Vascular remodelling in chronic inflammatory periodontal disease

Efficacy of injectable platelet-rich fibrin on clinical and biochemical parameters in non-surgical periodontal treatment: a split-mouth randomized controlled trial

OBJECTIVES

The purpose of this clinical trial was to evaluate the potential clinical and biochemical effects of injectable platelet-rich fibrin (i-PRF) application adjunct to scaling and root planning (ScRp) in deep periodontal pockets.

MATERIALS AND METHODS

In this split-mouth-designed study, 17 patients with 34 deep periodontal pockets were randomly treated with ScRp + i-PRF (test group) and ScRp + saline (control group). Clinical periodontal measurements were recorded at baseline, 1st, 3rd, and 6th months after the treatments. The levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α), and interleukin (IL)-10 in gingival crevicular fluid (GCF) samples were analyzed using the ELISA method at baseline, 7th, and 14th days.

RESULTS

Clinical periodontal parameters showed significant improvements with both treatment modalities. Mean pocket reduction (PD) and clinical attachment (CAL) gain were significantly higher in the test group than in controls at follow-up visits (p < 0.05). In the test group, gingival recession (GR) values were significantly lower compared to the control group. VEGF and IL-10 levels in the test group were significantly higher than in controls at the 14th day, and TNF-α levels were found significantly lower in the test group at the 7th and 14th days.

CONCLUSIONS

Especially in the test group, the significant increase in VEGF and IL-10 expressions and the decrease in TNF-α levels may have accelerated the periodontal healing observed in the clinical parameters.

CLINICAL RELEVANCE

The result of the present study demonstrated the beneficial effects of adjunctive i-PRF administration during non-surgical periodontal treatment of deep periodontal pockets.

CLINICAL TRIAL REGISTRATION NUMBER

NCT05753631.

HIF-1α and periodontitis: Novel insights linking host-environment interplay to periodontal phenotypes

Periodontitis, the sixth most prevalent epidemic disease globally, profoundly impacts oral aesthetics and masticatory functionality. Hypoxia-inducible factor-1α (HIF-1α), an oxygen-dependent transcriptional activator, has emerged as a pivotal regulator in periodontal tissue and alveolar bone metabolism, exerts critical functions in angiogenesis, erythropoiesis, energy metabolism, and cell fate determination. Numerous essential phenotypes regulated by HIF are intricately associated with bone metabolism in periodontal tissues. Extensive investigations have highlighted the central role of HIF and its downstream target genes and pathways in the coupling of angiogenesis and osteogenesis. Within this concise perspective, we comprehensively review the cellular phenotypic alterations and microenvironmental dynamics linking HIF to periodontitis. We analyze current research on the HIF pathway, elucidating its impact on bone repair and regeneration, while unraveling the involved cellular and molecular mechanisms. Furthermore, we briefly discuss the potential application of targeted interventions aimed at HIF in the field of bone tissue regeneration engineering. This review expands our biological understanding of the intricate relationship between the HIF gene and bone angiogenesis in periodontitis and offers valuable insights for the development of innovative therapies to expedite bone repair and regeneration.

Promising Antimicrobial Action of Sustained Released Curcumin-Loaded Silica Nanoparticles against Clinically Isolated Porphyromonas gingivalis

BACKGROUND

Porphyromonas gingivalis (P. gingivalis) has always been one of the leading causes of periodontal disease, and antibiotics are commonly used to control it. Numerous side effects of synthetic drugs, as well as the spread of drug resistance, have led to a tendency toward using natural antimicrobials, such as curcumin. The present study aimed to prepare and physicochemically characterize curcumin-loaded silica nanoparticles and to detect their antimicrobial effects on P. gingivalis.

METHODS

Curcumin-loaded silica nanoparticles were prepared using the chemical precipitation method and then were characterized using conventional methods (properties such as the particle size, drug loading percentage, and release pattern). P. gingivalis was isolated from one patient with chronic periodontal diseases. The patient's gingival crevice fluid was sampled using sterile filter paper and was transferred to the microbiology laboratory in less than 30 min. The disk diffusion method was used to determine the sensitivity of clinically isolated P. gingivalis to curcumin-loaded silica nanoparticles. SPSS software, version 20, was used to compare the data between groups with a p value of <0.05 as the level of significance. Then, one-way ANOVA testing was utilized to compare the groups.

RESULTS

The curcumin-loaded silica nanoparticles showed a nanometric size and a drug loading percentage of 68% for curcumin. The nanoparticles had a mesoporous structure and rod-shaped morphology. They showed a relatively rapid release pattern in the first 5 days. The release of the drug from the nanoparticles continued slowly until the 45th day. The results of in vitro antimicrobial tests showed that P. gingivalis was sensitive to the curcumin-loaded silica nanoparticles at concentrations of 50, 25, 12.5, and 6.25 µg/mL. One-way ANOVA showed that there was a significant difference between the mean growth inhibition zone, and the concentration of 50 µg/mL showed the highest inhibition zone (p ≤ 0.05).

CONCLUSION

Based on the obtained results, it can be concluded that the local nanocurcumin application for periodontal disease and implant-related infections can be considered a promising method for the near future in dentistry.

Cone-beam-computed tomography evaluation of mandibular nutrient canals in patients with periodontal diseases

Background and Aim

The aim of this study was to evaluate radiographically the prevalence of mandibular nutrient canals (NCs) in patients with/without periodontal bone loss with aging and to correlate the number of NCs with the severity of bone loss using cone-beam-computed tomography (CBCT).

Patients and Methods

CBCT examinations of 208 patients were evaluated retrospectively of all patients, 114 had periodontal bone loss, whereas 94 patients were control subjects. Alveolar bone loss investigations were performed according to the Progressive Rate Index.

Results

NCs were observed in 55% of the control group and 86% of the periodontitis patients. NCs were more prevalent in the elderly age group with periodontal bone loss. In the study group, the NCs were statistically more frequent than in the control subjects (P > 0.05).

Conclusion

Statistical analysis showed a significant difference between the age groups and the prevalence of NCs increased in patients with periodontal alveolar bone loss with aging (P < 0.05).

The Relationship between Pulse Pressure and Periodontal Disease in Korean Populations with or without Hypertension

Aims: This study evaluated the relationship between pulse pressure (PP) and periodontal disease in Korean adults with or without hypertension (classified as HTN and non-HTN, respectively). Methods: Data on 3496 adults (≥20 years) were obtained from the Korean National Health and Nutrition Examination Survey (2015). We classified those with HTN as SBP ≥ 140 mmHg, DBP ≥ 90 mmHg, or current use of anti-hypertensive medications. Results: There were a few key findings: when logistic regression analysis was applied for periodontal disease (community periodontal index score ≥ 3), the odds ratios (OR) were significantly higher in the high PP (PP > 60 mmHg) than in the normal PP (PP ≤ 60 mmHg) in the HTN group (OR, 2.131; 95% confidence interval (CI), 1.579–2.876). However, periodontal disease was not associated with high PP in the non-HTN group and was not significant (OR, 0.866; 95% CI, 0.494–1.518). Conclusions: In Korean adults, periodontal disease was positively associated with PP in the HTN group but not in the non-HTN group.

Ghrelin and oral diseases

Eating food is one of the most complicated behaviours in mammals, especially humans. The primary function of ghrelin is regulation of the appetite level and its stimulation. It is also responsible for the body's energy balance and glucose homeostasis. Ghrelin has been shown to affect many brain structures, which confirms the presence of ghrelin receptors in the brain. Studies are also conducted to assess the possible role of ghrelin in anxiety states and in memory disorders and motor dysfunctions. Ghrelin has been found in saliva and salivary glands, teeth and gums, and in the taste buds of the tongue epithelium; it is also secreted by mucosal cells and gingival fibroblasts. The presence of ghrelin in developmental enamel, especially in odontoblasts and ameloblasts, may suggest its regulatory role in the development of teeth. Patients with chronic periodontitis have significantly higher concentrations of ghrelin in the peripheral blood serum, as compared to the control group. Ghrelin plays a special role in the proliferation of cancer cells and in the development of neoplastic metastases. The abundant presence of ghrelin receptors in cancer cells is considered an important target in the treatment of neoplasms. Ghrelin is a hormone whose multidirectional mechanism of action has not yet been fully understood. However, its ubiquitous occurrence in the human body and its very diverse participation in metabolic processes may prove to be a significant obstacle in achieving the expected clinical effect of ghrelin as an effective drug in selected disease units.

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.

Effect of non-surgical periodontal treatment on gingival crevicular fluid hypoxia inducible factor-1 alpha, vascular endothelial growth factor and tumor necrosis factor-alpha levels in generalized aggressive periodontitis patients

BACKGROUND

Hypoxia-inducible angiogenic pathway involving hypoxia inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor (VEGF) and tumor necrosis factor-alpha (TNF-α) may regulate several biological processes related to inflammation. The present study aimed to assess the effect of non-surgical periodontal treatment on gingival crevicular fluid (GCF) HIF-1α, VEGF, and TNF-α levels in generalized aggressive periodontitis (G-AgP).

METHODS

Twenty G-AgP patients and 20 periodontally healthy individuals were included. G-AgP patients received scaling and root planning (SRP), per quadrant at a 1-week-interval, performed with ultrasonic and periodontal hand instruments. GCF samples were collected and clinical periodontal parameters including probing depth, clinical attachment level, gingival index and plaque index were recorded at baseline, 1 and 3 months after treatment. Biomarker levels in GCF were analyzed by ELISA.

RESULTS

At baseline all clinical parameters and GCF HIF-1α, VEGF, and TNF-α levels were significantly higher in G-AgP patients compared to healthy control (P < 0.05). All clinical parameters improved over the 3-month-period in G-AgP patients (P < 0.05). GCF HIF-1α levels in G-AgP reduced at 1 and 3 months post-treatment, however, this did not reach to statistical significance (P > 0.05). GCF VEGF and TNF-α levels remained unchanged throughout the study period (P > 0.05).

CONCLUSIONS

Within the limitations of the present study, although HIF-1α seems to possess a potential diagnostic value for G-AgP, it might not be a proper predictor of clinically favorable treatment outcome. SRP plus different adjunctive therapies could provide better information about the prognostic role of hypoxia-inducible angiogenic pathway in G-AgP.

Histopathological and biochemical evaluation of paeoniflorin administration in an experimental periodontitis model

The purpose of this study was to evaluate the effects of administered Paeoniflorin (Pae) on periodontal tissues within an experimental periodontitis model. Forty male Wistar rats were used in this study and experimental periodontitis was created in all rats except in the control group (n = 10, first group). In the periodontitis group, experimental periodontitis was created but no other application was performed (n = 10, second group). In the other groups created experimental periodontitis, systemic Pae (n = 10, third group) or saline (n = 10, fourth group) was applied. A biochemical analysis of the gingival vascular endothelial growth factor (VEGF) levels and a histomorphometric analysis (measurements of the area of alveolar bone, alveolar bone resorption, and attachment loss) were performed. In the Pae group, the area of the alveolar bone was increased, while alveolar bone resorption and attachment loss decreased. Gingival VEGF levels increased in all groups that created experimental periodontitis and the greatest increase seen in the Pae group. Histomorphometric and biochemical analyses in this study suggest that Pae has a curative effect on periodontal tissues. However, additional studies are needed to confirm these results.

Titanium dioxide nanoparticles induce COX-2 expression through ROS generation in human periodontal ligament cells

Titanium dioxide nanoparticles (TiO₂-NPs) are used to improve the aesthetic of toothpaste. While TiO₂-NPs have been used safely in toothpaste products for a long time, there haven't been studies to determine whether absorption of TiO₂-NPs by the mucous membranes in the mouth induces pathogenic conditions. Here, we assessed whether TiO₂-NPs induce cyclooxygenase-2 (COX-2) and investigated the molecular mechanisms underlying the pro-inflammatory effect of TiO₂-NPs on human periodontal ligament (PDL) cells. Treatment of PDL cells with TiO₂-NPs led to induction of both COX-2 mRNA and protein expression. TiO₂-NPs stimulated the nuclear translocation of nuclear factor-kappaB (NF-κB) as well as its DNA binding by inducing phosphorylation and subsequent degradation of the inhibitory protein IκBα in PDL cells. TiO₂-NPs treatment resulted in rapid activation of extracellular signal-regulated kinase (ERK)1/2 and Akt, which could be upstream of NF-κB. Treatment of PDL cells with both the MEK1/2 inhibitor U0126 and the PI3K inhibitor LY294002 strongly attenuated TiO₂-NPs-induced activation of NF-κB, and also the expression of COX-2. PDL cells treated with TiO₂-NPs exhibited increased accumulation of intracellular reactive oxygen species (ROS). Pretreatment of cells with ROS scavenger N-acetyl cysteine (NAC) abrogated the stimulatory effect of TiO₂-NPs on p65, p50, and COX-2 expression. In conclusion, ROS, concomitantly overproduced by TiO₂-NPs, induce COX-2 expression through activation of NF-κB signaling, which may contribute to the inflammatory effect of PDL cells.

Immune response profiling of primary monocytes and oral keratinocytes to different Tannerella forsythia strains and their cell surface mutants

The oral pathogen Tannerella forsythia possesses a unique surface (S-) layer with a complex O-glycan containing a bacterial sialic acid mimic in the form of either pseudaminic acid or legionaminic acid at its terminal position. We hypothesize that different T. forsythia strains employ these stereoisomeric sugar acids for interacting with the immune system and resident host tissues in the periodontium. Here, we show how T. forsythia strains ATCC 43037 and UB4 displaying pseudaminic acid and legionaminic acid, respectively, and selected cell surface mutants of these strains modulate the immune response in monocytes and human oral keratinocytes (HOK) using a multiplex immunoassay. When challenged with T. forsythia, monocytes secrete proinflammatory cytokines, chemokines and vascular endothelial growth factor (VEGF) with the release of interleukin-1β (IL-1β) and IL-7 being differentially regulated by the two T. forsythia wild-type strains. Truncation of the bacteria's O-glycan leads to significant reduction of IL-1β and regulates macrophage inflammatory protein-1. HOK infected with T. forsythia produce IL-1Ra, chemokines and VEGF. Although the two wild-type strains elicit preferential immune responses for IL-8, both truncation of the O-glycan and deletion of the S-layer result in significantly increased release of IL-8, granulocyte-macrophage colony-stimulating factor and monocyte chemoattractant protein-1. Through immunofluorescence and confocal laser scanning microscopy of infected HOK we additionally show that T. forsythia is highly invasive and tends to localize to the perinuclear region. This indicates, that the T. forsythia S-layer and attached sugars, particularly pseudaminic acid in ATCC 43037, contribute to dampening the response of epithelial tissues to initial infection and hence play a pivotal role in orchestrating the bacterium's virulence.

Biomarker levels in gingival crevicular fluid of generalized aggressive periodontitis patients after non-surgical periodontal treatment

OBJECTIVES

The aim of this study was to assess the effects of non-surgical periodontal treatment on gingival crevicular fluid (GCF) cytokines in patients with generalized aggressive periodontitis (GAgP), in relation to clinical parameters.

MATERIALS AND METHODS

Data were obtained from 16 GAgP patients and 15 periodontally healthy controls. Periodontal parameters and GCF biomarker levels were evaluated at baseline and repeated 3 and 6 months after treatment for GAgP subjects. Moderate and deep pocket sites were analyzed separately. The amount of interleukin (IL)-1β, IL-9, tumor necrosis factor (TNF)-α, platelet-derived growth factor (PDGF-bb), and vascular endothelial growth factor (VEGF) were measured using a highly specific and sensitive multiplex bead immunoassay.

RESULTS

At baseline, cytokine levels in the moderate and deep pocket sites of GAgP patients were higher than those of the healthy control sites. In GAgP group, periodontal treatment led to improvement in all examined clinical parameters and resulted in a statistically significant reduction in the total amounts of IL-1β, VEGF, and TNF-α, in comparison to baseline, already 3 months after therapy in both moderate and deep pocket sites and of PDGF-bb in deep sites (p < 0.01). At the concentration level, only IL-1β and VEGF were affected.

CONCLUSION

Non-surgical treatment of GAgP provided significant clinical benefits leading to a marked decrease in the GCF levels of some pro-inflammatory and pro-angiogenic cytokines, but not of IL-9 and PDGF-bb.

CLINICAL RELEVANCE

Although the periodontal therapy successfully decreased clinical signs of inflammation, the GCF levels of some inflammatory cytokines were still elevated.

Quantitative Parameters of Interdental Gingiva in Chronic Periodontitis Patients with IFN-γ Gene Polymorphism

Chronic periodontitis (CP), an infectious disease resulting in inflammation within the periodontal tissue, is the main cause of adult tooth loss. CP is a multi-factorial disorder and the interaction between multiple genetic and environmental factors results in the manifestation of this disease. Recent researches in periodontitis has focused on cytokine gene polymorphisms that play important role in periodontal inflammation, but few studies investigated histological change that occur during CP in the supporting tissue of teeth. The aims of this study were to investigate the association of IFN-γ +874 A/T polymorphisms and quantitative parameters of interdental gingiva in CP patients. The study samples were interdental gingiva biopsies from 60 individuals including 38 patients and 22 healthy subjects. After determination of IFN-γ +874 A/T gene polymorphism by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR), patients were divided in three subgroups: 10 AA, 18 AT and 10 TT. After slides preparation, quantitative parameters were estimated by Cavalieri's point-counting method. Statistical analyses were performed using Mann-Whitney and Kruskal-Wallis test to compare differences between groups. The volume density (Vv) of epithelium, connective tissue and its components were significantly different between the control and CP groups (P&lt;0.05). Statistically significant differences in the Vv of collagenous and non-collagenous matrix of interdental gingiva between AA, AT and TT groups were found (P&lt;0.05). Result of present study shows that IFN-γ +874 A/T is strongly associated with some quantitative parameters of connective tissue constituents of interdental papilla in CP patients.

Role of the adjunctive antimicrobial photodynamic therapy to periodontal treatment at plasmatic oxidative stress and vascular behavior

BACKGROUND

To evaluate for the first time in vivo the effects of methylene blue (MB) photosensitizer dissolved in ethanol in antimicrobial photodynamic therapy (aPDT) as adjuvant periodontal treatment, at plasmatic oxidative stress and vascular behavior in rat model.

METHODS

Wistar rats were divided into negative control (NC, no periodontitis) and positive control (PC, with periodontitis, without any treatment). The other groups had periodontitis and were treated with scaling and root planing (SRP); SRP+aPDT+MB dissolved in water (aPDT I); SRP+aPDT+MB dissolved in ethanol (aPDT II). The periodontitis was induced by ligature at the mandibular right first molar. At 7/15/30days, rats were euthanized, the plasma was used to determine oxidative stress parameters and gingival tissue for histomorphometric analysis.

RESULTS

PC showed higher thiobarbituric acid reactive substances levels in 7/15/30days. aPDT II was able to block the lipid peroxidation, especially between 15th and 30th days. Glutathione reduced levels were consumed in PC, aPDT I and II groups throughout the experiment. aPDT II increased the vitamin C levels which were restored in this group in the 30th day. aPDT II group showed the highest number of blood vessels.

CONCLUSION

In summary, the aPDT with MB dissolved in ethanol provides better therapeutic responses in periodontitis treatment.

Immunoexpression of HIF-1α and VEGF in Periodontal Disease and Healthy Gingival Tissues

Hypoxia-inducible factor 1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) are proteins that stimulate the proliferation and migration of endothelial cells. These proteins have been described in many pathologic and inflammatory conditions, but their involvement in the development of periodontitis has not been thoroughly investigated. This study compared the immunohistochemical expression of these proteins, involved in angiogenesis and hypoxia, by immunostained inflammatory and endothelial cells in periodontal disease and healthy gingival tissues. Gingival tissue samples were divided as follows: 30 samples with chronic periodontitis, 30 with chronic gingivitis, and 30 of healthy gingiva. Results were analyzed statistically by the Kruskal-Wallis, Mann-Whitney and Spearman correlation tests (p=0.01). Inflammatory and endothelial cells were found to express these proteins. Periodontitis showed median percentage of HIF-1α-positive cells of 39.6%, 22.0% in cases of gingivitis and 0.9% in the healthy gingiva group (p=0.001). For VEGF, median percentage of immunopositive cells was 68.7% for periodontitis, 66.1% in cases for gingivitis, and 19.2% for healthy gingival specimens (p<0.001). Significant correlation between VEGF and HIF-1α was also observed in healthy gingiva (p<0.001).The increased expression of HIF-1α and VEGF in periodontitis, compared to gingivitis and healthy gingiva, suggests possible activation of the HIF-1α pathway in advanced periodontal disease. The correlation between HIF-1α and VEGF expression in healthy gingiva suggests a physiological function for these proteins in conditions of homeostasis. In periodontal disease, HIF-1α and VEGF expression may be regulated by other factors, in addition to hypoxia, such as bacterial endotoxins and inflammatory cytokines.

Vascular endothelial growth factor levels in gingival crevicular fluid before and after periodontal therapy

INTRODUCTION

Of the various cytokines and growth factors regulating angiogenesis, the most potent agent acting on vascular endothelium is vascular endothelial growth factor(VEGF). The present study aims to access VEGF concentration in periodontal diseases and the effect of periodontal therapy on its concentration in gingival crevicular fluid (GCF).

MATERIALS AND METHODS

Ninety five subjects (47 females and 48 males) 25- 47 y of age were divided into healthy (group-1), gingivitis (group-2), and periodontitis (group-3). GCF samples were collected using micro-capillary pipettes & were transferred immediately to plastic vials and stored at -70˚C until the time of the assay. The concentration of VEGF was determined using commercially available ELISA kit.

RESULTS

The mean VEGF concentration was highest in periodontitis patients (Group 3) (88.08±8.04pg/ml), with lowest in healthy patients (Group 1). VEGF levels reduced significantly after therapy in Groups 2 and 3.

CONCLUSION

VEGF levels in GCF had a significant correlation with both periodontal disease progression and healing after therapy.

Secondary lymphoid organ homing phenotype of human myeloid dendritic cells disrupted by an intracellular oral pathogen

Several intracellular pathogens, including a key etiological agent of chronic periodontitis, Porphyromonas gingivalis, infect blood myeloid dendritic cells (mDCs). This infection results in pathogen dissemination to distant inflammatory sites (i.e., pathogen trafficking). The alteration in chemokine-chemokine receptor expression that contributes to this pathogen trafficking function, particularly toward sites of neovascularization in humans, is unclear. To investigate this, we utilized human monocyte-derived DCs (MoDCs) and primary endothelial cells in vitro, combined with ex vivo-isolated blood mDCs and serum from chronic periodontitis subjects and healthy controls. Our results, using conditional fimbria mutants of P. gingivalis, show that P. gingivalis infection of MoDCs induces an angiogenic migratory profile. This profile is enhanced by expression of DC-SIGN on MoDCs and minor mfa-1 fimbriae on P. gingivalis and is evidenced by robust upregulation of CXCR4, but not secondary lymphoid organ (SLO)-homing CCR7. This disruption of SLO-homing capacity in response to respective chemokines closely matches surface expression of CXCR4 and CCR7 and is consistent with directed MoDC migration through an endothelial monolayer. Ex vivo-isolated mDCs from the blood of chronic periodontitis subjects, but not healthy controls, expressed a similar migratory profile; moreover, sera from chronic periodontitis subjects expressed elevated levels of CXCL12. Overall, we conclude that P. gingivalis actively "commandeers" DCs by reprogramming the chemokine receptor profile, thus disrupting SLO homing, while driving migration toward inflammatory vascular sites.

Association of cytokines, high sensitive C-reactive protein, VEGF and beta-defensin-1 gene polymorphisms and their protein expressions with chronic periodontitis in the Chinese population

PURPOSES

This study aimed at investigating the association between interleukin-6 (IL-6), interleukin-12 (IL-12), C-reactive protein (CRP), vascular endothelial growth factor (VEGF) and β-defensin-1polymorphisms and the susceptibility to periodontitis in the Chinese population.

METHODS

DNA was extracted from the blood samples of 532 healthy individuals and 122 chronic periodontitis (CP) patients enrolled in the study. The genes encoding IL-6, IL-12, CRP, VEGF and β-defensin-1 were amplified using PCR and digested with restriction enzymes. The protein expression of the abovementioned genes was determined by ELISA. Differences in the allele/genotype frequencies were assessed with the chi-square test.

RESULTS

The frequencies of the C/C genotypes of IL-6, IL-12, and VEGF were higher in CP patients than healthy controls (66.3% vs 25.9%; 27.8% vs 19.9%; and 64.8% vs 52.1%, respectively). In the patients' group we also recorded frequencies of the A/A genotypes of CRP and VEGF higher than in healthy controls (63.1% vs 58.1% and 64.8% vs 35.2%, respectively). Protein production evaluated by ELISA demonstrated significant differences between CP patients and healthy controls for IL-6, IL-12, CRP, VEGF and β-defensin-1.

CONCLUSIONS

The genotypes of IL-6, IL-12, VEGF and β-defensin-1 and their protein productions were associated with CP in a Chinese population. Genotypes and serum levels of CRP were associated with CP, but alleles frequency showed no difference between CP patients and healthy controls.

Slit-Robo: a potential way to treat periodontitis

Slit is a secreted protein known to function through the Roundabout (Robo) receptor. Slit has recently been shown to be an endogenously available inhibitor of leukocyte chemotaxis and as a chemoattractant to recruit vascular endothelial cells to sites for angiogenesis both in vivo and in vitro. The initiation and progression of periodontal diseases, is the result of complex interactions between the colonizing bacteria in the periodontal pockets and host immune and inflammatory responses. Antibiotics such as tetracyclines are commonly used in the management of periodontal infections and yet, have shown modest success in reducing neutrophil-mediated injury. Angiogenesis is important for the maintenance of homeostatus of periodontal tissues. However, few studies have been reported about angiogenesis targeted treatment for periodontitis. Based on its angiogenesis promoting effect and leukocyte chemotaxis inhibition effect, we hypothesize that Slit can be an effective immunotherapeutic agent in the treatment of periodontitis.

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.

Oral microcirculation in post-menopause: a possible correlation with periodontitis

OBJECTIVES

The reduction in the level of oestrogen, typical in menopause, has some effect on the health of the oral cavity. In fact, post-menopausal women present more severe periodontal disease than pre-menopausal women. Numerous factors can be held to be responsible for this increase, among which are the effects of oestrogens on the oral epithelium, on the salivary glands, on bone tissue and on the endothelium. Our double blind study aims to evaluate the possible variations in oral microcirculation in post-menopausal women.

METHODS

Twenty-seven women in post-menopause (age: Mean ± SD: 57.3 ± 8.73) and 27 women in pre-menopause (age: Mean ± SD: 27.77 ± 3.56) were examined. Oral microcirculation was investigated using oral videocapillaroscopy.

RESULTS

The study showed significant differences between cases and controls for the following parameters: decrease in diameter of loops (mean ± SD: 0.038 ± 0.008; 0.045 ± 0.005), increase in tortuosity (mean ± SD: 3.83 ± 1.13; 1.83 ± 1.06) in labial mucosa and decrease in density in periodontal mucosa (Mean ± SD: 28.86 ± 10.92; 89.62 ± 17.83).

CONCLUSION

The decrease in periodontal density may compromise the epithelium tropism, making it prone to inflammation. The tortuosity may indicate a greater permanence of inflammatory factors, increased in post-menopausal women.

Analysis of vascular distribution and growth factors in human gingival tissue associated with periodontal probing depth

Vascular endothelial growth factor (VEGF) is a key regulator of blood vessel endothelium. Tissue levels of this angiogenesis marker are unknown in human gingival tissue, as is the correlation between vascular growth factors and hypoxia-inducible factor. We examined the expression of VEGF, type III tyrosine kinase receptors (VEGF-R2), platelet-endothelial cell adhesion molecule (CD31) and hypoxia-inducible factor (HIF) mRNA from human gingival tissue of the oral cavity. Tissue samples were from a small quantity of gingival sample biopsy with gingival sulcular depth (GSD) < 2 mm (Group 1), 2 to 4 mm (Group 2), and > 4 mm (Group 3). We found that the levels of VEGF-R2, CD31 and HIF mRNA were higher in the gingival tissue of Group 2 than that of Group 1, and VEGF in the Group 3 was also higher than that of Group 1. The different mRNA levels of these markers may reflect the mRNA levels reflect the vasculature state of gingival tissue based on GSD. VEGF-R2 and HIF also indicate the presence of an elongated blood vessel in the gingival tissue. In the early stage of angiogenesis, VEGF-R2 leads to expression of VEGF, and HIF-1 mediates increased VEGF expression in response to hypoxia in swollen tissues or during the expansion of periodontal tissues, which is useful in the early diagnosis of periodontal diseases.

Effects of enamel matrix derivative on vascular endothelial growth factor expression and microvessel density in gingival tissues of periodontal pocket: a comparative study

BACKGROUND

Vascular endothelial growth factor (VEGF) stimulates proliferation and migration of endothelial cells, and correlates with inflammatory resolution and periodontal tissue healing. Enamel matrix derivative (EMD) seems to stimulate soft tissue healing. Our aim was to assess if topical EMD application in an instrumented periodontal pocket could affect angiogenesis at the gingival level.

METHODS

A total of 56 periodontal sites in 28 patients were treated with a single session of comprehensive scaling and root planing under local anesthesia after recording the clinical attachment level (CAL). EMD gel in the test site or only the vehicle propylene glycol alginate in aqueous solution in the control site of the same mouth was applied onto the root surfaces and into the pocket and left in place for 3 minutes. After 48 hours, gingival biopsies were collected for histologic and immunohistochemical analysis for VEGF and CD34 (for microvessel density [MVD] count) antibodies. Statistical comparisons were performed by analysis of variance test.

RESULTS

Endothelial VEGF expression and MVD were statistically different in the test site compared to the control site. VEGF expression and MVD of the control site were not correlated with CAL, whereas the test site showed high correlations among CAL and endothelial VEGF or MVD.

CONCLUSIONS

EMD induces proliferation and viability and angiogenesis of human microvascular cells. Recent clinical and histologic studies found EMD to be useful as an adjunct to scaling and root planing in single-rooted teeth. Our findings may help to understand the mechanisms involved in soft tissue healing, through the ability of EMD to increase angiogenesis at periodontal pockets.

Immunoexpression of angiogenesis, nitric oxide synthase, and proliferation markers in gingival samples of patients with aggressive and chronic periodontitis

BACKGROUND

In periodontal tissues, angiogenesis seems to be important for the maintenance of healthy tissues and in periodontal diseases. Angiogenesis is regulated through a complex interplay of molecular signals mediated by growth factors involving extracellular matrix remodeling, endothelial cell migration and proliferation, capillary differentiation and anastomosis. However, the influence of angiogenesis in the development, progression, and healing of periodontal lesions is currently under investigation. This immunohistochemical study evaluates the expression of vascular endothelial growth factor (VEGF), microvessel density (MVD), nitric oxide synthase (NOS) 1 and 3, and Ki-67 in gingival tissues of patients with aggressive and chronic periodontitis.

METHODS

Twenty-seven human gingival biopsies were taken from patients with chronic periodontitis (n = 14 patients), generalized aggressive periodontitis (n = 6 patients), and healthy periodontia (n = 7 patients). The specimens were immunohistochemically stained for VEGF, MVD, NOS 1 and 3, and Ki-67.

RESULTS

The levels of VEGF, MVD, NOS 1 and 3, and Ki-67 were found to be significantly different among groups (P >0.001). Patients with aggressive periodontitis had higher levels of these markers compared to those in patients with chronic periodontitis and healthy patients.

CONCLUSIONS

The analysis demonstrates a higher expression of all immunologic markers particularly in subjects with aggressive periodontitis. In summary, the data from this pilot investigation suggests that VEGF is an important factor in the pathogenesis of the aggressive and chronic forms of periodontitis.

The Expression of Vascular Endothelial Growth Factor in a Rat Model at Destruction and Healing Stages of Periodontal Disease

BACKGROUND

The major role of vascular endothelial growth factor (VEGF), an angiogenic mediator, in promoting the progression or the healing of periodontal disease is still unclear. The aim of this study was to evaluate the VEGF expression in the destruction and healing stages of periodontal disease and to investigate the association between VEGF expression and vascularization with regard to the number and diameters of blood vessels.

METHODS

Thirty rats were distributed equally into two test groups and a control group. Experimental periodontal disease was induced in the test groups by silk ligatures, which were kept in position for 40 days. On the 40th day, ligatures were removed from the healing group, whereas ligatures were left in position in the destruction group. On the 60th day, rats were sacrificed; histomorphometric and biochemical analyses were carried out to determine the number and diameters of blood vessels and the assessment of VEGF concentration by enzyme-linked immunosorbent assay, respectively.

RESULTS

There was a statistically significant increase in the number of blood vessels in the healing group and in the diameters of blood vessels in the destruction group compared to the control group (P <0.001). In vivo VEGF expressions were highest in the healing group (P <0.001) and correlated significantly with the number of blood vessels (r(2) = 0.814; P = 0.001).

CONCLUSION

VEGF expression may be related more to the healing stage of periodontal disease than to the destruction stage of the lesion.

Gingipains of Porphyromonas gingivalis modulate leukocyte adhesion molecule expression induced in human endothelial cells by ligation of CD99

Porphyromonas gingivalis has been implicated as a key etiologic agent in the pathogenesis of destructive chronic periodontitis. Among virulence factors of this organism are cysteine proteinases, or gingipains, that have the capacity to modulate host inflammatory defenses. Intercellular adhesion molecule expression by vascular endothelium represents a crucial process for leukocyte transendothelial migration into inflamed tissue. Ligation of CD99 on endothelial cells was shown to induce expression of endothelial leukocyte adhesion molecule 1, vascular cell adhesion molecule 1, intercellular adhesion molecule 1, and major histocompatibility complex class II molecules and to increase adhesion of leukocytes. CD99 ligation was also found to induce nuclear translocation of NF-kappaB. These results indicate that endothelial cell activation by CD99 ligation may lead to the up-regulation of adhesion molecule expression via NF-kappaB activation. However, pretreatment of endothelial cells with gingipains caused a dose-dependent reduction of adhesion molecule expression and leukocyte adhesion induced by ligation of CD99 on endothelial cells. The data provide evidence that the gingipains can reduce the functional expression of CD99 on endothelial cells, leading indirectly to the disruption of adhesion molecule expression and of leukocyte recruitment to inflammatory foci.

Screw vs cement-implant-retained restorations: an experimental study in the beagle. Part 2. Immunohistochemical evaluation of the peri-implant tissues

Crestal bone loss has been reported to occur around dental implants. Even if the causes of this bone loss are not completely understood, the presence of a microgap between implant and abutment with a possible contamination of the internal portion of the implants has been suggested. The aim of this study was to see if there were differences in the vascular endothelial growth factor (VEGF) expression, microvessel density (MVD), proliferative activity (MIB-1), and inflammatory infiltrate in the soft tissues around implants with screwed and cemented abutments. Sandblasted and acid-etched implants were inserted in the mandibles of 6 Beagle dogs. Ten 3.5- x 10-mm root-form implants were inserted in each mandible. A total of 60 implants (30 with screwed abutments and 30 with cemented abutments) were used. After 12 months, all the bridges were removed and all abutments were checked for mobility. A total of 8 loosened screws (27%) were found in the screwed abutments, whereas no loosening was observed in cemented abutments. A gingival biopsy was performed in 8 implants with cemented abutments, in 8 implants with screwed abutments, and in 8 implants with unscrewed abutments. No statistically significant differences were found in the inflammatory infiltrate and in the MIB-1 among the different groups. No statistically significant difference was found in the MVD between screwed and cemented abutments (P = .2111), whereas there was a statistically significant difference in MVD between screwed and unscrewed abutments (P = .0277) and between cemented and unscrewed abutments (P = .0431). A low intensity of VEGF was prevalent in screwed and in cemented abutments, whereas a high intensity of VEGF was prevalent in unscrewed abutments. These facts could be explained by the effects induced, in the abutments that underwent a screw loosening, by the presence of bacteria inside the hollow portion of the implants or by enhanced reparative processes.

Risk factors and prevalence of periodontitis in community-dwelling elders in Mexico

AIM

The objective of this study was to determine whether an association existed between chronic systemic diseases/conditions, risk factors common in old age, and the extent and severity of chronic periodontal disease.

MATERIALS AND METHODS

Sociodemographic and lifestyle characteristics were examined by contrasting rural, urban-marginal, and urban social environments in Central Mexico. Data were analysed with Analysis of Variance, chi2 tests, and multivariable logistic regression.

RESULTS

A total of 473 adults 60 years old and over were interviewed; 315 were also examined and underwent laboratory assays (participation rate, 66%); women, 62%; mean age 73+/-8 years; 23% edentulous. The distribution of periodontitis by sociodemographic variables showed differences across locales (73% low-urban, 57% middle-urban, 29% rural). The regression model indicated that periodontitis was more frequently associated with low-urban locale, higher systolic blood pressure, higher body mass index, and worse calculus readings, with an interaction whereby being obese and having a high calculus index was associated with a high probability of having periodontitis.

CONCLUSIONS

Overall periodontal conditions were fair. While we identified oral, systemic, and social variables that modulated the experience of periodontitis, it would appear that urban, low social class elders appeared to have worse periodontal conditions.

Functional implication of the hydrolysis of platelet endothelial cell adhesion molecule 1 (CD31) by gingipains of Porphyromonas gingivalis for the pathology of periodontal disease

Periodontitis is a response of highly vascularized tissues to the adjacent microflora of dental plaque. Progressive disease has been related to consortia of anaerobic bacteria, with the gram-negative organism Porphyromonas gingivalis particularly implicated. The gingipains, comprising a group of cysteine proteinases and associated hemagglutinin domains, are major virulence determinants of this organism. As vascular expression of leukocyte adhesion molecules is a critical determinant of tissue response to microbial challenge, the objective of this study was to determine the capacity of gingipains to modulate the expression and function of these receptors. Given the potential multifunctional role of platelet endothelial cell adhesion molecule 1 (PECAM-1) in the vasculature, the effect of gingipains on PECAM-1 expression by endothelial cells was examined. Activated gingipains preferentially down-regulated PECAM-1 expression on endothelial cells compared with vascular cell adhesion molecule 1 and endothelial-leukocyte adhesion molecule 1, but the reduction in PECAM-1 expression was completely inhibited in the presence of the cysteine proteinase inhibitor TLCK (Nalpha-p-tosyl-l-lysine chloromethyl ketone). Endothelial monolayers treated with activated gingipains demonstrated progressive intercellular gap formation that correlated with reduced intercellular junctional PECAM-1 expression as determined by Western blotting and immunofluorescence microscopy. This was accompanied by enhanced transfer of both albumin and neutrophils across the monolayer. The results suggest that degradation of PECAM-1 by gingipains contributes to increased vascular permeability and neutrophil flux at disease sites.

Oral health, atherosclerosis, and cardiovascular disease

During the last two decades, there has been an increasing interest in the impact of oral health on atherosclerosis and subsequent cardiovascular disease (CVD). The advent of the inflammation paradigm in coronary pathogenesis stimulated research in chronic infections caused by a variety of micro-organisms-such as Chlamydia pneumoniae, Helicobacter pylori, and cytomegalovirus-as well as dental pathogens, since these chronic infections are thought to be involved in the etiopathogenesis of CVD by releasing cytokines and other pro-inflammatory mediators (e.g., C-reactive protein [CRP], tumor necrosis factor [TNF-alpha]) that may initiate a cascade of biochemical reactions and cause endothelial damage and facilitate cholesterol plaque attachment. Yet, due to the multi-factorial nature of dental infection and CVD, confirming a causal association is difficult, and the published results are conflicting. The main deficit in the majority of these studies has been the inadequate control of numerous confounding factors, leading to an overestimation and the imprecise measurement of the predictor or overadjustment of the confounding variables, resulting in underestimation of the risks. A meta-analysis of prospective and retrospective follow-up studies has shown that periodontal disease may increase the risk of CVD by approximately 20% (95% confidence interval [CI], 1.08-1.32). Similarly, the reported risk ratio between periodontal disease and stroke is even stronger, varying from 2.85 (CI 1.78-4.56) to 1.74 (CI 1.08-2.81). The association between peripheral vascular disease and oral health parameters has been explored in only two studies, and the resultant relative risks among individuals with periodontitis were 1.41 (CI 1.12-1.77) and 2.27 (CI 1.32-3.90), respectively. Overall, it appears that periodontal disease may indeed contribute to the pathogenesis of cardiovascular disease, although the statistical effect size is small.

Mathematical estimation of the potential effect of vascular remodelling/dilatation on B-mode ultrasound intima-medial thickness

BACKGROUND

Arterial diameter changes are known to impact wall thickness, but the clinical relevance of the changes is unclear.

AIM

To use known mathematical relationships to estimate anticipated changes in arterial wall thicknesses occurring with enlargement of atherosclerotic regions.

DESIGN

Mathematical relationships between a cylinder's diameter and its wall thickness were used to calculate the theoretical effect of diameter enlargement on the thickness of an atherosclerotic wall.

METHODS

Equating the wall areas of two cylinders, one of smaller diameter than the other, allowed estimation of the degree of thickening that would be needed to maintain intima-medial thickness (IMT) after arterial remodelling. The difference in cylinder diameters was based on arterial diameter enlargement reported with atherosclerosis progression. Thus, the calculated wall changes estimate arterial changes which could go undetected if only IMT is measured by ultrasound.

RESULTS

The expected IMT change for diameter enlargement is not a linear function of the diameter change, but varies depending upon initial size (diameter and IMT). Thus a 0.6 mm arterial diameter enlargement would be expected to cause a 0.039-0.235 mm change in IMT, depending on artery size. The estimated IMT change is similar to that associated with major atherosclerotic risk factors.

DISCUSSION

The level of vascular remodelling reported with atherosclerosis could have a measurable impact on IMT, suggesting that indicators incorporating both diameter and IMT may be better disease indicators than IMT alone. Arterial diameters, as well as IMT, should be obtained in ultrasound studies of atherosclerosis.

The Effect of Menstrual Cycle on Periodontal Health

BACKGROUND

Fluctuation in estrogen/progesterone levels has been shown to affect the periodontium. The effects of pregnancy, prepuberty, and oral contraceptives on gingival health has been studied extensively, with gingival scores reported to be higher, in most instances, than in controls. Fluctuation in steroid sex hormone is also noticeable through women's menstrual cycle. Many women report an increase in gingival inflammation and discomfort associated with their menstrual cycle, most commonly around the menses period. However, this well-known phenomenon has never been studied. The purpose of this longitudinal, prospective study was to compare the periodontal status of premenopausal women at different times during their menstrual cycle.

METHODS

Eighteen premenopausal women, enrolled in our maintenance program, were recruited. Clinical examination was performed before the recall visit at three different time points in their menstrual cycle: ovulation (OV), premenstruation (PM), and menstruation (M). Plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) were examined around the Ramfjord index teeth. Analysis of variance, with Scheffe modification, was used to determine differences between the menstrual time points.

RESULTS

Several women in this study reported appreciable oral symptoms just before or during menses. Mean PI (0.85 +/- 0.06) was almost identical at all time points. Despite this, GI was significantly higher (P = 0.0245) in OV (0.54 +/- 0.07) and in PM (0.5 +/- 0.08) than in M (0.38 +/- 0.07). Mean patient's PD (2.22 +/- 0.08 mm) and CAL (2.92 +/- 0.15 mm) was not significantly different between examinations.

CONCLUSIONS

We observed changes in gingival scores during the menstrual cycles of periodontally healthy women. These changes need to be addressed when analyzing data from epidemiological and treatment studies in premenopausal women.

Vascular Endothelial Growth Factor in Gingival Tissues and Crevicular Fluids of Diabetic and Healthy Periodontal Patients

BACKGROUND

Periodontal disease is one of the major oral problems encountered in patients with diabetes mellitus (DM). Vascular changes, neutrophil dysfunction, altered collagen synthesis, and genetic predisposition observed in DM may contribute to periodontitis; and the vascular alterations observed in such patients may depend on vascular endothelial growth factor (VEGF) actions. Few reports are available about the mechanism of neovascularization and the angiogenic factors that contribute to the periodontal pathology and the role of VEGF in periodontal diseases. The aim of this study is to compare VEGF expression in healthy and periodontally diseased tissues with gingival crevice fluid (GCF) of healthy persons and diabetic patients.

METHODS

Gingival tissue and GCF samples were collected from sites of periodontitis in 10 healthy subjects and in 10 type 2 diabetic patients, and from the sites of healthy gingiva within the same groups. Therefore, each patient became his/her own control. Additionally, 10 people without any systemic or periodontal diseases were enrolled, forming a negative control group. Thus, a total of 50 tissue and 50 GCF samples were provided.

RESULTS

No VEGF staining was observed in the negative control group or in the systemically healthy people's healthy tissue samples, whereas four samples of diabetic patients showed positive staining (P < 0.05). However, VEGF was revealed in two tissue samples of periodontal sites of systemically healthy people and in six samples of the diabetic patients (P > 0.05). In all test groups, GCF VEGF levels were higher in periodontal sites (P < 0.05) than in healthy sites.

CONCLUSION

The results of this study showed that VEGF is increased in all periodontal tissues of both groups and in the healthy sites of diabetic patients. Additionally, GCF VEGF values increased in periodontal sites of all test groups.

Association between periodontal disease and left ventricle mass in essential hypertension

Chronic periodontitis has been associated with an increased risk for cardiovascular disease. Left ventricular mass is an established independent predictor of cardiovascular disease. In the present cross-sectional study, we tested the association between periodontitis and left ventricular mass in subjects with essential hypertension. One hundred four untreated subjects with essential hypertension underwent clinical examinations, including echocardiographic study, laboratory tests, and assessment of periodontal status according to the community periodontal index of treatment needs (CPITN). With increasing severity of periodontitis, there was a progressive increase in left ventricle mass. Mean values (g/height2.7) were 39.0 (+/-2.7) in CPITN 0 (periodontal health), 40.2 (+/-6.4) in CPITN 1 (gingival bleeding), 42.7 (+/-6.8) in CPITN 2 (calculus), 51.4 (+/-11.7) in CPITN 3 (pockets 4 to 5 mm), and 76.7 (+/-11.3) in CPITN 4 (pockets > or =6 mm) (overall F 51.2; P<0.0001). Body surface area (P=0.04), systolic (P<0.0001) and diastolic (P<0.01) blood pressure, and left ventricular mass (P<0.0001) were determinants of a composite of CPITN 3 and 4. In a multivariate logistic analysis, left ventricular mass was the sole determinant (P<0.0001) of CPITN stages 3 and 4. Our findings suggest a direct association between severity of periodontitis and left ventricular mass in subjects with essential hypertension. Periodontal evaluation might contribute to refine cardiovascular risk assessment in hypertensive subjects.

Expression of vascular endothelial growth factor in human periodontal tissues: comparison of healthy and diabetic patients

BACKGROUND

Vascular endothelial growth factor (VEGF) induces proliferation of endothelial cells, stimulates angiogenesis, and increases vascular permeability, but information about its role in periodontal lesions is limited. The aim of this study is to determine the association between VEGF expression in healthy and periodontally diseased tissues of healthy and diabetic patients.

METHODS

Ten systemically healthy and 10 Type 2 diabetic patients (DM) all diagnosed with periodontitis were enrolled into the study. Gingival samples were collected from both periodontal and healthy sites in all patients. Each patient served as his/her own control. Additionally, 10 people without any systemic or periodontal diseases were enrolled as a negative control group.

RESULTS

In the negative control group tissue samples, no VEGF expression was observed. Among the 10 systemically healthy people, no evidence of VEGF was observed in healthy gingival samples, but was found in diseased tissues in 2 cases. In the diabetic patients, VEGF was observed in 4 healthy gingival tissues and in 6 periodontal sites. VEGF was intensely present in monocytes and macrophages.

CONCLUSION

The results of this study show that VEGF is increased in gingival tissues of diabetic patients, especially those with periodontal disease.

Microvasculature in gingivitis and chronic periodontitis: disruption of vascular networks with protracted inflammation

Gingivitis occurring when bacterial plaque accumulates in the gingival crevice provides a convenient and interesting model for chronic inflammation in humans. In some patients, gingivitis progresses to the destructive lesion of periodontitis, involving the formation of periodontal pockets. The basis for pocket formation and progression is not as yet clear, although neutrophilic polymorphonuclear leukocytes (PMN) appear to play a protective role. Vascular changes appear to either facilitate or inhibit PMN function with the effect of either protecting from, or stimulating, periodontitis. Contrary to most circumstances, high endothelial cells in periodontitis are involved with PMN rather than lymphocyte emigration. Expansion of the microvasculature through increased vascular diameter and tortuosity as well as the development of high endothelial cells appears to protect from periodontitis by increasing the supply of both plasma defense factors and PMN to the tissues. Vascular changes that may oppose this and promote periodontitis are the formation of perivascular hyaline material and accumulation of basement membrane rests. The inadequate tissue turnover that accumulation of these vascular products represents can be argued as a vascular response to a chronic inflammation that has failed to eliminate the irritant. It is suggested that these vascular changes may account for the highly localized and burst-like pattern of pocket formation in periodontitis. Finally, it is possible that the recent observation that periodontitis is an independent risk factor for systemic vascular disease may reflect stimulation of acute phase protein synthesis by cytokines released by periodontal high endothelial cells.

Immunohistochemical study of vestibular gingival blood vessel density and internal circumference in smokers and non-smokers

BACKGROUND

This study was undertaken to determine: 1) if sections stained with monoclonal antibody to CD34 can be used for measurement of gingival blood vessel density and circumference and 2) if long-term smoking affects either of these 2 parameters.

METHODS

Vestibular gingival biopsy samples were obtained from 17 adults (5 smokers and 12 non-smokers) who were undergoing routine periodontal surgery independently of this study. Hematoxylin and eosin staining was used for histological assessment of inflammation, while immunohistochemical staining with CD34 mouse monoclonal antibody was used to mark the endothelial cells of the blood vessels within each sample. Stringent selection criteria were applied to the 17 biopsy samples, and 7 (from 3 smokers and 4 non-smokers) were chosen to have their vascular density (number of vessels/unit area) and internal vessel circumference (IC) measured under a blinded protocol.

RESULTS

Repeated measurements of vascular density and internal circumference showed small standard deviations, indicating the high reproducibility of the measurement technique. The smoker group showed a higher proportion of small (IC < 50 microns) and a lower proportion of large blood vessels (IC > 100 microns), which was statistically significant (P = 0.0403 and P < 0.001, respectively). The difference between the vascular density of smokers and non-smokers was not significant (P = 0.092).

CONCLUSIONS

The present study indicates that the CD34 immunohistochemical staining technique is a simple and reproducible method for the measurement of density and internal circumference of gingival blood vessels. Based on this technique, cigarette smokers show a higher percentage of smaller blood vessels and a lower percentage of larger vessels, but similar vascular density, to non-smokers.