The colonization of mutans streptococci in a child’s mouth
is directly related to the risk of caries. It is known that S.
mutans is the most decisive microorganism for the onset of
caries, while S. sobrinus is related to the progression and
development of carious lesions. For this reason, children
harboring both S. mutans and S. sobrinus species experience
more caries than those only S. mutans or S. sobrinus.