THE DIGESTIVE SYSTEM 235 



Organic matter, 28.01 



Calcium phosphate and fluoric!, 66.72 



Calcium carbonate, 3-36 



Magnesium phosphate, i . 18 



Other salts, 0.73 



Dentine constitutes the bulk of the tooth and is peculiar in that 

 it contains canaliculi, dentinal canals (Figs. 139 and 140, Dk), but 

 no lacunae or bone cells. The latter are represented by the odonto- 

 id 











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L**- ^'-i- '.■'•. .'i » 



j^;-^*? ^* • •'.. ^- *# 



« 



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1*** -fee •■ x: ^% '■ 



ip* st If ,■/■■■/* * ■■ -> 





Fig. i39.^Cro33 Section through Root of Human Canine Tooth (X25) (Sobotta), 

 showing relations of pulp cavity, dentine, and cementum. P, Pulp cavity; D, dentine; 

 C, cementum; K, Tomes' granular layer. 



blasts of the pulp, which, as already noted, lie at the inner side of the 

 dentine, into the canaliculi of which they send the dentinal jihres. 

 Dentine is non-vascular. The dentinal canals begin at the dental 

 pulp, into which they open and where they have a calibre of 2 to 5/*. 

 They pass outward radially, to the limit of the dentine, and, while 

 taking different directions in different parts of the dentine, are essen- 



