Tooth Decay: What It Is, Signs, and Types

You noticed a dark spot on a tooth or felt a hole with your tongue — and you're already wondering how bad it is. Take it easy: this may be tooth decay, and the sooner you get to a dentist, the simpler and cheaper the repair. Below — what this disease is, what it looks like, and why a hole doesn't heal on its own.

What tooth decay is

Tooth decay (Latin caries — "rotting") is a chronic disease of the teeth in which hard tissues are destroyed by acids produced by bacteria. The process is slow: first the enamel is affected, then the dentin, and without treatment — the pulp and periodontium. Cavities can be any color, from yellow to black. It is the most common disease in humans — over 93% of people. In children, tooth decay ranks first among chronic diseases and occurs 5–8 times more often than bronchial asthma. By the end of school, about 80% of adolescents have cavities, and 95–98% of adults have filled teeth.

What causes tooth decay

In short: lots of sugar and not enough brushing. Bacteria in the mouth turn sugar and starch into acids, and together with food particles and saliva form a sticky coating — dental plaque. Plaque builds up within 20 minutes after eating. Favorite spots are the chewing teeth, the area just above the gum, and the edges of fillings. If plaque is not removed, it hardens and turns into tartar.

Acids damage the enamel: it is 96% minerals, mainly hydroxyapatites, and begins to break down at a pH of 4.5. For the process to start, four things must coincide: a susceptible tooth surface, cariogenic bacteria, fermentable carbohydrates, and time. Enamel fluoride saturation, the amount and quality of saliva, and eating patterns also matter — frequent snacking keeps acids on the tooth longer. According to WHO recommendations, fluoridation of drinking water reduces the incidence of tooth decay by 30–50%.

Signs of tooth decay and what a cavity looks like

The most unpleasant part: at the start, tooth decay may not show at all. Most cavities are found during a routine checkup in someone who came in "just to get checked." When symptoms do appear, they are usually:

• pain or a nagging sensation in the tooth, especially after sweets, hot or cold;
• sharp pain when eating or drinking something hot, cold, or sweet — sensitive teeth;
• visible pits, holes, or dark spots on the enamel;
• white, brown, or black spots on the tooth.

A cavity is already a hole, that is, structural damage to the tooth; a spot without a hole is the initial stage, demineralization of the enamel. And one more thing: a cavity may not hurt. Tooth decay usually does not cause pain until it becomes very large, affects the nerves, or leads to a tooth fracture.

Stages of tooth decay

By the depth of the process, a distinction is made between the initial stage — focal demineralization of the enamel with a spot, decay within the dentin, when the cavity has already formed, and complicated forms, when inflammation spreads to the pulp and periodontium.

How a doctor detects tooth decay

First, an examination of the oral cavity: the surface of the affected area is usually soft. Then an X-ray — images show cavities that are not yet visible to the eye. There are also tests for susceptibility to tooth decay: enamel staining, detection of plaque and bacterial traces, and checking the resistance of hard tissues to acids. From these, the doctor determines high, medium, or low resistance to tooth decay. For people at risk, images may be taken once a year.

Why tooth decay is dangerous and when to see a dentist

A hole does not heal on its own. Without treatment, tooth decay destroys the pulp, and then more extensive treatment is needed — up to tooth extraction. Complications: pain, tooth fracture, inability to chew on that side, abscess, sensitivity, bone infection, bone loss, and tooth loss.

See a dentist if a tooth hurts or aches, if there is sharp pain from hot, cold, or sweet, if dark spots and pits are visible on a tooth, if the gums hurt, swell, or bleed when brushing. And even without complaints: if you haven't had a checkup in 2 years, or in 1 year if you are under 18. Doctors recommend a preventive checkup and cleaning every six months.

Tooth decay itself is not a reason to call an ambulance: for a hole and pain from sweets, go to a dentist. 103/112 — for a life-threatening condition.

This is reference material, not a diagnosis: what exactly is going on in your tooth and how serious it is is decided by a dentist at an appointment.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer