Baby bottle alert: even infants and toddlers can suffer from tooth decay.

At 3 years old, she refused new foods. Then she rejected hot, cold, and hard foods. Now she will not eat any solid foods. Her brown, rubbery front teeth embarrass her around her preschoolmates. She sleeps poorly and pays scant attention in school because of the dull, chronic pain in her mouth.

Did this child eat too much candy? No, she suffers from the long-term effects of baby bottle tooth decay, also called nursing caries. It develops in children whose teeth are exposed to bacteria-containing liquids over long periods from the time their teeth erupt in babyhood. The telltale mark is that decay appears on the upper front teeth, where it is not normally found.

No national data exist stating how common this disease is, but David Johnsen, D.D.S., of the College of Dentistry, University of Iowa, estimates that it occurs in 5 percent of middle-class children.

Baby bottle tooth decay (BBTD) can be traced to improper bottle contents or improper feeding techniques. "Most often, a baby has slept with a bottle filled with a liquid other than water," says Dr. Johnsen. "The digestive action of the saliva slows during sleep, and whatever is in the bottle pools around the teeth. This gives sugars in the liquid ample time to react with plaque to form acids that damage tooth enamel and cause decay."

Another common scenario is the toddler who carries a bottle around, sipping juice or milk from it several hours a day. This gives the teeth direct, prolonged contact with sugar. Each time a child eats sugar in any form, acid attacks the teeth for 20 minutes unless they're cleansed immediately.

While milk can cause BBTD, more frequent culprits are fruit juices, sugar or honey water, sweetened gelatin water, or carbonated beverages. Even formula or cereal can be harmful. Water is the only safe liquid.

"Normally milk protects the teeth," says Lou Ripa, D.D.S., M.S., professor and chair, Department of Children's Dentistry, State University of New York at Stony Brook. "But when it sits on the teeth for long periods of time, a bacteria called streptococcus mutans establishes itself, and rampant decay sets in if the teeth aren't cleaned."

Is BBTD a problem before the teeth come in? Technically it is not, but poor habits set the stage for decay. "The bacteria doesn't appear until teeth come in, because it adheres to a hard, nonsloughing surface," says Dr. Ripa. "But if this pooling of carbohydrate liquids is present before teeth erupt, then even as they come in, they're going to be attacked."

How Can BBTD Be Prevented?

These steps are recommended to parents of babies in which one or more teeth have come in.

* Clean infants' teeth after feeding.

Jeff Mabry, D.D.S., pediatric dentist with the U.S. Public Health Service, tells parents to begin brushing or wiping their baby's teeth as soon as the teeth come in. What if the baby falls asleep? "Make sure they have swallowed the milk and then use a clean finger or damp washcloth to gently wipe the front four baby teeth without waking them," says Dr. Mabry.

* Fill comfort bottles with water only.

If the baby refuses water, try progressively diluting the milk or other liquid until there is only water in it.

* Never coat a pacifier with honey or sugar.

* Limit the bottle to feeding times only.

Many pediatric dentists as well as the Children's Dental Care Foundation at Children's Hospital Medical Center in Cincinnati, Ohio, recommend that parents do not offer the bottle or breast for comfort only. They encourage alternate ways of comforting baby at bedtime or naptime: offering a security blanket or teddy bear, singing or playing soft music, providing a musical mobile, giving a back rub, or rocking in mommy's arms or an infant swing.

Alice Horowitz, education specialist with the Institute of Dental Research in Bethesda, Maryland, points out that these methods don't always work. "There are some children who need more sucking than others," says Horowitz. "No teddy bear or favorite book will replace it. In that case, parents shouldn't feel guilty about giving a bottle at bedtime. But they should be careful to fill it only with water."

* Wean the child by 1 year of age.

The American Academy of Pediatric Dentistry and the Children's Dental Care Foundation recommend that babies be weaned by 1 year of age. Then if BBTD is developing, it would be halted before progressing further.

Horowitz believes weaning at I year is unnecessary if the causes of BBTD (improper contents and improper methods) are not present.

"We don't have enough evidence to say that babies should be weaned by 12 months. The problem is not how long a child uses a bottle, but the carbohydrate inside the bottle." Besides taking precautions to prevent BBTD, parents should recognize its earliest stages. It first appears as a "white spot." The normal glossiness of the enamel is replaced by a matte white appearance. This can occur even before the child is 1 year old.

At this stage a pediatric dentist can use a sealant to restore the tooth to a healthy state. More advanced decay requires tooth-colored or silver fillings. If tooth damage is severe, there may be nerve damage, and a stainless-steel crown might be required. Teeth that have turned brown and rubbery can crumble, causing painful infections and abscesses.

The best way to avoid these problems is to brush your baby's teeth. "Use a soft, circular scrubbing motion," says Dr. Johnsen. "Some parents like to use toothpaste because it contains fluoride and gives a freshening effect. Others find that by not using toothpaste they can better see if they've removed the plaque. The most important thing is brushing."

Baby bottle tooth decay is a serious problem, but preventing it is simple. It's your responsibility to establish early a routine that will protect your child's dental health so your child can face the world with a smile.