Association Of Peri-implant Health Conditions With Oral Microbiome And The Influencing Factors

Peri-implant disease,including peri-implant mucositis and peri-implantitis,is a common biological complication after implant restoration.Clinical studies have shown that the incidence of peri-implant disease is high,and the clinical treatment of peri-implant disease is not effective.Therefore the prevention of peri-implant disease is particularly important.However,there are few studies on the risk factors of long-term morbidity of periimplant disease in China,which cannot meet the urgent needs of early personalized prevention.At present,there is clear evidence that oral microorganisms play an important role in the pathogenesis of peri-implant diseases.However,the research results of periimplant subgingival plaque are influenced by many factors such as region,diet,detection technology,etc.There is still no consensus on the relationship between subgingival plaque community structure of peri-implant diseases and salivary microorganisms and implant health status.Therefore,more studies are needed to expand the understanding of the relationship between oral microecology and peri-implant diseases.In order to investigate the relationship between microorganisms and peri-implant disease in northwest China and to examine the similarities and differences between various types of oral microorganisms,this study employed risk factor investigation and high-throughput sequencing technology.These findings will serve as additional references for the etiological study of peri-implant disease[Objective]This study aims to clarify the influence of patient and implant related factors on the incidence of peri-implantitis and peri-implant mucositis in a prospective cohort,analyze the association between saliva and subgingival plaque microbial community structure of implant repair patients and its influencing factors,and research the characteristics and influencing factors of subgingival plaque microbial community structure of peri-implant under different health conditions.The objective is to provide a basis for the formulation of individualized strategies to prevent the disease in patients with mid-and long-term implant denture restoration.[Methods](1)Prospective cohort study of risk factors for peri-implant diseaseA cohort of patients who underwent implant denture restoration in the prosthodontics department of Stomatology Hospital of the Fourth Military Medical University from June2014 to September 2015 was followed up.Basic information of patients,factors related to implant and prosthesis such as adjacency and occlusal contact area,as well as oral health maintenance were collected through questionnaire survey and clinical examination.The cumulative incidence of peri-implantitis and peri-implant mucositis at patient level and implant level and the incidence density at implant level were calculated.Logrank test and Cox proportional hazard regression model were used to analyze univariate and multivariate factors that may affect the incidence of peri-implantitis and peri-implant mucositis.Univariate and multivariate logistic regression were used to analyze the factors that might affect peri-implanttis after implantation.(2)Study on the relationship between saliva and subgingival plaque community structure in patients undergoing implant repair and its influencing factors.According to inclusion and exclusion criteria,saliva and peri-implant subgingival plaque samples were collected,from which paired saliva and peri-implant subgingival plaque samples were selected for 16 S r RNA V3 ～ V4 double-ended sequencing.Alpha diversity analysis,Beta diversity analysis,Wilcoxon rank sum test and LEf Se discriminant discriminant were used to analyze the microbial community richness,community diversity and species abundance of salivary and peri-implant subgingival plaque.(3)Subgingival plaque community structure around implants and its influencing factorsThe subgingival plaque sequencing data around the implant were analyzed by Alpha diversity analysis,Beta diversity analysis,Circos map,comparison analysis between the two groups,and LEf Se multistage species difference discriminant.The differences of microbial community richness,community diversity,community composition and species abundance in peri-implant health,peri-implant inflammation and peri-implant mucositis were analyzed.The correlation Heatmap was used to analyze the relationship between subgingival plaque of patients with periimplantitis and the related factors of patients and implants,and Spearman correlation coefficient was used to evaluate the correlation between the them.[Results](1)Prospective cohort study of risk factors for peri-implant disease.A total of 111 people and 195 implants were followed up,the mean follow-up time was 7.17±0.37 years.The cumulative incidence of periimplantitis was 25.23%(95%CI:17.00%-33.40%),the cumulative incidence of peri-implantitis was 21.03%,and the incidence density was 3.00/100 person-year.The cumulative incidence of peri-implant mucositis was 58.56%(95%CI: 49.30%-67.90%)and 52.82% at implant level,with an incidence density of 9.45/100 person-years.(1)Cox proportional hazard regression model analysis showed that the independent risk factors affecting the incidence of peri-implant inflammation before implantation were age >64 years old(HR= 11.30,95%CI: 1.60-79.65)and heavy smoking(HR= 6.18,95%CI: 1.89-20.16),mild periodontitis(HR=2.83,95%CI:1.06-7.57),lack of implant site due to periodontitis(HR=2.601,95%CI: 1.385-4.887).Multivariate Logistic regression analysis showed that independent risk factors affecting the incidence of peri-implanttis after implantation were cardiovascular disease(OR=3.55,95%CI: 1.26-9.96),mild periodontitis(OR=3.57,95%CI:1.08-11.84),moderate to severe periodontitis(OR=5.95,95%CI: 1.64-21.54),keratosis mucosa width < 2mm(OR=3.47,95%CI: 1.29-9.332).(2)Cox proportional hazard regression model analysis showed that the independent risk factors affecting the incidence of peri-implant mucositis before implantation were moderate smoking(HR= 4.51,95%CI: 2.42-8.42)and heavy smoking(HR= 3.138,95%CI: 1.796-5.481),mild periodontitis(HR=1.85,95%CI: 1.10-3.11)titanium base(HR= 2.653,95%CI: 1.15-6.10),screw fixation(HR= 1.77,95%CI: 1.115-2.81).(2)Study on the relationship between saliva and subgingival plaque community structure in patients undergoing implant repair and its influencing factors.Finally,23,49 and 45 pairs of saliva and subgingival plaque samples were included in peri-implanttis,peri-implant mucositis and peri-implant health,respectively.(1)The results of Alpha diversity showed that the difference of microbial community richness in saliva and subgingival plaque of implant repair patients was statistically significant(Sobs index and Chao index: P < 0.05),while the difference in community diversity was not statistically significant(Shannon index and Simpson index: P > 0.05).The results of PCo A analysis showed that the microbial community composition of saliva and subgingival plaque in implant denture restoration patients had statistical significance(P < 0.05).In the Wilcoxon rank sum test,there were 12 species and 14 species at the genus level that ranked top 15 in abundance between the two groups,and the differences were statistically significant(P <0.05).In LEf Se analysis,there were 11 species at the genus level with LDA > 4.(2)Subgroup analysis showed that the difference of saliva and subgingival plaque microbial community richness in patients with peri-implant health,peri-implant mucositis and periperi-implantitis was still statistically significant(P < 0.05),while the difference of community diversity was not statistically significant(P > 0.05).(3)Wilcoxon rank-sum test showed that Neisseria,Acinetobacter and Fusobacterium had no significant difference in the proportion of saliva and subgingival plaque between the two groups(P > 0.05).The species with no significant difference in the proportion of salivary and subgingival plaque in patients with peri-implant mucositis were Neisseria,Porphyromonas,Fusobacterium and Hemophilus(P > 0.05).Compared with the healthy group,the saliva contained a higher proportion of Neisseria,porphyromonas and Haemophilus(P < 0.05).(3)Subgingival plaque community structure around implants and its influencing factors.(1)The results of Alpha diversity analysis showed that there were no significant differences in subgingival microbial community richness and community diversity between peri-implant inflammation and peri-implant healthy patients(P > 0.05).PCo A analysis showed that there was significant difference in community composition between the two groups(P=0.05).Wilcoxon rank sum test showed that the abundances of the top 15 species in the two groups were statistically significant(P < 0.05),and the abundances of porphyromonas and Treponema at the phyla level,and the abundances of porphyromonas and Treponema at the genus level were all >1%.LEf Se analysis results showed that there were differences in phyla level microorganisms between the two groups,and the difference in genus level porphyromonas between the two groups was statistically significant(LDA >4).(2)There was no significant difference in subgingival plaque Alpha diversity between peri-implant mucositis and peri-implant healthy patients(P > 0.05).PCo A analysis showed that there was no significant difference in microbial community composition between the two groups(P > 0.05).Wilcoxon rank sum test showed that there were statistically significant differences between the two groups(P < 0.05)in the genera of Dialister、Phocaeicola、Atopobium、Peptostreptococcus,but the abundance was lower than 1%.(3)Cardiovascular disease was positively correlated with Porphyromonas abundance(R=0.526),while alcohol consumption was negatively correlated with Porphyromonas abundance(R=-0.624)and Treponema abundance(R=-0.523).[Conclusion](1)The incidence of peri-implant disease is high,and various factors have different degrees of influence on the incidence of peri-implant disease.Both mild periodontitis and heavy smoking before implantation had influence on the incidence of peri-implant disease,suggesting that clinicians should strictly control the indications of implant restoration before implantation,and the mild periodontitis before implantation should not be ignored.Periodontitis of different degrees after implantation has an effect on peri-implantitis.It is suggested that regular follow-up should be conducted after implantation to strengthen implant maintenance education for patients so as to further reduce the incidence of periimplantitis(2)The diversity of subgingival plaque microbial community is closely related to the saliva of patients undergoing implant restoration,but there is a great difference in microbial species.The difference in saliva and subgingival plaque community richness of patients with different health conditions around the implant was statistically significant,while the difference in community diversity was not statistically significant.When comparing the abundance of microbial species between saliva and subgingival plaque of patients with periimplantitis,Treponemas in subgingival plaque increased.(3)The dominant bacteria genera of peri-implantitis are spirochaeta and synergistetes,and the dominant bacteria genera are porphyromonas and Treponema,which provide important clues for the prevention and treatment of peri-implantitis from the aspect of microorganisms.Cardiovascular disease and alcohol consumption were positively and negatively correlated with dominant bacteria of peri-implantitis.