THE TEETH. 671 



(4) The indifferent elements originating through the carious process from 

 enamel, dentine, and cement do not proceed in new formation of living matter, but 

 become disintegrated and transformed into a mass crowded with micrococci and 

 leptothrix. 



(5) Caries of a living tooth, therefore, is an inflammatory process, which, 

 beginning as a chemical process, in turn reduces the tissues of the tooth into 

 embryonic or medullary elements, evidently the same as during the development 

 of the tooth have shared in its formation ; and its development and intensity are 

 in direct proportion to the amount of living matter which they contain, as com- 

 pared with other tissues. 



(6) The medullary elements, owing to lack of nutrition and to continuous 

 irritation, become necrosed, and the seat of an active new growth of organisms 

 common to all decomposing organic material. 



(7) Micrococci and leptothrix by no means produce caries; they do not pene- 

 trate the cavities in the basis-substance of the tissues of the tooth, but appear only 

 as secondary formations, owing to the decay of the medullary elements. 



(8) In dead and artificial teeth, caries is a chemical process, assisted only by 

 the decomposition of the glue-yielding basis-substance of dentine and cement. 



History. John Hunter* says: " The most common disease to which the 

 teeth are exposed is such a decay as would appear to deserve the name of 

 mortification. But there is something more, for the simple death of the part 

 would produce but little effect, as we find that teeth are not subject to 

 putrefaction after death, and therefore I am apt to suspect that during life 

 there is some operation going on which produces a change in the diseased 

 part." 



Joseph Foxt says : " The diseases to which the teeth are subject are simi- 

 lar to those which affect bones in general, and in like manner they have their 

 origin in inflammation. The teeth differ only from bones in not possessing 

 sufficient living power to effect the process of exfoliation." 



Thomas Bell,+ under the heading of " Gangrene of the Teeth, commonly 

 called Caries," says: "The most common disease to which the teeth are 

 liable is that which has hitherto been universally known under the name of 

 caries a name which, although authorized both by English and Continental 

 writers, is in this instance totally misapplied. It is, in fact, calculated essen- 

 tially to mislead, as the disease has not the slightest analogy to true caries of 

 bone." "Still, however, the true proximate cause of dental gangrene is 

 inflammation. That the bony structure of the teeth is liable to inflammation 

 appears not only from the identity of the symptoms which take place in them, 

 when exposed to causes likely to produce it, with those which are observed 

 in the other bones when inflamed, but more conclusively still from the fact, 

 already mentioned, that teeth are occasionally found in which distinct patches, 

 injected with the red particles of blood, have been produced by this cause 

 after the continuance of severe pain." 



Dr. E. Magitot, in his general conclusions, says: "Dental caries is a 

 purely chemical alteration of the enamel and ivory of the teeth. Lesions of 

 the enamel consist, after the removal of the cuticle, in a purely passive 

 chemical disorganization of the prisms composing its tissue. Lesions of the 



* " Diseases of the Teeth," etc., 1778. 



t " The History and Treatment of the Diseases of the Teeth and Gums," 1806. 



t " Anatomy, Physiology, and Diseases of Teeth," 1831. 



" Treatise on Dental Caries" (English translation by Dr. T. H. Chandler, 1878). 



