Factors Influencing the Initiation, 

 Transmission, and Inhibition 

 of Dental Caries 



PAUL H. KEYES, Laboratory of Histology and Pathology, National In- 

 stitute of Dental Research, Bethesda, Maryland 



HAROLD V. JORDAN, Laboratory of Microbiology, National Institute 

 of Dental Research, Bethesda, Maryland 



THE discussion which follows represents observations, speculations, 

 questions, and a few pertinent criticisms. In an attempt to present a 

 broader perspective on dental caries we have tried to scan facets of 

 the problem and not to focus narrowly on any special one. Our ulti- 

 mate objective is to gain greater insight, to open doors, to reexamine 

 postulations, to challenge concepts, and not to forge any idea into a 

 fact. We feel that the emphasis belongs on a better understanding 

 of the biology of caries and not on arguments over hypotheses. 



Dental caries is a complicated infection which, for the most part, 

 can be considered to originate outside the body proper. Lesions be- 

 gin as a demineralization of enamel, a tissue of ectodermal origin, 

 and later penetrate into the dentin and pulp, both of mesodermal 

 origin. For many years most investigators of the disease have recog- 

 nized that the substrate upon which the pathogenic bacteria sub- 

 sist is composed largely of ingested food substances which come into 

 contact with the teeth when conditions are favorable. Much atten- 

 tion has been directed to the role of acidogenesis, lactobacilli, and 



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