PREVALENCE OF STREPTOCOCCUS SANGUIS AND STREPTOCOCCUS MUTANS IN MOUTH OF PERSONS WEARING FULL-DENTURES

In 20 edentulous persons wearing full dentures the prevalence of Streptococcus sanguis, Streptococcus mutans and Streptococcus salivarius was studied in samples of the bacterial plaque on the dentures and in samples of the saliva. Streptococcus sanguis could be recovered from 17 and Streptococcus mutans from 14 of the subjects. These organisms constituted a higher percentage of the streptococcal flora in the denture plaque than in saliva. Seven subjects refrained from using their dentures for 2 days after which the number of these streptococci was so few in saliva that they could not be recovered with the methods used. Streptococcus salivarius was present in all 20 subjects and constituted a higher percentage of the streptococcal flora in the saliva than in the denture plaque. The composition of the streptococcal flora on the dentures was similar to that previously found on teeth. The accumulated evidence on the ecology of Streptococcus sanguis and Streptococcus mutans indicate that these streptococci can only be established in the mouth if solid surfaces such as on teeth and dentures are present. © 1969.