ON CAPPING THE EXPOSED PULP. 139 



would be more probable in patients of middle age 

 and upwards than in the young, because there is in 

 the former a greater tendency to ossific formations, 

 and because, in the latter, the pulp is more highly 

 vascular, and more liable to inflammation or injury. 

 I do not consider it to be absolutely necessary that 

 every particle of decomposed dentine should be 

 removed from contact with the pulp, but that the 

 exposure of that organ should be as slight, and for 

 as short a time (allowing for the cessation of 

 haemorrhage) as possible, and I therefore proceed to 

 the completion of the operation the instant of feel- 

 ing sure that the nerve is in the least touched. 



As regards the theory of the operation, it is weU 

 known that anything which has a tendency to cause 

 irritation of the pulp, sets up a disposition in that 

 organ to deposit ossific matter in the direction of 

 the irritation. TMs fact, however, is firmly estab- 

 lished only in cases where the pulp is not actually 

 exposed; and further observation is needed to 

 decide absolutely whether, after exposure of the 

 nerve, and its preservation from contact with any 

 foreign substances, it will still take on ossific action, 

 whether by conversion of its substance into osteo- 

 dentine, or by efiusion of lymph into the space left 

 vacant under the cap, and subsequent organization. 

 Drs. Harwood, Foster, and Dwinelle are of opinion 

 that the pulp does ossify under these circumstances ; 

 in which of the methods I have alluded to, they 

 do not say. Harris details three cases occurring in 



