CHAPTER VI 

 CEMENT 



THIS tissue, both by its structure, its chemical composi 

 tion, and its mode of development, is seen to be simply 

 a slightly modified form of bone. This, the. ' crusta petrosa ' 

 of early authors, is usually termed cement by the general 

 anatomist ; but cementum is the term which has been 

 usually applied to it by dental histologists, although the 

 French have retained the word ' cement J . 1 



Cement in man is confined to the roots of the teeth, 

 where it forms a continuous investment of the dentine, but 

 in many compound teeth it forms the cementing substance 

 between the plates, as in the Elephant and the Capybara, 

 and in Ungulates before the teeth come into use it forms 

 a complete investment of the crown. 



As previously pointed out and as shown in the compound 

 teeth above referred to, a sharp masticating surface to the 

 tooth is maintained by the unequal wear of the different 

 tissues. The cement, being the least resistant, is worn 

 down more readily than the dentine, and the latter more 

 easily than the hard enamel, which by projecting above the 

 other tissues affords a rough sharpened surface for the 

 purposes of mastication. 



At the neck of the human tooth the cement is usually 

 considered to terminate at the point of contact with the 

 enamel, but there are considerable variations in the relations 

 of the two tissues in this situation in normal teeth. This 

 question was especially studied by J. Choquet, who from the 



1 In the present work the author has ventured to adopt the word 

 'cement' for this tissue. The Committee on nomenclature of the 

 Anatomical Society have confirmed the use of the word cement, and 

 it is the term in use in all the text-books of general anatomy. It would 

 appear very desirable that one word only should be employed to describe 

 the same tissue, and for these reasons the author has thought it advisable 

 to use the word cement instead of cementum, although the latter has 

 been in use for a long time in English and American works on dental 

 anatomy 



