Additive composition for making dental materials
AssigneeThe United States of America as represented by the Department of Health, Education and Welfare
InventorCurtis P. Mabie
Life of this patent
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Abstract
Addition of ammonium stabilized colloidal silica, borax and boric acid to the distilled water in which dental porcelain is fired greatly increases the firing range by reducing "balling" or edge rounding, and flow deformation. Greatly increased machinability and indefinitely prolonged green-biscuit strength is also obtained by the use of the present additive without deleterious effects on the porcelain.
Claims2
Additive composition for use in dental porcelain products, comprising an aqueous solution including 1 to 8% of a colloidal silica and/or alumina sol and 0.5 to 1.25% of a water soluble flux for aiding in maturation and development of bond strength when used in dental porcelain products, which flux is compatible with the colloid used, said flux comprising a combination of boric acid and borax with a weight ratio of boric acid to borax of 0.1-1.5:1.
Dependencies are inferred from the claim text.