Dental fillings allow repairing lesions created by tooth decay. They can also give the tooth shape and function in case of worse damage or fracture.

There are many materials available to restore a decayed tooth. The choice of the ideal material is done according to the location, extent of the cavity, cost of repair, and the dentist’s recommendation.

Silver filings (amalgam)

Amalgam is a basic material that has been used to repair decayed teeth for over 100 years. It consists of a metallic alloy of silver, copper, tin, and mercury. Amalgam fillings can be unadvised by many dentists because of the content of mercury, a metal that can be toxic though it is present in a very small quantity in the alloy.


  • Durability (10 to 15 years).
  • Solidity (can resist the chewing forces).
  • Cost (they are the least expensive permanent restorations).


  • Poor aesthetics (the grey colour does not go well with the ivory colour of teeth).
  • Destruction of tooth matter (more space is needed in the cavity for a silver filling to hold well).
  • Discolouration (grey fillings can create a grayish tint on the teeth).
  • Cracks and fractures (amalgam fillings tend to expand and contract during temperature changes in the mouth, much more than the teeth or the other restorative materials do. This can fracture a restored tooth).
  • Allergic reactions (about 1% of the population is allergic to the mercury present in sliver fillings).

White fillings (composite)

Composites are materials in the shape of paste containing particles of quartz, silicate, and zirconium. They are very aesthetic and allow invisible restorations thanks to a multitude of shades. Initially used for the anterior teeth, the focus on more resistance to wear has allowed their use to restore posterior teeth as well.


  • Improved aesthetics (the colour of composite can be identical to the colour of a tooth).
  • Solid bond with the tooth (the composite is chemically bonded to the tooth, offering it a better support).
  • Versatile usage (in addition to being a restorative material, composite can also be used to repair fractured or worn down teeth).
  • Less destruction to tooth matter (during the repair less tooth structure must be removed for the restorations done in composite compared to those done in amalgam).


  • Less durable than silver fillings (seven to ten years).
  • Cost (composite restorations are slightly more expensive that the amalgam ones).

Gold fillings


  • Durability (they are the fillings that last the longest, at least 15 years if they are well maintained).
  • Solidity (they can resist top chewing forces).
  • Aesthetics (some people find gold more appealing than silver fillings).


  • Cost (a lot more expensive than composite or amalgam fillings).
  • Sometimes require many visits to the dentist.
  • Galvanic shock (it’s a rare occurrence, when a gold filling is placed next to an amalgam filling, the interaction between the metals and the saliva can cause an electric current and a sharp pain).
  • Aesthetics (some people don’t find that gold is appealing on their teeth).

Porcelain fillings

Porcelain inlays and onlays are more aesthetic than composite and resist more to stains, though they are more abrasive. This material last longer, at least 15 years, and cost as much as the gold fillings.

Glass ionomer fillings

Glass ionomer is a mixture of acrylic and a specific type of glass material. It can be used to restore teeth that are decayed under the gum line, or on primary teeth. Glass ionomer releases fluoride, which protects the tooth from further decay. However, this material is weaker than composite and is more susceptible to fracture. Its lifespan is less than five years.

Temporary fillings

Temporary fillings can be used under these circumstances:

  • For restorations that require more than one appointment, for example for gold or porcelain inlays.
  • Following a root canal.
  • In the case where the pulp is partially irritated and a permanent filling cannot be done right away.

As their name states, temporary restorations do not last a long time, from a few weeks to a few months. It is important not to stay with a temporary filling longer than three months to avoid infecting the tooth it is placed in or having other complications.

Steps in filling a tooth

  • The dentist must first proceed to the local anesthesia of the area where the tooth is located.
  • He then removes the cavity by drilling. He can also use air abrasion or laser if the cavity is very small.
  • Once there is no more cavity left and the tooth is clean of the bacterial debris, the dentist can place a glass ionomer base or another material, if the cavity is deep.
  • The restorative material is then placed in the cavity. If it is composite, a blue light is applied on the tooth for a few seconds to harden the filling, and this is done in many layers.
  • The filling is then adjusted according to the other teeth, and is finalized with a polishing.

Maintenance of fillings

To well maintain restorations one must follow the usual methods of oral hygiene:

  • Brushing the teeth after each meal.
  • Flossing at least once a day.
  • Visiting the dentist for routine exams. The dentist checks to make sure that the fillings are not cracked, and the seal with the teeth is not broken. By taking x-rays, the dentist can also make sure that there are no cavities newly formed underneath the fillings.

Cost of fillings

 The price depends in the size of the cavity and the material used to restore it. Restorations cost between 80$ and 1,300$, and this can vary depending on which part of the country we live in.


WebMD (
Wikipedia (
Ordre des Dentistes du Québec (

The information above should be used as a reference only. Any medical decision should not be taken before consulting a health care professional.

The masculine gender may have been more used in the article, but without prejudice, to make reading easier.

Category Treatments