You can’t fix a cavity at home once it’s formed. A cavity is a permanent hole in your tooth caused by decay, and it requires professional dental treatment to repair. The good news: most cavities are straightforward to treat, the procedure is quick, and you have several options depending on how far the decay has progressed.
How Cavities Form and Why They Can’t Heal on Their Own
Tooth decay happens in stages, and understanding where you are in that process determines what kind of fix you need. It starts with demineralization, where acids from bacteria dissolve minerals from your enamel. At this early stage, you might notice white spots on your teeth. This is the only point where decay can actually be reversed, through fluoride treatments and better oral hygiene, because the tooth structure hasn’t broken down yet.
Once enamel breaks down enough to form an actual hole, that’s a cavity, and no amount of brushing or rinsing will close it. Left alone, decay moves through two more dangerous stages. It reaches the dentin, the softer tissue beneath enamel, where it spreads faster because dentin is less resistant to acid. This is when you start feeling sensitivity to hot, cold, or sweet foods. Eventually, decay can reach the pulp, the innermost part of the tooth containing nerves and blood vessels. At that point, you’re looking at serious pain and a more involved procedure.
Fillings: The Most Common Fix
Most cavities are treated with a dental filling, and the procedure is simpler than many people expect. Your dentist numbs the area with local anesthesia, removes the decayed tissue with a small drill or other instrument, fills the hole with a filling material, then shapes and polishes it so your bite feels normal. For tooth-colored composite fillings, a special curing light hardens the material in seconds. The whole process typically takes 20 to 60 minutes depending on the size and location of the cavity.
Getting a filling shouldn’t hurt. The local anesthesia numbs the tooth and surrounding tissue. If you feel discomfort during the procedure, your dentist can add more numbing medication. If dental anxiety is a concern, many offices offer sedation options ranging from nitrous oxide to oral sedatives.
Filling Materials
The two most common filling materials are composite resin and amalgam. Composite resin is tooth-colored and blends in with your natural teeth, making it the popular choice for visible areas. It costs roughly $100 to $400 per tooth, with an average around $190 to $225. Amalgam (silver-colored) fillings are slightly cheaper, averaging about $160, and range from $100 to $350.
The tradeoff is durability. Amalgam fillings last approximately 10 to 15 years, while composite fillings last about 5 to 10 years. Gold or ceramic inlays can last 15 years or more but cost significantly more. Your dentist will recommend a material based on where the cavity is, how large it is, and your budget.
When a Filling Isn’t Enough
If decay has destroyed a large portion of the tooth, a standard filling won’t provide enough structural support. In these cases, your dentist may recommend a crown, which is a cap that covers the entire visible portion of the tooth. Crowns are also common when a tooth has already been restored multiple times, since each round of treatment removes a bit more natural tooth structure.
When decay reaches the pulp and infects the nerve, the treatment is a root canal. Your dentist or an endodontist removes the infected pulp tissue, cleans and seals the inside of the tooth, then typically places a crown on top. Despite their reputation, root canals use the same local anesthesia as fillings and most people compare the experience to getting a large filling. After a root canal, molars and premolars that have lost a lot of structure almost always need a crown. Teeth that retain most of their structure and aren’t at high risk for fracture may be suitable for a filling-only restoration.
Silver Diamine Fluoride: A Non-Drill Option
For people who can’t undergo traditional treatment, whether due to age, anxiety, medical conditions, or access to care, silver diamine fluoride (SDF) offers an alternative. It’s a liquid painted directly onto the cavity that kills bacteria and hardens the decayed surface, stopping the cavity from getting worse. According to the American Dental Association, SDF prevented root cavities with success rates 72% higher than placebo in a large review of studies.
The major downside is cosmetic. SDF permanently stains the treated area black. Healthy enamel isn’t affected, but any decayed or demineralized tooth surface turns noticeably dark. It also has a metallic taste and can irritate the gums if it contacts soft tissue during application. SDF doesn’t restore the tooth’s shape or fill the hole. It’s a way to stop decay in its tracks, not a replacement for a filling.
What Recovery Feels Like
After a filling, expect the most noticeable sensitivity in the first two days. By days three to five, most people feel significantly better. Shallow to moderate fillings typically heal completely within two weeks. Deeper fillings placed close to the nerve may take three to four weeks for sensitivity to fully resolve.
One thing to watch for is a “high bite,” where the filling sits slightly too tall. Even a microscopic elevation creates repeated stress every time your teeth come together, causing progressively worsening pain when you chew. This is easy to fix with a quick adjustment at your dentist’s office.
A more concerning sign is spontaneous throbbing pain that happens without any trigger, especially if your tooth starts hurting intensely while you’re sitting still doing nothing. This suggests the nerve inside the tooth is inflamed. Similarly, if pain lingers for several minutes after drinking something cold or eating something sweet, that extended response points to compromised pulp tissue. Both of these warrant a call to your dentist.
Preventing the Next Cavity
Once you’ve had one cavity filled, you’re statistically more likely to develop another. The bacteria responsible for decay don’t disappear after treatment. Fluoride toothpaste remains the single most effective daily tool for strengthening enamel and resisting acid attacks.
Xylitol, a sugar substitute found in certain gums and mints, actively reduces cavity-causing bacteria in your mouth. The California Dental Association recommends using xylitol gum or mints three to five times daily for a total intake of about 5 grams. Look for products where xylitol is listed as the first ingredient.
Beyond that, the basics matter more than any single product. Brushing twice a day, flossing daily, and limiting how often you snack on sugary or acidic foods all reduce the acid exposure that starts the decay process. Cavities form over months, not days, so consistent habits are what keep small spots of demineralization from becoming holes that need a drill to fix.