Effect Of Different Prosthodontic Materials On Oral Microbial Community Diversity Based On 16S RDNA Sequencing Technology

Objective: Oral microbes are of vital importance to oral health and even systemic health.16 S ribosome DNA（rDNA）sequencing technology can directly and comprehensively analyze the composition and diversity of bacteria,making it possible to study unculturable microorganisms in the oral environment.The purpose of this study was to use 16 S rDNA sequencing technology to explore the changes in the structure diversity and function of oral microbial communities after treatment with five commonly used prosthodontic materials,and to provide experimental evidence for the effects of prosthetic materials on oral microbial communities and their long-term safety.Methods: Experiment 1: Patients with missing first molars aged 18-60 who visited the Prosthodontics Department of Lanzhou University Stomatological Hospital from December 2020 to September 2021 were selected as the research subjects.The patients treated with full crown repair were taken as the experimental group,and were randomly divided into porcelain-porcelain crown group and all-ceramic crown group.The patients without repair treatment were recorded as the control group,and a total of 9 subjects were included.We collected supragingival plaque samples from subjects3 to 6 months after restorative treatment.Experiment 2: 18-60-year-old patients with caries involving subgingival who visited the General Department and Endodontics of Lanzhou University Stomatological Hospital from December 2020 to September2021 were selected as the experimental group,and they were randomly divided into 3groups: flow resin group,composite resin group and glass ionomer group.We collected supragingival plaque and gingival crevicular fluid before treatment,48 hours after treatment,and 1 month after treatment.The supragingival plaque and gingival crevicular fluid of the same-named healthy teeth on the opposite side of the test teeth were collected as the negative control group.We selected 3 oral healthy people as blank control group,and a total of 12 subjects were included.All sample DNAs were sequenced by 16 S rDNA high-throughput sequencing technology,and the sequencing data were bioinformatically analyzed by Qiime software,R software and PICRUSt2 software.Results: 1.A total of 110,209 valid sequences are obtained from 9 supragingival plaque samples in experiment 1,which belong to 1 kingdom,11 phyla,23 classes,44 orders,74 families,120 genera and 188 species.The highest detection rates of the three groups at the phylum and genus levels are phylum Actinobacteria,Bacteroidetes,Firmicutes,Fusobacteria,Proteobacteria,and genus Rothia,Porphyromonas,Prevotella,Streptococcus,Veillonella,Leptinophylla,Neisseria,Citrobacter,and Pseudomonas.Compared with the control group,genus Haemophilus,Veillonella,Leptotrichia,Citrobacter and Pseudomonas significantly increase in the subjects treated with full crown.The functional potential prediction analysis shows that compared with the control group,the cell motility function increases after full crown restoration,while the replication and repair and translation functions decrease.2.A total of 660,204 valid sequences are obtained from 39 supragingival plaque samples in experiment 2,which belong to 1 kingdom,15 phyla,29 classes,54 orders,90 families,162 genera and 293 species.Group by filling material,the highest detection rates of the five groups of samples at the phylum and genus levels are phylum Proteobacteria,Bacteroidetes,Firmicutes,Fusobacteria,Actinobacteria,Spirochaetes and genus Neisseria,Haemophilus,Campylobacter,Lautropia,Prevotella,Capnocytophaga,Porphyromonas,Streptococcus,Veillonella,Selenomonas,Fusobacterium,Leptotrichia,Actinomyces,Rothia,Treponema.Phylum Chloroflexi and genus Oribacterium,Catonella,Peptostreptococcus,Johnsonella,Filifactor,Peptococcus,Desuifobulbus,Flexilinea in glass ionomer group are significantly higher than other groups;genus Neisseria and Parascardovia in composite resin group are significantly higher.The functional potential prediction analysis shows that the cell motility function of glass ionomer group increass,and the membrane transport function decreases;the cell motility function of flow resin group decreases,but the translation,replication and repair,as well as the metabolic functions of cofactors and vitamins significantly increase;the carbohydrate metabolism function of composite resins group significantly increase.Group by time,the highest detection rates of the five groups of samples at the phylum and genus levels are phylum Proteobacteria,Bacteroidetes,Firmicutes,Fusobacteria,Actinobacteria,Spirochaetes and genus Neisseria,Haemophilus,Campylobacter,Prevotella,Porphyromonas,Capnocytophaga,Lautropia,Streptococcus,Veillonella,Selenomonas,Fusobacterium,Leptotrichia,Actinomyces,Treponema.Genus Provotella and Propionibacterium significantly increase before treatment,and genus Actinomyces and Atopobiaceae significantly increase 1 month after treatment.The predictive analysis of functional potential shows that membrane transport function decrease before treatment,cell motility function increases 48 hours after treatment,while translation,transcription,replication and repair,folding,sorting and degradation,and cofactor and vitamin metabolism functions decrease.A total of 184,902 valid sequences are obtained from 15 gingival crevicular fluid samples in experiment 2,which belong to 1 kingdom,15 phyla,30 classes,51 orders,86 families,165 genera,and 283 species.Group by filling material,the highest detection rates of the five groups of samples at the phylum and genus levels are phylum Proteobacteria,Bacteroidetes,Firmicutes,Fusobacteria,Actinobacteria,Spirochaetes and genus Neisseria,Haemophilus,Campylobacter,Prevotella,Alloprevotella,Streptococcus,Fusobacterium,and Leptotrichia.Genus Bradyrhizobium and Bifidobacterium in composite resin group significantly increase,genus Fusobacterium and Paludibacter in glass ionomer group are significantly higher than other groups,and genus Bergeyella and Abiotrophia in flow resin group significantly increase.The functional potential prediction analysis shows that the translation,replication and repair functions of flow resin group and composite resin group significantly decrease,while the metabolism and xenobiotic biodegradation and metabolic functions of other amino acids functions significantly increase;the membrane transport function of flow resin group and negative control group significantly increase.Group by time,the highest detection rates of the five groups of samples at the phylum and genus levels are phylum Proteobacteria,Bacteroidetes,Firmicutes,Fusobacteria,Actinobacteria,Spirochaetes and genus Neisseria,Haemophilus,Campylobacter,Prevotella,Porphyromonas,Alloprevotella,Streptococcus,Fusobacterium,Veillonella,Leptotrichia.The functional potential prediction analysis shows that the membrane transport function increases before treatment and in the negative control group;lipid metabolism and amino acid metabolism increase 48 hours after treatment and 1 month after treatment,while glycan biosynthesis and metabolic functions significantly decrease.Conclusion: There are differences in the composition of oral microbial communities after treatment with three direct restorative materials（composite resin,flow resin,and glass-ionomer composite）and two indirect restorative materials（all-ceramic and porcelain）,while the difference before and after treatment was not significant.The differences did not cause significant changes in the structure and function of oral microbial communities.