Selection Criteria
The authors focused on controlled clinical trials and randomized clinical
trials with a study period of at least 1 year. They also included systematic re-
views. Studies were located using the Ovid MEDLINE (1956 to November
2009) and PubMed (1950 to November 2009) databases. The search strat-
egy was adapted to also include literature from the ISI Web of Science
(1945 to November 2009) and Latin American and Caribbean Health Sci-
ence (LILACS; 1982 to November 2009) databases. The Cochrane Library
was also searched (accessed first week of November 2009) for clinical trials
and systematic reviews of the effect of xylitol on caries progression. Hand
searching and ‘‘Related Articles’’ link searches were performed in selected
articles, where applicable.