Should you be recommending xylitol to your patients, or is it just another gimmick on the market? 

Consider this: A recent meta-analysis determined the preventive fraction of xylitol to be 17%.1 This means if 100 people who are susceptible to caries are exposed to xylitol, 17 might not get a carious lesion. It’s up to the clinician’s discretion to determine if a preventive fraction of 17% makes the agent worthwhile.   

Xylitol's capacity to combat caries is limited
Xylitol's capacity to combat caries may be limited.

Another systematic review reported a much larger preventive fraction for xylitol — 58%!2 This review included randomized controlled trials in which members chewed xylitol-containing gum, which begs the question: To what extent was xylitol effective in preventing caries, versus salivary secretion?  

(In case you’re curious, saliva is 99% water.3

Xylitol is unproven as a standalone preventive agent

Yes, xylitol is effective in suppressing S. mutans without affecting normal oral flora.4 However, S. mutans count is a poor predictor of dental caries.  

The other confounding consideration about studying xylitol's efficacy is that it has never been studied as a standalone product. When its efficacy has been evaluated, participants were already using other preventive materials and products such as fluoride. 

It should be noted that another review by Marghalani concluded that the evidence to support xylitol's use as a preventive agent was “low.”5  

Xylitol requires frequent usage, large daily dose

There are a lot of xylitol-containing products on the market — lozenges, candies, etc. — but many of them may not stimulate the same volume of saliva a xylitol-containing gum can. Many patients might quickly chew the xylitol-containing candy or lozenge, then swallow it, which would decrease the product’s efficacy.  

Dosage and frequency of use of xylitol are important for harnessing its benefits: 

It needs to be consumed three to five times a day, preferably after meals. 

The dose is a total of 5–10 grams per day, which is enough to cause gastrointestinal distress in some patients. 

In effect, the challenge with xylitol is compliance. In some cases, but certainly not all, it’s already challenging enough to motivate a patient at high risk for caries to brush twice a day — now you’re going to ask them to further complicate their oral health regimen?  

If a patient is going to include xylitol in their regimen, it’s advisable they use a product relatively high in xylitol (1 gram or so). Many over-the-counter products with xylitol don’t contain enough to make a worthwhile difference: One stick of Wrigley’s Extra gum, for example, has only 0.08 grams of xylitol, and a piece of Trident gum has 0.17 grams. This means a person would have to chew about 29 pieces of Trident gum every day to get the minimum daily recommended dosage of xylitol. 

Xylitol requires a lot of work and consistency for a patient, with limited caries preventive benefits.  

The bottom line

  • Xylitol's capacity to combat caries is limited. Agents such as fluoride are arguably far more effective. 
  • It may be beneficial for patients to consume xylitol gum rather than lozenges so they can harness the salivary-stimulating benefits of gum.  
  • Patients need 5 to 10 grams of xylitol three to five times a day for it to be effective — this amount may cause GI distress.  ​

References

  1. ALHumaid J, Bamashmous M. Meta-analysis on the effectiveness of xylitol in caries prevention. J Int Soc Prev Community Dent. 2022 Apr 8; 12(2):133–138.

  2. Deshpande A, Jadad AR. The impact of polyol-containing chewing gums on dental caries: A systematic review of original randomized controlled trials and observational studies. J Am Dent Assoc. 2008 Dec;139(12):1602–14.

  3. Iorgulescu G. Saliva between normal and pathological. Important factors in determining systemic and oral health. J Med Life. 2009 Jul-Sep;2(3):303–7.

  4. Decker EM, Maier G, Axmann D, Brecx M, von Ohle C. Effect of xylitol/chlorhexidine versus xylitol or chlorhexidine as single rinses on initial biofilm formation of cariogenic streptococci. Quintessence Int. 2008;39:17–22.

  5. Marghalani AA, Guinto E, Phan M, Dhar V, Tinanoff N. Effectiveness of xylitol in reducing dental caries in children. Pediatr Dent. 2017;39:103–10.