| 摘要 |
PURPOSE:To obtain the titled porcelain material resistant to yellowing phenomenon in the baking of the porcelain material on a porcelain-baking alloy composed mainly of a silver-containing palladium without considerably varying the physical properties of the porcelain material, by including a nitric acid compound into a baking porcelain for dental use. CONSTITUTION:Total or a part of a principal composition constituting a baking porcelain material for dental use, e.g. opaque, body, incisal or translucent is surface-treated with an aqueous solution of a nitric acid compound and dried. As an alternative method, said porcelain material is mixed with 0.2-2.0wt.% of an insoluble or scarcely soluble nitric acid compound to include the nitric acid compound into the porcelain material. An artificial dental crown having a color tone close to that of natural tooth can be produced with normal operation by the above process. The obtained artificial dental crown is resistant to the yellowing phenomenon (yellow discoloration) caused by silver and developed in the application and baking of the porcelain material on an inexpensive and easily solderable porcelain-baking alloy composed mainly of a silver-containing palladium without considerably varying the physical properties of the porcelain material. |
