Plaque Microbiome in Caries-Active and Caries-Free Teeth by Dentition.

OBJECTIVE

Describe associations between dental caries and dental plaque microbiome, by dentition and family membership.

METHODS

This cross-sectional analysis included 584 participants in the Center for Oral Health Research in Appalachia Cohort 1 (COHRA1). We sequenced the 16S ribosomal RNA gene (V4 region) of frozen supragingival plaque, collected 10 y prior, from 185 caries-active (enamel and dentinal) and 565 caries-free (no lesions) teeth using the Illumina MiSeq platform. Sequences were filtered using the R DADA2 package and assigned taxonomy using the Human Oral Microbiome Database.

RESULTS

Microbiomes of caries-active and caries-free teeth were most similar in primary dentition and least similar in permanent dentition, but caries-active teeth were significantly less diverse than caries-free teeth in all dentition types. Streptococcus mutans had greater relative abundance in caries-active than caries-free teeth in all dentition types ( < 0.01), as did in primary and mixed dentition ( < 0.01). sp. HMT 203 had significantly higher relative abundance in caries-free than caries-active teeth in all dentition types ( < 0.01). In a linear mixed model adjusted for confounders, the relative abundance of was significantly greater in plaque from caries-active than caries-free teeth ( < 0.001), and the relative abundance of sp. HMT 203 was significantly lower in plaque from caries-active than caries-free teeth ( < 0.001). Adding an effect for family improved model fit for sp. HMT 203 but not.

CONCLUSIONS

The diversity of supragingival plaque composition from caries-active and caries-free teeth changed with dentition, but was positively and sp. HMT 203 was negatively associated with caries regardless of dentition. There was a strong effect of family on the associations of sp. HMT 203 with the caries-free state, but this was not true for and the caries-active state.

KNOWLEDGE TRANSFER STATEMENT

Patients' and dentists' concerns about transmission of bacteria within families causing caries should be tempered by the evidence that some shared bacteria may contribute to good oral health.