THE DENTAL TISSUES. 



95 



CEMENTUM. 



The cement forms a coating of variable thickness over 

 the roots of the teeth, sometimes, when the several roots are 

 very close to another, or the cement is thickened by disease, 

 uniting the several roots into One. 



The cement is ordinarily said to be absent from the 

 crowns of the teeth of man, the carnivora, &c., and to com- 

 mence by a thin edge just at the neck of the tooth, over- 

 lapping the enamel to a slight extent ; it is, in the healthy 

 state, thickest in the interspaces between the roots of molar 

 or bicuspid teeth : it is, however, often thickened at the end 



Fia. 51 I 1 ). 



of a root by a dental exostosis. In compound teeth, the 

 cementum forms the connecting substance between the den- 

 ticles (see the figures of the tooth of the Capybara, the 

 Elephant, <fec.), and, before the tooth has been subject to 

 wear, forms a complete investment over the top of the 

 crown. The cementum also covers the crowns of the com- 



( l ) Thick laminated cementum from the root of a human tootK 



