[Identification of the mineral constituents of various salivary calculi by study of their thermal behavior].

Studies of the physicochemical nature of five salivary calculi have shown that they are practically similar. They are composed of a nucleus and a shell which contain an organic phase and two crystalline mineral phases. These two phases are respectively a whitlockite and an apatite: the composition of the last agrees with the general formula: Ca10-(x+y) (PO4) T-(x+y) (CO3) x (HPO4) y (20H,CO3) (Formula: see text). The shell is different from the nucleus by the fact that it is less mineralized than the nucleus. The apatite of the shell contains more carbonate ions than the apatite of the nucleus.