Tooth Decay and Cavities: Causes, Signs, Treatment and Prevention

What it is

Tooth decay is damage to a tooth's surface, the enamel. It happens when bacteria in the mouth make acids that attack the enamel, and it can lead to cavities (dental caries) — holes in the teeth. Untreated, it can cause pain, infection and even tooth loss.

How it happens

1. Plaque: some mouth bacteria combine with food into a soft, sticky film.
2. Acid: bacteria in plaque use the sugar and starch you eat and drink to make acids that eat away the enamel's minerals.
3. Tartar: over time plaque hardens; plaque and tartar also irritate the gums and cause gum disease.
4. Repair — up to a point: fluoride (from toothpaste, water and elsewhere), with your saliva, helps enamel rebuild its minerals. Teeth lose and regain minerals all day. But poor care and lots of sugary or starchy food mean enamel keeps losing.
5. The warning sign: a white spot where minerals are lost. At this stage decay can be stopped or reversed with better care and less sugar and starch.
6. The cavity: if loss continues, the enamel weakens and breaks down into a hole — permanent damage a dentist must fill.

Who's at risk

The main risks are not caring for your teeth and too many sugary or starchy foods and drinks. Risk is higher for people who:

• have too little saliva, from medicines, certain diseases or some cancer treatments;
• don't get enough fluoride;
• are very young — babies and toddlers drinking from bottles, especially juice or bottles at bedtime, bathe their teeth in sugar for long periods;
• are older — receding gums and worn teeth expose root surfaces to decay.

Symptoms

Early decay usually has none. As it worsens:

• toothache;
• sensitivity to sweets, hot or cold;
• white or brown stains;
• a cavity;
• an infection, possibly an abscess (pocket of pus) with pain, facial swelling and fever.

Diagnosis

Dentists look at and probe the teeth with instruments, ask about symptoms, and sometimes take an X-ray.

Treatment

Prevention

• Get enough fluoride: fluoride toothpaste, fluoridated tap water (most bottled water has none), and fluoride mouth rinse.
• Brush twice a day with fluoride toothpaste and floss regularly.
• Eat smart: limit sugary and starchy foods and drinks, eat balanced meals, and limit snacking.
• No tobacco, including smokeless — consider quitting if you use it.
• See a dentist for regular check-ups and cleanings.
• Sealants for children: thin plastic coatings on the chewing surfaces of the back teeth, applied as soon as those teeth come in.

Sources

Based on "Tooth Decay," MedlinePlus, U.S. National Library of Medicine, drawing on the NIH National Institute of Dental and Craniofacial Research; a work of the United States government in the public domain.