Sugar serves as food for the cariogenic, or cavity-causing, bacteria that live in your mouth. When those bacteria feed on fermentable sugars, they produce lactic acid that damages tooth enamel. That damage can eventually lead to cavities.
Xylitol is an unfermentable sugar alcohol that the bacteria can’t process. That means no lactic acid is produced to damage the enamel.
Some experts think that xylitol helps to kill off cariogenic bacteria by interfering with their “energy consumption cycle.” According to a 2017 study analysis of 16 articles, xylitol showed insignificant results in killing bacteria.
Toothpaste can be a delivery system for xylitol. However, a 2015 laboratory study published in the European Archives of Paediatric Dentistry found that xylitol toothpaste didn’t significantly inhibit the growth of S. mutans.
A 2015 literature review of 10 studies compared fluoride toothpaste to fluoride toothpaste with 10 percent xylitol added. When children used the xylitol-fluoride toothpaste over a period of 2.5 to 3 years, it reduced their cavities by an additional 13 percent. The quality of the evidence was deemed to be low-quality.
Xylitol proponents suggest that it’s very effective when combined with fluoride in toothpaste. Xylitol helps protect the teeth from damage, and fluoride helps repair any damage that the teeth might sustain.
However, a found no significant difference — in terms of the reduction of tooth decay — between children using a xylitol-fluoride toothpaste and those using a fluoride-only toothpaste.
The American Academy of Pediatric Dentistry (AAPD) has endorsed xylitol as part of a complete strategy to prevent tooth decay or cavities. Due to “inconclusive” research, the AAPD doesn’t recommend using xylitol toothpaste.
The AAPD has also stated its support of additional research “to clarify the impact of xylitol delivery vehicles, the frequency of exposure, and the optimal dosage to reduce caries and improve the oral health of children.”
Many dentists suggest chewing gum that’s been sweetened with xylitol. A 2012 literature review indicates that chewing may enhance xylitol’s anticariogenic, or anti-tooth decay, effect. The results of the review ultimately found that xylitol’s anticariogenic effect is unknown and more research is needed.
According to the California Dental Association (CDA), to get the optimal dental benefits from xylitol, your daily intake should be 5 grams. You should use xylitol gum or mints three to five times per day.
The CDA also suggests that the frequency and the duration of xylitol use are both important. They recommend that gum be chewed for about five minutes and that mints be fully dissolved in the mouth and not chewed.
Be aware that xylitol is exceptionally toxic to dogs. If your dog eats xylitol toothpaste — or xylitol in any form — take them to the veterinarian immediately. Also bring along the packaging from the xylitol product, for the vet’s reference.
Xylitol is a sugar replacement that may be able to prevent tooth decay. Other positive attributes include not raising blood sugar levels and having fewer calories than sugar.
It’s too soon to make a definitive statement about xylitol toothpaste making — or not making — a significant impact on cavity prevention.
Although xylitol may be a defense against several bacteria, toothpaste may not be the most effective delivery system for it. If you’re considering switching to a toothpaste with xylitol, consult your dentist first.
If you decide to use a xylitol toothpaste, use it as part of your oral hygiene routine. Using xylitol toothpaste shouldn't be considered a substitute for standard dental care, like flossing and making regular visits to the dentist.