PLAQUE FLUORIDE AND MUTANS STREPTOCOCCI IN PLAQUE AND SALIVA BEFORE AND AFTER DISCONTINUATION OF WATER FLUORIDATION

Our aim was to compare plaque fluoride and the level of mutans strepto cocci in saliva and plaque before and 1 and 2 years after discontinuat ion of water fluoridation in Kuopio, Finland, For comparison, a low-fl uoride community was included in the study. Pooled plaque and saliva w ere collected from a random sample of 12-year-olds in both communities (n = 139). Enumeration of mutans streptococci in plaque was made on M SB agar and the level of salivary mutans streptococci was measured usi ng the Strip mutans(R) method. Fluoride was analyzed using a fluoride specific electrode. Caries, mutans gingival status, fluoride varnish a pplications and self-reported oral health habits were recorded at base line. Before discontinuation of fluoridation, the level of mutans stre ptococci in saliva was significantly lower in the fluoridated than in the non-fluoridated community. The difference in plaque mutans strepto cocci was not statistically significant. After discontinuation of wate r fluoridation? there was a significant shift towards elevated values of salivary mutans streptococci in the fluoridated community, but the level of mutans streptococci in plaque remained at the baseline level. There was no significant difference between the communities in the fl uoride content of plaque either before or after discontinuation of flu oridation. From the background factors, only caries scores (higher in the non-fluoridated community) and oral hygiene (better in the non-flu oridated community) were significantly different between the communiti es.