends above and across edge 250 of jaw 242 (tip 200) to preclude contact between the crown to be gripped and the jaw (or tip) .

The insert to be fitted within the jaw and its depression depicted in Figure 25 and in Figures 26a, 26b and 26c will compressingly conform with the depression to receive the commensurate lingual or labial surface of a crown and exert uniform forces there against upon gripping of the crown by the forceps. Such uniformity of gripping forces along the surface contacted will reduce stress concentrations to minimize damage or deformation to the crown and minimize the likelihood of slipping while providing a high degree of control to manipulation of the crown during extraction.

Figures 27a and 27b partially illustrate a variant 252 of jaw 242 for accommodating anomalies of the dental prosthetic to be removed. In jaw 242, edges 254,256 join with terminal edge 246 at locations which define relatively sharp points 258,260. Depending upon the structure and configuration of both the tooth and the associated dental prosthetic, there may be anomalies in the area of the cervical ridge and primarily in the mesio/distal length. The presence of sharp points 258,260 on jaw 242 may create difficulties in effecting facile gripping and removal of the dental prosthetic. To eliminate such cause for difficulty, variant jaw 252 may be used (partially shown in Figure 27b) . In the area of one of the pair of sharp points identified within circle 262 in Figure 27a, segments of edges 254,246 extending from the junction (sharp point 258) to locations identified by numerals 264,266 are removed. The resulting edge, identified by numeral 268 in Figure 27b, eliminates point 258 present in jaw 242. A similar modification is performed on edges 256,246 forming point 260 of jaw 242 to replace this point with an edge equivalent to edge 268. Such modification to jaw 242 will not negatively affect the efficacy of edge 246 in engaging the cervical ridge of the dental prosthetic as a functional equivalent of a dentist's fingernail and it will accommodate the aforementioned possible anomalies.

Claims

1. A pair of forceps for gripping a dental prosthetic device in a non damaging manner to effect removal of the dental prosthetic device, said pair of forceps comprising in combination: a) a pair of handles for manipulating said pair of forceps; b) a pair of jaws for gripping opposed sides of the dental prosthetic device, one end of each handle of said pair of handles including one jaw of said pair of jaws; c) means for pivotally interconnecting said pair of handles to relocate said pair of jaws toward and away from one another in response to pivotal movement of said pair of handles relative to one another; d) at least one jaw of said pair of jaws including a depression and a perimeter defining said depression, each said depression being in opposed facing relationship to the other jaw of said pair of jaws; and e) an insert demountably mountable within each of said depressions for contacting the dental prosthetic device and for restraining contact between the dental prosthetic device and the respective one of each of said perimeters.

2. The apparatus as st forth in Claim 1 wherein each of said depressions embodies the geometric profile of one of the labial and lingual surfaces of the prosthetic device to be removed.

3. The apparatus as set forth in Claim 1 wherein each of said inserts in combination with the respective on of said depressions includes means for transmitting relatively constant forces across the respective contact area of the dental prosthetic device.

4. The apparatus as set forth in Claim 1 wherein each of said inserts is of resilient flexible material.

5. The apparatus as set forth in Claim 1 wherein each of said inserts is compressively conformable with the contacted surface of the dental prosthetic device and extends beyond the respective perimeter of the associated one of said depressions to prevent direct contact between the dental prosthetic device and the respective one of said perimeters.

6. The apparatus as set forth in Claim 1 wherein at least one of said depressions includes a passageway extending through the respective one of said jaws and wherein the respective one of said inserts includes a tang for penetrably engaging said passageway.

7. The apparatus as set forth in Claim 1 wherein each of said depressions is elongated in the direction of the longitudinal axis of the respective one of said pair of jaws.

8. The apparatus as set forth in Claim 1 wherein at least one of said inserts includes a sleeve for receiving a segment of the respective jaw of said pair of jaws to mount said insert upon said jaw.

9. The apparatus as set forth in Claim 8 wherein each of said sleeved insert includes a bulbous element for engaging said depression of the respective one of said pair of jaws.

10. The apparatus as set forth in Claim 1 wherein each jaw of said pair of jaws includes a fitting and including a pair of tips for contacting opposed sides of the dental prosthetic device and means for detachably attaching each tip of said pair of tips to one fitting of said pair of fittings, each of said tips including one of said depressions for receiving one of said inserts.

11. The apparatus as set forth in Claim 10 wherein each fitting of said pair of fittings includes a longitudinal axis and wherein said attaching means includes means for detachably securing one tip of said pair of tips in alignment with the longitudinal axis of the respective fitting of said pair of fittings.

12. The apparatus as set forth in Claim 10 wherein said attaching means includes a cavity disposed in each fitting of said pair of fittings and a member extending from each tip of said pair of tips for insertion within said cavity of the respective one of said pair of fittings.

13. The apparatus as set forth in Claim 10 wherein each of said depressions embodies the geometric profile of one of the labial and lingual surfaces of the dental prosthetic device to be removed.

14. The apparatus as set forth in Claim 10 including means for detachably attaching each insert of said pair of inserts with the respective depression of said pair of depressions.

15. The apparatus as set forth in Claim 14 wherein said attaching means includes a passageway extending from each depression of said pair of depressions and a tang extending from each insert of said pair of inserts for penetrably engaging the respective one of said passageways.

16. The apparatus as set forth in Claim 1 wherein said interconnecting means in combination with the orientation of said pair of jaws locates said pair of jaws movable within a plane outside of a plane defined by the pivotal movement of said pair of handles.

17. The apparatus as set forth in Claim 1 wherein said interconnecting means in combination with the orientation of said pair of jaws locates said pair of jaws movable within a plane defined by the pivotal movement of said pair of handles.

18. A method for gripping a dental prosthetic device with a pair of forceps in a non damaging manner to effect removal of the dental prosthetic device, said method comprising the steps of: a) pivotally manipulating a pair of handles of the pair of forceps to grip opposed sides of the dental prosthetic device with jaws disposed at one end of the pair of handles; b) contacting the labial and lingual surfaces of the dental prosthetic device with an insert demountably mounted within a depression formed in each of the jaws and having an encircling perimeter in opposed faces of the pair of jaws; c) applying constant forces to the dental prosthetic device across the area of contact by the inserts due to the configuration of each depression at least generally conforming with the corresponding labial and lingual surfaces of the contacted dental prosthetic device; and d) discouraging contact between the dental prosthetic device and the perimeter of the respective depression and urging the contact with the dental prosthetic device to be solely with the respective inserts.

19. The method as set forth in Claim 18 including the step of removably mounting each of the inserts in the respective ones of the depressions.