Title:
CROWN AND BRIDGE REMOVER
United States Patent 3579834


Abstract:
A crown and bridge remover comprises an arch bar, a pair of stabilizers and two pronged crown lifters. The lifter prongs are adapted to fit under the crown. The arch bar is substantially the shape of an average row of teeth and is bendable to fit the mouth of an individual patient. The stabilizers are mounted on the arch bar so that they may be on either side of the crown or bridge to be pulled. The lifter is mounted on the arch bar between the stabilizers and provided with threaded means to draw the prongs toward the arch bar and thus remove the crown.



Inventors:
REED CHARLES C JR
Application Number:
04/851801
Publication Date:
05/25/1971
Filing Date:
08/21/1969
Assignee:
CHARLES C. REED JR.
Primary Class:
Other Classes:
433/161
International Classes:
A61C3/16; (IPC1-7): A61C3/16
Field of Search:
32/41,43,44,34,61
View Patent Images:
US Patent References:
2977683Hydraulic tooth extractor1961-04-04Wiltse
1756245Dental crown remover1930-04-29Flegsted et al.
1666860Tooth extractor1928-04-17Maranda
1522916Dental instrument1925-01-13Suida et al.



Primary Examiner:
Peshock, Robert
Claims:
I claim

1. A dentist's tool for crown or bridge removal comprising in combination:

2. A tool as described in claim 1 in which each stabilizer has a concave surface for fitting the biting edges of teeth on either side of the lifter.

3. A tool as described in claim 1 in which one of the stabilizers has a soft surface for resting upon the gum of the patient when a crown or bridge is to be removed at the end of a row of teeth.

4. A tool as described in claim 1 in which the lifter means comprise a pair of lifters each adapted for lifting an end crown of a bridge.

5. A tool as described in claim 1 which the lifter means comprise a shank and a rotating member, each having threads, the threads mating with a portion of the rotating member bearing against the arch bar, whereby rotation thereof draws the lifter prong toward the arch bar.

6. A tool as described in claim 5 in which the shank carries a bent sheet metal member with arms having the ends thereof bent to form the lifter prongs.

7. A tool as described in claim 5 in which the lifter shank is slotted and straddles the arch bar and the rotating member is a nut engaging the arch bar for drawing the lifter prongs upward with respect to the arch bar.

8. A tool as described in claim 7 in which a washer is interposed between the nut and the arch bar and surrounds the shank.

9. A tool as described in claim 1 in which the arch bar is composed of bendable material for adapting it to the shape of the set of teeth of each patient.

10. A tool as described in claim 6 wherein a sleeve with a tapered inner surface is provided, surrounding the shank and having means for pushing it against the lifter prong arms to move the prongs inward against a crown.

Description:
The invention has for its principal object provision of a safe, reliable tool for removing crowns, without mutilating them, breaking teeth, allowing the tool to slip or risking an injury to the patient.

In carrying out the invention according to a preferred form thereof, an arch bar has a shank mounted thereon carrying prongs and means for pulling the shank upward on the arch bar. The arch bar is held in position by stabilizers on each side of the shank, bearing against biting surfaces of sound teeth beside the crown. When the crown is at the end of the row of teeth one of the stabilizers bears on the gum.

DRAWINGS

A better understanding of the invention will be afforded by the following detailed description considered in conjunction with the accompanying drawings, on which:

FIG. 1 is a side view of a crown and bridge removing tool forming an embodiment of the invention.

FIG. 2 is a plan view of FIG. 1.

FIG. 3 is an elevation showing the position in the mouth of the tool illustrated in FIGS. 1 and 2.

FIG. 4 is a view of longitudinal section of the crown lifter.

FIG. 5 is a front elevation of the tool in a mouth showing the arrangement of the tool for lifting end crowns of a bridge.

DETAILED DESCRIPTION

Like reference characters are employed to designate like parts throughout the drawing.

As shown in FIG. 1 the bridge and crown lifter utilizes an arch bar 11, somewhat in the shape of a "U" to conform generally to the shape of the row of teeth of the patient. The arch bar 11 is of a bendable material, such as a stainless steel strip, which may be shaped to conform to the shape of the teeth of the individual patient.

Mounted upon the arch bar 11 is a single lifter 12 as shown in FIGS. 1--2, for removing a crown or a pair of lifters 12 and 13 as shown in FIG. 5 for removing a bridge attached to two crowns. The lifters have prongs for engaging a crown. Also mounted on the arch bar 11 are stabilizers 14.

The lifters 12 and 13 and stabilizers 14 are preferably slidably mounted along the arch bar 11 so that they may be located anywhere along the arch bar depending upon where a crown or bridge is to be removed. The stabilizers 14 are provided with means such as setscrews 15 for fixing them in a position along the arch bar 11, while lifting a crown. Each stabilizer 14 has a pad 16 attached to it with a concave base to bear against edges of the teeth beyond the crown or bridge to be removed.

If the crown is to be removed at the end of the row of teeth, one of the stabilizer pads is composed of a soft material, such as soft rubber, so that it may bear against the gum without undue patient discomfort.

As shown more clearly in FIG. 4, the lifter member comprises a shank 18 mounted upon the arch bar 11 and a rotatable member 19. Members 18 and 19 are threaded with the threads mating. The lower end of the shank 18 has a member 21 secured thereto by means of a screw 22 and then member 21 has four arms 23. The arms are bent at the ends to form hooks 24 that serve as prongs. Member 21 is composed of suitable material such as stainless spring steel so that the arms 23 may be bent in to fit against the sides of the crown, with prongs 24 under the edges of the crown.

In the illustrated embodiment the shank 18 is in the form of a split or slotted screw, having a rectangular opening 25 making a sliding fit with the arch bar 11.

The rotating number 19 is in the form of a knurled nut threaded upon shank 18. A washer 26 may be interposed between the nut 19 and arch bar 11 to distribute bearing surface to the nut 19.

As shown in FIG. 3, in using the crown lifter the prongs 24 are placed under the lower edges of the crown 27. Invariably there is unavoidable spacing between the lower edge of the crown and the shoulder on the tooth 28 which has been capped by the crown 27. With the pads 16 of the stabilizers bearing against the biting surfaces or edges of the neighboring sound teeth 29, the nut 19 is rotated to draw the crown 27 from the tooth 28.

As shown in FIG. 5, a bridge is removed in the same manner, utilizing two lifters 12 and 13, each acting on one of the end crowns of the bridge.

Although springiness of the prong member 21 serves to hold the prongs 24 under the edges of the crown 27, positive means for holding the member 21 on the crown may be provided. As shown in FIG. 4, a sleeve member 31 is provided, having a tapering inner surface 32 adapted to bear inwardly against the arms 23 when the sleeve 31 is pushed downward. For this purpose a second knurled nut 33 is threaded on the shank 18. The stabilizer pads 16 shown in FIG. 1 have curved surfaces 17 especially adapted to fit over and beyond the biting surface of a molar tooth and thus insure retention of the crown-lifting tool in the proper position in the mouth while the crown is being removed, since the shape of the surface 17 prevents slippage. Slippage is prevented also when the surface 17 bears against the end of a canine tooth or the biting edge of an incisor. Nevertheless, separate stabilizers with cap-shaped pad surfaces for canine teeth and grooved surfaces for incisors may be provided.

While the invention has been described as embodied in concrete form and as operating in a specific manner in accordance with the provisions of the patent statutes, it should be understood that the invention is not limited thereto, since various modifications will suggest themselves to those skilled in the art without departing from the spirit of the invention.