Fillings treat tooth decay, preventing further damage and tooth loss, as well as the possibility of pain and infection. A filling seals a hole, or cavity, in the tooth.

Having a cavity filled may cause some discomfort, but it should not cause pain. Anyone who experiences moderate or severe pain during or after the procedure should let their dentist know.

Below, we describe the materials in fillings and give details about the procedure, including how much it costs and when to contact the dentist afterward.

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There are a few types of fillings, including:

  • Amalgam fillings: Amalgam is a silver mixture of different metals, such as copper, tin, and mercury. These fillings may be more appropriate for the back molars. The material is durable and lasts a long time.
  • Composite fillings: The material is tooth-colored and consists of resin and glass.
  • Glass ionomer fillings: The material is also tooth-colored and made of powdered glass that bonds with the teeth. These fillings release fluoride to help prevent further tooth decay.
  • Gold fillings: The material is an alloy of copper, gold, and other metals. These are the most durable fillings, lasting for 20 or more years.

Resin-based composite and glass ionomer fillings are less durable than amalgam fillings. However, they are also less visible and do not contain heavy metals.

The Food and Drug Administration (FDA) notes that resin-based fillings also cost more and may shrink over time, leading to gaps between the tooth and its filling.

Are amalgam fillings safe?

Amalgam fillings may release low levels of mercury vapor, especially during a filling’s placement and removal. However, according to the FDA, the levels of mercury vapor released are low compared to the levels that cause signs of toxicity.

The FDA have concluded that exposure to mercury from fillings does not lead to adverse health effects in the general population, including people with multiple sclerosis, Parkinson’s disease, or Alzheimer’s disease.

Some may have a higher risk of experiencing negative effects of this vapor from amalgam fillings, however. This group includes people who:

  • are pregnant or planning to be
  • are chest- or breastfeeding
  • are younger than 6 years
  • have impaired kidney function
  • have a known allergy to amalgam fillings
  • have a preexisting neurological condition

Anyone concerned about the possible effects of amalgam fillings should discuss other options with their dentist.

In addition, the FDA does not recommend having an amalgam filling replaced or removed if it is in good condition and there is no sign of decay beneath it. This is because an unecessary removal can result in the loss of healthy tooth structure and unnecessary exposure to mercury vapors.

Having a filling is typically an in-office procedure. Children and anyone with severe dental anxiety may require sedation or even general anesthesia. If a person needs to prepare for the procedure in any way, their dentist will let them know beforehand.

What to expect during the procedure

The steps may vary, depending on the filling’s location and the materials used. But the general steps are:

  1. The dentist applies a numbing gel to the gums. Once this has taken effect, they inject a local anesthetic into the gum.
  2. Using a drill or another specialized tool, the dentist removes the decayed area of the tooth.
  3. They then fill the hole in the tooth.
  4. Lastly, they polish the filling and may adjust it so that the person’s bite feels normal.

If they use a composite filling material, the dentist also needs to “cure,” or harden, it with a special light.

The dentist may recommend not eating or drinking until the numbing medication wears off. This is to prevent a person from accidentally biting their tongue or the inside of their cheek.

Tooth pain after a filling

There may be some minor soreness or discomfort, and over-the-counter medication, such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) should help.

Other times, pain may occur because the teeth do not fit together well due to the filling. This issue is called malocclusion, and the dentist should correct it to prevent further discomfort.

Tooth sensitivity after a filling

A person may experience increased sensitivity to hot and cold after a filling. This can occur due to minor nerve irritation, gum irritation, or inflammation due to the drilling.

These sensations typically improve with time. If they get worse instead of better, call the dentist. In some cases, the sensitivity can result from the shrinking of a composite filling.

Learn more about tooth sensitivity after a filling here.

A person who experiences any of the following should let their dentist know:

  • worsening or severe pain
  • a fever
  • redness or warmth of the gums
  • severe tooth sensitivity
  • swelling

The cost of a filling depends on the location in the mouth, the material used, and the size of the cavity.

Medicare does not cover the cost of most dental procedures, including fillings.

States are required to provide dental care for children covered by Medicaid. Adults may also receive dental care under Medicaid, depending on their state’s policy.

To make the procedure more affordable, a person might also consider:

  • Dental clinics with reduced costs: Some may offer dental care for free, at a low cost, or at a sliding scale. NeedyMeds has a directory of more than 4,000 dental clinics in the United States that may be able to help.
  • Dental schools: Teaching facilities allow students to gain experience under the supervision of experienced dentists, and they provide care at a reduced cost. A person can find a school using this online tool.
  • Financing plans: Some dental practices offer payment plans to make their care more affordable. There are also dental financing organizations, such as Care Credit.

According to the American Dental Association (ADA), all fillings need to be replaced eventually. This is because the materials wear down due to eating, drinking, clenching, and grinding the teeth.

Worn or damaged fillings can be entry points for bacteria, leading to new tooth decay and possibly tooth loss. A person may not realize that their filling has worn down, which is one reason why it is important to visit the dentist regularly.

It is safe to have a cavity filled during pregnancy, according to the ADA, which also notes that pregnant people have an increased risk of gingivitis and tooth decay.

Overall, it is important to keep routine dentist appointments during pregnancy.

A dental filling treats tooth decay. Having a filling can prevent further damage, reduce the risks of pain and infection, and help maintain overall dental health.

There are different types of fillings, including amalgam, gold, composite, and glass ionomer. A person should discuss the options with their dentist.

After having a filling, a person may experience mild sensitivity or discomfort. Anyone who experiences more significant pain or sensitivity, or signs of an infection, such as a fever or swelling, should contact their dentist.