Inhibitory effect of barium on caries formation in rats.

The aim of this investigation was to study the effect of barium and fluoride in drinking water on caries formation in rats. Sprague-Dawley rats were fed a cariogenic diet (MIT-200) 17 times daily in a König-Hofer programmed feeding machine for 37 days. Drinking water containing barium (0, 50 or 100 ppm) and fluoride (0 or 10 ppm) was available ad libitum. Rats to whose water was added 50 ppm barium had significant reductions in the mean severity of both buccolingual lesions and sulcal lesions compared with those rats whose water contained no barium. As expected, F at 10 ppm in the drinking water significantly reduced caries severity but this F effect was independent of the barium effect. This suggests that the inhibitory effects of barium and fluoride at these levels are additive and operate by separate mechanisms.