WordNet sense 1 (an incrustation that forms on the teeth and gums):

tartar, tophus

WordNet sense 2 (a hard lump produced by the concretion of mineral salts; found in hollow organs or ducts of the body):

concretion

WordNet sense 3 (the branch of mathematics that is concerned with limits and with the differentiation and integration of functions):

infinitesimal calculus