![]() Zinc phosphate cement has only a low flexural strength and it does not stick to the dentin (it is a cement and not an adhesive). glass ionomer cement), but they have not displaced the classic phosphate cement, which continues to hold its own in the dental market with its simple and safe processing and good price-performance ratio. In recent years, newer adhesive cements on a different chemical basis have been added (e.g. It has the longest track record of use in dentistry. ![]() It is the standard cement to measure against. It is prepared by mixing zinc oxide (ZnO) and magnesium oxide (MgO 2) powders with a liquid consisting principally of phosphoric acid, water, and buffers. Zinc phosphate cement is used for cementation of inlays, crowns, bridges, and orthodontic appliances and occasionally as a temporary restoration. ![]() It is commonly used for luting permanent metal and zirconium dioxide restorations and as a base for dental restorations. Zinc phosphate cement is the classic dental cement par excellence. The anhydrous form has not yet been found naturally. Both are known from oxidation zones of Zn ore beds and were formed through oxidation of sphalerite by the presence of phosphate-rich solutions. A somewhat similar mineral is natural hydrous zinc phosphate called tarbuttite, Zn 2(PO 4)(OH). Natural forms of zinc phosphate include minerals hopeite and parahopeite. One common agent is sodium pyrophosphate. Zinc phosphate coats better on a crystalline structure than bare metal, so a seeding agent is often used as a pre-treatment. It has largely displaced toxic materials based on lead or chromium, and by 2006 it had become the most commonly used corrosion inhibitor. This white powder is widely used as a corrosion resistant coating on metal surfaces either as part of an electroplating process or applied as a primer pigment (see also red lead). Zinc phosphate is an inorganic compound with the formula Zn 3( PO 4) 2.
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