OBJECTIVE: Since 1984 a weekly supervised fluoride mouthrinsing programme has been implemented for schoolchildren in Hisayama, Japan. Consequently, four years after the start of the programme the DMFT index for 12.5-year-old schoolchildren in Hisayama decreased to a value of less than 3.0. However, since 1992 it has increased. The purpose of this study was to investigate the causes of this increasing prevalence of dental caries since 1992. PARTICIPANTS: One hundred and one schoolchildren aged 12 years in 1994 were selected. This age group showed the highest increase in the prevalence of dental caries in that year. OUTCOME MEASURES: Children who had discontinued the use of fluoride mouthrinse for one year or more were identified by means of a confidential questionnaire. Oral examination was carried out, by three examiners, under a suitable artificial light using a mirror and an explorer. RESULTS: The DMFT and DMFS indices of the continuous mouthrinsing (CM) group were significantly lower than those of the discontinuous mouthrinsing (DM) group (P < 0.001). Significant differences between the CM and DM groups were also observed in the DMFT rates for premolars (P < 0.05) and for the first molar (P < 0.001). CONCLUSIONS: The continuation of fluoride mouthrinsing for children of school age was important in achieving the advantages of the programme in Hisayama.
OBJECTIVE: Since 1984 a weekly supervised fluoride mouthrinsing programme has been implemented for schoolchildren in Hisayama, Japan. Consequently, four years after the start of the programme the DMFT index for 12.5-year-old schoolchildren in Hisayama decreased to a value of less than 3.0. However, since 1992 it has increased. The purpose of this study was to investigate the causes of this increasing prevalence of dental caries since 1992. PARTICIPANTS: One hundred and one schoolchildren aged 12 years in 1994 were selected. This age group showed the highest increase in the prevalence of dental caries in that year. OUTCOME MEASURES: Children who had discontinued the use of fluoride mouthrinse for one year or more were identified by means of a confidential questionnaire. Oral examination was carried out, by three examiners, under a suitable artificial light using a mirror and an explorer. RESULTS: The DMFT and DMFS indices of the continuous mouthrinsing (CM) group were significantly lower than those of the discontinuous mouthrinsing (DM) group (P < 0.001). Significant differences between the CM and DM groups were also observed in the DMFT rates for premolars (P < 0.05) and for the first molar (P < 0.001). CONCLUSIONS: The continuation of fluoride mouthrinsing for children of school age was important in achieving the advantages of the programme in Hisayama.