Xylitol versus sorbitol for preventing tooth decay
What it found
Across eight clinical trials, most results favoured xylitol over sorbitol for preventing or reversing tooth decay, but the results were inconsistent and the trials had flaws.
The authors say the evidence is contradictory and more good-quality trials are needed.
What they found
Studies in people
Most results favoured xylitol
Of 18 datasets, 13 favoured xylitol, four showed no difference between xylitol and sorbitol, and one favoured sorbitol. For example, chewing 10.5 g of 100% xylitol gum five times daily for 5 minutes was linked to 50 to 70% fewer new caries lesions on previously caries-free surfaces after 5 years compared with sorbitol gum.
Results were inconsistent
The same xylitol gum chewed three times daily instead of five times daily did not show more rehardening of lesions. One trial found sorbitol gum was better than xylitol gum after 2 years, but xylitol gum was better after 3 years.
High risk of selection bias
None of the trials reported enough detail to show that patients were randomly allocated in a way that prevented anyone from predicting which group they would be in. Only one trial described a random allocation method, but it also had a run-in phase where everyone got xylitol first.
Risk of attrition bias
For three of the seven datasets where it could be checked, the conclusions changed if a worst-case scenario was assumed for people lost to follow-up. For the other 11 datasets, there was not enough information to check.
Possible confounders
Fluoride exposure and saliva stimulation from chewing gum may have affected the results, especially because the trials had a high risk of selection bias. These factors could have made xylitol look better than it really is.
Other findings
Low risk of publication bias
A funnel plot and Egger's regression suggested that publication bias was low, but the authors say there were too few data to be sure.
What the authors conclude
- They recommend that such trials should use proper randomisation and allocation concealment, report numbers lost to follow-up, and follow the CONSORT statement.
How it was done
Xylitol is thought to have specific tooth-protecting effects beyond other sugar alcohols like sorbitol, based on laboratory observations. The authors wanted to see whether clinical trials in people actually show that xylitol is better than sorbitol at preventing and treating tooth decay.
They searched databases up to 19 March 2011 for clinical trials that compared xylitol with sorbitol and measured tooth decay outcomes. Nine articles were found, eight were accepted, and data were extracted from six separate trials in places including Belize, Lithuania, the Marshall Islands, Michigan and Ohio. The trials used chewing gum, syrup or dragees, and lasted from 10.5 months to 5 years.
What it can’t tell you
- The trials were not well randomised, so it is unclear whether the differences seen were truly due to xylitol or sorbitol.
- Many trials did not report enough information to check for attrition bias, so the results may have been affected by people dropping out.
- Fluoride exposure and saliva stimulation from chewing gum could have influenced the results, so the true effect of xylitol alone is uncertain.
Who paid
- Authors work at
- University of the Witwatersrand, South Africa
The paper
- Title
- Effect of xylitol versus sorbitol: a quantitative systematic review of clinical trials
- Type
- Systematic review
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Mickenautsch S, Yengopal V (2012). Effect of xylitol versus sorbitol: a quantitative systematic review of clinical trials. International dental journal. doi:10.1111/j.1875-595X.2011.00113.xFree full textPubMed 23016999DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error