Association of interleukin-17A gene promoter polymorphism with the susceptibility to generalized chronic periodontitis in an Iranian population.

Background: Chronic periodontitis (CP) is characterized by an immune response, leading to the destruction of periodontal supporting tissue. The effect of inflammatory and genetic factors on periodontitis has been evaluated previously. The interleukin (IL-17) as an inflammation regulator seems to play a critical role in periodontitis pathogenesis. Here, in the current study, we aimed to investigate the association of -197 G > A (rs2275913) IL-17 gene promoter polymorphism with generalized severe CP in an Iranian population. Materials and Methods: In this case-control study, a total of 54 patients with periodontitis and 118 normals were enrolled. The polymerase chain reaction-restriction fragment length polymorphism technique was applied to detect IL-17 promoter rs2275913 genotypes in association with the susceptibility to severe CP. Chi-square test or Fisher's exact test was employed to compare genotype frequencies between groups. P < 0.05 were considered statistically significant. Results: The distribution of genotypes and alleles was in Hardy-Weinberg equilibrium. Although no significant association was observed between the risk of periodontitis and genotype frequencies under any of the inheritance models, the GG genotype was higher in healthy controls, while the AG genotype was more frequently observed in patients under the codominant model ([odd ratio [OR] = 2.14, 95% confidence interval (CI) (1.01-4.53), P = 0.13]). The frequency of AG-AA genotype was higher in patients under dominant inheritance model ([OR = 1.92, 95% CI (0.94-3.93), P = 0.068]), while GG-AA and AG genotypes were higher in healthy controls under over dominant model (OR = 0.1.95, 95% CI [0.98-3.86], P = 0.055). Conclusion: The results of this study showed that the presence of allele A and AG genotypes could be considered possible factors in increasing the risk of developing CP, although the differences of allele and genotype frequencies were remarkable but not statistically significant between the two groups.

Periodontal Condition in Patients with Rheumatoid Arthritis: Effect of Anti-rheumatic Drugs.

STATEMENT OF THE PROBLEM: Rheumatoid arthritis and periodontitis are chronic inflammatory diseases with a possible bidirectional relationship. This link may be affected by many factors like drug consumption. PURPOSE: This study was designed to evaluate the periodontal condition in patients with rheumatoid arthritis, considering the effect of disease modifying anti-rheumatic drugs. MATERIALS AND METHOD: This case-control study included 25 newly diagnosed rheumatoid arthritis patients with negative history of taking anti-rheumatic drugs, 25 patients who received anti-rheumatic drugs for more than three years and 50 healthy individuals as a control group. Periodontal indices, including plaque index, gingival index, probing depth, clinical attachment loss, and rheumatologic indices were recorded and compared between these groups. RESULTS: Rheumatoid arthritis patients were significantly more affected by periodontitis compared with healthy subjects (p= 0.006). There was no significant difference in rheumatologic indices between patients with and without periodontitis. Clinical attachment loss in old rheumatoid arthritis patients and gingival index in newly diagnosed ones were significantly more compared to the control group (p= 0.003 and p< 0.001 respectively). We could not find a linear relationship between the severity of rheumatoid arthritis and chronic periodontitis (p= 0.1, r= -0.224). CONCLUSION: Periodontitis and clinical attachment loss were more in patients with rheumatoid arthritis than the healthy group, especially in drug consumers. Gingival index in patients without the history of consuming anti-rheumatic drugs was significantly higher than those who were drug consumers, indicating the effect of the medications on the signs of inflammation.

Association between interleukin-10 gene polymorphisms and severe chronic periodontitis.

OBJECTIVE: Periodontitis is an inflammatory disease that is a result of the interaction between pathogenic bacteria and host immune response. Genetic alterations in interleukin-10 (IL-10) gene may be associated with the increased risk of periodontitis. We investigated the association between genotype and haplotype frequencies of IL-10 gene polymorphisms and susceptibility to periodontitis in an Iranian population. METHODS: In this case-control study, a total of 64 patients with periodontitis and 128 healthy subjects were recruited. The PCR-RFLP technique was used to detect IL-10 promoter genotypes at the positions of -1082 (G/A), -819 (C/T), and -592 (C/A) in association with the susceptibility to severe chronic periodontitis. RESULTS: Regarding IL-10 -592 (C/A) and IL-10 -819 (C/T) alleles and genotypes, no significant association was observed between the risk of periodontitis and genotype frequencies. However, the frequency of GG genotype in IL-10 -1082 (G/A) polymorphic region was higher in normal subjects and was associated with the decreased risk of periodontitis under recessive model [OR = 2.89, 95% CI (0.99-8.43), p = 0.039]. Haplotype analysis revealed a significantly higher presence of H7 (AGC; -592/-1082/-819) [OR = 97.74, 95% CI (95.52-99.96), p < 0.0001]. CONCLUSION: IL-10 -1082(G/A) polymorphism and AGC (-592/-1082/-819) haplotype could be associated with the susceptibility to chronic periodontitis.

Comparison of bone regeneration using three demineralized freeze-dried bone allografts: A histological and histomorphometric study in rabbit calvaria.

BACKGROUND: It has been stated that the bone allografts from different tissue banks may lead to various amount of bone induction, so the aim of this study was to evaluate bone regeneration of three demineralized allografts both histologically and histomorphometrically in rabbits calvaria bone defects. MATERIALS AND METHODS: In this double-blind randomized experimental animal study, 32 critical size defects (11-mm diameter) in the calvaria of 16 male New Zealand white rabbits were randomly filled with three demineralized freeze-dried bone allografts (DBM, CENOBONE, DEMBONE), while the nongrafted defect was regarded as control group. After 6 and 12 weeks of healing, the experimental animals were euthanized for specimen preparation. After histological evaluation, histomorphometric analysis was performed to quantify new bone formation and remained graft particles. The data were analyzed by one-way ANOVA with Tukey's ad-hoc test and t-test. (P < 0.05 was considered to be statistically significant). RESULTS: Mean percentage of bone formation increased between two healing time, but it was not statistically significant in all groups except DBM which the bone formation significantly decreased (P = 0.04). There were not statistically significant differences between three allografts in remained particles and bone formation in both healing times and they could not induce significantly more bone formation than control group. CONCLUSION: Both test and control groups resulted in successful new bone formation. No difference was noted in bone formation and remained particles between three commercial bone allografts. Further studies in this issue may be needed.