154 NORMAL HISTOLOGY ANb ORGANOGRAPHY. 



must be smoothed or trimmed by a shaving motion 

 of the chisel, increasing the inclination of the wall 

 slightly. This is done so as to be sure and reach the 

 rod directions and remove the portions of the tissue 

 that has been splintered by the cleavage. Then the 

 cavo-surface may or may not be trimmed, as the 

 position demands" (Fig. in, Noyes). 



Enamel. 



Dentinal tubule; 



Fig. 113. A portion of a ground tooth from man, showing enamel 

 and dentin (Bohm and Davidoff). 



Grooves, fissures, pits and developmental lines 

 are points of weakness and in operative work cavi- 

 ties must be excavated so as to establish a strong 

 margin, histologically, against which to pack the 



