Objectives: The aim of this study was to determine if there are associations between the level of social deprivation/affluence and the frequency isolation of caries-associated micro-organisms (Streptococcus mutans, Streptococcus sobrinus, lactobacilli and yeasts) in a large cohort of infants examined annually from 1 to 4 years of age.
Methods: DEPCAT was used to measure the socio-economic status of all consented infants (n=1099--1392) born in Dundee during a 1 year period (total n=1974). Caries-associated micro-organisms were cultured from saliva when the infants were 1, 2, 3 and 4 years of age. Standardised dental examinations were also carried out annually. Log linear analysis, which controlled for caries, was used to look for associations between DEPCAT and the isolation frequency of caries-associated micro-organisms.
Results: When controlling for caries, there was an association between DEPCAT and the isolation frequency of yeasts when the infants were 1 and 2 but not when 3 and 4 years old, whereas lactobacilli were associated only when the infants were 3 and 4 years old. Correlations between S. mutans and social deprivation were usually dependent on the caries status of the infants.
Conclusions: The relationship between social deprivation and the isolation frequencies of caries-associated micro-organisms is complex with lactobacilli developing an association when the infants were 3 and 4 years old in contrast to yeasts which were only associated when the infants were 1 and 2 years old. Streptococcus mutans was associated with social deprivation when the infants were 2 years old and older, but dependent on caries status in the 3 and 4 year olds.