To treat tooth decay, dentists remove the decayed area of the tooth, then filling it in with a material referred to as a “filling.” There are many different materials widely used in dental fillings. Some of the most common include silver amalgam, gold, porcelain, and composite resin.
Silver amalgam fillings are made of mercury, silver, tin, zinc, and copper. The least expensive type of filling, today it is used mainly for fillings in back teeth that won’t be visible. Although an extremely durable material, silver amalgam needs a larger space, that may require healthy parts of the tooth to be removed. They can create gray discoloration in the surrounding teeth, and do not match the color of natural teeth.
Gold fillings are also very strong, typically lasting about 10 to 15 years before needing to get replaced. They do not corrode, unlike silver amalgam fillings, and some people prefer the appearance of gold fillings over silver ones. However, like silver amalgam fillings, they will be visibly noticeable in the mouth. Because of the cost of gold, these fillings cost more than almost every other type, sometimes six to ten times more expensive than amalgam fillings.
Composite resin fillings are made of a mix of plastic and glass closely matched to the color of the teeth. It is favored for fillings in front teeth or areas of the teeth which are extremely visible. The downside is that composite fillings cost up to twice as much as amalgam ones. These modern materials form strong chemical bonds with the tooth structure, but the material wears out in about five years, usually sooner than silver amalgam fillings. These materials may not require as much as the tooth structure to be removed in comparison with amalgam fillings.
Porcelain or ceramic fillings are more resistant against staining than composite fillings. It lasts up to fifteen years, but can cost as much as gold fillings. A similar type of dental filling, known as glass ionomer, consists of acrylic and glass. It is typically found in fillings required below the gum line, in addition to those in children. The material releases fluoride, believed to prevent further tooth decay. However, the weaker material only lasts about five years, and costs about as much as composite resin fillings. Although this is also a tooth-colored material, it typically does not match the teeth as well as other materials, such as composite or porcelain fillings.
Some dental fillings, particularly those made of gold or composite materials, require more than one office visit. In this case, a temporary filling will be placed in the space created when the decayed portion of the tooth is taken off. These are meant to last about a month prior to being substituted with a permanent filling. If you are interested in this or how much dental implants cost check out the previous link.