Cavities explained: causes, decay without pain and treatment

Can you have a cavity without pain?

Yes. Many cavities cause no pain at first. NIDCR says early tooth decay usually has no symptoms. Pain and sensitivity tend to appear later, as decay moves deeper. By then the tooth may need more than a small repair.

This is why dentists look for decay even when nothing hurts. NIDCR says tooth decay can be found during a regular dental checkup. The dentist checks the teeth for staining and for soft or sticky spots, and may take an X-ray to show decay that you cannot see. A dentist can find a small cavity long before you feel it.

If a tooth does hurt, call the office. Do not wait to see whether it passes.

What is a cavity, and how does it form?

A cavity is a small hole in a tooth. It starts when bacteria in plaque make acid. The ADA’s MouthHealthy site explains the steps. Plaque is a sticky film of bacteria that forms on teeth all day. When you eat or drink foods with sugars, the bacteria make acids that attack the enamel. The stickiness of the plaque keeps the acid on the tooth. Over time the enamel breaks down, and a cavity can form.

NIDCR adds that sugars and starches both feed these bacteria. Each time acid attacks, the enamel loses minerals. If this happens often, the minerals do not get a chance to return. A white spot may appear where minerals have been lost. NIDCR calls it a sign of early decay.

The terms are close, and they overlap. “Tooth decay” is the process. A “cavity” is the hole it can leave. The glossary has short entries for cavity and for remineralization, the return of minerals to enamel.

What are the stages of tooth decay?

Decay moves in steps, from mineral loss to infection. The table summarizes what NIDCR and Cleveland Clinic describe. Your dentist can tell you where a tooth stands.

The stages blend into each other. The line between them is a judgment your dentist makes with the help of X-rays.

Can a cavity heal itself?

Not once a hole has formed. Before that, early damage can be stopped. NIDCR says enamel can repair itself, using minerals from saliva and fluoride from toothpaste or from a fluoride treatment given by a dentist or hygienist. If more minerals are lost than the tooth can restore, the enamel weakens and a cavity forms.

What this means for you:

• A white spot is a chance to act. Better cleaning, fluoride and fewer sugar hits may help.
• A hole does not close up. The dentist has to remove the decay and fill the tooth.
• Waiting does not make a hole smaller. NIDCR says untreated decay can cause pain, infection and even tooth loss.

Your dentist can tell you whether a spot is still at the early stage. That is a judgment made by looking at the tooth and the X-ray.

Does sugar alone cause cavities?

No. Sugar is only part of the chain. The ADA’s MouthHealthy site explains that bacteria in plaque turn sugars into acid, and the stickiness of plaque keeps that acid on the tooth. NIDCR notes that starches also feed the bacteria, and that repeated acid attacks are what wear the enamel down.

This is why how often you eat or sip matters, not only how much. NIDCR says enamel keeps losing minerals when a tooth is repeatedly exposed to acid, such as when you frequently consume food or drink high in sugar and starches. NIDCR advises limiting sugary drinks and foods, eating balanced meals and limiting snacking. Cleaning off the plaque and getting fluoride also change the outcome.

What are root cavities?

A root cavity is decay on the root of a tooth instead of the crown. It happens when gums pull back and expose the root. The ADA says roots are covered by cementum, a softer tissue than enamel, so they are more prone to decay and more sensitive to touch, heat and cold. NIDCR adds that older adults with receding gums can get decay on these exposed root surfaces.

If you notice that your gums have pulled back, or a notch near the gumline, mention it at your next visit. The dentist can check the root surface and suggest ways to protect it. Fluoride and careful cleaning at the gumline are the usual starting points.

What does a filling visit feel like?

Most fillings are done in one visit with local anesthetic. Cleveland Clinic describes the steps: the dentist numbs the tooth, removes the decayed tissue, fills the hole, hardens the material if it is composite, smooths the edges and checks your bite. You can return to routine activities when you finish unless you had sedation.

Minor sensitivity and gum soreness are normal for a week or two. Cleveland Clinic says to call the dentist if a filling breaks, or if you have severe pain that medication does not ease, a swollen face or jaw, or fever and chills. If you feel anxious about the visit, tell the office. The dentist will talk with you about what fits.

What should I ask my dentist about a cavity?

Questions that help you understand the plan:

1. How deep is the decay, and can you show me on the X-ray?
2. Is this early enough for fluoride and closer watching, or does it need a filling now?
3. What filling material do you suggest for this tooth?
4. Is there decay anywhere else I should know about?
5. What causes the decay in my mouth, and what can I change at home?
6. How often should I come back for checkups?

Good answers name the tooth, the depth of the decay and the reason for the choice.

What causes cavities?

Cavities come from a mix of bacteria, sugars and starches, and time. Several habits and conditions raise the risk. NIDCR and the ADA name these:

• Frequent sugars and starches. Each snack or sip starts an acid attack. NIDCR advises limiting sugary drinks and foods and limiting snacking.
• Not enough fluoride. Fluoride from toothpaste, tap water that contains fluoride, or a rinse helps enamel resist acid.
• Plaque left on the teeth. Cleaning between the teeth matters as much as brushing.
• Tobacco. NIDCR advises against all tobacco, including smokeless tobacco.
• Receding gums. The ADA says that when gums pull back, tooth roots are exposed to plaque. Roots are covered by a softer tissue than enamel, so they decay more easily.
• Older fillings. The ADA says decay around the edges of old fillings is common in older adults.

Who gets cavities?

People of every age can get them. NIDCR says people of all ages can get tooth decay once they have teeth. Children can get “early childhood caries,” which NIDCR describes as severe decay that starts in a baby’s front teeth and extends to the back teeth.

Adults get cavities too. The ADA says cavities are more common among children, but changes that occur with aging make cavities an adult problem as well. It adds that it is common for people over age 50 to have tooth-root decay.

The next steps for children are in our guide to kids’ cavities and fluoride.

How do dentists find cavities?

Dentists find cavities with a look, a touch and an X-ray. NIDCR lists signs of decay as white, brown or black staining on the tooth. A more advanced cavity may form a visible hole. The dentist also checks for soft or sticky areas and may take an X-ray.

Some decay hides between teeth or under old fillings. That is where X-rays help. Town Center Dental’s technology page names digital X-rays and a cone beam CT scan among its tools. Ask your dentist what images your visit includes and why.

How is a cavity treated?

The usual treatment is a filling. NIDCR says dentists commonly treat cavities by filling them. The dentist numbs the tooth, removes the decayed tissue and fills the space with a filling material. The tooth-colored vs silver fillings guide covers the materials.

Larger cavities may need more than a filling:

• An onlay or crown can replace more of the tooth. The guide to crowns, fillings and onlays explains the choice.
• A root canal treats a tooth whose nerve area is infected. Cleveland Clinic says a throbbing toothache after a filling can mean decay reached the pulp.
• A tooth that cannot be saved may be removed and replaced.

Early decay may need no drilling. NIDCR says that if decay is still in its early stages, before a hole forms, the dentist can apply fluoride.

What happens if a cavity is not treated?

An untreated cavity gets bigger. NIDCR says it can cause pain, infection and even tooth loss. If the tooth becomes infected, an abscess, a pocket of pus, may form. It can cause pain, facial swelling and fever.

Mayo Clinic says to go to an emergency room if you have trouble breathing or swallowing, or if you have a fever and facial swelling and cannot reach your dentist. These signs can mean the infection is spreading.

How can I lower my risk of cavities?

Small daily habits make the biggest difference. NIDCR suggests these steps:

1. Brush twice a day with fluoride toothpaste.
2. Clean between your teeth with floss or another between-the-teeth cleaner.
3. Limit sugary drinks and foods, and limit snacking.
4. Do not use tobacco.
5. See a dentist for regular checkups and professional cleanings.

NIDCR also points to fluoride from tap water that contains fluoride and from a fluoride rinse. For children, it suggests asking the dentist about sealants, a coating on the chewing surfaces of back teeth. Professional cleanings are part of that routine. Town Center Dental describes them on the teeth cleaning page.

Next step

If it has been a while since your last exam, a checkup is the way to find out. Read about dental fillings at Town Center Dental, then call (636) 273-5866 or request an appointment.