Investigation On The Relationship Between Gene Polymorphism Of Interleukin-6 And Peri-implant Diseases

Objective: To investigated the association and clinical significance between gene polymorphism of the interleukin(IL)-6 gene 174 G/C and susceptibility to peri-implant disease in patients with peri-implant diseases and healthy implant.Methods: 1.Research object: we enrolled 80 patients with peri-implant disease(periimplant disease group)and 80 health implant(health implant group)in Stomatology Department of the People's Hospital of China Medical University between October 2017 and February 2019.the peri-implant disease group was divided into two groups: 32 patients with peri-implant mucositis and 48 patients with peri-implantitis.All subjects were between 25 and 77 years old.At least one OSSTEM TSIII SA implants were implanted into the mouth,and the superstructure was repaired for more than one year.2.Data acquisition and experimental methods: case-control method was used for study.The clinical peri-implant soft and hard tissue indexes of all subjects were measured and recorded,including modified plaque index(mPLI),modified sulcus bleeding index(mSBI),peri-implant probing pocket depth(PPD)and peri-implant marginal bone resorption(MBL).Genome DNA was extracted from subjects exfoliated buccal mucosal epithelial cells using column Oral swab Genome DNA extraction Kit.Polymerase chain reaction(PCR)amplified target fragment.Sanger sequencing was used to detect gene polymorphism of the interleukin(IL)-6 gene 174 G/C.The data were analyzed by statistical analysis software SPSS 25.0,Chi-square test was used to analyze the difference of genotype and allele frequency distribution in the promoter region of IL-6-174 gene between the two groups,the difference was statistically significant(P< 0.05).Odds ratio(OR)was used to analyze the risk of genotypes and alleles in periimplant disease.Results: 1.General data: There were no significant difference in age,sex,periodontal disease,the position of maxillary and mandibular implants,the position of anterior and posterior implants in peri-implantitis group,peri-implant mucositis group and healthy implant group(P>0.05).2.Comparison of clinical peri-implant soft and hard tissue indexes: The peri-implantitis group and the peri-implant mucositis group showed significantly higher values of mSBI and PPD than the healthy implant group,respectively(P<0.01).The peri-implantitis group showed a significantly higher values of mPLI and MBLthan the healthy implant group(P<0.01).However,there was no significant difference in mPLI and MBL between the peri-implant mucositis group and the healthy implant group.The levels of mPLI,mSBI,PPD and MBL in peri-implantitis group were significantly higher than those in peri-implant mucositis group,the difference was statistically significant(P<0.01).3.Comparison of the frequency distribution of genotype and allele: A statistically significant difference was seen in the distribution frequencies of three genotypes and alleles of IL-6-174 between the periimplant disease group and the healthy implant group(genotypes: ?2 = 6.262,P = 0.044;alleles: ?2 = 5.033,P = 0.025).In addition,the odds ratio showed that individuals with CC genotype and C allele were 4.03 and 1.823 times more susceptible to peri-implant disease than healthy implant,respectively.Further analysis showed that there was also significant difference between peri-implantitis group and healthy implant group(genotypes: ?2 = 7.741,P = 0.021;alleles: ?2 = 6.711,P = 0.010).In addition,the odds ratio showed that individuals with CC genotype and C allele were 5.00 and 2.154 times more susceptible to peri-implantitis than healthy implant,respectively.However,there was no significant difference between peri-implant mucositis group and healthy implant group(genotypes: ?2 = 2.008,P = 0.366;alleles: ?2 = 0.817,P = 0.366).Conclusion: 1.There is association between IL-6-174 single nucleotide polymorphisms and susceptibility to peri-implant diseases in patients with implant denture prosthesis.And there is association between gene polymorphism of the interleukin(IL)-6 gene 174 G/C and susceptibility to peri-implantitis,However,IL-6 gene174G/C might not be associated with peri-implant mucositis.2.The presence of CC genotype in IL-6-174G/C is positively correlated with the risk of peri-implant diseases.carriers of CC genotype and C allele in IL-6-174G/C had an increased risk of peri-implant diseases,especially peri-implantitis.and the destruction of peri-implant soft and hard tissue by peri-implantitis was significantly higher than that of peri-implant mucositis.