Marked differences of opinion exist regarding the etiology and practical control of dental caries. One group is apparently convinced that caries is entirely the result of oral environment. They believe that environment permits the growth of specific bacteria which produce acid, which in turn attacks the tooth structure. They discount the importance of metabolic influences from within the body. Their thesis is: Control or destroy this particular type of bacteria, or modify the conditions which favor bacterial invasion, and prevention and control of caries follow.
Others believe that improving the nutritional status of children alters the tooth itself so that it becomes caries resistant. On the other hand, when certain dietary defects occur the tooth loses its resistance.
Fundamentally, these two approaches are not incompatible. The one deals with bacterial invasion of a tissue, the other with resistance to such invasion. The distinction between these two functions in disease is