School-based fluoride mouth rinse (FMR) programs offer substantial caries-prevention benefits to children in high-risk schools over the long term, according to a study in the Journal of Dental Research (December 27, 2011).
The benefits to children attending low-risk schools in North Carolina, where the study was conducted, were considerably less, according to the study authors.
High-risk students who participated in an FMR program over five to six years had a 55% reduction in total carious surfaces, while low-risk students only saw a 10% reduction. In contrast, high- and low-risk students saw a 15% and 1% reduction, respectively, in total carious surfaces after one year in an FMR program.
— Kimon Divaris, DDS
The study also produced a new means of determining what constitutes an "at-risk" school population with regard to caries, according to the study authors.
"For a long period of time, school selection has been based on the socioeconomic profile of the students attending each school," Kimon Divaris, DDS, an assistant adjunct professor at the University of North Carolina (UNC) at Chapel Hill School of Dentistry, told DrBicuspid.com. "Our results showed that using a more proximal risk indicator, such as levels of untreated caries, may be a superior criterion in determining risk status for program implementation purposes."
Dr. Divaris and his team set out to determine whether the effectiveness of school-based, weekly FMR programs varied by school-level caries risk. While 33 U.S. states had active FMR programs in 2008, new data on the effectiveness of these programs are minimal, according to Dr. Divaris and his co-authors.
But obtaining new data was only part of the team's goal.
"We wanted to inform and guide dental public health policy officials on the selection of schools where the program could be implemented," Dr. Divaris said. "This was an important question because of there is a trend of growing disparities and declining oral health levels among U.S. children ages 2 to 11. So the school population is a strategic target for caries preventive efforts."
Long-term effects evident
For this investigation the researchers studied clinical and parental-reported data from a 2003-2004 North Carolina oral health survey of children in kindergarten through grade 12; only data for children in grades 1 through 5 were considered. The analytical end points were caries experience in primary teeth and the entire dentition.
"We used information available from a statewide surveillance system on untreated caries in the primary dentition for students in all kindergarten classrooms in the study subjects' school to define risk," the study authors wrote. Untreated caries was chosen over caries experience because "untreated disease might capture some additional dimensions of socioeconomic risk."
Overall, 1,363 children were included in the study. The qualification for a high-risk school was an average of one untreated carious tooth per kindergarten student. Consequently, 23% of the sample was considered high-risk. Analyses were done to determine whether school-level caries risk had an impact on the effectiveness of FMR.
Fluoride mouth rinse was credited with minor reductions in the presence of caries on primary tooth surfaces, but the impact was greater in high-risk schools. Prediction models suggested that caries prevalence would be identical after students went through two years of FMR participation.
"After the two model-predicted caries experience functions intersect, they diverge in favor of students in the high-risk schools participating in the FMR program," the authors wrote. "Even though the overall preventative effectiveness of a weekly FMR program was found to be weak and statistically nonsignificant, long-term effects were evident in high-risk groups."
These results could help public health officials use their resources more effectively with certain populations.
"Each state has an oral health needs map, but we know that disparities are on the increase in most areas, and young age groups are the most vulnerable," Dr. Divaris explained. "We were able to use surveillance data and levels of untreated caries to define risk groups, which was the novel element in our research approach."
He and his collaborators were confident in this means of classification.
"Results from this study support the use of untreated decay during kindergarten enrollment risk stratification as a superior marker to some other methods in common use in public health," they wrote.
