You are at the dentist for your biannual cleaning when you get the news no one wants to hear: you have a cavity. There are many options for filling the cavity, but which to choose? A composite filling is becoming the standard for cavity treatment, and here’s why.

What is a composite filling?

A composite filling is made from tooth-colored resin material mixed with powdered glass. This type of composite resin has been used to fill cavities since the 1960s. Composite fillings may be a:

  • Direct filling: Placed directly into the cavity
  • Indirect filling: Shaped to fit around the tooth

Direct or indirect, the type of filling is determined by the size of the restoration. Larger areas of decay may require more reconstruction. Composite fillings used as indirect fillings are often the best choice for patients who want a more natural-looking filling.

A natural-appearance is one of the major pros of a composite filling. In addition to looking more natural, composite resin fillings are structurally supportive. Less tooth material needs to be removed for a composite filling, and the chemicals in the composite resin actually bond to your natural teeth.

This means less chance of cracks between the tooth and the filling itself, minimizing the chance of recurrent caries.

Other types of fillings

Before composite resin fillings, patients had two other main filling options.

Amalgam (Silver)

This may be the most common type of filling. As the name suggests, amalgam fillings are a mix of different metals.

Amalgam fillings are strong and durable, but they are also more expensive than a compound filling. Additionally, their silver color tends to darken over time, making them less cosmetically attractive.


In addition to being the most durable filling material, gold has the distinction of being the most expensive. Gold fillings are most often used as indirect fillings. For this reason, patients who choose gold fillings may opt only to use them for teeth that are less visible.

Two other types of filling material – porcelain and glass ionomer – are less frequently used, both due to their cost and their fragility.

How do composite fillings work?

Because they can be closely matched to your natural teeth, composite resin fillings can be used to not only fill cavities but also to fix minor cosmetic imperfections in teeth. These include:

This versatile material has many applications and is becoming a popular choice for structural and cosmetic dental work.

Is a composite filling safe?

If the idea of powdered glass in your mouth makes you nervous, don’t be.

The U.S. Food and Drug Administration approved composite resin fillings as a safe and effective treatment for cavity and other cosmetic dental procedures.

A composite resin filling is often used to replace mercury (amalgam) fillings that fall out. They are perfectly safe to treat cavity and perform other minor cosmetic dental restorations.

What can I expect during a composite filling procedure?

The composite filling procedure depends on which type of filling you are receiving: direct or indirect.

Direct composite filling

This procedure generally takes about 30 to 45 minutes, depending on the extent of the decay and whether or not you need anesthesia.

To begin, your dentist will apply anesthesia as needed and remove the decay. They will then prepare the composite filling material and completely dry the tooth’s surface to ensure a good bond.

Your doctor then packs the composite resin directly into your prepared tooth and gives it a few moments to bond. Your dentist will use a special light to help the material harden further. Finally, the dentist shapes and polishes the tooth before checking your bite. They may ask if you feel any rough edges and file those if needed.

Most direct composite resin fillings can be placed in just one office visit.

Indirect composite filling

Indirect composite fillings generally take two office visits.

As with a direct filling, your dentist will begin with anesthesia and cavity removal. They will then take an impression of your tooth so that one of two types of indirect filling – an inlay or an onlay – can be created in a lab. You will receive a temporary composite resin filling while your indirect filling is created.

When your indirect composite filling arrives, your dentist will check the fit and secure it in place with dental cement.

Regardless of the type of composite filling, you may find your teeth are a bit more sensitive to hot and cold for a few weeks after the procedure. Using a sensitive tooth toothpaste can help. Other than that, you should feel no pain in the days following your filling.

How long do composite fillings last?

The composite filling lifespan can run from five to 15 years. This range is so wide because there are a number of factors that affect how long they last. These include:

  • Size of the filling: Composite resin fillings are most effective for smaller cavities
  • Placement: Chewing surfaces of the teeth suffer from much more force, which can decrease the composite filling lifespan
  • Lack of dental hygiene: As with all types of filling material, poor dental hygiene can dramatically shorten the lifespan of a composite filling

How to take care of composite filling

To keep composite fillings strong and in place, there are four simple steps you can take:

  1. Visit the dentist twice yearly for cleanings and checkups
  2. Brush twice daily, floss at least once, and rinse with a non-alcoholic mouthwash once a day
  3. Avoid crunching down on hard foods like pretzels and hard candy
  4. Visit your dentist if you notice that your filling is cracked, loose, or otherwise feels different

Your composite filling will last much longer with a little TLC and this basic dental care.

Composite filling cost can vary depending on where you are located, the dentist you choose, and the locations of the filling itself. Many insurance companies will also pay up to the cost of an amalgam filling, making composite resin fillings more affordable. If you’re unsure about your coverage, talk to your insurance provider.

We are your full-service Phoenix area family dentist at AZ Dentist. Get in touch today to schedule a full exam!

Schedule Your Appointment