Frequency of fluoride varnish application in prevention of dental caries

Frequency of fluoride varnish application in prevention of dental caries

Mexico City is one of the areas with the highest dental caries experience in the country.

Objectives: the purpose study was to estimate the possible differences in dental caries increment in schoolchildren receiving one application every six months of fluoride varnish compared with three consecutive applications once a year.

Methods: schoolchildren from a low-income area of Mexico City were selected. The children were randomly assigned to one of three subgroups: (1) personal bushing instructions and education delivered every six months; (2) fluoride varnish applied once every six months; (3) fluoride varnish applied three consecutive times, once a year. The children were followed for two years. World Health Organization dental caries criteria were used. In addition, incipient lesions (IL) and Dean fluorosis index were assessed. MANOVA (repeated measurements) was applied for data analysis.

Results: a total of 221 children were examined 8.6% was lost during follow-up. Initially, the children mean age was 10.3 years-old. The dmft at base line was 3.24 (±2.9) , the DMFT was 0.74 (±1.15). Two years later the DMFT was 1.35 (±1.65). The permanent teeth caries increment was 0.63 (±1.09). The Dean Community Fluorosis index was 0.51. At base line 64.5% of the children had at least on active IL on first permanent molars and only 8.7% at the end of the follow-up period (p<0.001), no difference in the proportion of active IL was found among the three groups . The MANOVA model fitting DMFT (controlling for fluorosis, number of teeth present and sex) indicated that the use of three consecutive times a year protocol had lower caries increment than biannual administration; however, no difference was detected with the brushing instruction group.

Conclusion: The frequency of varnish application had an impact in DMFT increment, three consecutive annual application showed better results.

Dental caries, schoolchildren, fluoride varnish, fluorosis