title: Supragingival Microbial Profiles of Permanent and Deciduous Teeth in Children with Mixed Dentition.
abstract: OBJECTIVE
  The present study was designed to investigate the microbial profiles of teeth in different locations in mixed-dentition-stage children, and to compare the microbiomes of permanent and deciduous teeth in the same healthy oral cavity.
  
  
  METHODS
  Supragingival plaque samples of teeth in various locations-the first permanent molars, deciduous molars, deciduous canines and incisors and permanent incisors-were collected from 20 healthy mixed-dentition-stage children with 10-12 permanent teeth erupted. Plaque DNA was extracted, and the V3-V4 hypervariable region of the bacterial 16S rRNA gene was amplified and subjected to sequencing.
  
  
  RESULTS
  On average, 18,051 high-quality sequences per sample were generated. Permanent tooth sites tended to host more diverse bacterial communities than those of deciduous tooth sites. A total of 12 phyla, 21 classes, 38 orders, 66 families, 74 genera were detected ultimately. Five predominant phyla (Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria) were highly variable among sites. Of 26 genera with a mean relative abundance of >0.1%, 16 showed significant differences in relative abundance among the groups. More than 20% of the total operational taxonomical units were detected only in permanent or deciduous teeth. The variation in the microbial community composition was due mainly to permanent teeth being enriched in Actinomyces and deciduous teeth in Treponema. The core microbiome of supragingival plaque in mixed dentition comprised 19 genera with complex correlationships.
  
  
  CONCLUSIONS
  Our results suggest differences in microbial diversity and composition between permanent and deciduous teeth sites in mixed dentition. Moreover, the core microbiome of these sites was determined. These findings enhance our understanding of the development of the native oral microbiota with age.
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, Peking University, Beijing, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Shi
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, Peking University, Beijing, China.
authors.forename: Man
authors.initials: M
authors.lastname: Qin
authors.affiliation: Central Laboratory, School of Stomatology, Peking University, Beijing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, Peking University, Beijing, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xia
mesh_terms: D001419:Bacteria / Q000145:classification; D044822:Biodiversity; D002648:Child; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D003773:Dental Plaque / Q000382:microbiology; D003818:Dentition, Mixed; D004587:Electrophoresis, Agar Gel; D005260:Female; D005881:Gingiva / Q000382:microbiology*; D006801:Humans; D008297:Male; D059013:Microbial Consortia; D064307:Microbiota; D008963:Molar / Q000382:microbiology; D009055:Mouth / Q000382:microbiology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014078:Tooth Eruption; D014094:Tooth, Deciduous / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S