Dose de risco de fluorose dental a que são submetidas crianças em região de agua fluoretada : avaliação do efeito da temperatura ambiental e da exposição a dentifricios fluoretados

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

Considering the concem about the increase in dental fluorosis prevalence, all sources and factors that can contribute to systemic exposure to fluoride must be investigated. In fluoridated regions, temperature is an important factor, especialIy in tropical countries. The use of fluoridated dentifrices is also important because children, mainly those in the age of risk for dental fluorosis, ingest a lot of them during the brushing. In terms ofrisk, the threshold of 0.05 to 0.07mg F/ body weight/ day has been considered. This study evaluated the effect of environmental temperature on fluoride dose to which children were exposed due to fluoridated water, in the four seasons of the year. The contribution of toothbrushing with fluoride dentifrice was also determined. After local ethical committee approval and a preliminary study with five children during two seasons, 33 children (aged 20 to 30 months)from a local day nursery were selected for the final study. They drunk and ate food prepared with fluoridated water. To determine the total dose of fluoride exposure, duplicate-plate samples (solids and liquids) and products :from toothbrushing were collected, in the four seasons of the year. Fluoride from diet samples was extracted by HMDS-microdifusion method. The intake of fluoride from toothbrushing Was calculated by subtracting the amount of F recovered (expectorated and afier washing the fuush with distilled water) from the amount originally placed on each child s brush. Dose Was calculated through the division of fluoride intake during one day (mg F) by children s weight (kg). Fluoride analyses were done using F-specific electrode (Orion 9609). The results from fluoride concentration in drinking water (ppm F H2O), temperature (°C), dose (mg F/ kg/ day) deriving from diet (DoDi), dentiftice (DoDe) and total (DT), respectively in spring, summer, falI and winter, were: 1) ppm F H2O: 0.56+ 0.07 a, 0.54+ 0.07 a, 0.66+ 0.12 b and 0.66 +0.08 b. 2) °C: 22.7(16.8-28.5); 25.3(19.5-31.2); 17.2(9.7-24.8) and 18.1(10.3-25.9). 3) DoDi: 0.042+ 0.009 a; 0.039+0.009 a; 0.039+0.014 a and 0.039+0.014a. 4) DoDe: 0.058+0.046 a; 0.052+Q.020 a; 0.049+Q.021 a and 0.054+0.026 a. 5) DT: 0.094+0.049 a; 0.091+0.024 a; 0.087+0.019 a and 0.092+0.032 a. Values followed by distinct letters are statistically different (p<0.05). It can be concluded that: 1) considering temperature variation in this study (17 - 25°C), there wasn t a significant variation on fluoride dose to which children were submitted during the seasons of the year. However, fluoride concentration in drinking water was about 20% lower during the hottest seasons (spring and summer), masking the effect of larger amount of liquid intake and so, fluoride intake. If, during the hottest seasons, fluoride in drinking water had been 0.66 ppm, dose would have beco me 0.05 rng FI kgl day (instead of 0.04 mg F/ kg/ day), what would mean an increase of 0.2 in the fluorosis community index. 2) Children were exposed to a total dose deriving from diet and dentifrice that was above the threshold of 0.05 - 0.07 mg F/ kg/ day. Therefore, for safety in respect to dental fluorosis, three options are suggested for survey and latter evaluation: a) use reduced amounts of dentifrice (0.30 g) per brushing, maintaining the standard fluoride concentration of 1100 ppm F; b) develop dentiftices with lower fluoride concentration (600 ppm F); c) reduce fluoride concentration in drinking water to 0.3 ppm F. Among them, using reduced amounts of dentifrice seems to be the most appropriate option nowadays, considering the relation between risks and benefits of fluoride use

ASSUNTO(S)

dentifricio fluor fluorose dentaria

ACESSO AO ARTIGO

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