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It’s not uncommon to feel fear or concern about getting a cavity filled.

Dental fillings can hurt in some instances. But most cause little to no discomfort during the procedure.

If you’re avoiding your dental checkup over concerns about pain, take a deep breath, and read on. We’ll outline the procedure for filling cavities and let you know what to realistically expect in terms of pain or discomfort.

If you have a cavity, your dentist will probably recommend filling it as quickly as possible.

Fillings are done to reduce the pain caused by cavities and to eliminate the possibility of serious infection. If left untreated, a cavity can reach the tooth’s pulp, causing intense pain.

Untreated cavities may also lead to the need for more invasive procedures, such as root canals or extractions.

When you get a cavity filled, your dentist removes the existing tooth decay and restores the tooth back to its natural shape. This makes your mouth healthier and more comfortable.

Your dentist will go over what you can expect and how extensive the procedure will be. This is determined by several factors. Here are some factors that can affect how much a filling hurts.

Size and depth of the cavity

Tooth decay is progressive. It starts out as white spots caused by small amounts of mineral loss in the tooth’s enamel. You can help stop tooth decay with proper dental hygiene or fluoride treatment.

But if the tooth’s enamel continues to weaken, you may have a cavity that requires a filling.

Small cavities that are caught early are the easiest and quickest to fix. If your cavity isn’t deep, the discomfort may be very minimal.

Just keep in mind that topical numbing gel doesn’t numb the tooth tissue — just the gums themselves so that the needle doesn’t cause pain or discomfort during the injection.

Some people have a phobia of needles and dread getting the injection more than any other part of the procedure. But others simply don’t like the numb sensation that lingers in the cheek and tongue after a cavity has been filled.

In some instances, topically applied numbing gel is enough to eliminate discomfort completely on the gums. Otherwise, your dentist can stop drilling and provide you with an injected anesthetic if you start to feel pain.

Deeper cavities require the removal of more decay and take longer to fill. Deep cavities are also situated closer to the tooth’s nerve endings. These types of cavities have the potential to cause more pain during the procedure.

Unless you have a very high pain tolerance, your dentist will likely recommend an injected anesthetic for deep cavities.

Location of the cavity

There are three types of cavities:

  • smooth surface cavities, which form on the sides of the mouth
  • pit and fissure cavities, which occur on the biting surfaces of molars
  • root cavities, which form near the tooth’s root

Small root cavities are often easily filled with anesthetic, and most root cavities are simple to treat if they’re caught early.

The root of the tooth contains a soft substance called cementum, so it can decay much more quickly. Exposed roots from receding gums can also decay quickly because the roots aren’t as strong as tooth enamel.

These types of cavities most commonly occur if you have periodontal (gum) disease. Periodontal disease causes the gums to recede, exposing the soft root surface of the tooth.

Number of cavities

If you have many cavities located in the same area of your mouth, your dentist may recommend filling them all at once.

This may cause additional discomfort due to longer procedure times. During the procedure, you’ll have to hold your mouth open for a prolonged period, which can cause jaw pain or gagging.

You may also require additional anesthesia for the longer procedure.

From start to finish, small fillings typically take 20 to 30 minutes to complete. Deeper or multiple cavities take longer to fill.

Here’s the typical procedure you can expect for a filling:

  1. Your dentist will dry the area, then they’ll administer a numbing gel.
  2. Once your gum is numb, they’ll inject a local anesthetic, such as lidocaine. If your dentist is experienced, this shouldn’t hurt. You may feel a brief pinch or sting while the anesthetic starts to numb the tooth, gum, and jaw area.
  3. Your dentist will then use a drill to remove the decay. Many people find the sound of the drill to be the worst part of the experience. Listening to music, audiobooks, or podcast with headphones can help mask the sound and reduce your stress.
  4. Once the decay has been removed, the hole will be sterilized and filled. Deep fillings that occur near the pulp may require that a liner be laid in first to protect the nerve.
  5. After the filling is in place, your dentist will check your bite to make sure it is even and then polish the tooth.

Several types of fillings can affect the length of the procedure and, in turn, how much the procedure hurts. The type of filling itself typically won’t affect your discomfort level.

Filling materials include:

  • Composite resin. This is one of the most commonly used fillers. It’s applied in layers that harden into the tooth using an ultraviolet light. These popular fillings are tooth-colored and look natural, made from acrylic resin and polished glass. Composite resin fillings aren’t as durable as some other filling materials and can take longer to place in the tooth, so they’re not always recommended for deep fillings. This type of filling also takes longer than amalgam fillings.
  • Amalgam. These fillings are silvery gray and made from multiple metals, including mercury, silver, copper, and tin. They’re less expensive than composite resin and may last longer. Concerns about mercury toxicity mean these fillings have become less popular. There’s no clinical evidence that amalgam fillings cause mercury poisoning, and the American Dental Association has stated that they’re safe. But there’s an ongoing debate about their safety: Some studies suggest that amalgam fillings contribute to mercury toxicity in the body over time.
  • Gold. These fillings are durable, expensive, and highly visible in the mouth. They require multiple visits to place. After the decay in your tooth is cleared out, an impression of the tooth is made with a mold. The filling is bonded into your tooth at a subsequent appointment.
  • Glass ionomer. This is a less durable filling material used for baby teeth and temporary fillings. Glass ionomer also releases fluoride that helps prevent additional tooth decay.

Talk to your dentist about the pros and cons of each, including durability, appearance, and safety.

Numbing agents are designed to eliminate or reduce pain and discomfort.

Your dentist may have a personal preference for a specific type. Talk to your dentist about the numbing agent they plan to use and why they feel it’s best for you.

Here are some of the common agents used for numbing:

  • Lidocaine. This is one of the most commonly used numbing gels. It’s also used as an injected anesthetic.
  • Benzocaine. This is also used as a numbing gel in adults and children over age 2.
  • Epinephrine. This ingredient, which is included in some injections, can help the anesthetic last longer and work more effectively.

Make sure to let your dentist know if you’re allergic to these substances or any other type of anesthetic.

If you’re nervous, you may also benefit from nitrous oxide (laughing gas) administered through a breathing mask over the nose. Nitrous oxide can reduce pain, but it’s primarily used to reduce fear and anxiety.

Your tooth may feel uncomfortable or sensitive for a day or two after the procedure.

Mild discomfort is normal and should be temporary. If you feel significant pain or notice swelling or pus, tell your dentist immediately. This might signal an infection or the need for additional treatment, such as a root canal.

Any sensitivity or mild pain may worsen if you eat or drink something very hot or very cold. Breathing in cold air may also make your tooth feel uncomfortable or tingly.

Your gums may also feel raw or tender for a few days, especially when brushing or flossing your teeth.

Cavity warning signs include:

  • white spots
  • dark spots
  • sensitivity or pain for no apparent reason, when biting down on the tooth, or when eating or drinking something hot, cold, or sweet
  • obvious holes or pits

Cavities come on slowly and don’t always cause pain.

If you notice any cavity warning signs, let your dentist know. The earlier you treat a cavity, the less likely it is to cause pain.

The best way to avoid cavity pain is by avoiding cavities. Here are some tips for preventing cavities:

Getting a cavity filled can be stressful, but it doesn’t always need to cause pain.

Small surface cavities can be filled in less than 30 minutes with little to no discomfort. Deeper cavities that are near a tooth’s pulp may be more painful and take longer to fill.

There are several options for the type of filling used and the type of anesthetic you might need. Talk to your dentist about the best choices for you.