The most common signs of a cavity are sensitivity to sweets, hot or cold, a toothache or pain when biting, and a visible dark spot or hole in a tooth. But many early cavities cause no symptoms at all. The only reliable way to know is a dental exam, often with X-rays. The earlier a cavity is found, the smaller and simpler the treatment.
6 Signs You May Have a Cavity
- Sensitivity to sweets. A quick zing when you eat or drink something sugary is a classic early sign.
- Sensitivity to hot or cold. Discomfort that lingers after a cold drink or hot food can mean decay has reached the softer layer under the enamel.
- Toothache or pain when you bite down. Pain when chewing, or an ache that comes and goes, often means a cavity is getting deeper.
- A visible hole or pit. You may see or feel a small hole with your tongue, especially on chewing surfaces.
- Dark, brown or white spots. Chalky white spots can be early decay. Brown, black or gray spots can be more advanced. Not every stain is a cavity, but it is worth checking.
- Food catching in the same spot, or bad breath. Food that keeps getting stuck between two teeth, or a bad taste or odor that does not go away, can point to decay or a broken filling.
Get help the same day if you have severe tooth pain, swelling in your face or gums, a pimple-like bump on the gum, or a fever. These can be signs of an infection. If swelling makes it hard to swallow or breathe, go to the ER or call 911.
Why Early Cavities Often Have No Symptoms
Enamel, the hard outer layer of a tooth, has no nerves. A cavity that is only in the enamel usually does not hurt. Symptoms tend to start once decay reaches the dentin, the softer layer underneath that connects to the tooth's nerve. By the time a tooth really aches, decay may be close to the pulp (the soft center of the tooth that holds nerves and blood vessels).
Cavities also like to hide between teeth and under old fillings, where you cannot see them in the mirror. That is why waiting for pain is not a good plan. A cavity found early is usually a small, quick repair.
Think You Might Have a Cavity? Call (916) 929-3737 or book online. We will check the tooth, show you what we find and explain your options before any treatment.
How Dentists Find Cavities
During a dental exam, your dentist looks at each tooth closely, checks for soft or sticky spots, and looks at old fillings and crowns for wear or gaps. Digital X-rays show decay between teeth and below the surface that the eye cannot see. Bitewing X-rays (the ones where you bite on a small tab) are the main tool for finding cavities between back teeth.
Digital X-rays use much less radiation than older film X-rays, and the images appear on a screen right away so you can see what your dentist sees. At Fulton Family Dental, Dr. Kathiriya walks you through what she finds and explains your options before any treatment starts.
Treatment Options by Stage
Treatment depends on how deep the decay has gone. Here is the general path:
| Stage | What is happening | Typical treatment |
|---|---|---|
| Early (white spot) | Enamel is losing minerals but has no hole yet | Professional fluoride, better brushing and less snacking to help the enamel remineralize (rebuild) |
| Small to moderate cavity | A hole has formed in the enamel or reached the dentin | A tooth-colored filling |
| Large cavity | Too much of the tooth is lost for a filling to hold up | A dental crown to cover and protect the tooth |
| Decay reaches the pulp | The nerve is inflamed or infected; often painful | Root canal treatment, usually followed by a crown |
| Tooth cannot be saved | Severe damage or infection | Extraction, then options to replace the tooth |
The pattern is clear: the earlier a cavity is found, the less treatment it needs and the lower the cost. Most PPO plans cover checkups and X-rays at a high level, so regular visits are usually the least expensive way to stay ahead of decay.
What to Do if You Think You Have a Cavity
- Book an exam soon, even if the pain comes and goes. Cavities do not heal once they form a hole.
- Keep brushing and flossing gently around the sore tooth.
- Avoid very hot, cold or sugary foods on that side until you are seen.
- An over-the-counter pain reliever can help for a short time if it is safe for you. Do not put aspirin directly on the gum.
If you are in pain, our Sacramento office offers same-day appointments and toothache relief. To lower your chances of the next one, read our guide on how to prevent cavities.
Frequently Asked Questions
Can you have a cavity and not feel it?
Yes, very often. Cavities in the enamel usually do not hurt, because enamel has no nerves. Many cavities are found at routine checkups before any symptoms start, which is the best time to treat them.
Is a dark spot on my tooth always a cavity?
No. Dark spots can be stains from coffee, tea or tobacco, or old fillings. They can also be decay. Only a dentist can tell the difference, usually with a close exam and sometimes an X-ray.
How long can I wait to fill a cavity?
It is best not to wait. A cavity keeps growing, sometimes slowly and sometimes quickly. A small cavity that needs a simple filling today can grow into one that needs a crown or root canal treatment later.
Does getting a filling hurt?
Most people feel little more than pressure. Your dentist numbs the area first, so the procedure itself should be comfortable. If you feel anxious, ask about options such as nitrous oxide (laughing gas).
This article is general information, not a diagnosis or treatment plan. Every mouth is different. For advice about your own teeth, please schedule a visit or call (916) 929-3737.