SAN FRANCISCO --If a child is old enough to spit, he is probably old enough to brush his teeth unsupervised.

Nonetheless, parents should be counseled on the risk of fluorosis from swallowing toothpaste, especially in children under 2 years of age. Maturity level counts, too. "I've got

"The greatest risk of fluorosis [comes from] ingesting it between 1 and 6 years of age. We can't narrow it down too finely yet. That's why you need to be careful with [fluoride] supplements and swallowing tooth-paste," she said. Leave fluoride mouth rinses and supplements for high-risk groups only she continued.

Fluorosis can leave white spots on tooth enamel, and in the worst cases it can cause brown, pitted enamel with black spots. Treatment involves the use of hydrochloric acid to bleach the teeth. Dr. Keels considers this process a last resort, as it can be dangerous to use on young, wiggly children.

"Too little fluoride, you have a caries risk, and too much fluoride, you have a fluorosis risk," said Dr. Keels, a pediatric dentist in the department of surgery and pediatrics at Duke Children's Hospital and Health Center, Durham, N.C.

Low-fluoride toothpastes for children are widely available in Europe. But most of the toothpastes that are marketed for children in the United States actually contain an adult dose of fluoride. Several toothpastes specifically formulated for children that are glycerin-based and contain no fluoride are now available in the United States, including Baby Orajel Tooth and Gum Cleanser, First Teeth Baby Toothpaste by Laclede Inc., and Gerber Tooth and Gum Cleanser. Advise parents that baby toothpastes and gels are found in the baby aisle, not in the toothpaste aisle.

But even these products may be unnecessary Dr. Keels said, "unless you have sibling rivalry--that is, you have an older sibling who can spit and is using fluoridated toothpaste, and the little one wants their special toothpaste. Then I think you need to have something like this available for the [younger] child." Otherwise, a washcloth or just water and a toothbrush work fine.

"Fluoride supplements predominantly work to prevent caries by a topical effect. You should not prescribe a supplement until teeth are in," she said. The best fluoride supplement is the tablet form, because children chew it and get some of the fluoride on their back teeth where it is most needed.

Know the fluoride content of the water in your area. Well water along the East Coast can have fluoride content as high as 8 ppm--far above the Centers for Disease Control and Prevention's recommended limit of 2 ppm. "Those children shouldn't drink their water," Dr. Keels advised.

For more information on fluoride use, pediatricians can access new guidelines from the CDC entitled "Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States" (MMWR 50[14]:1-42, 2001). Copies of the guidelines can be ordered by contacting the Superintendent of Documents at 202-512-1800. The guidelines are also available online at www.cdc.gov/mmwr/preview/mmwrhtml/rr5Ol4al .htm.

Children taking medication for asthma and ADHD, which can cause dry mouth, should be encouraged to drink a lot of water and to brush frequently. If these children have their permanent teeth, a dentist might even prescribe a stronger fluoridated toothpaste. This also goes for children undergoing orthodontic treatment. "My kids with braces I put on the stronger fluoridated toothpastes," Dr. Keels said.