Expression of ICAM-1 and E-selectin in gingival tissues of smokers and non-smokers with periodontitis

Genetic Association of ICAM-1 (rs5498) Gene Polymorphism With Susceptibility to Stage II Grade B Periodontitis: A Case-Control Study in South Indian Population

INTRODUCTION

In the contemporary perspective, periodontitis is considered a complex issue triggered and perpetuated by bacteria but strongly influenced by the way the body reacts to bacterial plaque. Recent research has indicated that variations in genes might have an impact on the development of periodontitis. This study was conducted to explore a probable link between the genetic variations in intercellular adhesion molecule-1 (ICAM-1) represented by rs5498 and the occurrence of periodontitis.  Methods: A total of 100 participants, 50 with periodontitis and 50 with periodontally healthy or mild gingivitis, were recruited for this study. Whole blood drawn from the participants was used to obtain genomic DNA. The ICAM-1 gene polymorphism (rs5498) was determined using polymerase chain reaction (PCR) amplification and digestion. The ICAM-1 gene's flanking primers were used to amp up the DNA. For statistical analysis, the genotype that was analyzed using the pattern of restriction fragment length polymorphism was recorded. The Chi-square test compared genotype and allele frequency distributions between both groups. The odds ratio with 95% confidence intervals with each individual allele or genotype was used to compute the risk. Statistical significance was established in all tests when the p-value was less than 0.05.

RESULTS

 There was no discernible difference between the genotype frequencies of patients and controls χ2df (P = 0.6065). The findings demonstrated that no significant difference was present between the two groups for homozygous or heterozygous mutant genotypes (AA vs. AG+GG; P = 0.6854). There was no discernible difference in the detected frequencies of the A allele (58% vs. 61%), G allele (42% vs. 39%), TT (16% vs. 24%), AG (40% vs. 36%), and TT genotypes in the studied groups.

CONCLUSION

According to the results of the current investigation, the ICAM-1 (rs5498) gene polymorphism is not associated with periodontitis in the population investigated.

Tobacco-enhanced biofilm formation by Porphyromonas gingivalis and other oral microbes

Microbial biofilms promote pathogenesis by disguising antigens, facilitating immune evasion, providing protection against antibiotics and other antimicrobials and, generally, fostering survival and persistence. Environmental fluxes are known to influence biofilm formation and composition, with recent data suggesting that tobacco and tobacco-derived stimuli are particularly important mediators of biofilm initiation and development in vitro and determinants of polymicrobial communities in vivo. The evidence for tobacco-augmented biofilm formation by oral bacteria, tobacco-induced oral dysbiosis, tobacco-resistance strategies, and bacterial physiology is summarized herein. A general overview is provided alongside specific insights gained through studies of the model and archetypal, anaerobic, Gram-negative oral pathobiont, Porphyromonas gingivalis.

The effects of smoking on genotoxic and histopathologic damage in exfoliated oral epithelial cells and the periodontium: A cross-sectional study

Smoking negatively affects the prognosis of periodontal disease by impairing tissue healing. While micronucleus is the most popular parameter for demonstrating DNA damage, inflammatory cell and vascular densities are the most evaluated parameters for determining histopathologic changes in the periodontium. This study aimed to study the effects of periodontitis and cigarette smoking on genotoxic changes in exfoliated oral epithelial cells and histopathologic changes in periodontal tissue. A cross-sectional study was conducted between November 2018 and July 2019 at a dental university hospital in Turkey, and registered as NCT05484765. Eighty systemically healthy subjects were divided into four groups according to periodontal status and smoking habits: 20 smokers with generalized periodontitis (SGP), 20 nonsmokers with generalized periodontitis (NGP), 20 smokers with healthy periodontium (SHP), and 20 nonsmokers with healthy periodontium (NHP). For each study participant, full-mouth clinical periodontal parameters (CPPs) were measured, smear samples were taken from buccal and gingival mucosa, and periodontal tissue was biopsied from the maxillary molars. Cytogenetic and histopathologic assays (primary and secondary outcomes) were conducted using Feulgen reaction and hematoxylin-eosin staining, respectively. The mean CPPs of healthy periodontium groups were lower than generalized periodontitis groups. No significant differences were found between other groups regarding CPPs. Buccal micronuclei counts in groups decreased with the highest to lowest counts occurring in the order SGP > SHP > NGP > NHP. Gingival micronuclei counts in groups decreased from SGP > SHP > NGP = NHP. The most intense inflammatory cell and vascular densities occurred in SGP and NGP groups, respectively; and the mildest values were in healthy periodontium groups. Histopathological damage score decreased significantly by group in order SGP > NGP > SHP > NHP. The synergy arising from the combination of smoking and periodontitis exposures exacerbates genotoxic and histopathologic damage in oral cells and the periodontium.

Digital photometric analysis of gingival response to periodontal treatment

OBJECTIVES

The color is a major factor in determining inflammation status in most gingival indices. Current indices have limitations mainly due to subjective nature. Digital color analysis can provide objective and accurate measurements. Thus, the present study aimed to assess by digital tool the gingival color in the different stages of an active periodontal treatment.

METHODS

Forty patients (19 males and 21 females) diagnosed with periodontitis (stage III/ IV, grade C) and treated surgically were included in the study. Clinical data (probing depth, bleeding on probing, clinical attachment level, gingival index, and gingival recession) and photographs by digital single-lens-reflex (DSLR) camera were recorded before initial periodontal treatment, which included scaling and root surface debridement (T0); the same parameters were then re-evaluated 6-8 weeks (T1) and 3 months after periodontal surgery (regenerative/resective) (T2). Differences between clinical parameters were calculated. The color space defined by the International Commission on Illumination (CIELab) was used to analyze gingival color.

RESULTS

In 56 periodontal surgical sites, 168 photographs were taken. The a*-value of the CIELab color system (higher a*- value translate to a stronger red color) was significantly reduced between T0 to T1 and further decreased at T2 (32.01, 29.28, and 27.45 respectively). Significant improvement in clinical parameters were found between T0 to T1 and T1 to T2. Sub-analysis of two distinct surgical interventions revealed that only regenerative procedure improved the a*-value, which was significantly correlated with pocket depth reduction.

CONCLUSIONS

Photometric analysis can be used to assess gingival color change during periodontal treatment of patients with periodontitis.

CLINICAL SIGNIFICANCE

Gingival inflammation is a major factor in periodontal assessment; nevertheless, all current gingival inflammation indices are partially subjective and only semi-quantitative. The digital photometric analysis may allow for accurate and objective gingival color assessment during periodontal treatment.

Lymphocyte and CD62E expression in lichen planus and lichenoid reaction

Background

It is difficult to distinguish the clinical and histopathological aspects of oral lichen planus lesions from those of oral lichenoid reaction. Some criteria were proposed to distinguish them, mainly because they have different biological behaviors. The aim of the present study was to compare the lymphocyte population and the expression of E-selectin between these lesions.

Methods

Participants with a clinical diagnosis of oral lichen planus (GOLP) and oral lichenoid reaction (GOLR) who needed to perform a biopsy were selected. The tissue was frozen and immunostaining was performed for CD3/CD4, CD3/CD8, CD4/CLA, CD8/CLA, and CD62E. The analysis of each immunostaining was accomplished using the ImageJ program.

Results

In total, 25 participants with oral lichen planus and 11 with oral lichenoid reaction were seen. In the evaluation of CD3 + CD4+/CD3 + and CD3 + CD8+/CD3 + proportions, there was a higher percentage of these cells in the oral lichen planus group when compared with the oral lichenoid reaction group (p = 0.027 and p = 0.038 respectively). The average number of CLA + lymphocytes for CD4+/CLA + and CD8+/CLA + in both groups was not statistically significant (p = 0.840; d = 0.363). In GOLP, the number of CD4 + CLA+/E-selectin and CD8 + CLA+/E-selectin was not statistically significant (p = 0.951 and p = 0.454 respectively); neither in GOLR (p = 0.454 and p = 0.989 respectively).

Conclusion

Our results indicate that CD3 + CD4+, CD3 + CD8+, CD4 + CLA+, CD8 + CLA + lymphocytes and E-selectin are present in both lesions. However, the proportion of CD3 + CD4+/CD3 + and CD3 + CD8/CD3 + cells is higher in the oral lichen planus group when compared with the oral lichenoid reaction group, suggesting that these cells may be important for the etiopathogenic mechanism of these lesions.

Impact of smoking on peri-implant bleeding on probing

BACKGROUND

Studies around natural dentition demonstrated that smoking can reduce the tendency of inflamed tissue to bleed upon probing after controlling for possible confounders. In addition, previous research suggested that smokers may present alterations of the peri-implant microbiome.

AIM

This study aimed at investigating the impact of smoking on: (1) peri-implant bleeding on probing (BOP; primary objective); (2) the association between BOP/bone loss and BOP/visible gingival inflammation; (3) peri-implant microbiome.

METHODS

Partially edentulous patients with implants restored with a single crowns were included in this study. Subjects were either smokers (≥1 cigarettes per day) or nonsmokers (never smokers). The primary outcome of this cross-sectional study was BOP and secondary outcomes included: Probing pocket depth (PPD), Modified gingival Index (mGI) and Progressive Marginal Bone Loss. In addition, microbial profiles of the subjects were assessed through sequencing of the 16S rRNA gene. Univariate and multilevel multivariate analyses by means of Generalized Estimating Equations were conducted to analyze the association between smoking and peri-implant BOP.

RESULTS

Overall, 27 nonsmokers and 27 smokers were included and 96.3% and 77.78% of patients presented peri-implant BOP in the nonsmoker and smoker group, respectively (p = 0.046). Smoking was inversely associated with BOP in the multivariate multilevel analysis (OR = 0.356; 95% CI: 0.193-0.660; p = 0.001) whereas a positive correlation was demonstrated for mGI > 0 (OR = 3.289; 95% CI: 2.014-5.371; p < 0.001); PPD (OR = 1.692; 95% CI: 0.263-0.883; p = 0.039) and gender (OR = 2.323; 95% CI: 1.310-4.120 p = 0.004). A decrease of BOP sensitivity in detecting visible gingival inflammation (mGI > 0) was observed in smokers. Besides, taxonomic and changes in diversity regarding the peri-implant microbiota were detected comparing the two groups. Significantly higher richness of the microbiota was demonstrated in the smoker group when implants affected by peri-implantitis were compared to either healthy implants or implants presenting mucositis.

CONCLUSIONS

Smoking is a potential modifier of BOP and peri-implant microbiota.

Tobacco Use and Periodontal Disease-The Role of Microvascular Dysfunction

Periodontal disease consists in highly prevalent wide-ranging inflammatory conditions that affect the supporting apparatus of teeth. Tobacco use is the most important risk factor for periodontal disease as it increases disease severity and periodontal surgery complications. Tobacco use is harmful for the vasculature by causing microvascular dysfunction, which is known to negatively affect periodontal disease. To the author's knowledge this paper is the first comprehensive review on the mechanisms by which tobacco use affects oral microcirculation and impacts the pathophysiology of periodontal disease. In healthy subjects, acute nicotine administration or tobacco use (smoking/smokeless forms) increases the blood flow in the oral mucosa due to local irritation and increased blood pressure, which overcome neural- and endocrine-mediated vasoconstriction. Chronic tobacco smokers display an increased gingival microvascular density, which is attributed to an increased capillary recruitment, however, these microcirculatory units show higher tortuosity and lower caliber. These morphological changes, together with the repetitive vasoconstrictive insults, contribute to lower gingival perfusion in chronic smokers and do not completely regress upon smoking cessation. In periodontal disease there is considerable gingival inflammation and angiogenesis in non-smokers which, in chronic smokers, are considerably suppressed, in part due to local immune suppression and oxidative stress. Tobacco exposure, irrespective of the form of use, causes long-term microvascular dysfunction that increases the risk of complications due to the natural disease course or secondary therapeutic strategies.

Fagerström test for nicotine dependence as an indicator in tobacco-related studies in periodontology

BACKGROUND

Smoking is considered a risk factor for periodontitis genesis and progression. Numerous clinical studies have demonstrated the negative effect of smoking, in particular the number of cigarettes consumed (NCC), on periodontal clinical parameters. However, smoking addiction assessed by the Fagerström test for nicotine dependence (FTND) has received little attention in periodontal research.

METHODS

In smoking patients presenting with periodontitis, the periodontal clinical features were measured and correlated with smoking status. The ability of FTND and NCC to predict periodontitis severity was assessed and compared.

RESULTS

Thirty-four smoking patients aged 46.5 ± 11.5 years were included. The means of NCC and FTND were 16.6 ± 5.5 and 5.2 ±1.8, respectively. NCC and FTND were correlated with each other (r = 0.57, P < 0.001). Patients had stage III (44.1%) or stage IV (55.9%) periodontitis and 73.5% presented a generalized extension of periodontitis. The combination of FTND and NCC in discerning disease severity (ROC curve analysis: AUC = 0.746, P = 0.027) was superior to each indicator separately. A discriminant score based on both indicators (D = -0.42 - 0.15 × NCC + 0.63 × FTND) derived by logistic regression showed the opposite role of the indicators and the greater relevance of FTND (P = 0.031) compared to NCC (P = 0.084) in the relationship.

CONCLUSION

This study shows that FTND could substantially complement NCC as an indicator of smoking status in periodontal research.

Evaluation of the Papillary Gingival Vasculature in Smokers and Nonsmokers with Chronic Periodontitis: A Clinical In Vivo Study

Aim:

Cigarette smoking has been recognized as an important risk factor in periodontal diseases. One of the suggested mechanisms behind this association is that nicotine alters the microcirculation and causes vasoconstriction and reduced blood flow through the periodontal tissues. Scarce information is currently available relative to the microvascular alterations associated with smoking and the distribution of capillaries through the various areas of the gingival tissues. The aims of this study were to assess, in human interproximal gingival biopsies, the number and diameter of gingival capillaries in periodontally affected smokers and nonsmokers using the CD34 immunohistochemical staining method. The pattern of distribution of vessels in the different areas of the gingival tissues was also assessed.

Materials and Methods:

Systemically healthy patients with moderate chronic periodontitis and ranging in age between 30 and 60 years were recruited for the study from the patient population attending the Periodontology Department of the Faculty of Dental Medicine at the Lebanese University of Beirut. The patients were selected to have a group of 10 patients (Group SP) of smokers (>10 cigarettes/day for the last 10 years) and a second group (Group NP) consisting of nonsmoking periodontally affected patients. Three to four weeks following initial preparation, one interproximal gingival biopsy was obtained from each patient. Immunohistochemical staining with CD34 mouse monoclonal antibody was used to identify the endothelial cells of the blood vessels within each sample. Twelve biopsy samples (five in Group NP and seven in Group SP) were chosen for the measurement of the number and diameter of vessels in three regions of the connective tissue of the biopsy under a blinded protocol.

Results:

In the two groups, the quantitative distribution of small, medium, and large vessels followed a similar trend with the number of small vessels being significantly greater than both medium and large vessels. Small vessels prevailed in the peripheral regions, whereas large vessels were more abundant in the deeper connective tissue areas. The total number of vessels seemed unaffected by chronic cigarette smoking in both groups in the entire biopsy area and in the separate connective tissue regions. Quantitative alteration in the total number of gingival capillaries was not observed in chronic smokers. A redistribution of small and large vessels in the superficial and deeper connective tissue areas of the gingival papilla was noted as a result of smoking in periodontal patients.

Conclusion:

The quantitative distribution of small, medium, and large vessels follows a similar trend with the content in small vessels being significantly more important than both medium and large vessels. Smoking and periodontitis result in a redistribution of small and large vessels in the superficial and deeper connective tissue areas of the gingival papilla compared to nonsmoking periodontal patients. The significance and clinical implications of such rearrangement of vasculature within the gingival tissue need to be further investigated.

Salivary and serum markers of angiogenesis in periodontitis in relation to smoking

OBJECTIVE

Angiogenesis is essential in maintenance of periodontal homeostasis, and it is regulated by growth factors and cytokines, including basic fibroblast growth factor (b-FGF), endoglin, platelet and endothelial cell adhesion molecule (PECAM-1), vascular endothelial growth factor (VEGF), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1). In this study, the salivary and serum concentrations of these angiogenesis-related proteins in relation to smoking and periodontitis were examined.

MATERIAL AND METHODS

Full-mouth periodontal status together with unstimulated whole saliva and serum samples was collected from 78 individuals, including 40 periodontitis patients (20 smokers and 20 nonsmokers) and 38 periodontally healthy controls (20 smokers and 18 nonsmokers). The Luminex®-xMAP™ technique was used for protein analyses.

RESULTS

Concentrations of all tested proteins in saliva as well as VEGF in serum were significantly higher in periodontitis patients than in healthy controls. In smokers, serum concentrations of endoglin (p = 0.017) and sICAM-1 (p = 0.001) were elevated in comparison to nonsmokers. After adjusting for smoking and gender, periodontitis associated significantly with salivary concentrations of b-FGF, PECAM-1, VEGF, sICAM-1, and sVCAM-1 (p < 0.01).

CONCLUSION

Taken together, salivary concentrations of b-FGF, PECAM-1, and VEGF associate with periodontitis. The suppressive effect of smoking on salivary marker levels is limited to periodontitis patients only.

CLINICAL RELEVANCE

Smoking-related suppression of salivary marker levels is observed only in periodontitis patients.

Periodontitis lesions in smokers and non-smokers

Differences in the progression of periodontitis have been observed between smokers and non-smokers. The aim of the present study was to compare vascular and inflammatory cell densities in periodontitis lesions from smokers and non-smokers to gain further understanding of the influence of smoking on histopathological characteristics of the disease. Two groups of patients with generalized severe periodontitis were recruited. One group consisted of 25 current smokers, aged 33-69 yr, while the second group comprised 21 non-smokers, aged 35-76 yr. From each patient, gingival biopsies were harvested from one periodontitis site (probing pocket depth ≥6 mm and bleeding on probing) and one site without clinical signs of gingival inflammation (reference site). Immunohistochemical analyses were performed to assess the density of vessels and inflammatory cells. Small differences existed between smokers and non-smokers regarding the size, proportion, number, and density of cells in periodontitis lesions. However, the vascular density in periodontitis lesions was significantly higher in non-smokers than in smokers. In clinically healthy reference sites, lesions were considerably smaller than in periodontitis sites and presented with similar vascular densities in smokers and non-smokers.

Porphyromonas gingivalis W83 traffics via ICAM1 in microvascular endothelial cells and alters capillary organization in vivo

Objective: Microvascular dysfunction is a feature of periodontal disease. P. gingivalis, one of the most common oral bacteria present in gingival tissue biofilms, has also been identified in the gingival capillaries of patients with chronic periodontitis. We sought to determine the effect of P. gingivalis W83 infection on microvascular endothelium in vivo and in vitro. Methods and Results: Interdental papillae of rats with P. gingivalis-induced alveolar bone loss had a more dilated and denser subepithelial capillary network than uninfected controls. P. gingivalis W83 was detected in the epithelial layers, the subepithelial connective tissue matrix, and subgingival capillaries. P. gingivalis invaded human dermal microvascular endothelial cells (HD-MVECS) and persisted up termination (24 h). Colocalization analysis at 2.5, 6, and 24 h post-inoculation showed that 79-88% of internalized bacteria were in ICAM-1 positive endosomes, and 10-39% were in Rab5, Rab7, or LAMP1 positive compartments, but never in autophagosomes. Antibody-based blockade of ICAM-1 significantly reduced W83 invasion in HD-MVECS. P. gingivalis infected HD-MVECS were unable to form vascular networks in Matrigel. Conclusions: P. gingivalis perturbs microvascular endothelial function and invasion of these cells via ICAM-1 may be important for microbial persistence within tissues.

Tobacco-induced suppression of the vascular response to dental plaque

Cigarette smoking presents oral health professionals with a clinical and research conundrum: reduced periodontal vascular responsiveness to the oral biofilm accompanied by increased susceptibility to destructive periodontal diseases. This presents a significant problem, hampering diagnosis and complicating treatment planning. The aim of this review is to summarize contemporary hypotheses that help to explain mechanistically the phenomenon of a suppressed bleeding response to dysbiotic plaque in the periodontia of smokers. The influence of smoke exposure on angiogenesis, innate cell function, the production of inflammatory mediators including cytokines and proteases, tobacco-bacteria interactions, and potential genetic predisposition are discussed.

16S rRNA Long-Read Sequencing of the Granulation Tissue from Nonsmokers and Smokers-Severe Chronic Periodontitis Patients

Smoking has been associated with increased risk of periodontitis. The aim of the present study was to compare the periodontal disease severity among smokers and nonsmokers which may help in better understanding of predisposition to this chronic inflammation mediated diseases. We selected deep-seated infected granulation tissue removed during periodontal flap surgery procedures for identification and differential abundance of residential bacterial species among smokers and nonsmokers through long-read sequencing technology targeting full-length 16S rRNA gene. A total of 8 phyla were identified among which Firmicutes and Bacteroidetes were most dominating. Differential abundance analysis of OTUs through PICRUST showed significant (p>0.05) abundance of Phyla-Fusobacteria (Streptobacillus moniliformis); Phyla-Firmicutes (Streptococcus equi), and Phyla Proteobacteria (Enhydrobacter aerosaccus) in nonsmokers compared to smokers. The differential abundance of oral metagenomes in smokers showed significant enrichment of host genes modulating pathways involving primary immunodeficiency, citrate cycle, streptomycin biosynthesis, vitamin B6 metabolism, butanoate metabolism, glycine, serine, and threonine metabolism pathways. While thiamine metabolism, amino acid metabolism, homologous recombination, epithelial cell signaling, aminoacyl-tRNA biosynthesis, phosphonate/phosphinate metabolism, polycyclic aromatic hydrocarbon degradation, synthesis and degradation of ketone bodies, translation factors, Ascorbate and aldarate metabolism, and DNA replication pathways were significantly enriched in nonsmokers, modulation of these pathways in oral cavities due to differential enrichment of metagenomes in smokers may lead to an increased susceptibility to infections and/or higher formation of DNA adducts, which may increase the risk of carcinogenesis.

Evaluation of ICAM-1 and VCAM-1 Gene Polymorphisms in Patients with Periodontal Disease

BACKGROUND We aimed to investigate the potential genetic relationships between the polymorphisms of gene rs5498 ICAM-1 and rs1041163 VCAM-1 and chronic periodontitis in a Chinese population within Heilongjiang. MATERIAL AND METHODS Genomic DNA was extracted from oral mucosa cells of 584 periodontal patients and 182 healthy individuals. Genotyping of the rs5498 ICAM-1 and rs1041163 VCAM-1 gene polymorphisms was performed with the Multiplex SNaPshot technique. RESULTS Statistically significant associations were identified between the chronic periodontal patients and the controls in the gene polymorphisms of rs5498 ICAM-1 (P=0.007) and rs1041163 VCAM-1 (P=0.029). The distribution of rs5498 (P=0.029) and rs1041163 (P=0.049) differed significantly across the mild, moderate, and severe groups of periodontitis. CONCLUSIONS Our findings indicate that ICAM-1 rs5498 and VCAM-1 rs1041163 polymorphisms contribute to chronic periodontitis, and ICAM-1 rs5498 and VCAM-1 rs1041163 gene polymorphisms might be associated with periodontitis severity in the Heilongjiang Chinese population. Further studies should be conducted to determine whether these polymorphisms could be used as biomarkers of periodontitis.

Smoking and gingivitis: focus on inducible nitric oxide synthase, nitric oxide and basic fibroblast growth factor

BACKGROUND

Periodontal disease pathogenesis has been associated with smoking. Gingivitis is a mild and reversible form of periodontal disease and it tends to progress to periodontitis only in susceptible individuals. In the present study, we aimed to examine the impact of smoking on host responses in gingivitis and to evaluate and compare the inducible nitric oxide synthase (iNOS) activity in gingival tissue and NO and basic fibroblast growth factor (bFGF) levels in the gingival crevicular fluid of patients with gingivitis and healthy individuals.

MATERIAL AND METHODS

Forty-one participants were assigned to the gingivitis-smoker (n = 13), gingivitis (n = 13), healthy-smoker (n = 7) and healthy groups (n = 8). Clinical indices were recorded; gingival biopsy and gingival crevicular fluid samples were obtained from papillary regions. iNOS expression was evaluated by immunohistochemical staining. The immunoreactive cells were semiquantitatively assessed. For the quantitative determination of nitrite and nitrate in gingival crevicular fluid, the NO assay kit was used. The amount of bFGF in gingival crevicular fluid was determined by enzyme-linked immunosorbent assay.

RESULTS

The gingivitis-smoker group demonstrated a stronger iNOS expression than the non-smoker gingivitis group. iNOS expression intensity was lower in the non-smoker healthy group compared to that in healthy-smokers. No significant gingival crevicular fluid NO and bFGF level changes were observed between groups. Among patients with gingivitis, a positive correlation was detected between gingival crevicular fluid NO and bFGF levels (r = 0.806, p = 0.001).

CONCLUSIONS

Our data suggest that smoking has significant effects on iNOS expression but not on gingival crevicular fluid NO or bFGF levels in healthy and patients with gingivitis. However, our results suggest that bFGF might be involved in the regulation of NO production via iNOS.

Subgingival Plaque in Periodontal Health Antagonizes at Toll-Like Receptor 4 and Inhibits E-Selectin Expression on Endothelial Cells

The ability of the subgingival microbial community to induce an inappropriate inflammatory response ultimately results in the destruction of bone and gingival tissue. In this study, subgingival plaque samples from both healthy and diseased sites in the same individual were obtained from adults with chronic periodontitis and screened for their ability to either activate Toll-like receptor 2 (TLR2) or TLR4 and to antagonize TLR4-specific activation by agonist, Fusobacterium nucleatum LPS. Subgingival plaque from diseased sites strongly activated TLR4, whereas matched plaque samples obtained from healthy sites were significantly more variable, with some samples displaying strong TLR4 antagonism, while others were strong TLR4 agonists when combined with F. nucleatum LPS. Similar results were observed when TLR4 dependent E-selectin expression by endothelial cells was determined. These results are the first to demonstrate TLR4 antagonism from human plaque samples and demonstrate that healthy but not diseased sites display a wide variation in TLR4 agonist and antagonist behavior. The results have identified a novel characteristic of clinically healthy sites and warrant further study on the contribution of TLR4 antagonism in the progression of a healthy periodontal site to a diseased one.

CLA and CD62E expression in oral lichen planus lesions

OBJECTIVE

There are few reports on the migration of CLA+ T cells through E-selectin in cutaneous lichen planus, with only one study on oral lichen planus (OLP). This study aimed to analyze CLA expression and assess whether there is a correlation with E-selectin (CD62E) in OLP lesions.

MATERIAL AND METHODS

Biopsies were performed on 11 patients including two areas: one without clinical and histopathological features of OLP [perilesional group (PLG)] and the other with clinical and histopathological features of OLP [OLP group (OLPG)]. The specimens obtained were divided into two: One was fixed in formalin for routine analysis (H&E), and the other was frozen for CD3, CD4, CD8, CLA, and CD62E immunofluorescence markers.

RESULTS

More CD4+ (median 1409, range 860-2519), CD8+ (median 1568, range 654-3258), and CLA+ T cells (median 958, range 453-2198) and higher CD62E expression (median 37, range 27-85) were identified in OLPG (P = 0.003; P = 0.003; P = 0.004; P = 0.003, respectively) than those in PLG. The median prevalence analysis was also significantly higher for CLA+CD8+ T cells in OLPG (OLPG = 39.4%, range 18.4-64.2; PLG = 29.4%, range 12.1-47.1) (P = 0.026). None of the correlations between CD3+ or CLA+ T cells and CD62E in OLPG and in PLG were significant.

CONCLUSION

The significant presence of CLA+ T cells and E-selectin expressions in the OLPG suggests their involvement in the etiopathogenesis of OLP; however, only a weak correlation between CLA+ T cells and E-selectin was observed.

Altered antigenic profiling and infectivity of Porphyromonas gingivalis in smokers and non-smokers with periodontitis

BACKGROUND

Cigarette smokers are more susceptible to periodontal diseases and are more likely to be infected with Porphyromonas gingivalis than non-smokers. Furthermore, smoking is known to alter the expression of P. gingivalis surface components and compromise immunoglobulin (Ig)G generation. The aim of this study is to evaluate whether the overall IgG response to P. gingivalis is suppressed in smokers in vivo and whether previously established in vitro tobacco-induced phenotypic P. gingivalis changes would be reflected in vivo.

METHODS

The authors examined the humoral response to several P. gingivalis strains as well as specific tobacco-regulated outer membrane proteins (FimA and RagB) by enzyme-linked immunosorbent assay in biochemically validated (salivary cotinine) smokers and non-smokers with chronic periodontitis (CP: n = 13) or aggressive periodontitis (AgP: n = 20). The local and systemic presence of P. gingivalis DNA was also monitored by polymerase chain reaction.

RESULTS

Smoking was associated with decreased total IgG responses against clinical (10512, 5607, and 10208C; all P <0.05) but not laboratory (ATCC 33277, W83) P. gingivalis strains. Smoking did not influence IgG produced against specific cell-surface proteins, although a non-significant pattern toward increased total FimA-specific IgG in patients with CP, but not AgP, was observed. Seropositive smokers were more likely to be infected orally and systemically with P. gingivalis (P <0.001), as determined by 16S RNA analysis.

CONCLUSION

Smoking alters the humoral response against P. gingivalis and may increase P. gingivalis infectivity, strengthening the evidence that mechanisms of periodontal disease progression in smokers may differ from those of non-smokers with the same disease classification.

Pro-inflammatory, Th1, Th2, Th17 cytokines and dendritic cells: a cross-sectional study in chronic periodontitis

There are a limited number of studies correlating the different stages of dendritic cells (DC) maturation with cytokines in individuals presented chronic periodontitis (CP). The aim of the study was to evaluate the correlation among the expression of IL-2, IL-10, IL-4, IL-6, IFN-, TNF-α, and IL-17A with the presence of DC and mild-moderate or advanced CP. Gingival samples were obtained from 24 individuals with CP and six samples of normal mucosa (NM) overlapping third molar for controls of the levels of cytokines. Periodontal examination was performed. Immunohistochemical staining was carried out, revealing CD1a+ immature, Fator XIIIa+ immature, and CD83+ mature DCs. The inflammatory infiltrate was counted, and the cytokines were measured by flow cytometry. Densities of DCs and inflammatory infiltrate, cytokines, subtypes of CP, and clinical periodontal parameters were correlated and compared. IL-6 expression was correlated positively with the increased numbers of CD1a+ immature DCs. Levels of IL-2, TNF-α, IFN-, IL-10, and IL-17A were increased when compared with NM. The percentage of sites with clinical attachment level (CAL)>3 were positively correlated with densities of inflammatory infiltrate and negatively correlated with densities of immature DCs. IL-6 can contribute to the increase of the immature DCs in the CP. Higher levels of IL-2, TNF-α, IFN-, IL-10, and IL-17A cytokines were observed in CP. Higher densities of inflammatory infiltrate as well as lower densities of immature DCs can result in a more severe degree of human CP.

The role of smoking and gingival crevicular fluid markers on coronally advanced flap outcomes

BACKGROUND

This study evaluates possible effects of smoking on the following: 1) biochemical content in gingival crevicular fluid (GCF) samples from sites of gingival recession and saliva; and 2) clinical outcomes of coronally advanced flap (CAF) for root coverage.

METHODS

Eighteen defects in 15 patients were included in each of the smoker and non-smoker groups. Baseline cotinine, basic fibroblast growth factor, vascular endothelial growth factor, platelet-derived growth factor, interleukin (IL)-8, IL-10, IL-12, tumor necrosis factor-α, matrix metalloproteinase (MMP)-8, MMP-9, and plasminogen activator inhibitor-1 levels were determined in GCF and saliva samples. CAF with microsurgery technique was applied. Plaque index, papilla bleeding index, recession depth (RD), recession width (RW), and root surface area were evaluated at baseline and postoperative months 1, 3, and 6. Probing depth, clinical attachment level (CAL), and keratinized gingival width (KGW) was recorded at baseline and month 6. Percentage of root coverage and complete root coverage were calculated at postoperative months 1, 3, and 6.

RESULTS

All biochemical parameters were similar in the two groups apart from the definite difference in salivary cotinine concentrations (P = 0.000). Compared with the baseline values, RD, RW, CAL, and root surface area decreased, and KGW increased, with no significant difference between the study groups. CAL gain, percentage of root coverage, and complete root-coverage rates were similar in the study groups.

CONCLUSION

Similar baseline biochemical data and comparably high success rates of root coverage with CAF in systemically and periodontally healthy smokers versus non-smokers suggest lack of adverse effects of smoking on clinical outcomes.

Smoking and periodontal tissues: a review

The impact of smoking on general health has been widely studied and is directly related to several important medical problems including cancer, low birth weight, and pulmonary and cardiovascular disease. In the past 25 years, there has also been an increasing awareness of the role of cigarette consumption in oral health problems such as periodontal disease. Smoking is considered the major risk factor in the prevalence, extent and severity of periodontal diseases. This article will discuss the available evidence and provide the reader with an overview of the impact of smoking and its cessation on the pathogenesis and treatment of periodontal diseases.

Periodontal disease in habitual cigarette smokers and nonsmokers with and without prediabetes

INTRODUCTION

: Prediabetes and habitual cigarette smoking are significant risk factors contributing to periodontal disease. The aim was to assess the clinical and radiological markers of periodontal disease in habitual cigarette smokers and nonsmokers with and without prediabetes.

METHODS

Sixty-eight individuals with prediabetes (test group; 34 smokers and 34 nonsmokers) and 68 medically healthy individuals (control group; 34 smokers and 34 nonsmokers) were included. Sociodemographic information, duration of smoking habit and number of cigarettes smoked daily were recorded through a questionnaire. Fasting blood glucose levels and periodontal inflammatory conditions (plaque index [PI], bleeding on probing [BOP] and probing pocket depth [PPD] of 4 to <6 mm and ≥6 mm) were recorded. In both groups, marginal bone loss (MBL) was measured on digital panoramic radiographs.

RESULTS

Cigarette smokers and nonsmokers in the test group had significantly higher fasting blood glucose level when compared with cigarette smokers in the control group (P < 0.001). In the test group, there was no significant difference in PI, BOP, PPD (4 to <6 mm and ≥6 mm) and MBL among cigarette smokers and nonsmokers. Cigarette smokers in the control group had significantly higher PI (P < 0.001), PPD (4 to <6 mm; P < 0.001), PPD ≥6 mm (P < 0.01) and MBL (P < 0.05) than nonsmokers. BOP was significantly reduced in smokers when compared with nonsmokers in the control group (P < 0.001).

CONCLUSIONS

Cigarette smokers without prediabetes exhibit significantly severe periodontal disease than nonsmokers. In subjects with prediabetes, the severity of periodontal disease seems to be over shadowed by the hyperglycemic state, obscuring the effect of habitual smoking.

Subgingival microbiome in smokers and non-smokers in periodontitis: an exploratory study using traditional targeted techniques and a next-generation sequencing

AIM

To compare the results of two targeted techniques to an open-ended technique in periodontitis patients, differentiated on the basis of smoking habit.

MATERIALS & METHODS

Thirty periodontitis patients (15 smokers and 15 non-smokers) provided subgingival plaque samples for 16S rRNA gene amplicon sequencing, culturing and quantitative polymerase chain reaction (qPCR).

RESULTS

No differences were found in the composition of the subgingival microbiome between smokers and non-smokers with culture and qPCR. With pyrosequencing, operational taxonomic units (OTUs) classified to genera Fusobacterium, Prevotella and Selenomonas were more abundant in smokers, while OTUs belonging to the genera Peptococcus and Capnocytophaga were more abundant in non-smokers. Principal coordinate analysis identified two clusters; one was composed mainly of smokers (80%) and revealed significantly lower taxonomic diversity, higher attachment loss and higher proportion of the genera Fusobacterium, Paludibacter and Desulfobubus.

CONCLUSION

In periodontitis, there is a difference in the composition of the subgingival microbiome between smokers and non-smokers, as revealed by pyrosequencing. This difference was not identified by the targeted techniques. Low taxonomic diversity was associated with higher disease severity, especially in smokers. This supports the hypothesis of the ecological microbial-host interaction in the severity of periodontal disease.

Role of high endothelial postcapillary venules and selected adhesion molecules in periodontal diseases: a review

Periodontitis is accompanied by the proliferation of small blood vessels in the gingival lamina propria. Specialized postcapillary venules, termed periodontal high endothelial-like venules, are also present, and demonstrate morphological and functional traits similar to those of high endothelial venules (HEVs) in lymphatic organs. The suggested role of HEVs in the pathogenesis of chronic periodontitis involves participation in leukocyte transendothelial migration and therefore proinflammatory effects appear. Recent observations suggest that chronic periodontitis is an independent risk factor for systemic vascular disease and may result in stimulation of the synthesis of acute phase protein by cytokines released by periodontal high endothelial cells (HECs). However, tissue expression of HEV-linked adhesion molecules has not been evaluated in the gingiva of patients with chronic periodontitis. This is significant in relation to potential therapy targeting expression of the adhesion molecules. In this review, current knowledge of HEV structure and the related expression of four surface adhesion molecules of HECs [CD34, platelet endothelial cell adhesion molecule 1, endoglin and intercellular adhesion molecule 1 (ICAM-1)], involved in the key steps of the adhesion cascade in periodontal diseases, are discussed. Most studies on the expression of adhesion molecules in the development and progression of periodontal diseases pertain to ICAM-1 (CD54). Studies by the authors demonstrated quantitatively similar expression of three of four selected surface markers in gingival HEVs of patients with chronic periodontitis and in HEVs of reactive lymph nodes, confirming morphological and functional similarity of HEVs in pathologically altered tissues with those in lymphoid tissues.

Destructive effects of smoking on molecular and genetic factors of periodontal disease

Many epidemiological evidences have proven the association between smoking and periodontal disease. The causality can be further established by linking findings of traditional epidemiological studies with the developments in molecular techniques that occurred in the last decade. The present article reviews recent studies that address the effect of smoking on molecular and genetic factors in periodontal disease. Most findings support the fact that tobacco smoking modulates destruction of the periodontium through different pathways: microcirculatory and host immune systems, connective tissue, and bone metabolism. Although smokers experience an increased burden of inflammatory responses to microbial challenges compared to non-smokers, understanding the association between smoking and periodontal diseases involves substantial problems with respect to accuracy of measurements, and particularly, sampling of many subjects. It remains unclear whether genetic susceptibility to periodontal disease is influenced by exposure to smoking or the effect of smoking on periodontal disease is influenced by genetic susceptibility. Employment of molecular techniques may play a key role in further elucidation of mechanisms linking smoking and periodontal destruction, the direct relationship as environmental factors and indirect relationship through genetic factors.

Association of circulating adhesion molecules with lung function. The CARDIA study

BACKGROUND

Systemic inflammation has been associated with reduced lung function. Adhesion molecules, such as intercellular adhesion molecule (ICAM)-1 and P-selectin, figure importantly in initiating the inflammatory response. We studied the association between ICAM-1 and P-selectin concentrations and lung function in the Coronary Artery Risk Development in Young Adults study.

METHODS

Spirometry testing was conducted at years 5, 10, and 20. ICAM-1 and P-selectin were assayed at year 15.

RESULTS

Complete data were obtained from 2,455 participants. We first predicted year-20 lung function from year-15 ICAM-1 concentration data. After controlling for race, gender, height, age, physical activity, smoking status, alcohol intake, BMI, and asthma status, all taken at year 15, the year-20 FVC was 164 mL higher (p < 0.0001) and FEV(1) was 164 mL higher (p = 0.0003) in the lowest ICAM-1 concentration quartile than the highest ICAM-1 quartile, whereas the FEV(1)/FVC ratio showed no association (p = 0.25). We then predicted the year-15 ICAM-1 concentration from year-5 lung function and change in lung function (year 10 - year 5). The year-15 ICAM-1 concentration was about 13 ng/mL higher in the lowest vs highest quartile of either the year-5 FVC (p = 0.01) or year-5 FEV(1) (p = 0.005). Year-15 ICAM-1 concentration was unrelated to year-5 FEV(1)/FVC ratio. Greater loss in FVC and FEV(1) (year 10 - year 5) also was associated with higher year-15 ICAM-1 concentrations. Associations between P-selectin and lung function followed a similar but weaker pattern to that observed for ICAM-1.

CONCLUSIONS

These data suggest a bidirectional association between circulating adhesion molecules, such as ICAM-1 and P-selectin, and pattern of lung function change in adults.

Tobacco-induced alterations to Porphyromonas gingivalis-host interactions

Smokers are more susceptible than non-smokers to persistent infection by Porphyromonas gingivalis, a causative agent of periodontitis. Patients who smoke exhibit increased susceptibility to periodontitis and are more likely to display severe disease and be refractory to treatment. Paradoxically, smokers demonstrate reduced clinical inflammation. We show that P. gingivalis cells exposed to cigarette smoke extract (CSE) induce a lower proinflammatory response (tumour necrosis factor-alpha, interleukin-6, interleukin-12 p40) from monocytes and peripheral blood mononuclear cells than do unexposed bacteria. This effect is reversed when CSE-exposed bacteria are subcultured in fresh medium without CSE. Using microarrays representative of the P. gingivalis genome, CSE-exposure resulted in differential regulation of 6.8% of P. gingivalis genes, including detoxification and oxidative stress-related genes; DNA repair genes; and multiple genes related to P. gingivalis virulence, including genes in the major fimbrial and capsular operons. Exposure to CSE also altered the expression of outer membrane proteins, most notably by inducing the virulence factors RagA and RagB, and a putative lipoprotein cotranscribed with the minor fimbrial antigen. Therefore, CSE represents an environmental stress to which P. gingivalis adapts by altering gene expression and outer membrane proteins. These changes may explain, in part, the altered virulence and host-pathogen interactions that have been documented in vivo in smokers with periodontal disease.

Tobacco use increases susceptibility to bacterial infection

Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacterial function of leukocytes, including neutrophils, monocytes, T cells and B cells, providing a mechanistic explanation for increased infection risk. Further epidemiological, clinical and mechanistic research into this important area is warranted.

Influence of periodontal therapy on the regulation of soluble cell adhesion molecule expression in aggressive periodontitis patients

BACKGROUND

Inflammatory periodontal disease is associated with an increased risk of cardiovascular disease. Circulating cell adhesion molecules (CAM) (intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], and E-selectin) have been suggested as potential candidate markers of endothelial dysfunction, which contribute to the pathogenesis of cardiovascular diseases. The regulation of CAM in subjects with severe periodontitis and the influence of periodontal intervention on systemic CAM levels are not clear. The aim of this study was to determine whether intensive periodontal therapy reduces serum levels of CAM in patients with generalized aggressive periodontitis.

METHODS

Blood samples were collected at six treatment time points from 21 patients with previously untreated generalized aggressive periodontitis (mean age: 34.6 +/- 4.3 years). Patients received subgingival scaling and root planing and antibiotic therapy and were monitored over a 6-month recall period. Serum levels of soluble ICAM-1 (sICAM-1), VCAM-1 (sVCAM-1), and E-selectin (sE-selectin) were measured by enzyme-linked immunosorbent assay.

RESULTS

sE-selectin plasma levels decreased significantly (P <0.01) during periodontal therapy. Mean plasma levels were 65.95 ng/ml before treatment and 44.71 ng/ml 6 months after antibiotic therapy. sICAM-1 and sVCAM-2 serum levels were unaffected by therapeutic intervention.

CONCLUSIONS

Periodontal therapy reduces plasma sE-selectin levels. Whether this leads to a reduction in risk of future cardiovascular events in patients with aggressive periodontal disease warrants further studies.

Exploitation of the nicotinic anti-inflammatory pathway for the treatment of epithelial inflammatory diseases

Discoveries in the first few years of the 21st century have led to an understanding of important interactions between the nervous system and the inflammatory response at the molecular level, most notably the acetylcholine (ACh)-triggered, α7-nicotinic acetylcholine receptor (α7nAChR)-dependent nicotinic anti-inflammatory pathway. Studies using the α7nAChR agonist, nicotine, for the treatment of mucosal inflammation have been undertaken but the efficacy of nicotine as a treatment for inflammatory bowel diseases remains debatable. Further understanding of the nicotinic anti-inflammatory pathway and other endogenous anti-inflammatory mechanisms is required in order to develop refined and specific therapeutic strategies for the treatment of a number of inflammatory diseases and conditions, including periodontitis, psoriasis, sarcoidosis, and ulcerative colitis.

Increased local matrix metalloproteinase-8 expression in the periodontal connective tissues of smokers with periodontal disease

Matrix metalloproteinase (MMP)-8 has been associated with the progression of periodontitis, a common inflammatory disease of the supporting structures of the teeth, and with other degradative diseases. Tobacco smokers are at high risk of developing periodontitis that may progress more rapidly and respond poorly to treatment. Therefore, MMP-8 expression was determined by immunofluorescence staining in 60 random, computer-selected fields in the excised periodontal tissues of smokers and non-smokers, balanced for age, gender, and periodontal status. Immunofluorescence intensity, representing MMP-8 expression, in the periodontal tissues of smokers (30 fields from 6 subjects, mean 1154+/-124 units) was significantly higher than that in the periodontal tissues of non-smokers (30 fields from 6 subjects, mean 817+/-60 units; p < 0.05). Serum MMP-8 concentrations were measured by ELISA and compared in a larger group of smokers (n = 20) and age- and gender-balanced non-smokers (n = 20). Systemic MMP-8 concentrations in smokers and non-smokers were not significantly different (p > 0.05). A local tobacco-related increase in MMP-8 burden may contribute to periodontal disease progression in tobacco smokers. This finding may also have relevance to other tobacco-induced inflammatory diseases, such as vascular and pulmonary diseases.

The Influence of Current and Former Smoking on Gingival Bleeding: The Hisayama Study

BACKGROUND

Previous studies have shown that smoking is a risk factor for periodontitis and that it has a suppressive effect on gingival bleeding. This study examined the relationship between smoking, including past smoking, and periodontal conditions, mainly gingival bleeding, in a community-based health investigation.

METHODS

Smoking status was examined in 958 subjects, along with the quantity of tobacco currently or previously smoked (never, former light, former heavy, current light, and current heavy). We analyzed the influence of smoking on probing depth (PD), clinical attachment loss (CAL), and gingival bleeding on probing (BOP).

RESULTS

In multivariate logistic regression analyses, current heavy smokers were at a significantly greater risk for having a higher proportion of teeth with PD > or =4 mm and a higher proportion of teeth with CAL > or =5 mm; however, they had a lower risk for having a high BOP than did those who had never smoked. Moreover, both former light and former heavy smokers had significantly lower risks for high BOP. When the analysis was limited to subjects with PD > or =4 mm, former heavy and current heavy smokers showed a significant suppression of high BOP compared to never smokers.

CONCLUSION

This study suggests that smoking is significantly associated with PD and CAL and that current and past smoking has a suppressive effect on BOP.

Suppression of overt gingival inflammation in tobacco smokers - clinical and mechanistic considerations

Gingivitis is a reversible inflammatory disease of the periodontal tissues. Periodontitis, in addition, involves destruction of the supporting structures of teeth. Diagnoses of gingivitis and periodontitis are predominantly dependent on clinical measurements of key inflammatory indices. Smokers are more susceptible to developing periodontal diseases, yet smoking masks overt signs of inflammation, presenting dental professionals with a clinical conundrum. We review the evidence that tobacco smoke may (i) cause acute periodontal vasoconstriction, (ii) inhibit periodontal angiogenesis in response to inflammatory stimuli, and/or (iii) suppress the production of pro-inflammatory mediators. It is clear that the mechanisms by which cigarette smoking dampens the periodontal inflammatory response are not yet fully understood. Further research into inflammatory suppression is warranted and should point to improved methods of diagnosis, not only in smokers, but also in non-smokers.

Cytokines differentially regulate ICAM-1 and VCAM-1 expression on human gingival fibroblasts

The expression of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) on human gingival fibroblasts (HGF) may be important for migration and retention of inflammatory cells in periodontally diseased tissue. This study aimed to assess which cytokines regulate ICAM-1 and VCAM-1 expression on HGF. Tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma enhanced both ICAM-1 and VCAM-1 expression on HGF. Interleukin (IL)-1beta mainly up-regulated ICAM-1 expression. On the other hand, IL-4 and IL-13 enhanced only VCAM-1 expression on HGF. IL-10 did not modulate both ICAM-1 and VCAM-1 expression. Transforming growth factor (TGF)-beta1 enhanced ICAM-1 expression. However, TGF-beta1 inhibited the VCAM-1 expression induced by TNF-alpha or IL-4. Both ICAM-1 and VCAM-1 expression by HGF was inhibited by nuclear factor-kappaB (NF-kappaB) activation inhibitor (MG-132). Mitogen-activated protein kinases (MAPK) inhibitors did not influence ICAM-1 expression induced by TNF-alpha. Interestingly, VCAM-1 expression was enhanced by MEK inhibitor (PD98059) and c-Jun NH2-terminal kinase (JNK) inhibitor (SP600125). These results mean that the balance of cytokines in periodontally diseased tissue may be essential for control of ICAM-1 and VCAM-1 expression on HGF, and the balance of ICAM-1 and VCAM-1 expression might be important for regulation of leucocytes infiltration and retention in periodontally diseased tissue.

Effects of smoking and gingival inflammation on salivary antioxidant capacity

AIM

This study evaluated possible effects of smoking and gingival inflammation on salivary antioxidants in gingivitis patients.

METHODS

Twenty otherwise healthy gingivitis patients (10 self-reported smokers) and 20 periodontally and systemically healthy volunteer subjects were enrolled in the study. Whole saliva samples and full-mouth clinical periodontal recordings were obtained at baseline and one month following initial phase of treatment in gingivitis patients. Salivary cotinine, glutathione and ascorbic acid concentrations, and total antioxidant capacity were determined, and the data generated were tested by non-parametric tests.

RESULTS

Salivary cotinine measurements resulted in re-classification of three self-reported non-smokers as smokers. Smoker patients revealed significantly higher probing depths but lower bleeding values than non-smoker patients (p=0.044 and 0.001, respectively). Significant reductions in clinical recordings were obtained in non-smoker (all p<0.05) and smoker (all p<0.01) patients following periodontal treatment. Salivary total glutathione concentrations were reduced following therapy in gingivitis patients who smoke (p<0.01). Otherwise, no statistically significant differences were found between the groups in biochemical parameters at baseline or following treatment (p>0.05).

CONCLUSIONS

Within the limits of this study, neither smoking nor gingival inflammation compromised the antioxidant capacity of saliva in systemically healthy gingivitis patients.

No Association Between Selected Candidate Gene Polymorphisms and Severe Chronic Periodontitis

BACKGROUND

Chronic periodontitis (CP) risk is influenced by environmental and genetic factors. Using a case-control design, we tested for associations between CP and selected DNA sequence variations (single nucleotide polymorphisms [SNPs]) in or near genes coding for proteins that play a role in the pathogenesis of this disease.

METHODS

DNA was analyzed from 219 whites who were examined clinically. Cases (N=137) were >or=35 years of age with eight or more teeth having >or=5 mm of proximal clinical attachment loss. Controls (N=82) were >or=45 years of age with minimal or no proximal attachment loss or pocketing. Nine diallelic polymorphisms (gene and SNP descriptor) were studied in subjects: cytotoxic T-lymphocyte antigen-4 (CTLA-4, 49 A>G), human beta-defensin-1 (DEFB1, 692 G>A), intercellular adhesion molecule-1 (ICAM-1, 1548 A>G), Fas ligand (fasL, -844 C>T), inducible costimulator (ICOS, 3990 G>T), interleukin-6 (IL-6, -174 G>C), cysteine-cysteine chemokine receptor-5 (CCR5, 59653 C>T), osteoprotegerin (OPG, 245 T>G), and osteopontin (OPN, 707 C>T). Genotypes were determined using an automated fluorogenic 5'-nuclease, polymerase chain reaction-based assay. Gender and smoking history (pack-years) were included as covariates in logistic regression analyses.

RESULTS

Heavy smoking (>10 pack-years) and male gender were significantly associated with disease (P<0.001). For all SNPs tested, the allele frequencies and distributions of genotypes did not differ between cases and controls (P>0.05). No unadjusted or adjusted odds ratios (comparing genotypes in cases versus controls) were significantly different than 1.0 (P>0.05) under any additive, dominant, or recessive inheritance model.

CONCLUSIONS

None of the SNPs tested were strongly associated with generalized severe chronic periodontitis in North American whites. A potentially more fruitful approach in future studies will be to test for associations between periodontitis and haplotype blocks constructed from either multiple SNPs in candidate gene regions or from panels of markers that span the entire genome.

Mechanisms of action of environmental factors--tobacco smoking

AIM

To review the potential biological mechanisms underlying the effects of tobacco smoking on periodontitis.

MAIN FINDINGS

Smoking has major effects on the host response, but there are also a number of studies that show some microbiological differences between smokers and non-smokers. Smoking has a long-term chronic effect on many important aspects of the inflammatory and immune responses. Histological studies have shown alterations in the vasculature of the periodontal tissues in smokers. Smoking induces a significant systemic neutrophilia, but neutrophil transmigration across the periodontal microvasculature is impeded. The suppression of neutrophil cell spreading, chemokinesis, chemotaxis and phagocytosis have been described. Protease release from neutrophils may be an important mechanism in tissue destruction. Tobacco smoke has been found to affect both cell-mediated immunity and humoral immunity. Research on gingival crevicular fluid has demonstrated that there are lower levels of cytokines, enzymes and possibly polymorphonuclear cells in smokers. In vitro studies have shown detrimental effects of nicotine and some other tobacco compounds on fibroblast function, including fibroblast proliferation, adhesion to root surfaces and cytotoxicity.

CONCLUSION

Tobacco smoking has widespread systemic effects, many of which may provide mechanisms for the increased susceptibility to periodontitis and the poorer response to treatment.