[The microhardness of dental tissues as an index of their normal functional stability and in pathological states].

Microhardness of dental tissues was assessed. Hard tissue specimens from 65 teeth removed for medical indications were examined. The enamel microhardness is 30-40% decreased in caries, whereas dentine is virtually intact. Depulpation decreases the enamel microhardness by 23-26%, while the microhardness of dentine is changed negligibly (by 1-1.5%).