There are a variety of materials that are used for filling teeth today. The decision as to which material to use is usually guided by a number of factors, including the size of the hole that is being filled, the location of the tooth, the cost to the patient and aesthetic preferences. Silver amalgam, cast gold, composite resin, ceramics, and glass ionomers can all be used for fillings.
Silver amalgam has been used for filling teeth longer than any other material. It is a mixture of metals including silver, tin, mercury, copper and zinc. Until not so long ago, this was the only material available for fillings, but today it is used mainly in the back teeth where the metal color can not easily be seen. Even with the availability of many new materials, this compound continues to be used because of its ability to endure intense forces generated by chewing motions, and because of its affordability to patients.
Cast gold is also used for fillings. It has the same ability to withstand chewing and lasts just as long as silver amalgam. Some patients find the color of gold more appealing than silver, although it is more expensive.
Another material that is used for filling teeth is known as composite resin. This material consists of a mixture of an organic compound and glass particles derived from elements such as quartz and lithium aluminum silicate. The organic makeup enables the fillings to chemically bond to the remaining portion of the tooth, which adds strength to the structure. Since this filling material can be produced in varying shades of white to match the patients natural teeth, it is usually used to fill or reconstruct teeth in the front of the mouth that are more visible. Although this material is quite durable, it generally does not last as long as a silver amalgam filling and costs more.
Ceramics can also be used for fillings when an extremely natural tooth appearance is needed. These fillings are usually made of porcelain, which does not stain as readily as other tooth colored materials. On the downside, however, it has a rougher surface and is much more expensive than other composite materials. Although the porcelain lasts as long or longer than other composite resins, it has a tendency to be susceptible to chipping and breakage.
In addition to the above materials, a substance known as glass ionomer can also be used. This material consists of a combination of acrylic and a certain type of glass. It is commonly used for fillings in children's teeth. An important aspect of filling teeth with glass ionomers is that the material releases fluoride into the tooth to help prevent more decay. Drawbacks to this material are that it is not as strong as composite resin; it is less durable and can fracture. Although its initial costs are comparable to composite resin fillings, glass ionomer fillings do not last as long.