Association between Urine Fluoride and Dental Fluorosis as a Toxicity Factor in a Rural Community in the State of San Luis Potosi

Abstract

Objective. The aim of this study is to investigate urine fluoride concentration as a toxicity factor in a rural community in the state of San Luis Potosi, Mexico. Materials and Methods. A sample of 111 children exposed to high concentrations of fluoride in drinking water (4.13 mg/L) was evaluated. Fluoride exposure was determined by measuring urine fluoride concentration using the potentiometric method with an ion selective electrode. The diagnosis of dental fluorosis was performed by clinical examination, and the severity of damage was determined using Dean's index and the Thylstrup-Fejerskov (TF) index. Results. The range of exposure in the study population, evaluated through the fluoride content in urine, was 1.1 to 5.9 mg/L, with a mean of 3.14 ± 1.09 mg/L. Dental fluorosis was present in all subjects, of which 95% had severe cases. Higher urine fluoride levels and greater degrees of severity occurred in older children. Conclusions. The results show that dental fluorosis was determined by the presence of fluoride exposure finding a high positive correlation between the severity of fluorosis and urine fluoride concentration and the years of exposure suggested a cumulative effect.

Prevalence of dental fluorosis in Mexico 2005-2015: a literature review

“…Regarding fluorosis severity, we observed percentages in moderate or severe forms reaching 71.2% in Chihuahua 28 and 100% in San Luis Potosí 16 which is like that found in an Ethiopia community though in Mexican studied areas concentration of fluoride in water was not as high as that found in Ethiopia (8.5 ± 4.1 ppm) where prevalence of moderate or severe forms represented 74%. 40 DF cannot be attributed to water fluoride content only, even if it is a major risk factor, but to a confluence of different risk factors 19 such as consuming boiled water, living at a high altitude, 29 having malnutrition, specially low calcium consumption, 27 also the age children started brushing with toothpaste at (especially before two years of age), 17 type of water used for drinking or cooking,…”

“…using tap water which was highly prevalent in a population in San Luis Potosí), 16 and consumption of bottled beverages, 21 soft drinks, 22,26 and juices. As Perez-Perez 27 indicated that moderate and severe fluorosis was associated with soft drink consumption even when controlling for age, socio-economic status, and water fluoride concentration.…”

Dental fluorosis, fluoride in urine, and nutritional status in adolescent students living in the rural areas of Guanajuato, Mexico

“…In San Luis Potosí State, in an area where fluoride level was similar (4.54 ppm), DF was present in all participants, of which 95% had severe cases. [15] In a Mexican community where fluoride concentration was lower (1.9 ppm) than that found in our study area, DF prevalence was 98%, being severe in 47%. [16] Rodriguez et al .…”

“…[1517] In an Indian group aged 6 to 18, the highest UF concentration recorded was 17 mg/L when fluoride water concentration was of 2.11 mg/l. [2] In other study in Indian population, in individuals aged 11–16 years, fluoride concentration found in urine samples ranged from 0.90 to 3.25 mg/L with an average of 2.35 mg/L.…”

“…[15] who found that urine fluoride concentration was more elevated in those showing greater fluorosis severity. They reported levels of 2.66 (0.89) in children with TFI of 4–5, 3.11 (1.06) in the TFI of 6–7, and 3.75 (1.10) ppm in TFI of 8–9.…”