US1397082A - Replaceable facing and pins therefor - Google Patents

Description

G. E. COX. REPLACEABLE FACING AND PINS THEREFOR.

APPLICATION FILED SEPT. 8,1921- Patented Nov. 15, 1921 Greo. E. OX

A SWO .PATENT QFFIQE.

GEORGE E. COX, 0F

WILMENGTON,

DELAWARE.

.REPLACEABLE FACING AND FEES THEREFGB.

135E168 2,. Specification of Application filed September To all 201 mm. may conccm Be it known that l, GEORGE E. Cox, a citizen of the United States, residing at .l ilmington, in the county of New Castle and State of Delaware, have invented certain new and useful improvements in Replaceable Facings and Pins Therefor; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

This invention relates to dental facings in tended for bridge W Fla, and has for its objeot the provision of a system that will provide a superior article at a less cost than the present facing with permanently attached pins.

A further object of the present invention is the provision of a replaceable facing that may be protected with a gold tip, this being impossible with the popular oteeles interchangeable teeth. A further object of the present invention is the provision of a facing that can be made more convenient for the dentist than the present-day facing in that the tip of the facing here described may be ground by the maker so that the facing-s will be interchangeable without further grinding by the dentist. A still further but important object of the present invention relates to the pins per se, these pins being characterized by the provision of a central collar intended to abut against the porcelain facing on one side and against the 22-karat gold backing on the other side.

In crown and bridge work the dental facings which are almost invariably of porcelain very often crack when the metal is being soldered, and since these backings have the pins inserted in them permanently they consequently cannot be removed when they crack. The present facing may be removed while the bridge work is being soldered and it also can be replaced if broken, while in the mouth, or it may be changed if the shade of the tooth does not match properly or is un satisfactory for any reason whatever to the patient.

In the present system it is contemplated to use porcelain facings having two relatively deep indentations or holes with preferably roughened interior walls and to cement in these holes a pair of connected dental pins each having a plurality of cement receiving grooves so as to form a permanent attachment to the facing. The pins are pointed, as

Patented Nov. 15, 192i.

Letters Patent.

8, 1921. Serial No. 499,167.

is quite customary, in order to pierce the soft gold backing. It will readily be understood by those skilled in the art that the pins are not permanently cemented to the facings until after the bridge is otherwise completed.

In order to secure interchangeability of the teeth i prefer to have the facings ground at the tip as shown in the drawing, but do not wish my invention limited (except by the claims hereinafter) to a ground tip facing, since teeth as usually furnished are not now ground and in view of the necessity for changing the molds it might be that some manufacturers would not care to grind the tips, but would desire to use the present invention. If the tips are so ground at the factory it will obviate further grinding by the dentist at his oflice.

In toe drawings,-

Figure l is a vertical section through a facing embodying the invention.

ig. 2 is a rear elcvatiton of the facing i the pins and backing in place.

' 3 is a view of the dental pins.

g. i is a section through a part of the bric ge with the facing, backing, and dental pins all in place.

The facing 10 is of quite ordinary shape, having a. bevel top 11 and a plane rear face 12 with the usual exposed surface 14: shaped to resemble a natural tooth. T prefer to grind away the tip as at 15 so as to protect the facing by the provision of a contact edge 16 of gold. A. plurality of indentations or holes 1'? and 18 are provided, the upper 'hole 1'? preferably being slightly deeper than the lower hole 18 but both being preferably of the same diameter and both preferably having roughened walls to facilitate the permanent connection by cement with the dental pins.

The backing 19 is preferably of 36-gage gold plate and is cut by the dentist from sheet material thus greatly reducing the comparative cost.

The pins 20 and 21 are quite similar generally, but the pin 20 is slightly longer than the pin 21 since it fits in the upper and deeper hole 17 in the facing. Each pin has a pointed tip 22 and a pair of annular flanges or heads, the outer head being numbered 23, and the intermediate head being numbered 2%. The pins 20 and 21 lie parallel and are connected together by a common collar 25 somewhat in the shape of a dumb bell, the ends 26 being circular as.

model.

4 similar cement receiving grooves 29 with the outer heads 23.

Expensive machine-made backings are required to be used with other types of removable and replaceable facings and the dentists are compelled to carry in stock a comparatively large assortment of such backings to meet the requirements for different size teeth, these, backings costing from seventy cents to a dollar or more. If the dentist has only large backings and requires a small one he must waste an appreciable amount of money since a dollar backing contains only about thirty-live'cents worth of gold. In the present system there is practically no loss, for the QQ-karat 36- gage gold plate furnished dentists does DOT, cost much in excess of its actual value so the dentist may cut his own backings as he needs them.

The operation of applying the pins and facings is as follows: hen a bridge is being made the work is usually mounted on a plaster model and the facings or teeth, such as 10, are first fitted in place and held for observation with beeswax. After the dentist is perfectly satisfied with his selection as to shape, color, etc, he fits the chosen teeth or facings to what is represented on the plaster model as gum tissue andafter carefully removing the facings one by one he inserts the pins 20 and 21 as a unit in the holes 17 and 18 and burnishes the gold backing 19 to the facing in the well known way and then returns the tooth facing to the If the tooth is a front one it is now ready to have the gold melted to the backing, but if the tooth is a back o-ne the biting surface or cusps 30 are swaged out of gold plate. I find it highly advantageous to let the gold cusps 80 lap over the gold backing 19 at 16 which allows the gold,

when melted, to permanently unite the limited except as set forth in the claims. I

wish to use pins of equal length for example, and I wish to knurl or otherwise roughen the ends intended for insertion in the facing, although I much prefer the formation shown with its two annular cement receiving grooves 28 and 29.

What I claim is:

i. In combination, a facing having two pin receiving holes, and a pair of pointed pins having a common central connecting collar, said pins fitting in the holes in said facing. V

2. A pair of dental pins connected together for simultaneous insertion in a facing each of said pins being pointed at one side of their connection and roughened on the other side thereof. 7

3. A pointed dental pin characterized by the provision of a plurality of annular flanges adapted to be received Within a facing and a collar of larger diameter and adapted to abut the inner face of said facing. I

at. A. pair of dental pins of unequal length connected together at their mid-portion by a collar lying at right angles to the axes of the pins.

A pair of pointed dental pins of unequal length characterized by the axes of the pins being parallel, said pins being connected by a common collar in a plane at riglitangles to said axes and by the further proi ision'of a plurality ofcement receiving grooves on each of said pins.

GEORGE E, (30X.

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