Inhibition of dental caries by lanthanum

Abstract

Dental caries is known as a disease of very high morbidity. In order to protect of dental caries, fluoride has been broadly used. This study deals with the effect of the rare earth element lanthanum in controlling dental caries. There are very few instances of application of lanthanum in dental study and practice. However, considering the fact that it is of low toxity and is used as a hardening reagent for glass, lanthanum could have hardening effects of dental enamel.As a preliminary study of the cariostatic effects of lanthanum, we examined its MIC for Str. mutans, its acute toxity in mice, and the inhibition of experimental caries in hamsters, using a water solution of Lanthanum nitrate.The result was as follows.1) The MIC of Lanthanum nitrate for Str. mutans was about 2000μg/ml.2) The LD50 of Lanthanum nitrate for mice was about 150mg/kg.3) Lanthanum at a concentration below 3μg/ml obviously reduced experimental caries produced by Str. mutans 1089 in hamsters.4) Very little inhibitory effect of Lanthanum nitrate on alveolar bone loss was observed.