Squirting the sugar substitute xylitol on infants' teeth could help prevent the tooth decay that afflicts an estimated 28% of U.S. children ages 2 to 5, according to a new study.
Severe tooth decay occurs when bacteria such as Streptococcus mutans proliferate in the mouth and attack enamel. Largely preventable, it strikes poor children twice as often as wealthier ones. The problem is compounded because decay is more likely to go untreated in poorer communities.
Native American, Alaska Native, and indigenous Hawaiian and Pacific Island children are hit the hardest, due to diets high in sugar, inadequate access to fluoride in water and toothpaste, and subpar dental care.
The study, by researchers of the University of Washington in Seattle, was conducted in the Republic of the Marshall Islands, where early childhood tooth decay occurs at double or triple the rate of the average U.S. mainland community. Just over half of Marshall Islands 2-year-olds have at least one decayed tooth.
Researchers instructed parents, aided by community healthcare workers, to give xylitol in a topical oral syrup to children ages 9 months to 15 months over a period of about a year. The 94 children in the study were divided into three groups: One group received a single 2.67-gram dose of xylitol a day; another got 8 grams a day delivered in two doses; the third got 8 grams in three doses.
Of the first group, 51.7% had some tooth decay. In the two-dose-a-day and three-dose-a-day groups, rates were 24.4% and 40.6%, respectively. In addition, the numbers of decayed teeth were significantly fewer in the latter two groups. No adverse effects of xylitol were reported.
The results, published in this month's Archives of Pediatrics & Adolescent Medicine, suggest that using an oral syrup with xylitol while baby teeth are growing could prevent as much as 70% of tooth decay, the authors said.
Xylitol is a naturally occurring sugar approved for use in foods since 1963. It can be found in chewing gum, gumdrops and hard candy. It has been used effectively in chewing gum or lozenges in older children to prevent decay in permanent teeth.
The sugar reduces the number of decay-causing bacteria by impeding their ability to produce lactic acid, which damages teeth; or glycans, substances that allow bacteria to stick to teeth.
"In our current state, where so many of pathogenic bacteria become drug-resistant, using novel approaches to prevent infectious diseases needs to be . . . thought about a lot more," said study coauthor and University of Washington professor Marilyn Roberts.
Roberts said that xylitol affects only the tooth-decay-causing bacteria, leaving other "good" bacteria alone.
Xylitol is at least twice as effective as fluoride in preventing tooth decay, said study coauthor Dr. Peter Milgrom, also of the University of Washington.
Fluoride repairs teeth by rebuilding them with calcium and phosphate in the mouth. If too much damage occurs, this process can't keep up. Taken together, fluoride and xylitol "would absolutely have a synergistic effect," Milgrom said.
The key is to start early, he said. Before they emerge, teeth have no bacteria on them. Once the teeth begin growing into the mouth, bacteria begin attacking. Intervention during the year when teeth are growing in could have a significant effect, he said: "If we go in there with xylitol early, the teeth don't get colonized with bad bacteria."
"This study gives us a lot of optimism about an agent that's relatively inexpensive, easy to apply, and safe to prevent tooth decay," said Dr. Paul Casamassimo, chief of dentistry at Nationwide Children's Hospital in Columbus, Ohio.
Oral syrup may be an easier regimen for patients to follow than more traditional xylitol gum and lozenges, he added. "It can be given in a quick dose, and the patient doesn't have to chew on it or suck on it frequently. . . . We worry about giving people too many things to do to take care of teeth, and it can fall to the wayside."
Still, there could be unintended consequences, said Dr. Michael Weitzman, professor of pediatrics and psychiatry at New York University. The same children prone to decay may also be prone to obesity.
"You have to think about the number of calories that you're now going to expose children to," Weitzman said. "Commercial products can have as many as 10 calories per tablespoon. If you up your intake of calories by 10 per day, that's a pound a year; 100 calories a day is a pound a month."