This research marks a new beginning to the evaluation of the effectiveness of 100% xylitol chewing gums on the salivary measures and oral micro flora which attribute to the caries preventive action.

The major findings of our double blind parallel arm Randomized controlled trial were that the mean age of the study subjects was 19.45+/- 1.37 years. The salivary pH in Group I had significantly increased after 30 days of intervention (5.83 to 6.62, p<0.05) as compared to the baseline but did not show a sustained effect at the follow-up at 60 and 90 days.

The salivary buffering capacity also significantly varied between the two groups after 30 days of intervention and had a sustained effect only upto 60 days follow-up period.

The results in our trial showed that there was a difference in the salivary flow rate between the two groups at 30 days of intervention (1.34 ml/minute to 2.46 ml/minute), but at the follow-up time intervals the salivary flow rate did not differ significantly between the two groups. However, Group I showed an increased salivary flow rate in the follow-up time intervals and sustained the effect till the end of our study.

There were significant reductions in salivary levels of mutans streptococci at 30 days after intervention when compared to the baseline and the effect was maintained even beyond interruption. Group I showed greater amounts of mutans streptococcus counts reduction at the end of follow-up phase when compared to Group II.

Thus our study supports the action of 100% xylitol chewing gums at the dose and frequency used in our study in reduction of mutans streptococci and this strategy can be used as a targeted caries-preventive measure after the evaluation of its cost-effectiveness through various preventive programs.