298 APPENDIX. 



CARIES OF HUMAN TEETH. 



BY FRANK ABBOTT, M. D., DEAN OF THE NEW YORK COLLEGE OF 

 DENTISTRY. 



Mr. President and Gentlemen of the Brooklyn Dental Society : 



IN discussing this subject I want it distinctly understood that I 

 do it with no feeling except that of a desire to get at the truth. If 

 any gentleman will convince me that I am wrong and that he is 

 right, I will abandon my position and as heartily advocate his as I 

 now do my own. But I am to-night placed in rather an awkward 

 position. The subject for discussion (printed in the notice for this 

 meeting) is in the form of a question, as follows: " Etiology of Den- 

 tal Caries, Acids or Germs! Which!" Now, without taking a 

 second thought. I should say neither; but that second thought 

 tells me that the beginning of the carious process in all teeth is 

 effected by means of acids, produced by the decomposition of food, 

 saliva, &c., which lodge around and between, as well as in depres- 

 sions, or upon irregular surfaces of the teeth. 



Perhaps before proceeding to consider this condition of pathology 

 it may be well for us all to understand alike a tooth in its physio- 

 logical state. Chemically the enamel of a tooth is said to be com- 

 posed of about 31-2 parts in a hundred of organic matter, and the 

 balance (96 1-2 parts) inorganic; the dentine of about 28 parts or- 

 ganic and 72 inorganic; the cement about 33 organic and 67 inor- 

 ganic. I give this analysis, not that I think it absolutely correct 

 for all teeth, as I have no doubt a different result would be obtained 

 from an analysis of the teeth of almost any two persons; further, I 

 have no doubt that considerable water would be found in every in- 

 stance, reducing perhaps both the organic and inorganic portions, 

 as we now understand it. But what I wish you to understand is 

 the fact that a tooth is an organ as perfectly and beautifully formed 

 as the eye, or any other of the delicately constituted organs of the 

 human bod}'; that it contains as much organic material in propor- 

 tion to its inorganic as is consistent with the strength and resisting 

 power demanded of it ; and that a portion only of that organic ma- 

 terial is possessed of life. 



Now, with this understanding of the tooth in a physiological con- 

 dition, let us examine it pathologically as to the process of caries, 

 and try and understand if possible its causes and progress. But 

 before I giye you my views, or rather reiterate my views (for they 



