Materials used

Main article: Dental restorative materials

These casting alloys are mostly used for making crowns, bridges and dentures. Titanium, usually commercially pure but sometimes a 90% alloy, is used as the anchor for dental implants as it is biocompatible and can integrate into bone.

Precious metallic alloys

• gold (high purity: 99.7%)

• gold alloys (with high gold content)

• gold-platina alloy

• silver-palladium alloy

Base metallic alloys

• cobalt-chrome alloy

• nickel-chrome alloy

Amalgam

• Silver amalgam (Consists of mercury (50%), silver (~22-32% ), tin (~14%), copper (~8%), and other trace metals)

Dental Amalgam is widely used because of the ease of fabricating the plastic material into rigid direct fillings, completed in single appointment, with acceptable strength, hardness, corrosion, and toxicity properties. It is more forgiving of preparation and technique than composite resins used for that purpose. It is now mainly used for posterior teeth. Although the mercury in cured amalgam is not available as free mercury, concern of its toxicity has existed since the invention of amalgam as a dental material. It is banned or restricted in Norway, Sweden and Finland. See Dental Amalgam Controversy.

Direct Gold

• Gold

Although rarely used, due to expense and specialized training requirements, gold foil can be used for direct dental restorations.

Tooth-colored

Dental composites are also called white fillings, used in direct fillings. Crowns and in-lays can be made in the laboratory from dental composites. These materials are similar to those used in direct fillings and are tooth-colored. Their strength and durability is not as high as porcelain or metal restorations and they are more prone to wear and discolouration.

Composite resin

Dental restoration using composite bonding^[3]

Dental composites, also called "white fillings", are a group of restorative materials used in dentistry. As with other composite materials, a dental composite typically consists of a resin-based matrix, such as a bisphenol A-glycidyl methacrylate (BISMA) resin like urethane dimethacrylate (UDMA), and an inorganic filler such as silica. Compositions vary widely, with proprietary mixes of resins forming the matrix, as well as engineered filler glasses and glass ceramics. The filler gives the composite wear resistance and translucency. A coupling agent such as silane is used to enhance the bond between these two components. An initiator package begins the polymerization reaction of the resins when external energy (light/heat, etc.) is applied.

After tooth preparation, a thin primer or bonding agent is used. Modern photo-polymerised composites are applied and cured in relatively thin layers as determined by their opacity.^[4] After some curing, the final surface will be shaped and polished.

Glass ionomer cement

A glass ionomer cement (GIC) is one of a class of materials commonly used in dentistry as filling materials and luting cements. These materials are based on the reaction of silicate glass powder and polyalkenoic acid. These tooth-coloured materials were introduced in 1972 for use as restorative materials for anterior teeth (particularly for eroded areas, Class III and V cavities).

As they bond chemically to dental hard tissues and release fluoride for a relatively long period, modern-day applications of GICs have expanded. The desirable properties of glass ionomer cements make them useful materials in the restoration of carious lesions in low-stress areas such as smooth-surface and small anterior proximal cavities in primary teeth. Results from clinical studies also support the use of conventional glass ionomer restorations in primary molars. They need not be put in layer by layer, like in composite fillings.