[Sugar studies at Turku].

This survey concerns the essential findings in two clinical trials. The first study involved almost complete substitution of sucrose (S) by fructose (F) or xylitol (X). After 2 years the mean DMFS-increment was 7.2 in the S-group, 3.8 in the F-group, and 0.0 in the X-group. The second study comprised partial substitution, the effects of a S- or X-containing chewing gum being compared during 1 year. The subjects consumed 4.0 chewing gums per day in the S-group and correspondingly 4.5 in the X-group. In the S-group the caries incidence assessed independently by clinical and radiographical means was significantly higher than in the X-group. It is concluded that the metabolic studies indicate the relative safety of perorally administered xylitol at the present dosage levels. In view on the findings in the chewing gum study it is suggested that the non- and anti-cariogenic properties of xylitol principally depend on its lack of suitability for microbial metabolism and the physico-chemical effects in plaque and saliva brought about through low and repeated dosage.