If you have a cavity, the single most important thing to do is schedule a dental appointment. Most cavities are painless in their early stages, which makes them easy to ignore, but decay only moves in one direction: deeper into the tooth. The good news is that treatment is straightforward, usually takes under an hour, and the earliest signs of decay can sometimes be reversed without a filling at all.
Early Decay Can Sometimes Be Reversed
Tooth decay doesn’t start as a hole. It begins with demineralization, a process where acids from bacteria strip calcium and phosphate from your enamel. At this stage, the surface of the tooth is still intact. You might see a white or chalky spot, but there’s no actual cavity yet.
This is the one window where you can reverse the damage. Fluoride plays a central role: when it’s present during remineralization, it helps rebuild the enamel into a structure that’s actually stronger and more acid-resistant than the original. Your dentist may apply a concentrated fluoride varnish every three to six months, place a dental sealant over vulnerable grooves on your molars, or recommend a high-fluoride prescription toothpaste for daily use. These interventions work on non-cavitated lesions, meaning the enamel surface hasn’t broken through yet.
Once a cavity forms (a physical hole in the enamel), remineralization alone won’t fix it. Enamel can’t regenerate itself the way skin or bone can. At that point, you need a dentist to remove the damaged material and restore the tooth.
What Happens During a Filling
Getting a filling is one of the most routine procedures in dentistry. Your dentist numbs the area with a local anesthetic injected into the gum tissue. You may feel a brief sting from the injection, but after that, the area goes numb and the rest is painless. The dentist uses a drill or laser to remove the decayed portion of the tooth, shapes the space, and may etch the surface with an acid gel so the filling material bonds properly. The filling is applied, hardened (sometimes with a curing light), and polished smooth so it doesn’t catch your tongue or cheek. The whole process typically takes under an hour per tooth.
If you have several cavities, your dentist may spread the work over multiple visits rather than doing everything at once.
Choosing a Filling Material
The two most common options are amalgam (silver-colored) and composite resin (tooth-colored), and they differ in durability, appearance, and cost.
- Amalgam fillings are made from a mix of mercury, silver, tin, and copper. They’re exceptionally strong and typically last 10 to 15 years or more. They’re also cheaper. The downside is their metallic appearance, which makes them noticeable on visible teeth. Although amalgam contains mercury, extensive research has found it safe for most patients.
- Composite fillings are a blend of plastic resin and fine glass particles. They match the natural color of your tooth, making them nearly invisible. They generally last 5 to 7 years, though newer materials are closing the durability gap. They cost more than amalgam, and some people have sensitivities to the resin components.
For front teeth, most people choose composite for cosmetic reasons. For molars that take heavy chewing force, amalgam offers longer-lasting durability, though composite is still a perfectly valid choice.
What Fillings Cost
Prices vary by the size of the cavity, measured by how many surfaces of the tooth are affected.
- 1-surface filling: $50 to $100 for amalgam, $90 to $150 for composite
- 2-surface filling: $75 to $150 for amalgam, $130 to $220 for composite
- 3+ surface filling: $120 to $250 for amalgam, $180 to $300 for composite
Most dental insurance plans cover fillings, though they may only reimburse at the amalgam rate if you choose composite for a back tooth. Without insurance, expect to pay somewhere in these ranges depending on your location and provider.
When a Filling Isn’t Enough
Decay that reaches the dentin, the softer layer beneath the enamel, spreads faster. If a large portion of the tooth is compromised, a standard filling may not provide enough structural support, and your dentist will recommend a crown instead. A crown is a cap that fits over the entire visible portion of the tooth, reinforcing it against the pressure of chewing. Back teeth (molars and premolars) are more likely to need crowns because they bear the heaviest bite force.
If decay reaches the pulp, the innermost layer containing nerves and blood vessels, a root canal becomes necessary. During this procedure, the infected pulp is removed and the interior of the tooth is sealed. After a root canal, most back teeth also need a crown, especially if the dentist had to remove a significant amount of tooth structure. Teeth that have undergone several prior restorations are also more likely to need a crown to maintain their integrity.
Extraction is typically a last resort, reserved for teeth too damaged to save or infections too severe to control with other treatments.
A Non-Drill Option: Silver Diamine Fluoride
Silver diamine fluoride (SDF) is a liquid applied directly to a cavity to stop decay from progressing. It doesn’t remove the damaged tooth structure or restore the tooth’s shape, but it can arrest an active cavity in place. According to the American Dental Association, SDF applied twice a year can stop decay on both baby teeth and permanent teeth. It’s been shown to be as effective as traditional restorative treatment at halting decay progression, at roughly one-twentieth the cost.
There’s a significant cosmetic tradeoff: SDF permanently stains the decayed area black. For that reason, it’s most commonly used on baby teeth that will eventually fall out, on hard-to-reach surfaces, or for patients who can’t tolerate traditional dental procedures due to age, anxiety, or medical conditions. It still requires a dentist’s diagnosis and a follow-up monitoring plan.
Managing Pain While You Wait
If your cavity is causing discomfort before you can get to a dentist, a few simple steps can help. Rinse your mouth with warm water and use dental floss to clear any food trapped near the affected tooth. An over-the-counter pain reliever like ibuprofen or acetaminophen can dull the ache. Don’t place aspirin directly against the gum tissue, as it can cause chemical burns.
If the pain resulted from trauma to the tooth, apply a cold compress to the outside of your cheek. Be cautious with topical numbing gels containing benzocaine. These shouldn’t be used on children under 2, and adults should follow the dosage directions carefully.
When a Cavity Becomes an Emergency
An untreated cavity can eventually lead to an abscess, a pocket of pus that forms at the root of the tooth when bacteria invade the pulp. Abscesses cause severe, throbbing pain that can radiate into the jaw, along with swollen gums and facial swelling. This is no longer a routine dental problem. Head to an emergency room if you experience a fever of 100.4°F or higher, difficulty swallowing, confusion, a rapid heart rate, or significant facial swelling. These signs suggest the infection may be spreading beyond the tooth.
Preventing the Next Cavity
Cavities form when bacteria in plaque convert sugars and carbohydrates into acids that eat away at tooth enamel. Prevention comes down to disrupting that cycle. Brush twice a day with fluoride toothpaste, floss daily to remove plaque from between teeth where your brush can’t reach, and keep up with regular dental cleanings so your dentist can catch new decay before it becomes a cavity.
Diet matters more than most people realize. It’s not just the amount of sugar you eat but the frequency. Every time you snack on something starchy or sugary, your mouth goes through a fresh acid attack that lasts about 20 to 30 minutes. Frequent snacking throughout the day keeps your teeth under near-constant assault. Reducing snack frequency and rinsing with water after meals gives your saliva time to neutralize acids and begin the natural remineralization process.