In Niigata Prefecture as of 1986, 536 educational institutions composed of kindergardens, primary schools, and junior high schools in 71 municipalities had adopted the school-based fluoride mouth rinsing (FMR) program and good results in the improvement of the dental caries situation have been obtained. The percentage of primary schoolchildren in the FMR program is 22%.
However, it will be impossible to attain the goal of the WHO in the year 2000 (DMFT 3.0 at 12 years of age), if only 22% of chldren participate in the FMR program.
The purpose of this study was to develop a prediction model to estimate the caries prevalence at 12 years of age in the year 2000 and to analyze conditions in order to attain the goal of the WHO.
Five parameters were designed to predict the caries prevalence for the future.
The parameters were as follows:
a. Percentage of children participating in the FMR program in 1992. (a) 22%: no increase from 1986, b) 41%: all towns and villages perform FMR in addition to the present cities' prevalence in 1992, c) 50%: reach 50% in 1992, d) 100%: reach 100% in 1992)
b. Effectiveness of dental caries reduction by FMR.
a) Clinical effectiveness; Effectiveness of dental caries reduction by FMR in ideal conditions.
b) Community effectiveness; Effectiveness of dental caries reduction in all schoolchildren participating in the FMR program in Niigata Prefecture.
c. Natural reduction of dental caries without FMR.
d. Annual increment of dental caries between 11 (6th grade of primary school) and 12 (1st grade of junior high school) years of age.
e. Annual change in children's population in municipalities in Niigata prefecture
Twenty-eight cases were assumed from these parameters.
Estimated values were calculated in these 28 cases.
The maximum DMFTindex in the year 2000 will be 4.05 if the percentage of children performing FMR by community effectiveness is 22% and there is no natural reduction of dental caries without FMR. The minimum will be 1.73 if the percentage of children in the FMR program because of clinical effectiveness is 100% continually from preschools and there is natural reduction of dental caries without FMR. Although there are 9 cases which attain the goal of the WHO, 6 of these suppose 100% participation in 1992. However, it seems impractical to expect 100% participation. The remaining 3 cases suppose participation of 41% or 50%, and the effectiveness of dental caries reduction by FMR is clinical effectiveness. And there are 2 cases which approach the goal of the WHO under the condition of 41%. One case is 3.26 (No. 8) based on the condition that there is natural reduction of dental caries without FMR, and another is 3.12 (No. 11) based on the condition that primary school-chidren perform FMR continually from preschools. Therefore, we suggest that in order to attain the 12-year-old children's goal of the WHO in Niigata Prefecture, the percentage of children performing FMR should be more than 41% (all towns and villages performing FMR in addition to the present cities' prevalence) in the year 1992, the schoolchildren should perform FMR continually from preschools, FMR program should be performed properly under the supervision of the people who are concerned with health and education to get more effective caries prevention, and the use of fluoride-containing dentifrices should be encouraged to get natural reduction of dental caries without FMR.