Claims:
What is claimed is
1. A dental tool for transmitting biting pressure from the occlusal surfaces in one arch to separate locations on the opposed occlusal surfaces in the other arch comprising:
2. A dental tool of claim 1 wherein the outermost opposed portions of the bearing member and the movable support members are provided with replaceable yieldable coverings.
3. A dental tool of claim 1 wherein the elongated track member comprises a T slot formed in a bar member and the movable support members comprise two separate compression elements slidably received in said T slot.
4. A dental tool of claim 1 wherein the bearing member, the movable support members, and the means for positioning are mounted on a bar member.
5. A dental tool of claim 1 wherein the bearing member, the movable support members, and the means for positioning are mounted on a bar member, said means for positioning including an elongated handle member, said elongated handle member being mounted on said bar member for limited pivotal movement.
6. A generally T-shaped dental tool for transmitting biting pressure from one arch to the opposed teeth in the other arch comprising:
7. A dental tool for transmitting pressure between teeth in opposite arches comprising:
8. A dental tool of claim 7 including a handle element projecting angularly from said bar element generally in a direction which is approximately perpendicular to said bar element.
Description:
This invention relates to a multiple inlay, crown and bridge seater.
During the course of dental restoration, often more than one tooth in the same arch is being restored with a crown or an inlay. Biting pressure is utilized in the seating of crowns and inlays as well as bridges. The distribution and proportioning of biting pressure between the various abutments of a bridge or between multiple inlays and crowns had previously presented substantial problems. According to the present invention, a dental instrument is provided which permits the seating of more than one inlay or crown at the same time with controlled distribution and proportioning of biting pressure on the different respective restorations while they are being cemented. This tool also provides for the application of accurately proportioned pressure on the abutments of a bridge while it is being cemented. In general, the dental instrument, according to the present invention, has a generally T-shaped configuration. The crossbar of the T is provided with a bearing member which projects outwardly from the plane of the tool in one direction and a plurality of movable contact points which project outwardly from the plane of the tool in approximately the opposite direction from the bearing member. The bearing member is located approximately equidistant from the ends of the elongated bar, and the contact points or support members are mounted for movement along the length of the bar member. The movable support members are independent of one another in their movement so that it is possible to position them in different locations with respect to the opposed bearing member. Biting pressure is thus transferred from the bearing member through the bar and is distributed between the movable support members. If the movable support members are positioned at locations which are equidistant from the bearing member, the pressure will be about equal on each of the movable support members. If the support members are positioned so that they are not equidistant from the bearing member, then the pressure will not be distributed equally between the movable support members. The support member which is closest to being in axial alignment with the bearing member will receive the greatest pressure. By positioning the support members at various locations, it is possible to proportion the biting pressure between the support members so that any one support member may receive from about 5 to 95 percent of the biting pressure with the balance being received by the other supporting member. In general, two supporting members are used because it becomes very difficult to distribute pressure with the required degree of precision when more than two supporting members are used. The supporting members contact the occlusal or chewing surfaces of the teeth and transmit the pressure which they receive to the occlusal surfaces of the teeth.
The leg of the generally T-shaped dental tool is defined by a handle. This handle serves both to stabilize the dental instrument when it is in position in the mouth and also as a convenient handle for positioning the tool in place in the mouth.
The opposed surfaces of the tool which come into contact with the occlusal surfaces of the teeth and receive and transmit the biting pressure are provided with resilient or deformable coverings so that they will not damage the teeth. Also, these coverings are preferably readily detachable from the tools so that, for sanitary purposes, they may be replaced after each use of the tool.
Referring particularly to the specific embodiments illustrated in the drawings:
FIG. 1 is a perspective view of a generally T-shaped dental tool of the present invention;
FIG. 2 is a front elevational view partially in section taken along line 2--2 of FIG. 1;
FIG. 3 is a cross-sectional side elevational view taken along line 3--3 of FIG. 2;
FIG. 4 is a front elevational view partially in cross section similar to FIG. 2 of a further embodiment in which the handle member is mounted for limited rocking movement about an axis generally parallel to the handle; and
FIG. 5 is an exploded perspective view of a movable support member utilized in the tool.
Referring particularly to the drawings, a dental tool having a general T-shaped configuration is illustrated generally at 10. Dental tool 10 is composed of a bar 12 which has a generally elongated configuration and which defines the cross member of the T-shaped dental tool. An elongated T slot 14 extends lengthwise in bar 12 and opens outwardly in a direction which is generally perpendicular to the plane which is occupied by dental tool 10. A bearing member holder 16 is positioned at the approximate midpoint of bar 12 on a side bar 12 which is generally opposed to the opening of T slot 14. Bearing member 18 which is resilient and replaceable is releasably mounted in bearing member holder 16. Bearing member 18 projects outwardly from the plane defined by dental tool 10 in a direction which is approximately opposed to the direction in which T slot 14 opens. A handle 20 is integral with bearing member holder 16 and projects in a generally perpendicular direction to bar 12 so as to define the leg of the generally T-shaped dental tool 10. Handle 20 is riveted to bar 12 by means of rivet 22.
Movable compression members indicated generally at 24 are slidably received in T slot 14. The movable compression members 24 define the movable support members and are constructed with a rectangular base 26, a pointed column 28 projecting generally perpendicularly from rectangular base 26, and a replaceable resilient point cover 30. Rectangular base 26 is proportioned so that it is slidably received and retained in T slot 14. Pointed column 28 projects outwardly through the outwardly opening leg of T slot 14 so that movable compression members 24 project outwardly from the plane defined by dental tool 10 in a direction which is generally opposed to the direction in which bearing member 18 projects. Taken together, the bearing member 16 and the movable compression members 24 define a working plane through which biting pressure is transmitted from one arch to another. This working plane is generally perpendicular to the plane occupied by the dental tool. The dental tool is positioned in approximately its own plane, which may be conveniently described as a positioning plane, and then pressure is transmitted through the working plane from one arch to another. The positioning plane is approximately perpendicular to the working plane.
In the specific embodiment of FIG. 4, the rivet 22 has been replaced with a rod 32 which is received in a socket 34. Socket 34 is formed in bar 12 and rod 32 is attached to bearing member holder 16. The rod and socket combination permits limited pivotal movement in one plane between bar 12 and bearing member holder 16 so as to provide for the adjustment of the position of bearing member 18 relative to the bearing teeth in first arch 36. Since the occlusal surfaces of the teeth in first arch 36 are very seldom positioned in exactly the same plane as the outermost surface of bearing member 18, the limited pivotal movement provided by the rod and socket permits accurate positioning of the bearing member 18 relative to the tooth or teeth in first arch 36. The provision of the outwardly tapering pointed column 28 on each of the movable compression members 24 permits the pressure which is transmitted from first arch 36 through the working plane to second arch 38 to be located in precisely the desired position in second arch 38. Movement of the movable compression members 24 in the track member which is formed by T slot 14 permits the positioning of the movable compression members longitudinally of bar 12. If the movable compression members 24 are spaced at approximately the same distance from the midpoint of bearing member 18, the biting pressure will be approximately equal on each movable compression member. If one compression member is moved closer to the midpoint of bearing member 18, the pressure on that movable compression member will increase, and the pressure on the remote movable compression member will decrease. The proportioning of the biting pressure is determined by the positioning of the movable compression members 24 relative to approximately the midpoint of bearing member 18.
In operation the point covers 30 and bearing member 18 are inserted in place, and the dental tool 10 is grasped by handle 20. The movable compression members 24 are adjusted to the desired location and proportioning of pressure, and tool 10 is inserted in position in the mouth with the movable compression members 24 positioned on the locations where pressure is to be applied. The handle 20, particularly in the embodiment of FIG. 4, is positioned so that it extends across the mouth and stabilizes the position of the working plane of the tool. In general, the handle 20 extends across the mouth and between the two arches 36 and 38 in an area which is remote from the area where the restoration work is being undertaken. This prevents the tool from rotating so that the working plane is tipped out of alignment with the teeth in the arches 36 and 38. If the bearing member 18 or pad were to slip out of alignment with the teeth in arch 36, the teeth might be damaged by coming in direct contact with bearing member holder 16 or bar 12. Also, such rotation would not transmit the biting force efficiently from first arch 36 to the teeth in second arch 38.
In general, the dental tool 10 is constructed of metal and the bearing member 18 and point covers 30 are constructed of some yieldable material, such as rubber, polyethylene, polypropylene, or the like. Preferably, the bearing member 18 is composed of an elastomeric material, such as rubber, which has the capacity of providing some frictional resistance to the movement of the pad relative to the first arch 36.