US2304416A - Dental alloy - Google Patents

Description

. am. a. a,- 1943 UNITED sTA'rEs PATENT o -"Pica v 2,304.43 y 'nnn'rar. also! 3 Iosef Deuser, Pforsheim, Germany, assignor to Chemical Marketing Company In, New vYork. .9 N. Y., a corporation of New York No Drawing. Application September 12, 1940, Se-

rial No. 356,562. in Germany August 25, 1939 .3 Claims.

In dentistry gold alloyswith at least 75% gold or gold plus platinum metal alloys are employed for orthodontic parts which must stand great stress. In these alloys which contain gold and a platinum metal a high percentage of precious metals was deemed necessary to secure a sufficient resistance against corrosion in mouth. Be-

sides gold and platinum metals thesealloys contain also silver, copper and, if desired, zinc, nickel, tin and other base metals. The content of platinum metals was increased up to 20% and more to procure thedesired strength, tenacity and durability of these alloys. The alloys have nearly almost a white color.

To reduce the cost price palladium silver alloys with small additions of gold and platinum as well aspale yellow alloys with a content of about 50% gold and several percent of palladium have also been used. These alloys possess the necessary strength, but not the tenacity and durability which are indispensable for numerous purposes in dentistry or they are very dliilcult to work. Now I have found that alloys with 60 to 70% of gold and platinum metals have an extraordinarily high strength, tenacity and durability, if

at least two platinum metals, preferably platinum and palladium, are used together. They are also very resistant against the influences of the mouth liquids. Thereby the content of platinum may exceed that of palladium but the palladium content should not be less than 1% of the whole alloy. Such alloys have an excellent hardness andstrength. They are easy to work and to roll and may also be subjected towire drawing. Their fusion point is advantageous and enables an easy casting. Their tenacity and alternating bending strength in a tempered and slowly. cooled condition is very remarkable. This is especially important with respect to the use in dentistry. Furthermore, these alloys have proved resistant against tarnishing as well as against all aggressive agents which may be present in the mouth. The alloys have a pale yellow or golden tinted color The following table describes the various compositions and qualities of the alloys:

Per cent Number Brineli oibends hardness, wire Au Pt Pd Ag Cu Zn Q? 55 '2 6 11.5 0.5 137 1B 5 2 N 11.5 0.5 106 18 55 l 0 2 22 11.5 0.5 1% 23 e0 5 5 l5 l4 1 109 18 67 4 3 14.5 ll 0.5 183 15 3 2 13.5 9.5 2 l 146 16 The alloys according to my invention may be used in dentistry for all parts which undergo a high stress such as, for instance, clasps, orthodontic appliances, root pins, tooth pins and the like. u 7

WhatI claim is: l

1. Dental alloy consisting of 55% gold, 2% platinum, 6% paladium, 11.5%00Plfil. 0.5% nine, 25% silver.

'2. Dental alloy consisting of 55% gold, 9% platinum, 2% palladium, 11.5% copper, 0.5% zinc, 22% silver.

3. A dental alloy consisting of,50% to 10% of gold, 2% to 9% of platinum, 1% to 6% of palladium, to 15% of copper, 0.1% to 2% of sins, and the remainder substantially all silver, the silveroonstituting 13.5%to 26% of the alloy.

Joan-moan.