Patent ID: 6361721
Filing Date: 2002-03-26
Classification: A61C

Abstract:
A method of forming a high-alumina based porcelain tooth restoration comprising the steps of:preparing a negative impression of the tooth structure on which a tooth restoration is to be placed; forming a positive replication of said tooth structure by pouring a mixture of refractory powder and aqueous dispersion into said negative impression, said refractory powder comprising 10% to 30% calcined alumina, 25% to 50% silica, 15% to 35% magnesium oxide, and 10% to 25% powdered phosphate; allowing said positive replication to harden; removing said positive replication from said negative impression for degassing and cooling; coating said positive replication with a mixture of high alumina porcelain, containing 50% or more alumina, in an aqueous carrier to form a core layer of porcelain; baking said core layer; and applying to said core layer one or more layers of high alumina porcelain, containing 50% or more alumina, to the shape and size of said tooth restoration.