Collaborative WHO xylitol field studies in Hungary. V. Three-year development of oral hygiene.

The oral hygiene conditions were evaluated within a 3-year field study aimed at assessing the cariostatic value of partial substitution of sucrose by xylitol (X group) in comparison with systemic fluoride (F group) and restorative treatment only (C group). Parallel to caries and further associated studies the visible plaque index, based on the total number of permanent and deciduous teeth, was determined longitudinally at annual examinations in 688 institutionalized children, initially 6 to 11 years old. The observations were analyzed with regard to sex, age, experimental grouping, and total development. The oral hygiene conditions were generally poor. At the base-line examination only 26% of the children had acceptable oral hygiene; at the end this level was reached by 42%. A definite improvement was measured only in the X group, in which the final values differed significantly (p less than 0.001) from the base-line values and also from the end situation in the F and C groups. It is concluded that the development was influenced by several factors, such as different snacking habits and access to sweets, the study per se, and xylitol-induced effects.