Dental porcelain is a porcelain used by a dental technician to create biocompatible lifelike crowns and bridges for the dentist. The dentist will usually specify a shade of porcelain, corresponding to a set of bottles in the lab containing the porcelain powder. A common shade system used is the Vita guide. The powder corresponding to the dentine base is mixed with water, and then fired. Further layers are built up to mimic the natural translucency of the enamel of the tooth. Often the porcelain is fused to a semi-precious metal or precious metal such as gold, for extra strength. Many new systems use an aluminium oxide or zirconium core. Recent developments in dental CAD-CAM technology have required specialized porcelains formed into sintered blocks. Of late China has become the largest exporter of dental porcelain crowns and veneers to the U.S.A. There are concerns that this offshoring has led to the use of potentially unsafe lead in porcelain mixes and poor quality in finished porcelain work.
References
1. The National Association of Dental Laboratories http://www.nadl.org/ 2. Napier, Bennett. Letter to the Food and Drug Administration. "Dear Interagency Working Group on Import Safety," National Association of Dental Laboratories, September 10, 2007. http://www.nadl.org/pdfs/NADLLettertoFDA09102007.pdf
