cementum

noun

1. (uncountable)A bony substance that covers the root of a tooth; cement.

   “From a purely anatomic standpoint, root cementum is part of the tooth, but also part of the periodontium.”

   “Cementum is the least known calcified tissue in vertebrates (Bosshardt and Schroeder 1996) and several questions about cementogenesis have not yet been answered.”

   “Whether epithelial cells from Hertwig's sheath contribute to initial cementum formation is controversial as has already been discussed in Chap. 1.”