Analysis The Microbial Flora Of Supragingival Plaque And Saliva Of Primary Dentition Of Dental Caries And Caries With Tooth Exogenous Pigmentation By 454 High-throughput Pyrosequencing

[Objective] In previous studies of unstimulated saliva and supragingival plaque microflora on pigmentation of primary dentition, based on the use of 454 high-throughput sequencing technology, to analysis the microflora on pigmentation of supragingival plaque and saliva of primary dentition,to explore dental caries and caries with pigment of microbial diversity in different parts of oral microflora overall environment (plaque and saliva), in order to have a in-depth understanding of dental caries and tooth surface pigmentation, to provide new ideas for prevention of dental caries and tooth exogenous pigmentation.[Methods] Samples were taken from supragingival plaque and unstimulated saliva of 45 primary dentition of 3-5 years old children, in which 20 children had caries but no pigmentation (marked as Q),25 children who had dental caries with pigmentation (marked as SQ), scraped healthy glossy enamel surface of plaque adjacent cavities of caries, dental supragingival plaque and unstimulative saliva were collected, total bacterial DNA were extracted and the V1-V3 region of 16SrRNA were amplified with specific primers. PCR products were detected by agarose gel electrophoresis, the purpose DNA fragments were purificated and collected. The concentration of DNA fragments was examined with the Qubit(?) 2.0 fluorometer. Equal dose of DNA fragments was mixed for sequencing by 454 pyrosequencing. The dedicated software was used for data processing and analysis.[Results] 454 pyrosequencing results on 90 subgingival plaque and unstimulated saliva samples of bacterial 16SrRNA gene sequencing V1-V3 region received a total of 511382 high-quality sequences, the average length of each sequence read was 279.97 bp, The average number of sequence reads was 5682 per sample. For 16SrRNA sequence database, a total of 45032 OTUS at 3% difference were obtained, covering 13 bacterial phylums and 145 genus. The sample species abundance distribution map and the diversity of Alpha diversity dilution curve indicated good bacteria coverage in this study.24 genus were significantly different (p<0.05) in group plaque and caries plaque with pigment group.5 genus were significantly different (p<0.05) in saliva and caries group with pigment group saliva.36 genus of caries plaque were significantly different, compare with saliva groups, (p<0.05), 54 genus of the pigment group with caries, caries plaque were significantly different compare with saliva groups(p<0.05).[Conclusions] In this study, there was a good bacteria coverage by 454 pyrosequencing analysis of eciduous caries and caries-associated gingival pigmentation supragingival plaque and unstimulated whole salivary microorganisms of primary dentition.The composition and diversity of microorganisms were different in different parts of dental plaque and unstimulated saliva.The diversity of microorganisms in saliva were more conservative than that of in dental plaque. With the development of dental decay, microbial species decrease.