Decline in dental caries among 12-year-old children in Brazil, 1980-2005.

OBJECTIVES: This study was conducted to determine changes in values on the decayed, missing and filled teeth (DMFT) index in 12-year-old children in Brazil between 1980 and 2005, and to correlate DMFT values with human development index (HDI) values, time, population size of municipality and fluoridation of the water supply. METHODS: The present study represents a retrospective ecological study using secondary data from epidemiological surveys published in indexed journals, as well as data obtained from epidemiological official surveys carried out in Brazil in 1986, 1996 and 2003, and in the State of São Paulo in 1998 and 2002. Units of study were represented by Brazilian municipalities holding average DMFT index values for 12-year-old children. Multiple regression analysis was used to examine the correlations among DMFT and HDI values, and time, population size and fluoridation of the water supply. RESULTS: The final database included 550 records of DMFT values in 428 different towns. Regression analysis showed statistically significant correlations between DMFT index values and time (P < 0.001), fluoridation of the water supply (P < 0.001) and size of municipality (P < 0.001). Estimated mean DMFT index values were 8.36 in 1980, 6.08 in 1985, 4.45 in 1990, 3.29 in 1995, 2.46 in 2000 and 1.86 in 2005. CONCLUSIONS: Data showed a significant decrease in dental caries across the entire country, with an average reduction of 25% occurring every 5 years. General trends indicated that a reduction in DMFT index values occurred over time, that a further reduction in DMFT index values occurred when a municipality fluoridated its water supply, and mean DMFT index values were lower in larger than in smaller municipalities.

Fingernails and toenails as biomarkers of subchronic exposure to fluoride from dentifrice in 2- to 3-year-old children.

This work evaluated the use of fingernails and toenails as biomarkers of subchronic exposure to fluoride (F) from fluoride dentifrice (FD) in 2- to 3-year-old children. Ten 2- to 3-year-old children used a placebo dentifrice (without F) for 28 days, FD (1,570 ppm F as monofluorophosphate) for the following 28 days, and then placebo dentifrice for an additional 28 days, then returned to their usual dentifrices. Fingernails and toenails were clipped every 2 weeks, during the experimental period and for an additional 22 weeks. Nail F was analyzed by electrode following hexamethyldisiloxane-facilitated diffusion. There were no significant differences between fingernail and toenail F concentrations. Mean peak F concentrations occurred 16 weeks after starting the use of FD. Results suggest that fingernails and toenails may be suitable biomarkers of subchronic exposure to F from FD in small children.

Evaluation of total pH and soluble and ionic fluoride concentrations in dentifrices commercially available in Brazil.

PURPOSE: To verify the total (TF), soluble (SF) and ionic (IF) fluoride concentrations in the main Brazilian dentifrices for comparison and quality control according to the current Brazilian Ministry of Health Regulations, 2000. MATERIALS AND METHODS: Nineteen brands, from 2 batches, fresh or aged at 45 degrees C/48 h, had their F concentrations and pH analyzed with a specific electrode and pHmeter. To analyze the TF, 0.25 ml of 2M HCL was added to 0.25 ml of the suspension of each dentifrice. This was kept at 45 degrees C/1 h and 0.50 ml of M NaOH and 1.0 ml of TISAB II was added. To assay SF and IF, after centrifugation, the supernatant was used and the same steps described above were followed for SF. The analysis of IF was made by adding 0.25 ml of the supernatant to 1.0 ml of TISAB II, 0.5 ml of M NaOH and 0.25 ml of 2M HCL. Paired t tests were used for statistical analysis. RESULTS: The concentration of TF, SF and IF ranged from 555.7 - 1835.1; 449.3 - 1619.3 and 96.9 - 1534.6 ppm respectively. After aging, a significant reduction in the SF concentration (p = 0.00002) was observed, which did not occur for TF and IF (p > 0.05). Only the brand Colgate Baby presented pH 6.8. The other dentifrices had an alkaline pH, ranging from 7.1 - 9.9. CONCLUSION: Although the term 'soluble' was suppressed by the new regulation, the dentifrices analyzed were in accordance to the Brazilian Ministry of Health Regulations, 1989.