FACTORS INFLUENCING DENTAL CARIES "267 



caries is open to question because of the recognized capacity of 

 such substances to favor the maintenance and growth of bacteria. 

 In many experimental diets, milk products furnish the main source 

 of protein for microorganisms as well as host, and two recent reports 

 of human studies merit thoughtful consideration. Magnusson ( 1962 ) 

 has reported that the saliva of newborn infants remains neutral to 

 weakly alkaline during the first 12 hours of life and becomes increas- 

 ingly acid during the remainder of the first and second day; on the 

 third day the pH levels off to a range between 5.0 and 5.5. "The 

 gradual increase of aciditv of the saliva during the first days of life 

 seems to proceed at the same rate as the bacterial colonization of 

 the oral cavity." In the light of these findings the question raised 

 by Fass (1962), "Is bottle feeding of milk a factor in dental caries?" 

 deserves attention not only for the cases he discusses, but also from 

 the viewpoint of the dietary and eating patterns of older individuals. 

 Because the implications of these observations are of considerable 

 magnitude, it might be desirable to recognize this possibility and 

 to consider whether anv measures should be recommended to re- 

 duce the potential of a deleterious effect after the consumption of 

 certain other foods not usuallv considered to be cariogenic and high 

 in carboh\'drate. 



The foregoing remarks are intended to point out that evaluations 

 of the cariogenic potential of foodstuffs are exceedingly difficult 

 because of the conditions illustrated in Fig. 3, and there would seem 

 to be a number of reservations and limitations to information ob- 

 tained from both in vivo and in vitro systems which attempt to de- 

 fine the role of monosaccharides, disaccharides, adhesiveness, and 

 the like. 



Microflora 



Generally speaking, caries has been regarded more as a nonspecific 

 disease than as a specific one ( MacDonald, 1962 ) . Numerous acido- 

 genic organisms have been implicated, with most attention directed 

 toward lactobacilli and streptococci. In gnotobiotic studies with 

 rats, certain strains of enterococci and streptococci have shown an 

 unquestionable cariogenic potential ( Orland et al., 1955; Fitzgerald 



