How you fix a decaying tooth depends entirely on how far the decay has progressed. Early-stage decay, where minerals are just starting to leach from the enamel, can actually be reversed at home with fluoride and good oral care. Once a cavity has formed, you’ll need professional treatment, and the options range from simple fillings to root canals to extraction, depending on which layer of the tooth is affected.
The Five Stages of Tooth Decay
Tooth decay isn’t a single event. It’s a process that moves through five distinct stages, and knowing where you are in that process determines what kind of fix is possible.
In stage one, acids from plaque bacteria begin stripping minerals from your enamel. You might notice white spots on the tooth surface. This is the only stage where decay is fully reversible without a dentist’s drill. In stage two, the enamel breaks down further, those white spots may darken to brown, and small holes (cavities) form. This requires a filling.
Stage three is when decay reaches the dentin, the softer tissue beneath the enamel. Because dentin is less dense than enamel, decay accelerates once it gets here. You’ll likely notice increased sensitivity. Stage four hits the pulp, the innermost part of the tooth containing nerves and blood vessels. The pulp swells, causing significant pain. At this point, a root canal is typically the only way to save the tooth. In stage five, bacteria invade the pulp and create an abscess: a pocket of pus at the root. This is an infection that can spread beyond the tooth.
Reversing Early Decay at Home
If your decay is still at the white-spot stage, with no actual hole in the tooth, you can reverse it through a process called remineralization. Your saliva naturally deposits calcium and phosphate back into weakened enamel. Fluoride supercharges this process by forming a mineral structure called fluorapatite, which is harder and more acid-resistant than the original enamel.
The practical steps are straightforward. Brush twice daily with fluoride toothpaste. Standard toothpaste in the U.S. contains 1,000 to 1,100 ppm fluoride, which is effective for most people. If your dentist considers you high-risk for cavities, they may recommend a toothpaste with 1,500 ppm fluoride or a prescription-strength home gel with 5,000 ppm. A daily fluoride mouthrinse (230 ppm, available over the counter) adds another layer of protection. Drinking fluoridated tap water, which contains 0.7 to 1.2 ppm fluoride, also contributes throughout the day.
Beyond fluoride, limit how often you eat sugary or acidic foods. Every time you snack, bacteria produce acid for about 20 to 30 minutes afterward. Frequent snacking means your teeth spend more time under acid attack than your saliva can compensate for. Chewing sugar-free gum after meals can help stimulate saliva flow and speed up the natural repair process.
Fillings for Small to Medium Cavities
Once decay has broken through the enamel and created a cavity, remineralization won’t close the hole. A filling is the standard fix. Your dentist removes the decayed material, cleans the area, and fills the space with a restorative material.
The most common filling materials today are:
- Composite resin: Tooth-colored and popular for visible teeth. Lasts at least five years, often longer with good care.
- Amalgam (silver fillings): Durable and inexpensive. Lasts 10 to 15 years or more, but the metallic color makes them less popular for front teeth.
- Ceramic: Tooth-colored and highly durable, generally lasting more than 15 years. They cost more than composite or amalgam.
- Glass ionomer: Releases fluoride, which may help prevent further decay around the filling. Less durable, lasting about five years or less, so it’s often used in areas with less chewing pressure or in children’s teeth.
For larger areas of decay that have weakened the tooth’s structure but haven’t reached the pulp, your dentist may recommend an inlay or onlay instead of a standard filling. These are custom-made pieces (usually ceramic or gold) that fit precisely into or over the damaged area. They can last up to 30 years.
Silver Diamine Fluoride: A Non-Drill Option
If you’re looking for a way to stop a cavity from getting worse without drilling, silver diamine fluoride (SDF) is worth knowing about. It’s a liquid that a dentist paints directly onto a cavity. The silver kills bacteria and hardens the decayed area, while the fluoride promotes remineralization around the lesion. The whole application takes minutes, requires no numbing, and costs significantly less than a filling.
A panel of dental experts has recommended biannual application of 38% SDF to arrest cavitated lesions on both baby teeth and permanent teeth. It’s especially useful for young children, elderly patients, or anyone who has difficulty tolerating traditional dental procedures.
The major trade-off: SDF permanently stains the treated decay black. On a back molar, this is barely noticeable. On a front tooth, most people find it cosmetically unacceptable. SDF also doesn’t restore the tooth’s shape, so if the cavity is large or in a spot that affects chewing, you’ll still eventually need a filling or crown. Think of it as a pause button for decay, not a permanent fix.
Root Canals and Crowns for Deep Decay
When decay reaches the pulp, the nerve-rich center of the tooth, a simple filling is no longer enough. The inflamed or infected pulp needs to be removed through a root canal. Signs that decay has gone this deep include severe pain while chewing, lingering sensitivity to hot or cold that doesn’t fade when the stimulus is removed, swollen or tender gums near the tooth, and darkening of the tooth.
During a root canal, the dentist or endodontist removes the damaged pulp, cleans and shapes the interior canals, then fills and seals them. The tooth remains in your mouth but is no longer alive. Most people describe the procedure as similar to getting a deep filling, not the nightmare reputation suggests.
After a root canal, the tooth is more brittle because it no longer has a living blood supply. Back teeth (molars and premolars) almost always need a crown placed over them to withstand chewing forces. Front teeth, which handle less pressure, don’t always require one. If the tooth has lost a lot of structure, a post may be placed inside the root to anchor the crown. A crown typically lasts 10 to 15 years or longer with proper care.
When Extraction Is the Only Option
If decay has destroyed so much of the tooth that there’s not enough healthy structure left to support a crown, or if an abscess has caused severe bone loss around the root, extraction may be the only remaining option. After extraction, you’ll want to discuss replacement options with your dentist. Leaving a gap can cause neighboring teeth to shift over time, affecting your bite and jaw alignment. Common replacements include dental implants, bridges, and partial dentures.
Managing Pain Before Your Appointment
If you’re dealing with a decaying tooth that hurts right now, there are a few things you can do while waiting to see a dentist. Rinse your mouth with warm water and use dental floss to clear any food trapped around the tooth. Over-the-counter pain relievers like ibuprofen can reduce both pain and inflammation. Don’t place aspirin directly against the gum tissue, as it can cause chemical burns.
If the pain follows trauma to the tooth, hold a cold compress against the outside of your cheek. Numbing gels containing benzocaine can provide temporary relief, but use only the recommended dose and avoid them entirely in children under two.
Certain symptoms signal something more urgent. If you develop a fever along with facial swelling, go to an emergency room. The same applies if you have trouble breathing or swallowing. These signs suggest the infection has spread beyond the tooth into the jaw, throat, or neck, which can become life-threatening without prompt treatment.