Dental Fillings: Materials, Types, Sensitivity & Allergy Issues (2024)

What are dental fillings?

Dental fillings are single or combinations of metals, plastics, glass or other materials used to repair or restore teeth. One of the most popular uses of fillings is to “fill” an area of tooth that your dentist has removed due to decay – “a cavity.” Fillings are also used to repair cracked or broken teeth and teeth that have been worn down from misuse (such as from nail-biting or tooth grinding).

What materials are dental fillings made from?

Dental filling materials include:

• Gold.
• Porcelain.
• Silver amalgam (contains mercury mixed with silver, tin, zinc, and copper).
• Tooth-colored, plastic and glass materials called composite resin fillings.

The location and extent of the decay, cost of filling material, your insurance coverage and your dentist’s recommendation help determine the type of filling that will best address your needs.

Are there advantages and disadvantages to various filling materials?

Yes. Advantages and disadvantages of the various dental filling materials are as follows:

Advantages:

• Gold: Lasts at least 10 to 15 years, some say gold presents a pleasing appearance.
• Silver fillings (amalgams): Lasts at least 10 to 15 years, less expensive than composite fillings.
• Tooth-colored composite fillings: Shade can be closely matched to color of existing teeth, bonds to existing tooth providing additional support, commonly used for repairs other than cavity filling, sometimes less tooth needs to be removed compared with amalgams.
• Ceramics/porcelain: Lasts more than 15 years, more resistant to staining than composite resin material.
• Glass ionomer (acrylic and a specific type of glass material): Mostly used for fillings below the gum line, releases fluoride that can help protect from further tooth decay.

Disadvantages:

• Gold: More expensive than other materials, may require more than one office visit to place.
• Silver: May require more tooth to be removed to make space large enough to hold filling, creates grayish hue to the surrounding tooth structure, may have higher risk of tooth cracks and fractures due to wider degree of expansion and contraction, allergic potential in some people.
• Tooth-colored composite fillings: Lasts at least five years (less than the 10 to 15 years of other materials), may chip off tooth depending on location, can cost up to twice as much as amalgams, can take more time to place and/or additional visits.
• Ceramics: Can cost as much as gold.
• Glass ionomer: Is weaker than composite resin, more likely to wear and prone to fracture, lasts five years or less, costs comparable to composite fillings.

What are indirect fillings?

Indirect fillings are similar to composite or tooth-colored fillings except that they are made in a dental laboratory and require two visits before being placed. Indirect fillings are considered when you don’t have enough tooth structure remains to support a filling, but your tooth is not so severely damaged that it needs a crown.

During the first visit, decay or an old filling is removed. An impression is taken to record the shape of the tooth being repaired and the teeth around it. The impression is sent to a dental laboratory that makes the indirect filling. A temporary filling (described below) is placed to protect the tooth while your restoration is being made. During the second visit, the temporary filling is removed, and the dentist checks the fit of the indirect restoration. If the fit is acceptable, it will be permanently cemented into place.

There are two types of indirect fillings – inlays and onlays.

• Inlays are similar to fillings but the entire work lies within the cusps (bumps) on the chewing surface of the tooth.
• Onlays are more extensive than inlays, covering one or more cusps. Onlays are sometimes called partial crowns.

Inlays and onlays are more durable and last much longer than traditional fillings – up to 30 years. They can be made of tooth-colored composite resin, porcelain or gold. Inlays and onlays weaken the tooth structure, but do so to a much lower extent than traditional fillings.

Another type of inlay and onlay – direct inlays and onlays – follow the same processes and procedures as the indirect, the difference is that direct inlays and onlays are made in the dental office and can be placed in one visit. The type of inlay or onlay used depends on how much sound tooth structure remains and cosmetic concerns.

What's a temporary filling and why would I need one?

You might need a temporary fillings:

• If more than one appointment is needed for your filling. For example, before placement of gold fillings and for indirect fillings that use composite materials.
• Following a root canal.
• To allow your tooth’s nerve to “settle down” if the pulp became irritated.
• If emergency dental treatment is needed (such as to address a toothache).

Temporary fillings are just that; they are not meant to last. They usually fall out, fracture, or wear out within one month. Be sure to keep your appointment to have your temporary filling replaced with a permanent one. If you don’t, your tooth could become infected or you could have other complications.