Ground section of a premolar (20X)

Image copyright: Mathias Nordvi, ARR.

This a ground section of two premolars. One is a cross section of the coronal part of a premolar, the other is a longitudinal section.

You can see the root canal (the space left behind by the pulp), dentine, enamel and the cementum.

The apical 2nd half of the surface of the root of the longitudinally sectioned premolar is covered by cementum. Closer to the crown, the cementum is acellular (cementum without cells). But closer to the apex, you'll find cellular cementum (cementum containing cells). The enamel is brown in this section.