Early colonization of the oral cavity in 6-and 12-month-old infants by cariogenic and periodontal pathogens: a case-control study

The colonization of the oral cavity by cariogenic and periodontal pathogens occurs earlier than previously thought. This study aimed to identify the presence and quantity of representative cariogenic and periodontal pathogens in the oral cavities of 6- and 12-month olds and to evaluate the influence of C-section delivery on early Streptococcus mutans (Sm) colonization of the oral cavity. The research cohort was composed of 59 infants (35 infants were delivered vaginally and 24 via C-section) and their mothers. At 6 months of age, the infants were examined, and unstimulated saliva samples were collected. Variables concerning mothers were DMF index and salivary levels of Sm. Repeated saliva samples were taken 6 months later. The representative cariogenic and periodontal microorganisms were identified, and their quantities were measured using a polymerase chain reaction-based method. The relationships between the presence of detected microbes, the mode of delivery, and maternal variables were evaluated using paired t tests, chi-squared test, and ANOVAs. High rates of cariogenic bacteria, Aggregatibacter actinomycetemcomitans (Aa) and Fusobacterium nucleatum (Fn), were found in both infant cohorts. An analysis of the differences between delivery methods revealed that the group of 6-month-old vaginally delivered infants had a significantly higher amount of Sm. We conclude that the cariogenic bacteria, Aa and Fn, are present in edentulous infants. This presence increases in the months following the eruption of the deciduous teeth. Results did not confirm the influence of C-section delivery on the early Sm colonization of the oral cavity.