Dental porcelain
Encyclopedia
Dental porcelain is a porcelain
used by a dental technician
to create biocompatible lifelike crowns
, bridges
, and veneers
for the patient. Evidence suggests they are effective (they are biocompatible, esthetic, insoluble and have hardness of 7 on the Mohs scale), although for three-unit molars porcelain fused to metal or in complete porcelain group only zirconia-based restorations are recommended.
The dentist will usually specify a shade or combination shades for different parts of the restoration, corresponding to a set of bottles in the lab containing the porcelain powder. A common shade system used is the Vita guide
(Vita Classical and Vita 3D Master). There are two types of porcelain restorations: porcelain fused to metal and complete porcelain. For porcelain fused to metal, the black color of metal is first masked with an opaque layer to make it a shade of white and then consequtive layers are built up. The powder corresponding to the desired shade of 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
. The porcelain is fused to a semi-precious metal or precious metal
such as gold
, for extra strength. Many systems use an aluminium oxide
or zirconium oxide or zirconia core instead of metal that makes complete porcelain restorations.
Recent developments in dental CAD-
CAM
technology have required specialized porcelains formed into sintered blocks. CAD/CAM restorations created with CEREC
technology appear to last well.
Dental porcelain is generally regarded as biologically inert. However, other toxicities may exist from depleted uranium and some of the other accessory materials, and the fillings may increase wear on opposing teeth.
Porcelain
Porcelain is a ceramic material made by heating raw materials, generally including clay in the form of kaolin, in a kiln to temperatures between and...
used by a dental technician
Dental technician
A dental technologist is a member of the dental team who, upon presciption from a dental clinician, constructs custom made restorative and dental appliances.There are four major disciplines within dental technology...
to create biocompatible lifelike crowns
Crown (dentistry)
A crown is a type of dental restoration which completely caps or encircles a tooth or dental implant. Crowns are often needed when a large cavity threatens the ongoing health of a tooth. They are typically bonded to the tooth using a dental cement. Crowns can be made from many materials, which...
, bridges
Bridge (dentistry)
A bridge, also known as a fixed partial denture, is a dental restoration used to replace a missing tooth by joining permanently to adjacent teeth or dental implants....
, and veneers
Veneer (dentistry)
In dentistry, a veneer is a thin layer of restorative material placed over a tooth surface, either to improve the aesthetics of a tooth, or to protect a damaged tooth surface. There are two main types of material used to fabricate a veneer, composite and dental porcelain...
for the patient. Evidence suggests they are effective (they are biocompatible, esthetic, insoluble and have hardness of 7 on the Mohs scale), although for three-unit molars porcelain fused to metal or in complete porcelain group only zirconia-based restorations are recommended.
The dentist will usually specify a shade or combination shades for different parts of the restoration, corresponding to a set of bottles in the lab containing the porcelain powder. A common shade system used is the Vita guide
VITA Zahnfabrik
VITA Zahnfabrik, also known as VITA Zahnfabrik H. Rauter GmbH & Co. KG, is a privately-owned independent German product development firm specializing in the design, production, and distribution of prosthetic dental devices including crowns, bridges, inlays, onlays, veneers, and fixed & removable...
(Vita Classical and Vita 3D Master). There are two types of porcelain restorations: porcelain fused to metal and complete porcelain. For porcelain fused to metal, the black color of metal is first masked with an opaque layer to make it a shade of white and then consequtive layers are built up. The powder corresponding to the desired shade of dentine base is mixed with water, and then fired. Further layers are built up to mimic the natural translucency of the enamel
Tooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
of the tooth
Tooth
Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...
. The porcelain is fused to a semi-precious metal or precious metal
Precious metal
A precious metal is a rare, naturally occurring metallic chemical element of high economic value.Chemically, the precious metals are less reactive than most elements, have high lustre, are softer or more ductile, and have higher melting points than other metals...
such as gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
, for extra strength. Many systems use an aluminium oxide
Aluminium oxide
Aluminium oxide is an amphoteric oxide with the chemical formula 23. It is commonly referred to as alumina, or corundum in its crystalline form, as well as many other names, reflecting its widespread occurrence in nature and industry...
or zirconium oxide or zirconia core instead of metal that makes complete porcelain restorations.
Recent developments in dental CAD-
Computer-aided design
Computer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...
CAM
Computer-aided manufacturing
Computer-aided manufacturing is the use of computer software to control machine tools and related machinery in the manufacturing of workpieces. This is not the only definition for CAM, but it is the most common; CAM may also refer to the use of a computer to assist in all operations of a...
technology have required specialized porcelains formed into sintered blocks. CAD/CAM restorations created with CEREC
CEREC
CEREC is a dental restoration product that allows a dental practitioner to produce an indirect ceramic dental restoration using a variety of computer assisted technologies, including 3D photography and CAD/CAM...
technology appear to last well.
Dental porcelain is generally regarded as biologically inert. However, other toxicities may exist from depleted uranium and some of the other accessory materials, and the fillings may increase wear on opposing teeth.