Acellular extrinsic fiber cementum is for anchorage Cellular intrinsic fiber cementum is for adaptation and repair Mixed fiber cementum is for adaptation..

root , cementum

The main difference between cellular and a cellular cementum is that cellular cementum contains cementocytes, while a cellular cementum does not contain any active cells and can not regenerate.

It is called the cementum and it's the third hardest substance in the human body, after the enamel and the dentin.

Cementum holds the teeth in the jaw, just as cement would.