The Crystalline Components of Dental Calculi: Human vs. Dog

Abstract
Dental calculus from the dog was found to consist principally of the calcite form of calcium carbonate mixed with small amounts of apatite; other calcium phosphates, consistently present in human calculus, were not present in dog calculus. Precipitable calcium salts from human saliva were mainly apatite; for the dog the principal precipitated salt was calcium carbonate (calcite form).