Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C7/00—Alloys based on mercury
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
  • A61K6/84—Preparations for artificial teeth, for filling teeth or for capping teeth comprising metals or alloys
  • A61K6/847—Amalgams

Definitions

• the present invention relates to a process of preparing amalgam for dental purposes.
• a further object of the present invention is the shaped unit of the aforesaid metal powder, said shaped unit preferably consisting of a compact shaped, for instance, in tablet, pill or bar form.
• the granular size of a commercial metal powder whether composed of filings, shavings, or millings, used in the preparation of a dental amalgam, shall be as uniform as possible. For instance,
• amalgams prepared from these metal powders show quite different properties, especially as to their initial and final hardness and expansion, and that these properties are due to the mode of preparation of the amalgam from the metal powder.
• these different properties are substantially caused by the way of grinding the metal powder with mercury in the mortar and, furthermore, that during such grinding the extent of comminution of the metal particles before amalgamation by the mercury plays a decisive part.
• This observation led to investigations on the influence of the granular size of the metal particles and resulted in finding a handy form of a metal powder that yields a uniform amalgam exhibiting inter alia a short setting time, high ultimate hardness and a controlled expansion.
• the metal powder must be prepared from an alloy with a definite silver content, secondly the metal powder must be present during amalgamation in different particle sizes, and thirdly a fixed weight of the metal powder must be brought into a handy shape, preferably into a compact shaped, for instance, in tablet, pill or bar form, and used in this shape as a starting material for the preparation of the dental amalgam.
• the metal alloy used for the preparation of dental amalgam may be obtained by milling an appropriate metal alloy.
• the silver content of this alloy substantially consisting of silver and tin shall amount to 60-75%,
• This shaped unit may, for instance, consist of a compact shaped in tablet form which tablet can be disintegrated by slight pressure into a granular mixture, two thirds of which consist of coarser particles of which the largest ones pass a sieve having 1600 meshes per square centimeter, whilst about a third of the total weight is present in form of particles whose individual weight corresponds to about of that of the coarser particles.
• the size of the metal powder tablets, pills etc. will preferably be such, that the amalgam prepared from it suffices for one average tooth filling.
• the mixing of the metal powder with mercury according to the invention must not result in a substantial change of the particle size. For this reason, after powdering the tablet etc., the blending in the mortar is to be accomplished by mere stirring only. lt is still more advisable to blend the metal powder and mercury in the rubber finger stall.
• the advantages attained by employing the tablets, pills etc. in accordance with the present invention may be summarized as follows:
• the amalgam prepared from this shaped unit shows a short setting time due to the finer particles, a high final hardness due to the coarser ones, and a controlled expansion due to the measured proportion of the finer and coarser particles.
• a constant mixing proportion of the metal powder and mercury is achieved by using the tablets, pills etc. together with a dispensing device for the mercury.
• the tablets thus prepared are used as starting material for the preparation of amalgam with the admixture of appropriate amounts of mercury.
• the proportion of the filings to the mercury amounts to 121.
• a process of preparing dental amalgam which comprises forming a compact consisting of a dental alloy powder, two-thirds of the total weight of which consists of coarser particles passing a sieve having 1600 meshes per square centimeter and one-third of the total Weight of which consists of particles whose individual Weight corresponds to about one-fiftieth of that of the coarser particles, said dental alloy containing 60-70% by Weight of silver, at least 25% of tin, not more than 6% of copper and not more than 2% of zinc, powdering said compact under a slight pressure corresponding to one which is exerted when preparing amalgam in the rubber fingerstall, whereby a dental alloy powder of different granular sizes is produced, and mixing said powder with a measured quantity of mercury.

Landscapes

• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Plastic & Reconstructive Surgery (AREA)
• Life Sciences & Earth Sciences (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Engineering & Computer Science (AREA)
• Epidemiology (AREA)
• Metallurgy (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Dental Preparations (AREA)
• Powder Metallurgy (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=6091304

Family Applications (1)

Country Status (4)

Cited By (2)

Citations (5)

• 1951
  • 1951-03-21 CH CH299529D patent/CH299529A/de unknown
  • 1951-05-15 US US226532A patent/US2698231A/en not_active Expired - Lifetime
  • 1951-05-17 FR FR1037182D patent/FR1037182A/fr not_active Expired
  • 1951-05-17 GB GB11568/51A patent/GB688741A/en not_active Expired

Patent Citations (5)

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