What do cavities look like?

What a cavity is

A cavity is a hole formed when decay breaks down the tooth's hard surface. ADA MouthHealthy explains that plaque, a sticky film of bacteria, forms on teeth all the time. After you eat or drink something sugary the bacteria make acids, and plaque holds those acids against the teeth until the enamel begins to break down.

Decay does not happen overnight. NIDCR describes it as a process, and that is why the look and feel of a cavity changes depending on how far it has progressed.

What early cavities look like

Cleveland Clinic describes the first stage as small, white, chalky spots on the tooth, caused by minerals breaking down in the enamel. NIDCR also describes early decay as a white spot, and notes that early decay usually has no symptoms at all. This is why many people only learn they have decay at a checkup.

At this stage the tooth has not yet formed a hole. NIDCR says that before a cavity forms, enamel can repair itself using minerals from saliva and fluoride from toothpaste, and that a dentist can apply fluoride to help reverse early decay. Cleveland Clinic similarly says very early enamel decay may be reversible with fluoride treatment and better oral hygiene.

How a cavity changes as it progresses

Cleveland Clinic describes five stages. The look and symptoms of each give a rough idea of how far decay has gone, though only a dentist can stage it.

• Stage 1, demineralization: small white, chalky spots.
• Stage 2, enamel decay: holes may become noticeable and the white spots may turn light brown.
• Stage 3, dentin decay: decay moves faster through the softer layer beneath the enamel, sensitivity may begin, and spots may darken to brown.
• Stage 4, pulp damage: pain, gum redness and swelling can occur, and the spot may turn dark brown or black.
• Stage 5, abscess: an untreated infection can form a pocket of pus at the root tip, with pain that can spread to the jaw or face, facial swelling and swollen lymph nodes in the neck.

What a cavity feels like

Healthline lists early signs as lingering sensitivity to hot or cold after eating or drinking, and lingering sensitivity to sweets. Later signs include ongoing toothache in one or more teeth that can come on suddenly or after eating, pain or pressure when biting down, staining that darkens over time, and a visible or detectable hole or pit.

Holes between teeth or in the grooves of a tooth may be impossible to see or feel yourself, yet can still cause pain or sensitivity. NIDCR adds that as decay advances it can cause toothache or sensitivity to sweet, hot or cold foods.

Is it a cavity or just a stain?

Healthline says cavity stains can be brown, black or white and usually sit on the tooth's surface, but it does not offer a reliable way to tell a cavity from an ordinary stain by appearance alone. Cleveland Clinic notes that staining from food or drink usually affects several teeth, while a single dark spot on one tooth is more likely to be a cavity.

Because other things such as stains or enamel problems can look similar, and because many cavities are hidden between teeth, the safe approach is to have any new spot checked rather than guess.

How dentists find cavities

Cleveland Clinic says dentists examine teeth with instruments, that a decayed area may feel softer when probed, and that X-rays can reveal decay before it is visible. That is why regular checkups matter: Cleveland Clinic recommends at least two a year, and Healthline suggests about every six months with regular X-rays to catch cavities early.

What happens if a cavity is not treated

Treatment depends on the stage. Cleveland Clinic lists fluoride treatments for the earliest stage, fillings once there is a hole, root canal therapy (sometimes followed by a crown) for advanced decay with pain, and extraction when a tooth cannot be saved. Untreated decay can lead to tooth loss, a painful abscess, and infection that can spread; Cleveland Clinic notes this is rarely fatal but is a reason not to ignore symptoms.

Preventing cavities

The advice is consistent across sources: brush at least twice a day with fluoride toothpaste, clean between your teeth daily, limit sugary and starchy foods and snacking, drink fluoridated water where available, avoid tobacco, and see your dentist regularly. ADA MouthHealthy and NIDCR also mention dental sealants for the chewing surfaces of back teeth.

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