Cavities are one of the most common dental concerns, but the moment they start to hurt can feel confusing. Sometimes, you can have decay forming long before you feel a thing. Other times, the pain seems to appear suddenly, as if overnight.
At Simply Dentistry, our goal is to simplify what’s happening in your mouth so that you can take smart, proactive steps for your oral health. Below, our trusted San Bruno dentist breaks down when cavities start to hurt, what that pain means, and how to stop decay before it causes lasting damage.
Cavities Don’t Start Out Painful. They Start Out Silent.
In their earliest stages, cavities are completely painless. They begin when bacteria in your mouth feed on sugars and starches, producing acids that wear down your enamel, the tooth’s outer protective layer. This enamel erosion creates a weak spot, but since enamel has no nerves, you won’t feel anything yet. The damage is happening quietly.
At this point, our San Bruno dentist can often detect the cavity through a routine dental exam or X-ray before it causes discomfort. Early detection is key because this is when decay can be reversed or treated with a small, simple dental filling.
Sensitivity: The First Warning Sign
As a cavity progresses deeper into the enamel and approaches the dentin beneath, you may start to notice mild sensitivity.
That might include:
- A sharp twinge when you eat something sweet, hot, or cold.
- A dull ache after brushing or flossing.
- Slight discomfort that fades quickly once you stop eating or drinking.
This sensitivity happens because dentin contains tiny tubules that connect to the tooth’s nerve center. Once the cavity breaches the enamel, it opens a pathway for temperature changes and bacteria to irritate those nerve endings.
If you notice this kind of fleeting pain, our San Bruno dentist can still intervene easily. Treating the cavity at this stage usually still means a small filling and no long-term sensitivity afterward.
When the Pain Becomes Noticeable
If decay continues untreated, the bacteria eventually reach the inner layer of the tooth, the pulp, which houses nerves and blood vessels. That’s when the real pain begins.
You might experience:
- Persistent, throbbing pain.
- Pressure when biting or chewing.
- Swelling in the gums near the affected tooth.
- A sudden toothache that keeps you up at night.
At this point, the cavity has become an infection inside the tooth. It can’t heal on its own and may require a root canal to remove the damaged tissue and save the tooth.
When the pain reaches this level, it’s your body’s way of saying the decay has gone too deep. The sooner you contact Simply Dentistry, the better your chances of preserving the tooth and avoiding further complications.
Why Cavities Can Suddenly “Flare Up”
Many people describe their first toothache as coming out of nowhere—fine one day, miserable the next. In reality, the decay has likely been developing for months. What happens is simple: as the cavity slowly grows, it stays below your pain threshold until it crosses that sensitive dentin or pulp layer. Once it does, the nerve responds quickly and strongly.
That’s why regular dental checkups are so important. Our San Bruno dentist can spot early signs of decay before it ever causes pain, saving you time, money, and unnecessary discomfort.
Preventing Cavities Before They Hurt
Cavity prevention doesn’t have to be complicated. It’s about consistent care and smart choices. Here are some habits we recommend to help stop decay in its tracks:
- Brush twice daily with a fluoride toothpaste to strengthen enamel.
- Floss once a day to remove plaque and food between teeth.
- Rinse with fluoride mouthwash if recommended by our dentist.
- Limit sugary snacks and drinks, especially sticky or acidic ones.
- Visit our office every six months for exams and cleanings.
Fluoride treatments and dental sealants can also add an extra layer of protection, especially for those prone to cavities or with deeper grooves in their teeth.
What to Do if You Think You Have a Cavity
If you start noticing tooth sensitivity, visible dark spots, or pain when biting, don’t wait for it to get worse. Cavities won’t go away on their own.
Our San Bruno dentist will evaluate the affected tooth with advanced diagnostic tools to determine the extent of the decay. From there, treatment might include a small filling or crown, depending on how much structure needs to be restored. The good news? When caught early, treatment is quick, straightforward, and long-lasting.
Don’t Wait for the Pain to Begin
Pain is a late symptom of tooth decay. The earlier you act, the easier and less invasive your treatment will be.
At Simply Dentistry, we believe great dental care is about simplicity, precision, and prevention. If you’ve noticed tooth sensitivity or think a cavity may be forming, schedule a visit with our San Bruno dentist today. We’ll take the mystery out of what’s happening and get your smile back to feeling its best.