Absence of painful neuropathy after chronic oral fluoride intake in Sprague-Dawley and Lou/C rats.

The possibility that chronicle oral ingestion of fluoride-rich water could modify peripheral pain sensitivity was studied in two strains of adult rats, Sprague-Dawley and Lou/C rats. Sodium fluoride was given orally in water to male Sprague-Dawley (75 and 150 ppm) and Lou rats (150 ppm) for 15 and 27 weeks, respectively. Using classical behavioural evaluation methods of pain symptoms, only slight tendencies to a thermal hyperalgia and a mechanical allodynia were observed in Sprague-Dawley rats.