Search

Objective: Chronic periodontitis (CP), aggressive periodontitis (AP), and peri-implantitis (PI) are chronic inflammatory diseases. Tumor necrosis factor-α (TNF-a) is an effective immune inflammatory mediator. Several studies have been conducted to explore the association between the TNF-α (G-308A) polymorphism and susceptibility to CP, AP, and PI. Our objective was to examine whether the TNF-α (G-308A) polymorphism is related to these diseases., Methods: We conducted a meta-analysis to investigate the association between the TNF-α (G-308A) polymorphism and CP, AP, and PI. The PubMed, Embase, CNKI, and Web of Science electronic databases were searched for studies published from inception to August 11, 2020; the reference lists of included studies were also searched. The included studies were assessed in the following genetic models: dominant model, recessive model, allelic model, heterozygous model, and homozygous model., Results: Forty articles (50 comparisons) with 2243 CP, 824 AP, 615 PI, 795 healthy peri-implant, and 3575 healthy controls were considered for the TNF-α (G-308A) polymorphism in this meta-analysis. Variant A of TNF-α (G-308A) was associated with increased AP risk in the general population, especially in Asians, and this polymorphism was significantly associated with elevated risk of CP in Asians and Caucasians. There was no association between the A allele and PI risk. None of the contrasts of the genetic model yielded a significant finding in Latin Americans. Different genotyping methods may affect the association between the TNF-α (G-308A) polymorphism and these diseases., Conclusion: These findings supported that variant A of the TNF-α (G-308A) polymorphism may contribute to CP and AP susceptibility, particularly in Asians and Caucasians. More efforts and further studies with larger sample sizes will be required to validate the risk of CP, AP, and PI., (Copyright © 2021 Elsevier Inc. All rights reserved.)

In chronic periodontitis and peri-implantitis, cells of the innate and adaptive immune systems are involved directly in the lesions within the tissues of the patient. Absence of a periodontal ligament around implants does not prevent a biologic process similar to that of periodontitis from affecting osseointegration. Our first focus is on factors in the biology of individuals that are responsible for the susceptibility of such individuals to chronic periodontitis and to peri-implantitis. Genetic factors are of significant importance in susceptibility to these diseases. Genetic factors of the host affect the composition of the oral microbiome in the same manner that they influence other microbiomes, such as those of the intestines and of the lungs. Our second focus is on the central role of stem cells in tissue regeneration, in the functioning of innate and adaptive immune systems, and in metabolism of bone. Epithelial cell rests of Malassez (ERM) are stem cells of epithelial origin that maintain the periodontal ligament as well as the cementum and alveolar bone associated with the ligament. The tissue niche within which ERM are found extends into the supracrestal areas of collagen fiber-containing tissues of the gingivae above the bony alveolar crest. Maintenance and regeneration of all periodontal tissues involves the activity of a variety of stem cells. The success of dental implants indicates that important groups of stem cells in the periodontium are active to enable that biologic success. Successful replantation of avulsed teeth and auto-transplantation of teeth is comparable to placing dental implants, and so must also involve periodontal stem cells. Biology of teeth and biology of implants represents the biology of the various stem cells that inhabit specialized niches within the periodontal tissues. Diverse biologic processes must function together successfully to maintain periodontal health. Osseointegration of dental implants does not involve formation of cementum or collagen fibers inserted into cementum - indicating that some stem cells are not active around dental implants or their niches are not available. Investigation of these similarities and differences between teeth and implants will help to develop a better understanding of the biology and physiologic functioning of the periodontium.

In inflammatory diseases such as peri-implantitis (PI) and chronic periodontitis (CP) both adaptive and innate immunity play a part. Natural resistance associated macrophage protein 1 (NRAMP1) has considerable effects on macrophage function (phagocytosis) and host innate immune response against infections. The present study was to investigate the relationship of NRAMP1 gene polymorphisms with PI and CP in an Iranian population. In this cross sectional study 79 patients with CP, 38 patients with PI and 84 healthy controls presenting to the Periodontology Department of Shahid Beheshti University of Medical Sciences were enrolled. DNA was extracted from fresh blood samples of arm vein of participants and transferred to KBiosience institute (United Kingdom) for genotyping. X2 and Fisher's exact tests were used by SPSS software v.19 for statistical analyzes. Significant differences were detected in the distribution of genotypes between control and CP groups both for rs17235409 and rs2276631 polymorphisms (P:0.044 and P:0.028 respectively). Distribution of genotypes differed insignificantly in comparison of PI and control groups for rs2276631 (P:0.623) and either rs17235409 (P:1) polymorphisms. Based on our results, we conclude that presence of G allele in both rs2276631 and rs17235409 location may be a protective factor against CP. More studies with a larger sample size in different populations are required for confirming NRAMP1 as a genetic determinant in periodontal disorders.

Background: Peri-implantitis is a chronic inflammation, resulting in loss of supporting bone around implants. Chronic periodontitis is a risk indicator for implant failure. Both diseases have a common etiology regarding inflammatory destructive response. BRINP3 gene is associated with aggressive periodontitis. However, is still unclear if chronic periodontitis and peri-implantitis have the same genetic background. The aim of this work was to investigate the association between BRINP3 genetic variation (rs1342913 and rs1935881) and expression and susceptibility to both diseases., Methods: Periodontal and peri-implant examinations were performed in 215 subjects, divided into: healthy (without chronic periodontitis and peri-implantitis, n = 93); diseased (with chronic periodontitis and peri-implantitis, n = 52); chronic periodontitis only (n = 36), and peri-implantitis only (n = 34). A replication sample of 92 subjects who lost implants and 185 subjects successfully treated with implants were tested. DNA was extracted from buccal cells. Two genetic markers of BRINP3 (rs1342913 and rs1935881) were genotyped using TaqMan chemistry. Chi-square (p < 0.05) compared genotype and allele frequency between groups. A subset of subjects (n = 31) had gingival biopsies harvested. The BRINP3 mRNA levels were studied by CT method (2(ΔΔCT)). Mann-Whitney test correlated the levels of BRINP3 in each group (p < 0.05)., Results: Statistically significant association between BRINP3 rs1342913 and peri-implantitis was found in both studied groups (p = 0.04). The levels of BRINP3 mRNA were significantly higher in diseased subjects compared to healthy individuals (p = 0.01)., Conclusion: This study provides evidence that the BRINP3 polymorphic variant rs1342913 and low level of BRINP3 expression are associated with peri-implantitis, independently from the presence of chronic periodontitis.

Aim: The haptoglobin-hemoglobin (Hp-Hb) complex plays a significant role in regulating immune responses and acts as a bacteriostatic agent. Haptoglobin polymorphisms result in different Hb binding affinities. This study sought to assess whether Hp 2-2 could be a genetic determinant for increasing the risk of peri-implantitis and chronic periodontitis., Methods: Of the Iranian subjects referred to the Department of Periodontics, Shahid Beheshti University, Tehran, 203 were entered into the study, including 117 patients and 86 periodontally healthy individuals. Polymerase chain reaction (PCR) was performed for genotyping. Data were analyzed by Kruskal-Wallis test using the SPSS statistics software package., Results: The prevalence of Hp 2-2, 2-1, and 1-1 did not differ significantly between patients and healthy subjects (P > 0.05). The highest frequencies of Hp 1-1, 2-1, and 2-2 genotypes were seen in the control (7%), peri-implantitis (51%) and periodontitis (64%) groups, respectively., Conclusions: Haptoglobin polymorphisms may not play a role in development of peri-implantitis or chronic periodontitis among Iranians but we strongly suggest researchers to evaluate this polymorphism in further studies on larger sample sizes, different populations, and other types of periodontitis., (© 2013 Wiley Publishing Asia Pty Ltd.)

Gene polymorphism of cytokines influencing their function has been known as a contributing factor in the pathogenesis of inflammatory diseases of the tooth and implant supporting tissues. The aim of this study was to investigate the association of IL-17R gene polymorphism (rs879576) with chronic periodontitis and periimplantitis in an Iranian population. 73 patients with chronic periodontitis, 37 patients with periimplantitis and 83 periodontally healthy patients were enrolled in this study. 5cc blood was obtained from each subject's arm vein and transferred to tubes containing EDTA. Genomic DNA was extracted using Miller's Salting Out technique. The DNA was transferred into 96 division plates, transported to Kbioscience Institute in United Kingdom and analyzed using the Kbioscience Competitive Allele Specific PCR (KASP) technique. Chi-square and Kruskal Wallis tests were used to analyze differences in the expression of genotypes and frequency of alleles in disease and control groups (P-Value less than 0.05 was considered statistically significant). There were no significant differences between periodontitis, periimplantitis with AA, GG, GA genotype of IL-17R gene (P=0.8239). Also comparison of frequency of alleles in SNP rs879576 of IL-17R gene between the chronic periodontitis group and periimplantitis group did not revealed statistically significant differences (P=0.8239). The enigma of IL-17 and its polymorphism-role in periodontitis and periimplantitis is yet to be investigated more carefully throughout further research but this article demonstrates that polymorphism of IL-17R plays no significant role in incidence of chronic periodontitis and Periimplantitis.

Objective: RANK/OPG/RANKL pathway plays a significant role in osteoclastogenesis, osteoclast activation, and regulation of bone resorption. The aim of this study was to investigate the association of RANKL gene polymorphisms (rs9533156 and rs2277438) with chronic periodontitis and peri-implantitis in an Iranian population., Design: 77 patients with chronic periodontitis, 40 patients with peri-implantitis and 89 periodontally healthy patients were enrolled in this study. 5cc of blood was obtained from the cephalic vein of subjects arms and transferred into tubes containing EDTA. Genomic DNA was extracted using Miller's Salting Out technique. The DNA was transferred into 96 division plates, transported to Kbioscience Institute in United Kingdom and analyzed using the Kbioscience Competitive Allele Specific PCR (KASP) technique. Differences in the frequencies of genotypes and alleles in the disease and control groups were analyzed using Chi-square and Fisher's exact statistical tests., Results: Comparison of frequency of alleles in SNP rs9533156 of RANKL gene between the chronic periodontitis group with the control and peri-implantitis groups revealed statistically significant differences (P=0.024 and P=0.027, respectively). Comparison of genotype expression of SNP rs9533156 on RANKL gene between the peri-implantitis group with chronic periodontitis and control groups revealed statistically significant differences (P=0.001); the prevalence of CT genotype was significantly higher amongst the chronic periodontitis group. Regarding SNP rs2277438 of RANKL gene, comparison of prevalence of genotypes and frequency of alleles did not reveal any significant differences (P=0.641/P=0.537, respectively)., Conclusions: The results of this study indicate that CT genotype of rs9533156 RANKL gene polymorphism was significantly associated with peri-implantitis, and may be considered as a genetic determinant for peri-implantitis., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: Peri-implantitis (PI) and chronic periodontitis (CP) are multifactorial diseases of implant/tooth supporting tissue that are caused by bacterial infection and increased host immune response. T-cell proliferation plays a pivotal role in the orchestration of host response to bacterial infection. BRAF is a positive regulator of T-cell proliferation. The aim of this study was to evaluate for the first time the role of a functional single nucleotide polymorphism (SNP) of the BRAF gene in association to PI and CP., Methods: A total of 194 individuals referred to the Periodontology Department of Shahid Beheshti Dental School, Tehran, Iran, were divided into three groups: 74 patients in the CP group (39 men and 35 women, with mean age of 48.3 years), 38 patients in the PI group (20 men and 18 women, with mean age of 50.2 years), and 82 patients in the healthy periodontium group (39 men and 43 women, with mean age of 45.4 years). DNA was extracted from fresh blood samples collected from the arm vein of participants and was transferred to KBiosience institute (United Kingdom) for genotyping. χ2 and Kruskal-Wallis tests were conducted using SPSS software v. 19 for statistical analysis (p<0.05)., Results: The allele (C/T) and genotype (CC, CT, TT) frequencies had insignificant differences among the three groups; however, the CC genotype was more prevalent in the healthy condition than in the disease conditions., Conclusions: The BRAF gene polymorphism (rs10487888) may not be a genetic determinant for increasing the risk of CP and PI among the Iranian population. More studies with more sample size in different populations are necessary for determining the effect of this SNP.

Background: Chronic periodontitis (CP) and peri-implantitis (PI) are inflammatory diseases that affect supporting tissues of teeth or implants. The involvement of hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) in neuronal excitability, hyperalgesia, allodynia, spontaneous pain, synaptic plasticity, and rebound activity was previously determined. Recently, scientists found that HCN2 plays an important role in chronic inflammatory pain. This study aimed to evaluate the relationship between gene polymorphisms of HCN2 and CP/PI., Methods: A total of 74 patients with CP, 37 patients with PI, and 80 healthy controls presenting to the Periodontology Department of Shahid Beheshti University of Medical Sciences were enrolled. DNA was extracted from fresh blood samples of the arm vein of participants and transferred to KBioscience Institute (UK) for genotyping. χ2-test was performed with SPSS software v.19 for statistical analyses. A p value <0.05 was considered significant., Results: Both rs55687900 and rs148730222 had significant differences in genotype frequencies between CP and healthy groups (p=0.005 and 0.006, respectively). The allele frequencies also revealed significant frequencies (p=0.004 and 0.006, respectively). The comparison of genotype and allele frequencies between PI and healthy groups had no significant difference., Conclusions: HCN2 polymorphism may play a role in CP but not in PI. Despite this approval, more studies with larger sample sizes in different populations are necessary.

Purpose: To investigate the association between interleukin-6 (IL-6) G174C polymorphism and susceptibility to peri-implant disease (PID) and/or chronic periodontitis (CP), in Brazilian subjects., Materials and Methods: A total of 103 Brazilian patients were submitted to peri-implant and periodontal examination. According to their peri-implant characteristics, patients were divided into: group A (healthy, n = 52), group B (peri-implant mucositis, n = 20), and group C (peri-implantitis, n = 31). All patients (n = 103) were also characterized as healthy periodontium patients without CP (HP, n = 60) or CP patients (CP, n = 43). DNA was extracted from buccal cells, and the IL-6 G174C polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism. Differences in the prevalence of genotypes and alleles between healthy and ill patients were analyzed by chi-square test (P < .05), considering PID, CP, and PID+CP., Results: Results considered the presence of PID and/or CP in all patients. The CC genotype was the least common in all groups. The chi-square test showed no significant correlation between genotypes. However, the odds ratio showed that individuals with GG genotype and allele G were 1.53 and 1.43 times more susceptible to PID, respectively. The risk of presenting CP was increased in patients with GG genotype and allele G 1.35 and 1.24 times, respectively. When both diseases were evaluated together, patients with GG genotypes and allele G were 1.75 and 1.50 times more likely to present PID and CP together. When PID was evaluated without CP, patients with allele G were 2.08 times more susceptible to PID., Conclusions: The frequency of the genotype IL-6 174GG and allele G was different between healthy and ill groups. Therefore, this genotype may be a common risk factor for both CP and PID in Brazilian populations.

Periodontal disease (PD) and peri-implantitis (PI) are characterized by an immune response leading to destructive inflammation. The prominent impact of genetic factors on periodontitis has been previously evaluated and IL-17 has found to play a critical role in this process. This cytokine has a controversial behavior. This study aimed at finding out whether the polymorphism of this cytokine plays a significant role in chronic periodontitis (CP) and PI or it is just a pro-inflammatory regulatory cytokine. Fresh human blood samples were obtained and three main genotypes were traced carefully. The samples were transferred into 96-well plates and sent to KBioscience Institute in the United Kingdom for genotyping the polymorphism using Competitive Allele Specific PCR (KASP) technique. SPSS version19 software and chi-square and Kruskal-Wallis tests were used for statistical differences considering p-value less than 0.05. A significant difference was detected between the three groups in terms of specific SNP studied in this experiment (P = 0.00). The CC genotype of IL17 polymorphism (rs10484879) may contribute to the pathogenesis of peri-implantitis and periodontitis. The association of IL-17 polymorphism with PI and CP is a promising finding that may help in future similar studies on other ethnicities and larger study populations.

Purpose: Receptor activator for nuclear factor kappa B ligand (RANKL)/RANK/OPG pathway plays a redundant role in osteoclastogenesis, osteoclast activation and regulation of bone resorption. Recently, single nucleotide polymorphisms (SNP) have been reported as a co-factor in pathogenesis of inflammatory diseases. The aim of this study was to investigate the relationship between osteoprotegerin (OPG) gene polymorphisms and chronic periodontitis and peri-implantitis in an Iranian population., Materials and Methods: 77 patients with chronic periodontitis (CP), 40 patients with peri-implantitis (PI) and 89 periodontally healthy subjects were enrolled in this study. A total of 5 ml of blood was obtained from the arm vein of participants. DNA was extracted based on the salting out method. Two functional SNPs (T950C and G1181C) were analysed by using polymerase chain reaction and restriction fragment length polymorphism (PCR&#95;RFLP). The prevalence differences in three batches were evaluated by chi-square test., Results: An evaluation of the T950C genotype found that there was no statistical difference between groups. A comparison of the G1181C genotype distribution between peri-implantitis and chronic periodontitis groups, and between peri-implantitis and normal groups found that the frequency of the CC genotype was significantly higher in patients with peri-implantitis (P = 0.005)., Conclusions: Our results indicate that a SNP at G1181C is associated with the presence of PI.

Aim: In the present study, we sought to assess the correlation of IKKi gene polymorphisms (rs1539243 and rs12728136) with chronic periodontitis and peri-implantitis in an Iranian population for the first time in dentistry., Materials and Methods: This cross-sectional study was conducted on 75 patients with chronic periodontitis, 38 patients with peri-implantitis, and 84 periodontally healthy subjects. Blood samples were taken from all subjects (5 cc venous) and transferred into Falcon tubes containing EDTA. Extracted DNA samples were evaluated with a spectrophotometer (75 ng), transferred into a 96-well plate, and sent to KBioscience Institute in the United Kingdom for analysis. Assessment of IKKi gene polymorphisms was performed at the KBioscience Institute. Data were analyzed using SPSS v19 software. Differences in genotype frequencies and allele among patients and controls were evaluated using the chi-squared test (P<0.05)., Results: A significant difference was detected between the peri-implantitis and chronic periodontitis groups in distribution of CC, TC, and TT genotypes in rs1539243 (P<0.05). Statistically significant differences were detected among the three groups in the frequency of T and C alleles for rs1539243 (P=0.03)., Conclusions: Within the limitations of the present study, the results showed a significant difference in IKKi gene polymorphism rs1539243 between the peri-implantitis and chronic periodontitis groups. However, such difference was not observed in rs12728136 between the two groups.

Unlabelled: This study sought to determine TANK (rs1921310, rs3820998) gene polymorphism in patients suffering from chronic periodontitis and peri-implantitis among an Iranian population., Materials and Methods: In this cross-sectional study, 77 chronic periodontitis and 40 peri-implantitis patients, along with 89 periodontally healthy subjects, were evaluated. A 5 cc venous blood sample was obtained from subjects. DNA was extracted using Miller's salting-out method and polymorphisms were determined by the use of KBioscience's Competitive Allele-Specific PCR (CASP) genotyping system. Data were analyzed using SPSS version 11.5 software. Differences in allele and genotype frequencies among patients and controls were evaluated with Kruskal-Wallis test. P<0.05 was considered statistically significant., Results: No significant differences were detected between understudy groups in distribution of CC and CA genotypes and alleles when evaluating rs3820998 polymorphism or in distribution of GA and AG genotypes and alleles when assessing rs1921310 polymorphism., Conclusions: Within the limitations of this study, it seems that these two polymorphisms do not play a significant role in pathogenesis of chronic periodontitis or peri-implantitis among the Iranian population. However, we recommend performing similar studies with larger sample sizes among the Iranian population and other communities.