In vitro and in vivo evaluations of Chinese traditional (kampo) medicines as anticalculus agents in the rat.

Inhibitory effects of two Chinese traditional (Kampo) medicines, Shigyaku-san and Shikunshi-to, on the in vitro formation of calcium phosphate precipitates and the in vivo deposition of supragingival dental calculus were studied. Both had inhibitory effects on hydroxyapatite transformation and induction; effects of Shigyaku-san and Shikunshi-to were 1/100 and 1/400 of that of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP). When used topically (in drinking water) for 4 weeks, 20-40 mg/ml of Shigyaku-san or Shikunshi-to reduced the formation of dental calculus by 40-60%, while 0.03% (w/v) HEBP decreased it by 70-98%. However, when these drugs were given by gastric intubation for 2 weeks, they were all ineffective, suggesting that the observed anticalculus effects were of topical rather than of systemic origin.