***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Previous in situ and in vitro studies have demonstrated that the chewing of sucrose-free gum after eating reduces the development of dental caries . To investigate the extrapolation of these findings to the clinical setting , we conducted a two-year study on 547 schoolchildren in Budapest , Hungary . Subjects in the " Gum " group were instructed to chew one stick of a commercially available sorbitol-sweetened chewing gum for 20 minutes after meals , three times daily . The " Control " group was not provided with chewing gum . After two years , the " Gum " group exhibited a 38.7 % reduction in incremental caries , excluding white spots , compared with the " Control " group . Including white spots , a corresponding 33.1 % reduction was indicated . These results clearly suggest that even in a moderate caries population practicing normal oral hygiene , including the use of fluoride dentifrices , an after-meal gum-chewing regimen can significantly reduce the rate of caries development Xylitol is effective as a non-cariogenic sugar substitute . Habitual xylitol consumption appears to select for mutans streptococci ( MS ) with impaired adhesion properties , i.e. , they shed easily to saliva from plaque . One hundred sixty-nine mother-child pairs participated in a two-year study exploring whether the mothers ' xylitol consumption could be used to prevent mother-child transmission of mutans streptococci . All mothers showed high salivary levels of mutans streptococci during pregnancy . The mothers in the xylitol group ( n = 106 ) were requested to chew xylitol-sweetened gum ( 65 % w/w ) at least 2 or 3 times a day , starting three months after delivery . In the two control groups , the mothers received either chlorhexidine ( n = 30 ) or fluoride ( n = 33 ) varnish treatments at 6 , 12 , and 18 months after delivery . The children did not chew gum or receive varnish treatments . MS were assessed from the mothers ' saliva at half-year intervals and from the children 's plaque at the one- and two-year examinations . The MS were cultured on Mitis salivarius agars containing bacitracin . The salivary MS levels of the mothers remained high and not significantly different among the three study groups throughout the study . At two years of age , 9.7 % of the children in the xylitol , 28.6 % in the chlorhexidine , and 48.5 % in the fluoride varnish group showed a detectable level of MS . In conclusion , therefore , habitual xylitol  consumption by mothers was associated with a statistically significant reduction of the probability of mother-child transmission of MS assessed at two years of age . The effect was superior to that obtained with either chlorhexidine or fluoride varnish treatments performed as single applications at six-month intervals 
    Output:
    
Polyols like maltitol and sorbitol are by no means inert and are thus not valid controls for xylitol .
Xylitol has beneficial effects on the oral flora not shared by other polyols .
The evidence so far supports specific xylitol-effects on oral bacteria , but not on saliva .
Xylitol can not be metabolized by plaque bacteria , contrary to sorbitol and other 6-carbon polyols , and may thus favour mineralization .
Some authors have cl aim ed that the beneficial effects of xylitol are solely based on saliva stimulation and that all sugar-free gums are similar in this respect .
In fact , in conditions where caries occurrence is high , even sorbitol gum can prevent caries.8 A recent study elegantly shows caries prevention with xylitol without any saliva stimulation .
Though strict inclusion criteria prevent conclusions based on systematic review s of the literature , evidence -based treatment guidelines can still be given for the use of xylitol .
Xylitol is a useful adjunct to traditional methods for caries control and prevention .