Dental cement

Zinc phosphate cement is unused in the dental cement, the powder ( 10% zinc oxide and magnesium oxide ), and liquid ( orthophosphoric acid H3PO4) is stirred and after setting gives a crystalline zinc phosphate. In dental cement is used for fastening of crowns and as underfill.

Processing

For the dental processing a dry, clean glass plate and a steel spatula used. The processing temperature should be at room temperature ( 18-20 ° C).

For fixing a creamy consistency is required so that the crown or bridge can safely press the prepared teeth.

The mixing ratio of powder to liquid is dependent on the degree of fineness of grinding (grain size) of the powder and the water content of the acid. As a filling of cement should be used as putty, are so mixed with more powder. By tamping pressure can be the glue in small cavities press without air pockets. At dryness of the tooth must be ensured.

Properties

The adhesiveness of the tooth, to the metal, or of zirconia appreciate the dentists a high, despite the strong acid that can Zahnmark (or the tooth nerve ) during the setting phase damage. Zinc phosphate cement has the highest adhesion of all conventional luting cements.

Production

The red oxide is burned with flux to a solid brick, then ground to powder and oxidized in air ( roasted). Then the white powders (ferrous and manganese ) is added in order to reach a tooth shade metal oxides. The phosphoric acid is produced by calcium phosphate - containing minerals by sulfuric acid.