| abstract |
1529267 Dental bonding composition JOHNSON & JOHNSON 11 June 1976 [13 June 1975] 24326/76 Heading C1M A composition for bonding dental porcelain to a non-precious metal alloy (i.e. based on Co or Ni) core comprises: (a) a bonding component comprising powdered aluminium and a powdered glass comprising, by weight, 47-74% SiO 2 , 1-16% Al 2 O 3 , 3-17% Na 2 O, 0À6-6% CaO and 0À4-4% MgO, the mixture being capable of bonding to the alloy core when heated to 1750-1850‹ F.; and (b) a carrier component comprising a liquid organosilicon compound which provides a reducing atmosphere when heated at 1200-1900‹ F. The glass may optionally include 0-12% K 2 O, 0-25% SnO 2 , 0-5% Li 2 O, 0-2% B 2 O 3 or 0-2% BaO. The weight ratio of Al to glass is preferably 0À67-2À3:1. The volume ratio of bonding component to liquid carrier is preferably 0À5-1À5 parts solid bonding component to 1 part of liquid carrier. The carrier may be a silicone oil or a liquid silane. In use, a non-precious metal alloy core of a dental restoration (of a Co or Ni alloy, preferably Ni-Cr) is cleaned and uniformly coated with the bonding composition; the coated core heated at 90-100 degree F. per minute from about 1200‹ F. to a temperature in the range 1800-1900‹ F.; the surfaces cleaned; and dental porcelain applied and fired. |