A review of two studies on xylitol shows that clinical evidence is unclear on the effectiveness of xylitol products in preventing dental caries. The review, published by the Cochrane Library, cautions dentists to consider the extent of scientific and clinical evidence before recommending xylitol products for the purpose of reducing tooth decay.
The review, titled “Xylitol-Containing Products for Preventing Dental Caries in Children and Adults,” and conducted by researchers at the University of Manchester, United Kingdom, concluded that while there is some evidence that using a fluoride toothpaste containing xylitol may reduce tooth decay in the permanent teeth of children by 13% over a 3-year period when compared to a fluoride-only toothpaste, the evidence is low quality.
Researchers came to the conclusion after examining information from 4,216 school children who took part in two Costa Rican studies. The researchers also found that for other xylitol-containing products, including syrup, lozenges, and tablets, there was little or no evidence of any benefit in preventing tooth decay.
Xylitol has been used as a popular sugar substitute in sweets and is already known to cause less damage to teeth than sugar. It has been suggested that the addition of xylitol to products may help prevent tooth decay by stopping the growth of decay-producing bacteria.
But this review showed “there is insufficient high-quality evidence to prove that xylitol prevents tooth decay, ” said the study’s lead author, Philip Riley, MPH, of the School of Dentistry at the University of Manchester. “More well-conducted, randomized placebo-controlled trials that are large enough (in terms of number of randomized participants) to show a difference, if one exists, are needed.”
The review also says that several of the studies included in it did not report sufficient information on the side effects of xylitol, which can include bloating, diarrhea, and laxative effects. Side effects of (sugarless) gum, sweets, and other products “should be clearly reported in future studies,” Riley said.
While sugarless varieties of gum and candies are still better than sugar, a proven cariogenic, for patients who want them, “The best evidence for preventing tooth decay,” Riley said, “is still brushing with fluoride toothpaste and eating less sugar.”
The review showed the strength of the recommendation was weak for advising parents and caregivers of children over 5 years old that using sucrose-free polyol (xylitol-only or polyol combinations) chewing gum for 10 to 20 minutes after meals may reduce incidence of coronal caries. For adults, this recommendation was based on expert opinion because the evidence was lacking. The expert panel also advised, based on opinion, that the use of xylitol-containing lozenges or hard candies by children 5 years or older also may reduce the incidence of coronal caries.