2000 Oct;28(5):382-9

Decline of caries prevalence after the cessation of water fluoridation in the former East Germany.

Kunzel W, Fischer T, Lorenz R, Bruhmann S

Dental School of Erfurt, Department of Preventive Dentistry, Friedrich-Schiller-University of Jena, Germany. Simionoff@zmkh.ef.uni-jena.de

In contrast to the anticipated increase in dental caries following the cessation of water fluoridation in the cities Chemnitz (formerly Karl-Marx-Stadt) and Plauen, a significant fall in caries prevalence was observed. This trend corresponded to the national caries decline and appeared to be a new population-wide phenomenon. Additional surveys (N=1017) carried out in the formerly-fluoridated towns of Spremberg (N=9042) and Zittau (N=6232) were carried out in order to support this unexpected epidemiological finding. Pupils from these towns, aged 8/9-, 12/13- and 15/16-years, have been examined repeatedly over the last 20 years using standardised caries-methodological procedures. While the data provided additional support for the established fact of a caries reduction brought about by the fluoridation of drinking water (48% on average), it has also provided further support for the contention that caries prevalence may continue to fall after the reduction of fluoride concentration in the water supply from about 1 ppm to below 0.2 ppm F. Caries levels for the 12-year-olds of both towns significantly decreased during the years 1993-96, following the cessation of water fluoridation. In Spremberg, DMFT fell from 2.36 to 1.45 (38.5%) and in Zittau from 2.47 to 1.96 (20.6%). These findings have therefore supported the previously observed change in the caries trend of Chemnitz and Plauen. The mean of 1.81 DMFT for the 12-year-olds, computed from data of the four towns, is the lowest observed in East Germany during the past 40 years. The causes for the changed caries trend were seen on the one hand in improvements in attitudes towards oral health behaviour and, on the other hand, to the broader availabilty and application of preventive measures (F-salt, F-toothpastes, fissure sealants etc.). There is, however, still no definitive explanation for the current pattern and further analysis of future caries trends in the formerly fluoridated towns would therefore seem to be necessary.

PMID: 11014515, UI: 20466443

Community Dent Oral Epidemiol

2000 Aug;28(4):281-8

Caries in the primary dentition, after discontinuation of water fluoridation, among children receiving comprehensive dental care.

Seppa L, Karkkainen S, Hausen H
Institute of Dentistry, University of Oulu, Finland. liisa.seppa@oulu.fi

The city of Kuopio in central Finland had fluoridated piped water for 33 years, beginning in 1959. Due to strong opposition by various civic groups, water fluoridation was stopped at the end of 1992. There is little information on the consequences of stopping fluoridation in a community with comprehensive dental care for all children and adolescents, who are frequently exposed to different fluoride measures both at home and in the dental office.

OBJECTIVES: The aim of this repeated cross-sectional survey was to examine how discontinuation of water fluoridation in Kuopio affected caries in the primary dentition. Changes in the mean dmfs values between 1992 and 1995 in Kuopio were compared to those in Jyvaskyla, a low-fluoride community that has repeatedly been used as the reference area for Kuopio.

METHODS: In 1992 and 1995, independent random samples of all children aged 3, 6 and 9 years were drawn in Kuopio and Jyvaskyla. The total number of subjects examined was 421 in 1992 and 894 in 1995. Calibrated dentists registered caries clinically and radiographically.

RESULTS: In all age groups both in 1992 and 1995, the point estimates for mean dmfs values were lower in the non-fluoridated town. In both towns, the observed mean dmfs values were smaller in 1995 than in 1992.

CONCLUSION: Despite discontinuation of water fluoridation, no increase of caries frequency in primary teeth was observed in Kuopio within a three-year period.