You can’t get rid of a cavity at home once it has broken through the enamel. A dentist can treat most cavities in a single appointment lasting 30 to 60 minutes, but the total timeline depends on how far the decay has progressed. A tiny white spot on your enamel can sometimes be reversed over weeks to months with fluoride and good hygiene. A cavity that has reached the inner pulp of your tooth requires a root canal and crown, stretching treatment across multiple visits over several weeks.
Early Decay Can Be Reversed
Cavities don’t appear overnight. They start as white spot lesions, small chalky or milky-white patches on the enamel surface. At this stage, the tooth’s outer layer has lost minerals but hasn’t actually developed a hole. The surface still feels smooth to the touch. This is the only stage where you can reverse the process without drilling.
Reversing a white spot lesion takes consistent effort over several weeks to a few months. Fluoride toothpaste, prescription-strength fluoride rinses, and professional fluoride varnish applications help minerals redeposit into the weakened enamel. For children, professional fluoride varnish applied every six months is standard for cavity prevention. Adults with early white spots may get more frequent applications. During this window, reducing sugar intake and keeping a solid brushing and flossing routine are just as important as the fluoride itself.
If a white spot lesion is still active, a dentist can also use a technique called resin infiltration. This involves applying a thin resin that soaks into the porous, demineralized enamel without any drilling or tooth structure loss. It’s painless and preserves healthy enamel that traditional filling prep would remove. Once the lesion becomes inactive (re-mineralized on the surface but still discolored), the resin has a harder time penetrating, so timing matters.
How Long a Filling Takes
Once decay has broken through the enamel and created an actual hole, the damage is permanent and needs a filling. Most fillings are completed in a single appointment that lasts 30 to 60 minutes, depending on the size and location of the cavity. The dentist numbs the area, removes the decayed material, and fills the space with either composite resin (tooth-colored) or amalgam (silver-colored).
Composite fillings harden instantly under a UV light, so the tooth is structurally ready as soon as you leave the chair. The main reason to wait before eating is the local anesthesia, which typically wears off within one to three hours. Chewing while numb raises the risk of biting your tongue, cheeks, or lips without realizing it. Amalgam fillings take longer to fully set. Dentists recommend waiting 24 hours before chewing on that side, since the material needs time to reach full strength.
Without insurance, a filling typically costs between $200 and $335. Most dental insurance plans cover up to 80% of filling costs once you’ve met your annual deductible.
Deeper Cavities Take Longer to Treat
When decay reaches the soft inner tissue of the tooth (the pulp), a simple filling won’t work. You’ll need a root canal, which removes the infected pulp and seals the interior of the tooth. The procedure itself takes 60 to 90 minutes and sometimes requires more than one visit if the infection is severe or the tooth has complex root anatomy.
After the root canal, the tooth still needs a crown to protect it from fracturing. That adds at least two more appointments: one to prepare the tooth and take impressions, and another to place the permanent crown. Factoring in scheduling and lab time for the crown to be fabricated, the entire process from root canal to finished crown typically spans three to six weeks. During that time you’ll have a temporary crown and should avoid chewing hard or sticky foods on that side.
Why Waiting Makes Treatment Longer
Nearly 21% of adults between ages 20 and 64 have at least one untreated cavity, according to CDC surveillance data from 2024. About 13% of adults 65 and older do as well. The most common reason people delay treatment is cost, fear, or simply not realizing the cavity exists because early and moderate decay often causes no pain at all.
The problem with waiting is that cavities only move in one direction. A small cavity that would have taken 30 minutes and a $200 filling to fix can progress to a root canal costing several times more and requiring weeks of treatment. In the worst case, a tooth becomes too damaged to save and needs extraction, followed by an implant or bridge that takes months and costs significantly more. The timeline to “get rid of” a cavity is shortest when you catch it early, ideally at the white spot stage or as a small area of decay that hasn’t reached the nerve.
What to Expect at Each Stage
- White spot lesion: Reversible with fluoride and hygiene changes over weeks to months. No drilling needed.
- Small to moderate cavity: One appointment, 30 to 60 minutes. You can eat within a few hours (composite) or the next day (amalgam).
- Deep cavity reaching the pulp: Root canal (60 to 90 minutes) plus crown placement over two additional visits. Total timeline of three to six weeks.
- Severely damaged tooth: Extraction followed by an implant or bridge, which can take three to six months for full healing and restoration.
Regular dental checkups every six months catch cavities at their smallest and most treatable. X-rays can reveal decay between teeth that you’d never see or feel on your own, keeping the fix quick and the cost low.