How you fix a cavity depends entirely on how far the decay has progressed. A cavity caught at its earliest stage, when minerals are just starting to leach from the enamel, can actually be reversed at home with fluoride. Once a physical hole has formed in the tooth, though, only a dentist can repair it. The good news: modern treatments are faster, less painful, and more precise than ever.
Not All Cavities Need a Drill
Tooth decay moves through five distinct stages, and only the very first one is reversible without professional intervention. That first stage is demineralization: acids from bacteria strip minerals from your enamel, leaving a chalky white spot on the tooth. There’s no hole yet, just weakened enamel. At this point, fluoride can actually push minerals back into the tooth and stop decay in its tracks.
Once decay breaks through the enamel and creates an actual hole, you’ve crossed a line. Enamel doesn’t regenerate. A cavity in the enamel (stage two) needs a filling. If decay reaches the softer layer underneath called dentin (stage three), you’ll likely start feeling sensitivity to hot and cold foods. This still usually calls for a filling, though a larger area of damage may need a crown instead. Stage four hits the nerve inside the tooth, causing real pain and swelling, which typically means a root canal. Stage five is an abscess, a pocket of infection at the root, which requires either a root canal or extraction.
The takeaway: if you’re reading this because you spotted a white mark on your tooth or your dentist mentioned early decay, you may be able to reverse it. If you already have sensitivity, a visible hole, or pain, you need professional treatment.
Reversing Early Decay With Fluoride
Fluoride works by helping your saliva deposit calcium and phosphate back into weakened enamel. For this to be effective, the concentration matters. Toothpaste needs to contain at least 1,000 parts per million (ppm) of fluoride to provide any real benefit. Most standard toothpastes meet this threshold, but check the label. Prescription-strength toothpastes go above 2,500 ppm, which allows fluoride to penetrate deeper into early lesions and concentrate where damage is forming.
Fluoride mouth rinses add another layer of protection. Daily rinses typically contain about 230 ppm, while weekly rinses deliver around 900 ppm. Your dentist can also apply professional-grade fluoride varnish or gel directly to the affected spot. Varnishes use 5% sodium fluoride, and gels contain over 12,000 ppm, concentrations far beyond what’s available over the counter. If your dentist identifies an early white-spot lesion, ask about in-office fluoride treatment to give remineralization the best chance.
What Happens During a Filling
For most people searching “how to fix a cavity,” a filling is the answer. The process is straightforward and usually takes 20 to 60 minutes per tooth. Your dentist numbs the area with a local anesthetic, removes the decayed tissue with a drill or laser, fills the cleaned-out space with a restorative material, then shapes and polishes it to match your bite. For tooth-colored composite fillings, a curing light hardens the material in place.
Expect some sensitivity to hot, cold, or pressure afterward. This is normal and generally fades within a few days to two weeks. If the sensitivity is sharp or you feel like your bite is off when you close your mouth, call your dentist. A filling that sits even slightly too high creates extra pressure every time you chew, which causes pain noticeably worse than typical post-filling tenderness. The fix is simple: your dentist shaves down the high spot in minutes.
Filling Materials and Costs
The two most common filling materials are amalgam (silver-colored) and composite resin (tooth-colored). Amalgam is cheaper and extremely durable, making it a solid choice for back teeth that take heavy chewing force. Composite resin blends in with your natural tooth and bonds directly to the enamel, but it costs more and may not last quite as long on heavily used surfaces.
Cost depends on the material and how many surfaces of the tooth are involved. A small, single-surface amalgam filling runs $50 to $100, while the same cavity filled with composite costs $90 to $150. A larger cavity spanning three or more surfaces jumps to $120 to $250 for amalgam and $180 to $300 for composite. Ceramic and porcelain restorations, often used for visible teeth, range from $250 to $4,500 depending on complexity. Gold fillings, which are rare now, fall between $300 and $1,000. Most dental insurance plans cover at least a portion of basic fillings.
Laser Fillings: Less Pain, No Needle
Traditional drills use mechanical force that creates vibration and can remove more healthy tooth than necessary. Laser cavity preparation uses a concentrated beam of light to vaporize decay with millimeter-level precision, preserving more of your natural tooth structure. The result is often a smaller filling that bonds more securely, since the laser etches the surface in a way that creates a stronger seal.
The biggest advantage for patients is comfort. Many routine cavities can be prepared with a laser and no anesthetic injection at all. Most people feel nothing beyond a light spray of water. Not every cavity qualifies for laser treatment, and not every dental office has the equipment, but it’s worth asking about if dental anxiety is a barrier for you.
Silver Diamine Fluoride: Stopping Decay Without Drilling
Silver diamine fluoride (SDF) is a liquid painted directly onto a cavity to halt decay. It doesn’t restore the tooth’s shape or fill the hole, but it kills bacteria and hardens the remaining tooth structure, effectively freezing the cavity where it is. The American Dental Association recommends 38% SDF applied twice a year for advanced cavities, and studies show it prevents root cavities at rates 72% higher than placebo.
SDF is particularly useful in specific situations: young children who can’t sit still for a filling, older adults with physical limitations, people without easy access to dental care, or anyone with so many cavities that they can’t all be treated in one visit. It stabilizes the disease so conventional fillings can happen later on a more manageable timeline. The main drawback is cosmetic. SDF permanently stains decayed areas black, which makes it less appealing for visible front teeth.
When a Filling Isn’t Enough
If decay has destroyed a large portion of the tooth, a filling alone won’t provide enough structural support. A crown covers the entire visible portion of the tooth, acting like a protective cap. This is common when decay has spread across multiple surfaces or when the remaining walls of the tooth are too thin to hold a filling.
Once bacteria reach the pulp, the living tissue inside the tooth, a root canal becomes necessary. Your dentist or an endodontist removes the infected pulp, cleans and disinfects the interior, then seals it. A crown is almost always placed on top afterward, since the tooth becomes more brittle without its blood supply. Despite its reputation, a root canal feels similar to getting a deep filling done. Recovery typically involves mild soreness for a few days.
An abscess, the most advanced stage, forms when infection at the root creates a pocket of pus. This causes severe, throbbing pain that can radiate into the jaw or ear. Treatment involves draining the infection, performing a root canal, and sometimes prescribing antibiotics. In cases where the tooth is too damaged to save, extraction is the final option.
Home Remedies Don’t Fix Cavities
Oil pulling, charcoal toothpaste, and various “natural cavity healing” protocols circulate widely online. The evidence doesn’t support them for repairing an existing cavity. A meta-analysis in the National Library of Medicine found that oil pulling may reduce overall bacterial counts in saliva, but showed no significant effect on plaque buildup or gum health. At best, it might slightly lower your susceptibility to new cavities from “marked” to “mild or moderate,” but it cannot fill a hole that already exists in your tooth.
Enamel is not living tissue. Once it’s gone, your body cannot grow it back regardless of diet, supplements, or rinses. The only stage of decay that responds to non-professional treatment is that initial demineralization, the white spot, and even then, fluoride is the intervention with actual evidence behind it. If you have a visible cavity, delaying professional treatment while experimenting with home remedies gives decay more time to deepen, potentially turning a simple filling into a crown or root canal.