Collaborative WHO xylitol field studies in Hungary. I. Three-year caries activity in institutionalized children.

The aim of this 3-year field study was to assess the value of partial substitution of sucrose with peroral xylitol (14-20 g/day) as a caries-preventive measure (X group) in comparison with systemic administration of fluoride (F group) and restorative treatment procedures solely (C group). An F dentifrice was used unsupervised in the X and F groups, the former containing 10% xylitol. The C group used customary, predominantly F-free dentifrices distributed by the local health authorities. The final material consisted of 689 institutionalized children (6-11 years). Caries was scored yearly in duplicate by two continuously calibrated teams. At base line the X group had a significantly higher caries prevalence than the F and C groups. The 3-year DMFS increment was 4.2 in the X group, 6.5 in the F group, and 7.7 in the C group. The corresponding ratio (RS) between caries incidence and the tooth surface population at risk was RSx, 4.9; RSF, 6.6; and RSC, 8.6. It is concluded that dietary xylitol in solid sweets resulted in a lower increment of caries than obtained in the F and C groups (p less than 0.001, covariance analysis, with base-line prevalence, number of permanent teeth, and visible plaque index as covariants).