If you get a cavity in one of your teeth, your dentist is probably going to recommend getting a filling as soon as possible to ward off infection and shore up your tooth.

There are several different kinds of materials used for dental restorations, but the most common types of fillings are amalgam and composite (or composite resin).

Amalgam was the most widely used material for many years, but composite fillings have been growing in popularity for their combination of looks and durability. In this article, we’ll explain what composite fillings are, how long they last, and how safe they are.

Composite fillings have a more natural appearance than other options. The composite material can be customized to match the shade of your tooth, so they’re almost unnoticeable to anyone who glances at your mouth.

But what is that tooth-colored material? It’s a mixture of plastic (acrylic) resin that’s reinforced with a powdered glass filler. It’s useful for a variety of dental restorations, including

Dentists also sometimes use this composite resin material to repair or restore parts of broken or chipped teeth.

Your dentist may offer several choices when it comes to materials for a filling. Here’s how they stack up against each other.

Amalgam (silver)

These were the most commonly used type of filling for many years, and they’re still widely used in many parts of the world. They’re very durable and may last about 15 years or more.

Plus, the process is relatively simple since the dentist doesn’t have to worry about keeping the tooth clean and dry during the installation. They also cost less than other materials used in dental restorations.

But their popularity has waned in recent years. Since they’re not tooth-colored, they don’t look as natural.

Amalgam fillings also contain mercury, although the American Dental Association has deemed it a “viable and safe” option. A 2014 review of research noted that there’s insufficient evidence of any adverse events, although more research is needed on that front.

Gold

Gold fillings are more expensive than other types of fillings, but you do get what you pay for. They’re durable and can last 20 years or more. They typically require a two-visit process.

Ceramic

Ceramic fillings, which incorporate a type of porcelain, also tend to be pretty long-lasting, with an expected lifespan of as much as 15 years. But they’re not very commonly used, tend to be very expensive, and also require a two-visit process.

Glass ionomer

Glass ionomer fillings are made with a glass filler. Like composite resin fillings, glass ionomer fillings are tooth-colored and can be shaded to blend in with a person’s teeth. This means they’ll be less obtrusive than an amalgam filling.

They also release fluoride, which lessens the chance of a new cavity forming. But they’re also less durable than amalgam fillings and will not last as many years. Also, they may not be appropriate for large cavities.

Composite fillings, while durable, tend to have a shorter life span. One 2010 study predicted a lifespan of about 7 years for a composite resin filling.

Another 2010 review of multiple research studies suggests that you might get 10 years out of a composite filling if the fillings are well taken care of. But that study also notes that someone at very high risk for cavities may not get that many years out of a composite filling.

Some people have expressed concern over the safety of composite fillings, most notably over the possibility that the composite material might be cytotoxic, or harmful to cells in the tissues surrounding the tooth with the filling.

A 2012 study suggested that the concern may be more relevant to fillings with a darker color as a result of the light curing unit used to harden the filling.

Another study noted that much more research is needed on possible risks. The researchers recommended that dentists closely follow the manufacturer’s instructions about things like light intensity and light curing time, and to avoid letting the material touch the skin directly.

If you have concerns, talk with your dentist. They can go over the details of the specific type of materials available for your dental work.

Unless there are special circumstances, the process of getting a composite filling is fairly straightforward and can be finished in one visit.

  1. Your dentist may start by selecting the shade of composite to use in your filling at the beginning of your visit. Some research says it’s better to make this match early on, before your teeth and mouth dry out, which may affect the brightness of your teeth.
  2. You’ll get a shot of a numbing agent for local anesthesia to numb the tooth and surrounding area.
  3. The dentist will drill into your tooth enamel and remove the decayed part of your tooth.
  4. They’ll clean and dry the area and prepare the tooth. With more extensive damage, this might entail some tooth shaving.
  5. The dentist will etch and bond the tooth.
  6. They’ll begin layering the composite material into the hole in your tooth. The dentist will use a light to cure the composite filling and get it to set. Since the composite is applied in layers, the light will be used to cure each layer before going on to the next.
  7. The dentist will shape and contour the tooth, then polish it.
  8. Your dentist will check your bite to make sure you’re comfortable with the restoration.

Afterward, you might have a little short-lived sensitivity to heat and cold, but it should go away pretty quickly.

If installed properly, a composite filling won’t look too different from your actual tooth.

A composite filling may satisfy your desire for a filling that looks good and doesn’t detract from your smile. Additionally, it may prevent further tooth decay from weakening your tooth.

A dentist can talk with you about your options to make sure this is the best one for you. That way, you’ll know what to expect from your filling.