Salivary microbiota and caries occurrence in Mutans Streptococcipositive school children

Aim To compare the composition of the salivary microbiota in caries-affected vs. caries-free mutans streptococci (MS)-positive children with mixed dentition. Methods Twenty eight healthy, 11-12-year-old schoolchildren with high MS counts ( > 105CFU/mL) were included in this study. The children were screened with the Dentocult® SM Strip Mutans test (Orion Diagnostica, Espoo, Finland) and examined using the International Caries Detection and Assessment System (ICDAS). The microbial composition of the saliva was assessed using the Human Oral Microbe Identification Microarray (HOMIM). Microbial differences between caries-affected (n=18) and caries-free children (n=10) were compared by Mann-Whitney analysis. Results The microbiota of the caries-affected vs. cariesfree children was rather similar. Abiotrophia defectiva and Actinomyces meyeri/A. odontolyticus were significantly higher in caries-affected than in caries-free children (p=0.006, 0.046, respectively). Shuttleworthia satelles was significantly higher in caries-free compared to caries-affected children (p=0.031). A. defectiva and A. meyeri/A. odontolyticus correlated positively with caries severity measured by ICDAS Caries Index (p = 0.494, 0.454, 0.400 respectively) while S. satelles was negatively correlated with caries severity (p= -0.489). Conclusions Salivary A. defectiva and A. meyeri/A. odontolyticus and are associated with caries occurrence in MS-positive children with mixed dentition.