RESTORING DECAYED TEETH

Dental Fillings

What's in a Filling?

Fillings, known clinically as amalgams, are synthetic materials that are used to restore a portion of a tooth damaged by decay or traumatic injury. There are different types of materials used to fill cavities, including gold and metal alloys.
Conventional amalgams are the silver-colored material many people have had placed in their teeth following treatment of a cavity. Many amalgams are actually a combination of various metal alloys, including copper, tin, silver and mercury. Mercury, a binding agent used in amalgams, has come under scrutiny lately by some health officials who claim it may cause long-term health problems.

Is Mercury in a Dental Filling Safe?

The American Dental Association cautions that emotional reports claiming amalgam is responsible for a variety of diseases are confusing and perhaps even alarming people to the point where they will not seek necessary dental care. Moreover, the ADA maintains that there has been no scientific evidence to show that amalgams are harmful because the miniscule amounts of mercury are so stable, they present no risks to humans. There have been rare cases of patients developing allergic reactions to amalgams.

Alternative Materials

There are alternatives to conventional substances used in amalgams, such as gold and metal alloys. These include materials made from porcelain and composite resins, which are colored to match natural tooth enamel. Unfortunately, few materials can match the strength and durability of conventional dental amalgam and may need more frequent replacement.

Common amalgam alternatives include:

  • Composite fillings - As stated, composite fillings are just what the name implies: a mixture of resins and fine particles designed to mimic the color of natural teeth. While not as strong as dental amalgam, composite fillings provide a pleasing aesthetic alternative. Sometimes composite resins need to be cemented or bonded to a tooth to allow for better adhesion.
  • Ionomers - Like composite resins, these materials are tooth-colored. Ionomers are made from a combination of various materials, including ground glass and acrylic resins. Ionomers are typically used for fillings near the gum line or tooth root, where biting pressure is not a factor. They are more fragile than dental amalgam, however. A small amount of fluoride is released by these compounds in order to facilitate strengthened enamel in the affected area.
  • Porcelain (ceramic) - These materials are usually a combination of porcelain, glass powder, and ceramic. Candidates for porcelain fillings are typically crowns, veneers, and onlays and inlays. Unlike ionomers, porcelain fillings are more durable, but can become fractured if exposed to prolonged biting pressures.

Crowns

Crowns are synthetic caps, usually made of a material like porcelain, placed on the top of a tooth.

Crowns are typically used to restore a tooth's function and appearance following a restorative procedure such as a root canal. When decay in a tooth has become so advanced that large portions of the tooth must be removed, crowns are often used to restore the tooth.

Crowns are also used to attach bridges, cover implants, prevent a cracked tooth from becoming worse, or an existing filling is in jeopardy of becoming loose or dislocated. Crowns also serve an aesthetic use, and are applied when a discolored or stained tooth needs to be restored to its natural appearance.

Procedures

A tooth must usually be reduced in size to accommodate a crown. A cast is made of the existing tooth and an impression is made. The impression is sent to a special lab, which manufactures a custom-designed crown. In some cases, a temporary crown is applied until the permanent crown is ready. Permanent crowns are cemented in place.
Crowns are sometimes confused with veneers, but they are quite different. Veneers are typically applied only to relatively small areas.

Caring For Your Crowns

With proper care, a good quality crown could last up to eight years or longer. It is very important to floss in the area of the crown to avoid excess plaque or collection of debris around the restoration.

Certain behaviors such as jaw clenching or bruxism (teeth grinding) significantly shorten the life of a crown. Moreover, eating brittle foods, ice or hard candy can compromise the adhesion of the crown, or even damage the crown.