Temporal change in the total amount of bacteria, microbial richness and diversity in subjects with caries experience (CE) and caries-free (CF) subjects (10 and 9 subjects, respectively).
(A) Temporal change in the total amount of bacteria on a hydroxyapatite disk in CE and CF subjects. *P < 0.05, using a Student's t-test analyzed per sampling time. The error bars indicate standard error. (B) Temporal change in the number of OTUs, Shannon diversity index and phylogenetic diversity in the plaque microbiota in CF and CE subjects. To correct for the unequal number of sequences, we evaluated 800 randomly selected sequences. The error bars indicate standard error.