cementum vs grout

cementum

noun
  • A bony substance that covers the root of a tooth; cement. 

grout

noun
  • A thin mortar used to fill the gaps between tiles and cavities in masonry. 

verb
  • To insert mortar between tiles. 

  • To affix with mortar. 

How often have the words cementum and grout occurred in a corpus of books? (source: Google Ngram Viewer )