Comparative Microbial Profiles of Caries and Black Extrinsic Tooth Stain in Primary Dentition

Abstract

Extrinsic black tooth stain (BS) is a common oral disease associated with lower caries experience in preschool children, although the microbiotic features contributing to the low risk of caries in this group remain elusive. In this study, we aimed at identifying the dominant bacteria in dental plaque to indicate the incidence of caries in the primary dentition. Subjects were divided into 3 groups based on the clinical examination: group CF, children without pigment who had no caries lesions or restorations (<i>n</i> = 18); group CS, children who were diagnosed with severe early childhood caries (<i>n</i> = 17); and group BS, children with pigment (black extrinsic stain) without caries or restorations (<i>n</i> = 15). The total microbial genomic DNA was extracted and subjected to bacterial 16S ribosomal RNA gene sequencing using an Illumina HiSeq platform. The differential dominant bacteria were determined using Wilcoxon rank-sum testing and linear discriminant analysis effect size (LEfSe). Co-occurrence network analysis was performed using sparse correlations for compositional data, calculation and functional features were predicted using PICRUSt. Interestingly, our results showed that the relative abundance of <i>Pseudopropionibacterium</i>, <i>Actinomyces</i>, <i>Rothia</i>, and <i>Cardiobacterium</i> was from high to low and that of <i>Porphyromonas</i> was low to high in the BS, CF, and CS groups, consistent with the clinical incidence of caries in the 3 groups. Moreover, an increased level of <i>Selenomonas_3</i>, <i>Fusobacterium</i>, and <i>Leptotrichia</i> was associated with high caries prevalence. We found that the interactions among genera in the BS and CS plaque communities are less complex than those in the CF communities at the taxon level. Functional features, including cofactor and vitamin metabolism, glycan biosynthesis and metabolism, and translation, significantly increased in caries plaque samples. These bacterial competition- and commensalism-induced changes in microbiota would result in a change of their symbiotic function, finally affecting the balance of oral microflora.

The Crosstalk Between Saliva Bacteria and Fungi in Early Childhood Caries

“…The relationship between filtered taxa and host properties was assessed by Spearman correlation analysis. Being the member of the “orange” complex in subgingival plaque, Fusobacterium was traditionally regarded as a critical periodontal pathogen ( Socransky et al., 1998 ), while increasing studies have noticed its enrichment and predictive potentiality on ECC occurrence ( Zhu et al., 2018 ; Chen et al., 2021 ). Here, a significant positive correlation between Fusobacterium and caries indexes was observed, re-emphasizing its possible roles in caries progression.…”

Epidemiological and Microbiome Characterization of Black Tooth Stain in Preschool Children

“…Actinomyces has been reported to have the capability to produce black or brown pigmentation (33). The predominance of Actinomyces in the oral cavity is associated with BTS in children (4,8,31). Furthermore, hydrogen sulfide produced by oral microorganisms (such as Actinomycetes) can react with ferric ions present in saliva, resulting in the formation of BTS.…”

“…and Fusobacterium nucleatum (11). A recent study reported the relative abundance of Pseudopropionibacterium, Actinomyces, Rothia, and Cardiobacterium was higher and that of Porphyromonas was lower in the BTS group (4). Although these findings clearly indicate an association between BTS and altered oral microbiota, the basic microbial features and association between the microbial assemblies and BTS are not fully understood.…”

“…Black tooth stain (BTS) is a common condition characterized by an extrinsic discoloration of teeth due to the deposition of bacterial plaque enriched in calcium phosphate minerals and insoluble iron-containing compounds (1,2). BTS is clinically diagnosed based on the deposition of dark-colored lines or dots parallel to the gingival margin in the cervical half of the crown (3,4). Due to the high mineral content, conventional tooth brushing is unlikely to remove BTS, and BTS has a tendency to reform after professional scaling and debridement (5).…”

Candida albicans enriched in orthodontic derived white spot lesions and shaped focal supragingival bacteriome

“…In addition to bacteria, fungi were much less abundant but a non-negligible kingdom in the oral microbiome, which have been widely reported in multiple oral diseases ( Dağistan et al, 2009 ; Peleg et al, 2010 ; Xu et al, 2013 ). Candida albicans ( C. albicans ) could be isolated in dental caries diseases such as early childhood caries (ECC) and root caries ( Valm, 2019 ; Chen Y. et al, 2021 ). In these caries lesions, C. albicans had active interkingdom interactions with bacteria like S. mutans , which synergistically contribute to the development of dental caries ( Valm, 2019 ; Ev et al, 2020 ).…”