Whether you can get rid of a cavity depends entirely on how far it has progressed. A very early cavity, one that hasn’t yet broken through the enamel surface, can actually be reversed at home with the right approach. Once decay creates a physical hole in your tooth, though, no amount of brushing or rinsing will fix it. You’ll need a dentist to remove the damaged material and restore the tooth.
How Cavities Form in the First Place
Cavities start with bacteria, primarily a species called Streptococcus mutans, that live on the surface of your teeth. These bacteria feed on sugars and starches from your food and produce acid as a byproduct. That acid gets trapped between the bacterial film (plaque) and your tooth, dropping the local pH below 5.5, which is the threshold where enamel starts to dissolve.
Your saliva normally fights back. It’s naturally supersaturated with calcium and phosphate, the same minerals your enamel is made of. When the acid clears and pH rises back toward neutral (6.5 to 7.4), those minerals redeposit onto weakened enamel. This back-and-forth between mineral loss and mineral gain happens all day long. A cavity forms when the balance tips toward loss, usually because of frequent snacking, poor brushing, or both.
Reversing a Cavity Before It’s Too Late
In its earliest stage, a cavity shows up as a white spot on your tooth. The enamel has lost minerals but hasn’t physically broken down yet. At this point, you can reverse the damage through remineralization. Fluoride is the most effective tool here. When fluoride is present during remineralization, it bonds with calcium to form fluorapatite, a crystal structure that’s harder and more acid-resistant than the original enamel. Standard fluoride toothpaste, used twice daily, delivers this directly to your teeth.
Your dentist may also recommend a professional fluoride varnish or a product containing casein phosphopeptide-amorphous calcium phosphate (often sold as MI Paste). This milk-derived compound releases calcium and phosphate ions into the bacterial film on your teeth, keeping the local environment saturated with the minerals needed for repair.
Xylitol, a sugar alcohol found in certain gums and mints, offers additional protection. Consuming 5 to 10 grams per day, spread across three to five doses after meals, reduces cavity incidence by 30% to 80%. Frequencies below three times a day show no benefit, so consistency matters. Xylitol works because cavity-causing bacteria can’t metabolize it the way they metabolize regular sugar, which starves them of fuel.
What Happens Once the Enamel Breaks
Once decay eats through the enamel and creates an actual hole, remineralization can no longer close the gap. The damaged tooth structure is gone, and bacteria have a protected space to keep producing acid. At this stage, the cavity will only get larger without professional treatment. You might not feel anything at first, since enamel has no nerves. But as decay reaches the softer layer underneath (dentin), you’ll likely notice sensitivity to sweets, cold drinks, or hot food.
If the decay continues deeper and reaches the pulp, the living tissue at the center of your tooth, you’re in different territory. The hallmark sign is a lingering sensitivity to heat or cold that lasts more than a few seconds, often described as throbbing or aching. At that point, the inflammation is typically irreversible, and a root canal or extraction becomes necessary.
How Dentists Fix a Cavity
For most cavities, the standard treatment is a filling. Your dentist removes the decayed material and fills the space with a restorative material. The two main options are composite resin (tooth-colored) and amalgam (silver-colored). Amalgam fillings last longer on average and cost less. Composite fillings blend in with your natural tooth and are the more popular choice for visible teeth.
Cost depends primarily on how much of the tooth is involved. For a small cavity affecting one surface, expect to pay $50 to $100 for amalgam or $90 to $150 for composite. A cavity between teeth that involves two surfaces runs $75 to $150 for amalgam and $130 to $220 for composite. Large cavities spanning three or more surfaces cost $120 to $250 for amalgam and $180 to $300 for composite. These are out-of-pocket estimates; dental insurance typically covers a significant portion.
Laser Cavity Removal
Some dental offices now use lasers instead of traditional drills to remove decay. The advantages are real: less invasive tissue removal, antimicrobial properties that reduce infection risk, and faster recovery. Many patients find the experience less anxiety-inducing than a drill. The downsides are equally straightforward. Laser equipment is expensive, which raises the cost of your visit. Some procedures take longer than they would with a conventional drill. And lasers aren’t always suitable for deep cavities, so your dentist may still need traditional tools for more advanced decay.
Silver Diamine Fluoride
For people who can’t undergo a traditional filling, whether due to age, anxiety, or medical conditions, silver diamine fluoride (SDF) offers an alternative. This liquid is painted directly onto the cavity to stop decay from progressing. Studies on baby teeth show a caries arrest rate of about 52% when 38% SDF is applied once or twice a year. It doesn’t restore the tooth’s shape or remove the damaged material, so it’s more of a holding strategy than a permanent fix. The biggest cosmetic drawback: SDF turns decayed areas black.
Slowing Decay Between Appointments
If you’ve spotted a cavity or been told you have one but can’t get into the dentist right away, a few steps can slow its progression. Brush with fluoride toothpaste at least twice a day, paying extra attention to the affected area. Cut back on sugary and acidic foods and drinks, especially between meals. Every time you eat sugar, bacteria produce acid for roughly 20 to 30 minutes afterward, so frequent snacking keeps your mouth in a constant state of mineral loss. Chewing xylitol gum after meals helps shift the balance back in your favor.
Rinsing with a fluoride mouthwash adds another layer of mineral support, particularly before bed when saliva production drops and your teeth are most vulnerable. None of these steps will heal a cavity that’s already formed a hole, but they can buy you time and protect the rest of your teeth from developing new ones.