RESUMO
Twenty children with endemic vesical stones showed normal plasma and urinary excretion of fluoride on a mean fluoride intake of 2.5 +/- 0.8 mg/24 h. The mean fluoride content of the stones obtained from these children was 315.6 +/- 264.9 micrograms/g in the nucleus and 229.9 +/- 212.8 micrograms/g in the periphery (this was not statistically significant). Calcium-containing stones had a higher fluoride content than stones containing uric acid and ammonium urate. It was concluded that children with endemic vesical stones have normal fluoride metabolism. Trace quantities of fluoride present equally in the nucleus and peripheral parts of the stones suggest that fluoride does not cause initiation or growth of the nucleus of vesical stones and is adventitiously deposited with calcium salts in these stones.