^204 



K. JOIIANSEN 



5^ 2.0 - 



V— -v SOUND 

 O— O CARIOUS 



100 200 300 400 500 600 700 800 

 TEMPERATURE IN "C 



Fig. 27. The effect of heat treatment on the carbonate content of sound 

 and cariou.s human dentin. 



increases in lead and iron were also noted. The relative significance 

 of these elements in the carious process is not known. 



Discussion 



A matter of particular interest in relation to the carious process was 

 the pattern of distribution of mineral in carious enamel and dentin. 

 It has been shown that dissolution of enamel may extend to a depth 



TABLE V. Fluoride Content of Sound and Soft Carious Human Dentin 

 (Ash weight; means of 38 samples. From Joliansen and Nordbaok, 1962) 



Fluoride (ppm) 



Sound 

 Carious 



Carious/sound ratio: 10.4 ± 7.0 



180 ± 25 

 1730 ± 1400 



