DNA methylation profile of genes related to immune response in generalized periodontitis.

BACKGROUND AND OBJECTIVE: Epigenetic events, as the DNA methylation, may be related to development of inflammatory diseases. Due to the important role of host's response in the pathogenesis of periodontitis, the purpose of the present study was to investigate the methylation profile of genes related to immune response in gingival tissues from patients with generalized periodontitis (GP) compared to healthy individuals. METHODS: Gingival tissues were collected from 20 individuals with GP and 20 healthy individuals. Genomic DNA was extracted and submitted to enzymatic digestions. An initial screening using a panel of genes involved with the response immune was performed in pools containing six samples of each group. Genes that presented different levels of methylation between the groups were selected for individual assays for validation. RESULTS: The array results showed an unmethylated profile in the majority of genes evaluated in both groups. MALT1, LTB, and STAT5 genes presented a profile of partial methylation in the control compared with GP group. Validation individual assays using a larger number of samples (n = 20, each group) confirmed the hypomethylation of STAT5 in the GP group compared with control group (P < .001). CONCLUSION: Generalized periodontitis is associated with hypomethylation of the STAT5 gene. Further studies are necessary to evaluate the functional impact these findings.

Brain-derived neurotrophic factor in chronic periodontitis.

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophic factor family. Outside the nervous system, BDNF has been shown to be expressed in various nonneural tissues, such as periodontal ligament, dental pulp, and odontoblasts. Although a role for BDNF in periodontal regeneration has been suggested, a function for BDNF in periodontal disease has not yet been studied. The aim of this study was to analyze the BDNF levels in periodontal tissues of patients with chronic periodontitis (CP) and periodontally healthy controls (HC). All subjects were genotyped for the rs4923463 and rs6265 BDNF polymorphisms. Periodontal tissues were collected for ELISA, myeloperoxidase (MPO), and microscopic analysis from 28 CP patients and 29 HC subjects. BDNF levels were increased in CP patients compared to HC subjects. A negative correlation was observed when analyzing concentration of BDNF and IL-10 in inflamed periodontium. No differences in frequencies of BDNF genotypes between CP and HC subjects were observed. However, BDNF genotype GG was associated with increased levels of BDNF, TNF-α, and CXCL10 in CP patients. In conclusion, BDNF seems to be associated with periodontal disease process, but the specific role of BDNF still needs to be clarified.

Transcription factor STAT1 gene polymorphism is associated with the development of severe forms of periodontal disease.

INTRODUCTION: Periodontal disease (PD) is one of the most common inflammatory diseases, affecting about 10 % of the world population. The establishment of PD is influenced by polymorphisms in genes involved with the inflammatory response. Signal Transducer and Activator of Transcription (STAT)-1 is a transcription factor that plays a key role in the intracellular signaling triggered by cytokines and, thus, its activation is critical in inflammatory diseases. AIM AND METHODS: We aim to evaluate the occurrence of association between STAT-1 (rs3771300) polymorphism and distinct clinical forms and severity of PD; we genotyped 180 subjects using realtime PCR. RESULTS AND CONCLUSION: We observed that the presence of the G allele for STAT-1 was associated with twice as high of a chance to develop aggressive periodontitis, and the most severe form of the disease.

Peri-implant disease in subjects with and without preventive maintenance: a 5-year follow-up.

AIM: To determine the incidence of peri-implantitis in individuals with mucositis in a 5-year follow-up study. MATERIAL AND METHODS: A sample of 212 partially edentulous individuals, rehabilitated with dental implants, underwent periodontal and peri-implant clinical examinations in 2005 (baseline). Five years later, 80 individuals who had been diagnosed with mucositis in the baseline examination were re-examined. These individuals were divided into two groups: one group with preventive maintenance during the study period (GTP; n = 39), and another group without preventive maintenance (GNTP; n = 41). The following parameters were clinically evaluated: plaque index, bleeding on periodontal and peri-implant probing, periodontal and peri-implant probing depth, suppuration and peri-implant bone loss. The influence of biological and behavioural risk variables associated with the occurrence of peri-implantitis was analysed using univariate and multivariate logistic regression analyses. RESULTS: The incidence of peri-implantitis in the global sample was 31.2% (GNTP = 43.9% and GTP = 18.0%). CONCLUSION: The absence of preventive maintenance in individuals with pre-existing peri-implant mucositis was associated with a high incidence of peri-implantitis. Clinical parameters, such as bleeding on peri-implant probing, periodontal probing depth and the presence of periodontitis were associated with a higher risk of developing peri-implantitis.

Association between severity of body mass index and periodontal condition in women.

This study evaluated the association between body mass index (BMI) and periodontal condition in a population of Brazilian women. A hospital convenience sample of 594 eligible women was recruited from a women's health reference center of Belo Horizonte, Brazil. Four groups were formed considering BMI levels: BMI normal group (n = 352), overweight (n = 54), obesity level I (n = 48), obesity level II (n = 56), and obesity level III (n = 74). Full-mouth periodontal examination was performed and biological, demographic, and behavioral risk variables were evaluated. Obese and overweight women showed statistically significant differences in bleeding on probing, probing depth and clinical attachment level ≥ 4 mm, and frequency of periodontitis (p < 0.05) compared to women showing normal BMI. The final multivariate model for the occurrence of periodontitis revealed that obesity groups were significantly associated with periodontitis. In addition, age (25-45), smoking, diabetes, and hypertension remained significantly associated with the occurrence of periodontitis (p < 0.05). Periodontitis was positively associated with obesity, and this association was more evident as obesity levels increases. These findings indicate the need for early diagnosis and the inclusion of periodontal care in health care programs for obese women.

Association between periodontal condition and use of tongue piercing: a case-control study.

OBJECTIVE: This cross-sectional study aimed to evaluate the periodontal status and risk factors for gingival recession in individuals with tongue piercings. METHODS: Sixty cases (individuals with tongue piercings) and 120 controls (non-users) in Brazil, between 13 and 28 years of age, from both genders and a mix of races were selected. The clinical evaluation of patient oral health records included periodontal parameters and the presence of tooth fracture. Cases and controls were compared with demographic, behavioural and clinical variables of interest. Risk variables for the occurrence of gingival recession were identified in multivariate regression models, with linear and logistic regressions. RESULTS: The case group presented a higher prevalence and severity of gingival recession when compared with the control group. Individuals with tongue piercings presented an 11 times greater chance for the occurrence of gingival recession in the anterior lingual mandibular region as compared with controls (OR=11.0, 95% CI 5.02-24.09). The presence of gingival recession in the anterior lingual mandibular region was associated with the use of piercings, age, male gender and bleeding on probing. CONCLUSIONS: The use of tongue piercings was strongly associated with the occurrence of gingival recession in the anterior lingual mandibular region.

Quantification of five putative periodontal pathogens in female patients with and without chronic periodontitis by real-time polymerase chain reaction.

Chronic periodontitis is a highly prevalent endogenous polymicrobial disease. To better understand the etiology of the disease a quantitative approach is mandatory and real-time PCR is the molecular technique currently preferred to achieve this purpose. Taking into account that such a kind of study is still scarce, we aimed to evaluate the association between periodontal microbiota and chronic periodontitis. A total of 60 low-income age-matched female adults, 30 with chronic periodontitis and 30 without periodontal disease, were enrolled. DNA obtained from subgingival specimens was used for quantification of Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Fusobacterium nucleatum, Porphyromonas gingivalis, and Prevotella intermedia by real-time PCR. A. actinomycetemcomitans, E. corrodens, and F. nucleatum were detected in all subjects, P. gingivalis was observed in 70.0% and 46.6% and P. intermedia in 90.0% and 80.0% of chronic periodontitis patients and periodontally healthy subjects, respectively. P. gingivalis mean count was significantly higher in patients with chronic periodontitis than in periodontally healthy individuals. Accurate detection and quantification of five putative periodontal pathogens was feasible using a simple and fast real-time PCR protocol. Although P. gingivalis and P. intermedia have been found more commonly in chronic periodontitis patients, no statistical difference was observed between periodontally diseased and healthy groups. Quantitative data indicated association between P. gingivalis and chronic periodontitis. However, because of its uneven distribution, it should not be solely taken as a marker of periodontal status.

Effect of Periodontal Therapy on Serum Levels of IL-6 in Type 2 Diabetics: A Systematic Review.

The objective of this systematic review was to search for scientific evidence regarding the impact of periodontal therapy on serum levels of interleukin 6 (IL-6) in type 2 diabetics. A survey was conducted in five databases. Two researchers read titles and abstracts for initial selection and full text for inclusion. Data extraction and methodological quality assessment were performed. Four hundred and fifty-five studies were identified and 15 were included. Significant divergence on the effect of periodontal intervention on IL-6 levels in diabetics was observed among studies. The evaluation results of studies that controlled obesity indicate that periodontal therapy seems to have beneficial effects on IL-6 levels.

Gingival status of Brazilian renal transplant recipients under sirolimus-based regimens.

BACKGROUND: Although the prevalence of gingival overgrowth (GO) in calcineurin-inhibitor (CNI) immunosuppressive regimens has been well documented, to the best of our knowledge data from sirolimus (SIR) regimens have not been described. We sought to investigate the gingival status of renal transplant recipients under SIR-based regimens with regard to the prevalence and potential risk variables associated with GO. METHODS: A cross-sectional study was conducted at a public hospital in Belo Horizonte, MG, Brazil. Of 886 transplant recipients, an eligible sample of 144 subjects was selected. Medical, pharmacologic, and periodontal variables were recorded for each subject. GO was assessed through visual inspection and was evaluated in relation to variables of interest by univariate and multivariate analyses. RESULTS: Although not clinically significant, 20.8% of the samples had GO, with a mean GO score of 5.0% +/- 3.98% (range, 0% to 19%) and mean GO score per papilla of 0.378 +/- 0.361 (range, 0.1 to 1.9); the percentage of papilla affected by GO was 14.35% +/- 9.86% (range, 5% to 45%). The multivariate final model, excluding periodontal variables, showed that the concomitant use of calcium channel blockers (P = 0.033) and the interaction between time since transplant and previous CNI use (P <0.001) were associated with GO. Adding periodontal variables to the model improved its accuracy and retained papillary bleeding index as being strongly associated with GO (P <0.001). CONCLUSIONS: GO was observed in a considerable number of subjects under SIR-based immunosuppressive regimens, although the relationship was not clinically significant. Findings point to the importance of cooperation between medical and dental health care personnel in the maintenance of renal transplant recipients under SIR-based immunosuppressive regimens.

Maternal periodontitis as a potential risk variable for preeclampsia: a case-control study.

BACKGROUND: Association studies between maternal periodontitis and an elevated risk for preeclampsia have shown conflicting results. The aims of the present case-control study were: 1) to evaluate the association between maternal periodontitis and preeclampsia before and after matching, assessing confounding and interaction; and 2) to evaluate the influence of the extent and severity of periodontal parameters, bleeding on probing (BOP), probing depth (PD), and clinical attachment loss (CAL), in association with preeclampsia. METHODS: Initially, 1,206 Brazilian women were included and divided into a control group (1,042 non-preeclamptic women who gave birth to infants with adequate gestational age and birth weight) and a case group (164 preeclamptic women). Further, 125 preeclamptic women were matched according to age, chronic hypertension, and primiparity to 375 non-preeclamptic women randomly selected from the control group. Maternal periodontitis was defined as PD > or =4 mm and CAL > or =3 mm at the same site in at least four teeth. The effect of variables of interest and confounding were assessed by univariate and multivariate analysis. RESULTS: After controlling for confounders, maternal periodontitis was included in the multivariate final model (odds ratio [OR] = 1.94; 95% confidence interval [CI]: 1.37 to 2.77; P <0.001) and remained associated with preeclampsia after matching (OR = 1.52; 95% CI: 1.01 to 2.29; P = 0.045). The odds of preeclampsia were associated with an increase in the number of sites with BOP and PD and CAL > or =4 mm. CONCLUSION: Maternal periodontitis is a risk factor associated with preeclampsia, emphasizing the importance of periodontal care in prenatal programs.

Effect of compliance during periodontal maintenance therapy on levels of bacteria associated with periodontitis: A 6-year prospective study.

BACKGROUND: It is well established that regular compliance during periodontal maintenance therapy (PMT) maintains the stability of periodontal clinical parameters obtained after active periodontal therapy (APT). However, compliance during PMT has not yet been related to subgingival bacterial levels. Thus, this study followed individuals in PMT over 6 years and longitudinally evaluated the effects of compliance on periodontitis-associated bacterial levels and its relation to periodontal status. METHODS: From a 6-year prospective cohort study with 212 individuals in PMT, 91 were determined to be eligible. From this total, 28 regular compliers (RC) were randomly selected and matched for age and sex with 28 irregular compliers (IC). Complete periodontal examination and microbiological samples were obtained 5 times: T1 (prior to APT), T2 (after APT), T3 (2 years), T4 (4 years), and T5 (6 years). Total bacteria counts and levels of Actinomyces naeslundii, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were evaluated through quantitative polymerase chain reaction. RESULTS: RC had less tooth loss and better clinical and microbiological conditions over time when compared with IC. IC had higher total bacterial counts and higher levels of T. denticola. Moreover, among IC, total bacterial counts were positively associated with plaque index and bleeding on probing, while levels of A. naeslundii, T. forsythia, and T. denticola were negatively associated with clinical attachment loss (4 to 5 mm) among RC. CONCLUSIONS: Compliance positively influenced subgingival microbiota and contributed to stability of periodontal clinical status. Regular visits during PMT sustained microbiological benefits provided by APT over a 6-year period.

Periodontal disease progression among young subjects with no preventive dental care: a 52-month follow-up study.

BACKGROUND: The aim of the present study was to assess the incidence, severity, and extension of periodontal disease among young subjects. METHODS: Three hundred sixty subjects from a public school in Belo Horizonte, Brazil were examined. Forty-four subjects with bone loss (BL) and/or clinical attachment loss (CAL) > or = 4 mm, and no dental care during the following 52 months, were considered the reference sample and were recalled for a second examination. At both examinations, statistical analyses were performed for CAL and BL for subject, tooth, and site. Comparisons of CAL at subject, tooth, and site levels were performed with the Wilcoxon test for matched samples. Comparisons of BL at subject, tooth, and site levels were performed with the McNemar and Student t tests for dependent samples. RESULTS: Findings indicated an increase in the number of sites with CAL >4 mm from baseline to follow-up. Sites that exhibited BL increased from 2.14% at baseline to 7.5% at follow-up (P <0.001). The severity of periodontitis was characterized by increased CAL values at affected sites at both examinations (P <0.001) and an increase in BL over time (mean BL at 35 affected sites was 2.6 mm at baseline and 3.5 mm at follow-up; P = 0.001). In addition, a 34% incidence of BL was verified. CONCLUSIONS: The incidence, severity, and extension of CAL and BL were significant findings. They indicate the importance of early detection of the disease and the need for preventive health care programs geared toward young subjects.

Intrauterine growth restriction, low birth weight, and preterm birth: adverse pregnancy outcomes and their association with maternal periodontitis.

BACKGROUND: It has been suggested that periodontitis is associated with systemic alterations such as adverse pregnancy outcomes. However, some conflicting results have been reported. This case-control study was conducted to determine the association between maternal periodontitis and preterm birth (PTB), low birth weight (LBW), and intrauterine growth restriction (IUGR). METHODS: A total of 1,305 Brazilian women from multiethnic groups were enrolled and divided into four groups: control group (1,042 women who gave birth to infants with adequate gestational age and birth weight); PTB group (238 women, gestational age <37 complete weeks); LBW group (235 women, birth weight <2,500 g); and IUGR group (77 women who gave birth to infants with fetal growth retardation). Periodontitis was defined as the presence of at least four teeth with one or more sites with probing depth > or =4 mm and clinical attachment loss > or =3 mm. The effects of variables of interest, confounders, and interaction were tested through univariate and multivariate logistic regression tests. RESULTS: After adjusting for variables of interest, maternal periodontitis was retained in the final model for PTB (odds ratio [OR] = 1.77; 95% confidence interval [CI]: 1.12 to 2.59), LBW (OR = 1.67; 95% CI: 1.11 to 2.51), and IUGR (OR = 2.06; 95% CI: 1.07 to 4.19). When the interaction between periodontitis and previous PTB was tested, an OR of 5.94 (P <0.001), 9.12 (P <0.001), and 18.90 (P <0.001) was observed for PTB, LBW, and IUGR, respectively. CONCLUSIONS: Maternal periodontitis is associated with an increased risk for PTB, LBW, and IUGR. Results emphasize the importance of periodontal care in prenatal health programs.

Histopathological and morphological alterations of periodontium in rats treated with tacrolimus and cyclosporine.

OBJECTIVE: To evaluate and compare the possible morphological and histopathological changes in gingival tissue of rats under the administration of cyclosporine and tacrolimus. The present study was motivated by the high prevalence of gingival overgrowth observed in subjects under cyclosporine regimens and by studies reporting a significant decrease in gingival overgrowth after the substitution of tacrolimus. METHODS: Five Sprague-Dawley rat groups were administered therapeutic and greater-than-therapeutic doses of cyclosporine and tacrolimus over 54 days. The control group of 10 animals received distilled water as a placebo. The cyclosporine group was divided into two subgroups of 10 animals each, one receiving 10 mg/kg/day (CsA1) and one receiving 30 mg/kg/day (CsA2). The tacrolimus group was also divided in two subgroups of 10 animals each, receiving 3.2 mg/kg/day (Tcr1) or 6.4 mg/kg/day (Tcr2). RESULTS: Gingival overgrowth was higher in the group that was administered the higher cyclosporine dosage (CsA2) than in the group that received the therapeutic dosage, showing a positive relation between dosage and severity of gingival overgrowth. Hypercellularity, vascular congestion and focal inflammatory exudation were observed in the CsA2 subgroup only. There were no morphological or histological alterations in gingival tissue in either tacrolimus subgroups. CONCLUSION: Cyclosporine can induce adverse morphological and histopathological changes in gingival tissue of rats, and these effects are dose-dependent. Tacrolimus induced no gingival alterations in this rat model.

Association between maternal periodontitis and an increased risk of preeclampsia.

BACKGROUND: Periodontal disease has been considered a systemic exposure implicated in a higher risk of adverse pregnancy outcomes. The aim of the present study was to determine whether maternal periodontitis is associated with an increased risk of preeclampsia. METHODS: A case-control study was conducted in a public hospital in Belo Horizonte, Brazil. During the study period, 588 women, aged 14 to 46 years, were deemed eligible and had data available for analysis. Maternal demographic and medical data were collected from medical records. Preeclampsia was defined as blood pressure >140/90 mm Hg and > or =1+ proteinuria after 20 weeks of gestation. A periodontal examination was performed postpartum. Maternal periodontitis was defined as the presence of four or more teeth with one or more sites with a probing depth > or =4 mm and clinical attachment loss > or =3 mm at the same site. The effects of maternal age, chronic hypertension, primiparity, smoking, alcohol use, and number of prenatal visits were analyzed. Adjusted odds ratios (ORs) for preeclampsia were calculated using multivariate logistic regression. RESULTS: The prevalence of periodontitis was 63.9% and preeclampsia was 18.5%. Variables associated with preeclampsia were chronic hypertension (OR = 4.10; 95% confidence interval [CI] = 2.0 to 8.4; P = 0.001), primiparity (OR = 2.40; 95% CI = 1.5 to 3.9; P = 0.004), maternal age (OR = 1.07; 95% CI = 1.0 to 1.1; P = 0.001), and maternal periodontitis (OR = 1.88; 95% CI = 1.1 to 3.0; P = 0.001). CONCLUSION: Maternal periodontitis was determined to be associated with an increased risk of preeclampsia.

Prevalence, severity, and risk variables associated with gingival overgrowth in renal transplant subjects treated under tacrolimus or cyclosporin regimens.

BACKGROUND: Some reports suggest that the prevalence and severity of gingival overgrowth (GO) is lower in patients taking tacrolimus (Tcr) than in those taking cyclosporin A (CsA). The present study was conducted to determine the prevalence and severity of GO in a group of renal transplant recipients treated with Tcr in comparison to those treated with CsA and to evaluate the risk variables associated with the development of GO in these two drug regimens. METHODS: A cross-sectional study was conducted in a public hospital in Belo Horizonte City, Brazil. Demographic, pharmacological, and periodontal data were recorded for each subject. Variables from 134 subjects taking Tcr were compared to 451 subjects taking CsA using independent sample t, chi(2) statistic, or Mann-Whitney tests. The effects of potential risk factors on GO severity were determined using forward and backward stepwise regression analysis. RESULTS: Subjects taking CsA showed a higher mean GO score (29.03% +/- 22.9%) compared to subjects taking Tcr (16.9% +/- 3.4%) (P = 0.0038). In the Tcr group, 17.9% of the subjects had clinically significant GO compared to 38.1% in the CsA group (P = 0.045). In the multivariate final model, papillary bleeding index, azathioprine dosage, and concomitant use of calcium channel blockers (CCB) were significant variables associated with severity of GO in Tcr and CsA groups. In addition, previous CsA use also remained significant for GO in subjects under a Tcr regimen. CONCLUSIONS: The prevalence and severity of GO is lower in transplant subjects taking Tcr compared to CsA. GO severity in both groups was strongly associated with the papillary bleeding index, highlighting the role of inflammation in this condition. Concomitant CCB use, azathioprine dosage, and previous CsA use in the Tcr group reinforces the possible synergistic effects of these pharmacological variables on GO severity.

[Periodontal disease in the Arturo's black community in Contagem, Minas Gerais, Brazil]. / A doença periodontal na comunidade negra dos Arturo's, Contagem, Minas Gerais, Brasil.

This was a cross-sectional study on periodontal disease in a black community in Brazil. The sample consisted of 104 individuals over 13 years of age (63 females and 41 males). All teeth were examined except the third molars. Six sites per tooth were analyzed in order to measure pocket depth and clinical loss of attachment. Four sites per tooth were used to measure bleeding on probing and presence of calculus. It was observed that bleeding on probing occurred in 97.9% of the total of individuals with teeth, with probing depth >or= 4mm in 43.3% and clinical attachment loss in 63.5%. Calculus was detected in 81.2% of the sample. In the study, individuals 46 to 60 years of age showed the highest mean clinical attachment loss, 8.3mm (+/- 4.27), and a probing depth of 4.6mm (+/- 3.5). Prevalence rate for periodontal disease in this community was similar to rates elsewhere in Brazil and the world, i.e., 9.6% for the severe form. Age, schooling, and tobacco use were identified as risk indicators statistically associated with periodontal disease.

Halitosis in obese patients and those undergoing bariatric surgery.

BACKGROUND: Patients undergoing bariatric surgery often complain of bad breath. However, the relationship between bariatric surgery and halitosis is relatively unknown. The purpose of the present study was to evaluate and compare the occurrence of halitosis among patients before and after a specific type of bariatric surgery, Roux-en-Y gastric bypass, and its relationship with the tongue coating index, plaque index, and salivary flow rate. METHODS: A total of 62 patients with good oral health and in treatment for obesity at the walk-in clinic of Santa Casa Hospital, Belo Horizonte, Brazil, were selected. Of this sample, 31 were bariatric surgery candidates (control group) and 31 had already undergone Roux-en-Y gastric bypass surgery (case group). After completing a questionnaire, all patients underwent an oral clinical examination. Halitosis was measured using an organoleptic scale and a portable sulfide monitor. RESULTS: The Spearman correlation demonstrated a strong positive relation between the organoleptic rates and the concentration of volatile sulfur compounds determined using the sulfide monitor (rs = .58; P = .0001). No difference was found in the prevalence of halitosis between the 2 groups (P = .48). Only the salivary flow rate was significantly reduced in the control group compared with the case group (P = .02). In the case group, the concentration of volatile sulfur compounds correlated negatively with the salivary flow rate (P = .04) and positively with the tongue coating index (P = .005). The tongue coating index was significantly increased in those patients who did not brush the tongue (P < .04) and who had had episodes of vomiting (P = .02). CONCLUSION: These data suggest that no significant association exists between halitosis and Roux-en-Y gastric bypass. However, they do highlight the possible effect of this surgery on the oral cavity.

Expression, polymorphism and methylation pattern of interleukin-6 in periodontal tissues.

Periodontitis is considered an inflammatory disorder of bacterial etiology that results in periodontal tissue destruction, as a result of complex interactions between periodontal pathogens, host and immune response. Genetic and epigenetic mechanisms may modulate the individual response since it is able to influence the gene expression. The aim of this study was to evaluate the impact of -174 G/C polymorphism and the methylation status of the promoter region of IL-6 gene on the expression of IL-6 in gingival samples from individuals with chronic periodontitis. Gingival biopsies were collected from 21 patients with chronic periodontitis and 21 controls. Histologic sections stained by hematoxylin-eosin were used for histopathological evaluation. The IL-6 gene expression was assessed by quantitative real-time PCR. The polymorphism IL-6 -174 C/G was studied by polymerase chain reaction (PCR) amplification and restriction endonuclease digestion (HspII). Methylation-specific polymerase chain reaction was used to verify the DNA methylation pattern. The number of inflammatory cells in tissue fragments from individuals with chronic periodontitis was higher than in the control group and the inflammatory infiltrate was predominantly mononuclear. The expression of IL-6 was higher in the group with periodontitis. In polymorphism assay, no statistical difference in the distribution of genotypes and alleles in both groups were observed. The most of samples were partially methylated. No difference was observed in methylation pattern from two different regions of the IL-6 gene among groups. The high expression of IL-6 is an important factor related to chronic periodontitis, but was not associated with methylation status or the -174 (G/C) genetic polymorphism, suggesting that other mechanisms are involved in this gene transcription regulation.

Evaluation of IL17A expression and of IL17A, IL17F and IL23R gene polymorphisms in Brazilian individuals with periodontitis.

The IL23/Th17 axis plays an important role in the pathogenesis of cell-mediated tissue damage caused either by autoimmunity or immune responses against bacterial infection. Single nucleotide polymorphisms in the IL17A, IL17F and IL23R genes have been associated with several inflammatory diseases. However, these polymorphisms have not yet been studied in periodontitis. The aim of present study was to evaluate the expression of IL17A and occurrence of the IL17A (rs2275913), IL17F (rs763780) and IL23R (rs11209026) gene polymorphisms in different clinical forms or severity of periodontitis in a sample of Brazilian individuals. Peripheral blood was obtained from 30 non-smoker individuals and analyzed by flow cytometry to determine IL-17 expression. Genomic DNA was obtained from oral swabs in 180 individuals and analyzed by Real-time PCR. The study group was composed by individuals without periodontitis (control), with aggressive periodontitis (AP) and with chronic periodontitis (CP). Higher frequency of IL17A+CD4+ T cells was observed in control group. The A+ genotype from IL17A (rs2275913) was associated with lack of disease. No association was found considering the IL17F and IL23R polymorphisms. Our data suggest that IL17A and the presence of IL17A (rs2275913) A allele are associated with the absence of periodontal disease.