Occurrence of dental caries and gingivitis in low, medium and high fluoride areas in Finland

Abstract

The study was performed on a material of 365 Finnish schoolchildren aged 13--15 years. One-third of the children were from Jyväskylä, with 0.2 parts/10(6) fluoride in the drinking water, one-third from Kuopio, with an artificially corrected 1.0 parts/10(6) fluoride content since 1959, and one-third from Hamina, where the natural fluoride content of the drinking water varies between 2.5 and 5.0 parts/10(6). All the children were scored for the Visible Plaque Index (VPI), the Gingival Bleeding Index (GBI) and for past caries experience (DFS). With increasing fluoride content of the drinking water the DFS scores were found to decrease significantly. No such difference was observed with regard to the VPI scores. The prevalence of gingival bleeding was found to be highest in Hamina (2.5 parts/10(6)). A highly significant positive correlation was found between individual VPI and GBI scores in all three towns. No corresponding correlations were found between the individual VPD and DFS scores. The latter finding is in desagreement with the generally accepted view that oral hygiene is an efficient caries-preventive measure.