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Elevation of systemic markers related to cardiovascular diseases in the peripheral blood of periodontitis patients.

BACKGROUND: Periodontitis is a common, often undiagnosed, chronic infection of the supporting tissues of the teeth, epidemiologically associated with cardiovascular diseases. Since C-reactive protein (CRP) and other systemic markers of inflammation have been identified as risk factors for cardiovascular diseases, we investigated whether these factors were elevated in periodontitis. METHODS: Consecutive adult patients with periodontitis (localized n = 53; generalized n = 54), and healthy controls (n = 43), all without any other medical disorder, were recruited and peripheral blood samples were taken. RESULTS: Patients with generalized periodontitis and localized periodontitis had higher median CRP levels than controls (1.45 and 1.30 versus 0.90 mg/L, respectively, P = 0.030); 52% of generalized periodontitis patients and 36% of the localized periodontitis patients were sero-positive for interleukin-6 (IL-6), compared to 26% of controls (P= 0.008). Plasma IL-6 levels were higher in periodontitis patients than in controls (P = 0.015). Leukocytes were also elevated in generalized periodontitis (7.0 x 10(9)/L) compared to localized periodontitis and controls (6.0 and 5.8 x 10(9)/L, respectively, P= 0.002); this finding was primarily explained by higher numbers of neutrophils in periodontitis (P= 0.001). IL-6 and CRP correlated with each other, and both CRP and IL-6 levels correlated with neutrophils. The current findings for periodontitis were controlled for other known factors associated with cardiovascular diseases, including age, education, body mass index, smoking, hypertension, cholesterol, and sero-positivity for CMV, Chlamydia pneumoniae, and Helicobacter pylori. CONCLUSIONS: Periodontitis results in higher systemic levels of CRP, IL-6, and neutrophils. These elevated inflammatory factors may increase inflammatory activity in atherosclerotic lesions, potentially increasing the risk for cardiac or cerebrovascular events.

Adult↗

Overweight and obesity as risk indicators for periodontitis in adults.

BACKGROUND: Developed and developing countries are facing an obesity epidemic with various health consequences. Few studies have addressed the relationship between obesity and periodontal health. The present study assessed the association of overweight and obesity with periodontitis in Brazilian adults. METHODS: A representative probability sample comprising 706 subjects aged 30 to 65 years from south Brazil was examined clinically and using a structured interview. Overweight and obesity were assessed by body mass index (BMI) using the World Health Organization (WHO) criteria. Individuals with > or =30% teeth with attachment loss > or =5 mm were classified as having periodontitis. Statistical analysis accounted for survey design, and separate analyses were performed for non-smokers. RESULTS: In this population, 60% and 65% of males and females, respectively, were overweight or obese. Periodontitis was observed in 50.7% and 35.3% of males and females, respectively. The percentage of males with periodontitis was similar in the overweight/obese individuals compared to those with normal weight. In females, there was a positive correlation between the BMI index and the occurrence of periodontitis, with a significantly (P < 0.05) higher prevalence of periodontitis in obese than in normal weight females. The multivariable analysis showed that obese females were significantly more likely (odds ratio = 2.1) to have periodontitis than normal weight females. A separate analysis for non-smokers showed that obese females were approximately 3.4 times more likely to have periodontitis than the normal BMI group. There were no significant differences in the prevalence of periodontitis between BMI groups among smokers of both genders and in male non-smokers. CONCLUSIONS: Obesity was significantly associated with periodontitis in adult, non-smoker women. Overweight was not significantly associated with periodontitis. Smoking may attenuate the association of periodontitis with obesity.

Adult↗

A proposed model linking inflammation to obesity, diabetes, and periodontal infections.

BACKGROUND: Obesity is an important risk factor for diabetes, cardiovascular disease, and periodontal disease. Adipocytes appear to secrete proinflammatory cytokines which may be the molecules linking the pathogenesis of these diseases. We evaluated the relationship between obesity, periodontal disease, and diabetes mellitus insulin resistance as well as the plasma levels of tumor necrosis factor alpha (TNFalpha) and its soluble receptors (sTNFalpha) to assess the relationship of inflammation to obesity, diabetes, and periodontal infections. METHODS: The relationship between periodontal disease, obesity, and insulin resistance was examined in the Third National Health and Nutrition Examination Survey (NHANES III). In a population of 12,367 non-diabetic subjects, the variable body mass index (BMI) was used as an assessment of obesity and periodontal disease was assessed by mean clinical attachment loss. The plasma levels of TNFalpha and sTNFalpha were assessed in subsets of 1,221 adults from Erie County, New York, who represented the highest and lowest quartile of BMI. These subjects had extensive periodontal and medical evaluations. RESULTS: In the NHANES III portion of the study, BMI was positively related to severity of periodontal attachment loss (P <0.001). Weighted multiple logistic regressions showed that this relationship is likely mediated by insulin resistance, since overweight individuals (with BMI >or=27 kg/m2) with high levels of insulin resistance (IR) exhibited an odds ratio of 1.48 (95% confidence interval 1.13 - 1.93) for severe periodontal disease as compared to overweight subjects with low IR. In the Erie County adult population, the highest levels of TNFalpha and sTNFalpha receptors were found in those individuals in the highest quartile of BMI. A positive correlation of TNFalpha levels with periodontal disease was found only in those in the lowest quartile of BMI. CONCLUSIONS: Obesity is a significant predictor of periodontal disease and insulin resistance appears to mediate this relationship. Furthermore, obesity is associated with high plasma levels of TNFalpha and its soluble receptors, which in turn may lead to a hyperinflammatory state increasing the risk for periodontal disease and also accounting in part for insulin resistance. Further studies of the molecular basis of insulin resistance and its relationship to diabetes, periodontal disease, and obesity are necessary to fully test the hypothesis that adipocyte production of proinflammatory cytokines is a pathogenic factor linking obesity to diabetes and periodontal infections.

Adult↗

Clinical and microbiological profiles of human immunodeficiency virus (HIV)-seropositive Brazilians undergoing highly active antiretroviral therapy and HIV-seronegative Brazilians with chronic periodontitis.

BACKGROUND: This study compares the periodontal clinical profile and the composition of the subgingival microbiota of human immunodeficiency virus (HIV)-seropositive and HIV-seronegative subjects with chronic periodontitis. METHODS: A total of 172 subjects were distributed into two HIV-seropositive groups (37 chronic periodontitis [H+CP+] and 35 periodontally healthy [H+CP-] individuals) and two HIV-seronegative groups (49 chronic periodontitis [H-CP+] and 51 periodontally healthy [H-CP-] subjects). Subgingival samples were collected from six sites with the deepest probing depth in the periodontitis groups and six random sites in the groups with periodontal health. All HIV-infected patients had undergone highly active antiretroviral therapy (HAART) for at least 2 years. The presence and levels of 33 bacterial species were detected by DNA probes and the checkerboard method. Kruskal-Wallis and Mann-Whitney tests were used to seek for significant differences among and between groups. RESULTS: H-CP+ patients showed significantly more periodontal destruction and inflammation than H+CP+ patients, whereas H+CP- subjects presented a greater percentage of sites with bleeding than H-CP- subjects (P <0.01). Patients who were HIV seronegative showed higher prevalence and levels of most bacterial species than HIV seropositive patients. Periodontal pathogens including Tannerella forsythensis, Porphyromonas gingivalis, Prevotella nigrescens, Eubacterium nodatum, Fusobacterium nucleatum, and Selenomonas noxia were more frequently detected in H-CP+ subjects compared to H+CP+ and controls. In contrast, Enterococcus faecalis and Acinetobacter baumannii were more commonly found in HIV-infected than in non-HIV-infected subjects (P <0.05). CONCLUSION: Putative periodontal pathogens are more prevalent in the subgingival microbiota of HIV-seronegative patients with chronic periodontitis, whereas species not usually associated with periodontitis are detected in higher frequency in HIV-seropositive subjects under HAART.

Adult↗

Periodontal disease and mortality in type 2 diabetes.

OBJECTIVE: Periodontal disease may contribute to the increased mortality associated with diabetes. RESEARCH DESIGN AND METHODS: In a prospective longitudinal study of 628 subjects aged > or =35 years, we examined the effect of periodontal disease on overall and cardiovascular disease mortality in Pima Indians with type 2 diabetes. Periodontal abnormality was classified as no or mild, moderate, and severe, based on panoramic radiographs and clinical dental examinations. RESULTS: During a median follow-up of 11 years (range 0.3-16), 204 subjects died. The age- and sex-adjusted death rates for all natural causes expressed as the number of deaths per 1,000 person-years of follow-up were 3.7 (95% CI 0.7-6.6) for no or mild periodontal disease, 19.6 (10.7-28.5) for moderate periodontal disease, and 28.4 (22.3-34.6) for severe periodontal disease. Periodontal disease predicted deaths from ischemic heart disease (IHD) (P trend = 0.04) and diabetic nephropathy (P trend < 0.01). Death rates from other causes were not associated with periodontal disease. After adjustment for age, sex, duration of diabetes, HbA1c, macroalbuminuria, BMI, serum cholesterol concentration, hypertension, electrocardiographic abnormalities, and current smoking in a proportional hazards model, subjects with severe periodontal disease had 3.2 times the risk (95% CI 1.1-9.3) of cardiorenal mortality (IHD and diabetic nephropathy combined) compared with the reference group (no or mild periodontal disease and moderate periodontal disease combined). CONCLUSIONS: Periodontal disease is a strong predictor of mortality from IHD and diabetic nephropathy in Pima Indians with type 2 diabetes. The effect of periodontal disease is in addition to the effects of traditional risk factors for these diseases.

Adolescent↗

[An experimental study on healing process of replanted mature permanent teeth. Changes of periodontal vascular network].

This study was conducted to clarify both changes of periodontal vascular architecture and concomitant remodelling phenomena associated with hard tissues in the healing process of replanted teeth of first premolar. Utilizing both vascular corrosive resin casts method, scanning electron microscopy, and histological examinations, 45 matured mongrel dogs were used for this study. The results were as follows: 1. 4 days after operation: Newly formed vascular networks with a exceedingly irregular course were observed on lower two thirds of the alveolar wall. They derived from comparatively less damaged periodontal vascular components. No vascular networks were observed surrounding in the crevicular area of the replanted tooth where the periodontal membrane tissue was thoroughly damaged when tooth was extracted. 2. 1 week after operation: Newly formed periodontal vascular networks with a slightly irregular course were observed over the entire alveolar bone surface. 3. 2 weeks after operation: Formation of Sharpey's fibers occurred. The surrounding alveolar bone was remodelled and rearrangement of periodontal vascular architecture was observed. Also, several Howship's lacunae were observed on the root surface where characteristic capillary loops with glomerular-like appearance penetrated into these lacunae. 4. 3 weeks after operation: Root resorption was advanced and capillary loops with glomerular-like appearance were extensively distributed in association with each lacunae. On the other hand, the less space where periodontal membrane vasculature occupied, the more space was occupied by osteoid tissue. 5. 4 weeks after operation: Blood vessels within the periodontal space were reduced in number and the osteoid tissue showed bony fusion adjacent to the extensively resorbing surface of dentin. 6. 12 weeks after operation: Functional arrangement of Sharpey's fibers was completed. Restoration of Howship's lacunae on the root surface and two layered arrangements of vascular network within the periodontal space were observed. Newly formed periodontal vascular architecture showed a fine meshwork pattern, which was somewhat different from that of the control (noreplantation) group. 7. 20 weeks after operation: Increased number of capillary loops was observed with leakage of methacrylate resin through the weakened endothelial linings of capillaries in one case. It is supposed that this leakage through capillaries is correlated with the inflammatory root resorption that occurs clinically in marginal periodontitis. Also in some cases, periodontal capillary network showed secondary occlusal traumatic changes. Above results indicated that periodontal vascular architecture varied depending upon the reactions of periodontium following tooth replantation and the prognosis of replanted tooth was deeply associated with repair of periodontal vascular network.

Alveolar Process↗

Correlation of interleukin-1 beta, interleukin-6, and periodontitis.

In order to understand the role of IL-1 beta and IL-6 in the periodontal tissue destruction coincident to periodontitis, we assessed the levels of these two mediators in both the gingival tissue and the serum of patients with periodontal disease and of periodontally healthy subjects. In addition, production of IL-6 by six healthy human gingival fibroblast (HGF) strains in response to IL-1 beta was also investigated. The levels of IL-1 beta and IL-6 in gingival tissues and in serum were examined by ELISA. Both mediators were observed to increase in diseased tissues of patients with adult periodontitis, and there was a positively significant relationship between both mediators and clinical assessments of periodontal destruction. Moreover, a significant correlation was also noted between levels of IL-1 beta and IL-6 in gingival tissues of periodontitis patients (r = 0.4334, p < 0.01). However, there was no significant difference in the serum levels of IL-1 beta and IL-6 between periodontitis patients and periodontally healthy controls. In fibroblast cultures, confluent monolayers of HGF were incubated with recombinant human IL-1 beta for 48 h at 37 degrees C in 5% CO2 and air. At the end of the culture period, supernatants were collected and assayed for IL-6 activity by inducing proliferation in the IL-6-dependent hybridoma cell line 7TD1. A dose-dependent stimulatory effect of IL-1 beta on IL-6 production by HGF was noted, wherein 3 strains exhibited higher IL-6 activity than the other 3. These data indicate that the levels of IL-1 beta and IL-6 in gingival tissues are closely related to the severity of periodontal disease and that the IL-1 beta and IL-6 produced in gingival tissues may not reflect these two mediators levels in serum. Moreover, IL-1 beta responsiveness of HGF in IL-6 production depends on both the concentration of IL-1 beta and cells of individual subjects. Since HGF are present in periodontal lesion, it is possible that IL-6 secretion stimulated by exposure to inflammatory cell products such as IL-1 beta may participate in the destruction of periodontal tissue in periodontitis.

Adult↗

Tobacco smoking and chronic destructive periodontal disease.

Tobacco smoking is the main risk factor associated with chronic destructive periodontal disease. No other known factor can match the strength of smoking in causing harm to the periodontium. The harmful effects manifest themselves by interfering with vascular and immunologic reactions, as well as by undermining the supportive functions of the periodontal tissues. The typical characteristic of smoking-associated periodontal disease is the destruction of the supporting tissues of the teeth, with the ensuing clinical symptoms of bone loss, attachment loss, pocket formation, and eventually tooth loss. A review of the international literature that has accumulated over the past 20 years offers convincing evidence that smokers exhibit greater bone loss and attachment loss, as well as more pronounced frequencies of periodontal pockets, than non-smokers do. In addition, tooth loss is more extensive in smokers. Smoking, thus, considerably increases the risk for destructive periodontal disease. Depending on the definition of disease and the exposure to smoking, the risk is 5- to 20-fold elevated for a smoker compared to a never-smoker. For a smoker exposed to heavy long-life smoking, the risk of attracting destructive periodontal disease is equivalent to that of attracting lung cancer. The outcome of periodontal treatment is less favorable or even unfavorable in smokers. Although long-term studies are rare, available studies unanimously agree that treatment failures and relapse of disease are predominantly seen in smokers. This contention is valid irrespective of treatment modality, suggesting that smoking will interfere with an expected normal outcome following commonplace periodontal therapies. The majority of available studies agree that the subgingival microflora of smokers and non-smokers are no different given other conditions. As a consequence, the elevated morbidity in smokers does not depend on particular microflora. The mechanisms behind the destructive effects of smoking on the periodontal tissues, however, are not well understood. It has been speculated that interference with vascular and inflammatory phenomena may be one potential mechanism. Nicotine and carbon monoxide in tobacco smoke negatively influence wound healing. Smoking research over the past two decades has brought new knowledge into the domains of periodontology. Even more so, it has called into question the prevailing paradigm that the disease is primarily related to intraoral factors such as supra- and subgingival infection. Smoking research has revealed that environmental and lifestyle factors are involved in the onset and progression of the disease. Being the result of smoking, destructive periodontal disease shares a common feature with some 40 other diseases or disorders. As a consequence, periodontal disease should be regarded as a systemic disease in the same way as heart disease or lung disease. Thus, chronic destructive periodontal disease in smokers is initiated and driven by smoking. Its progression may or may not be amplified by unavoidable microbial colonization.

Alveolar Bone Loss↗

Calcitonin gene-related peptide in gingival crevicular fluid in periodontal health and disease.

The aims of the present study were to investigate whether calcitonin gene-related peptide (CGRP) was present in gingival crevicular fluid in both periodontal health and disease and to study the relationship with periodontal inflammation. Gingival crevicular fluid (GCF) was collected from a healthy, a gingivitis and a periodontitis site in 18 subjects with periodontitis and from a healthy site in 19 subjects without periodontitis. The volume of GCF was measured and each sample subsequently analysed for CGRP by radioimmunoassay. In subjects with periodontitis, CGRP immunoreactivity (CGRP-IR) was not detected in any periodontitis sites, nor in 67% of gingivitis and 28% of periodontally-healthy sites. The total amount of CGRP-IR was significantly elevated in periodontally healthy (p=0.0015) and gingivitis (p=0.027) compared with periodontitis sites. CGRP-IR was present in 89% of the healthy sites sampled in control subjects at comparable levels to those in healthy sites in periodontitis subjects. It is concluded that in periodontal inflammation, particularly in deep pockets, constituents of GCF process and degrade CGRP.

Adult↗

Bidirectional interrelationships between diabetes and periodontal diseases: an epidemiologic perspective.

This review evaluates evidence for a bidirectional relationship between diabetes and periodontal diseases. A comprehensive Medline search of the post-1960 English language literature was employed to identify primary research reports of relationships between diabetes and periodontal diseases. Reports included in the review on the adverse effects of diabetes on periodontal health (DM-->PD) were restricted to those comparing periodontal health in subjects with and without diabetes. Review of adverse affects of periodontal infection on glycemic control included reports of periodontal treatment studies and follow-up observational studies in which changes in glycemic control could be assessed. Observational studies reporting DM-->PD provided consistent evidence of greater prevalence, severity, extent, or progression of at least one manifestation of periodontal diseases in the large majority of reports (supportive evidence in 44/48 total reviewed; 37/41 cross-sectional and 7/7 cohort). Additionally, there were no studies reviewed with superior design features to refute this association. Treatment studies provided direct evidence to support periodontal infection having an adverse, yet modifiable, effect on glycemic control. However, not all investigations reported an improvement in glycemic control after periodontal treatment. Additional evidence to support the effect of severe periodontitis on increased risk for poorer glycemic control comes from 2 follow-up observational studies. The evidence reviewed supports viewing the relationship between diabetes and periodontal diseases as bidirectional. Further rigorous, systematic study is warranted to establish that treating periodontal infections can be influential in contributing to glycemic control management and possibly to the reduction of the burden of complications of diabetes mellitus.

Age Factors↗

Systemic release of endotoxins induced by gentle mastication: association with periodontitis severity.

BACKGROUND: Periodontitis has recently been identified as a potential risk factor for systemic pathologies such as cardiovascular disease, the hypothesis being that periodontal pockets could release pro-inflammatory bacterial components, for instance endotoxins, into the bloodstream. It is known that the oral cavity can be a source of circulating bacteria, but this has never been shown for bacterial endotoxins, and no evidence exists so far that the risk of systemic injury is related to the severity of periodontitis. The aim of the present study was to test the influence of gentle mastication on the occurrence of endotoxemia in patients with or without periodontal disease. METHODS: A total of 67 subjects were periodontally examined and grouped according to their periodontal status. This classification was based on an original index of severity of periodontal disease (periodontal index for risk of infectiousness, PIRI) aimed at reflecting the individual risk of systemic injury from the periodontal niches. Thus, the patients were classified into 3 risk groups: low, PIRI = 0; n = 25; moderate, 1 < or = PIRI < or = 5, n = 27; and high 6 < or = PIRI < or = 10, n = 15. Blood samples were collected before and 5 to 10 minutes after a standardized session of gentle mastication for detection of circulating endotoxins. Blood samples were tested with a chromogenic limulus amoebocyte lysate assay. RESULTS: Overall, blood levels of endotoxin after mastication were found to be significantly higher than before mastication (0.89 +/- 3.3 pg/ml versus 3.0 +/- 5.8 pg/ml; P= 0.0002). Likewise, the incidence of positive endotoxemia rose from 6% before mastication to 24% after mastication (P = 0.001). When accounting for the PIRI index, endotoxin levels and positive endotoxemia proved to be significantly higher in patients with severe periodontal disease than in the subjects with low or moderate periodontitis. CONCLUSIONS: Gentle mastication is able to induce the release of bacterial endotoxins from oral origin into the bloodstream, especially when patients have severe periodontal disease. This finding suggests that a diseased periodontium can be a major and underestimated source of chronic, or even permanent, release of bacterial pro-inflammatory components into the bloodstream.

Adult↗

The change of periodontal treatment needs in a population of Ljubljana, Slovenia, over a ten year period.

A follow-up study was performed to assess the change of periodontal treatment needs in the adult population of Ljubljana, Slovenia, over a ten year period. In the initial survey, conducted from 1983-1987, 1,609 dentate subjects in the range from 15-65 years of age were clinically examined. Ten years later of the 1,609 invited subjects a total 555 (34.5%) came to the oral re-examination. During the intervening period 3.1% of them had become edentulous. Periodontal treatment needs in both surveys were assessed by the Community Periodontal Index of Treatment Needs methodology. At the initial examination 2.4% of 1,609 subjects were found to be without any signs of periodontal disease, 97.6% needed oral hygiene instruction, 77.71% needed scaling and 20.3% of them needed complex periodontal treatment. Ten years later, of the 538 dentate subjects aged 25-75 years, only 0.7% of presented with healthy periodontal tissues, 99.3% needed oral hygiene instruction, 93.9% needed scaling and 27.3% needed periodontal surgery. In both surveys advanced periodontal disease in the Ljubljana population was limited to 6.0% and 8.3% of all sextants respectively. After evaluation of the population of the same age in both surveys (25-65-year-old groups) a slight decrease in subjects with healthy periodontal tissues (1.21% vs. 0.84%) was observed. In comparison, there was an increase of subjects with shallow pockets (24.8% vs. 31.1%) and a slight decrease of subjects with deep periodontal pockets (27.7% vs. 24.1%). Comparing the results we concluded that the prevalence and severity of periodontal disease in the Ljubljana population remained similar in both surveys. The findings of the present follow-up study suggest a need for more efficient primary and secondary preventive measures in order to decrease the prevalence and severity of periodontal disease in Ljubljana and Slovenia.

Adolescent↗

Pharmacologic management of periodontal diseases using systemically administered agents.

Since the establishment of bacteria-laden plaque as a causative agent in gingivitis, the search for specific bacteria that induce different types of periodontitis has generated extensive research. In contrast to many other microbial-induced disorders, the specific periodontal pathogen(s) has not been identified to date. Therefore, the search for an effective systemic agent to prevent the loss of attachment through the selective reduction of known periodontal pathogens has remained elusive. It is not surprising then that antibiotics are not used solely to manage periodontal diseases but rather as an adjunct to the mechanical débridement of root surfaces in select periodontal diseases. Further, the sole use of antibiotics in patients with adult periodontitis (or those who exhibit signs of inflammation but are periodontally stable) has shown little benefit and only increases the chance of microbial resistance to antibiotics. Despite these limitations, considerable progress in antibiotic therapy has delivered regimens that enhance the effectiveness of conventional therapy. In contrast to traditional antimicrobial therapy, new treatment modalities have begun to focus on modulating the responses of host cells to bacteria rather than modulating only the bacteria. Current drugs used to regulate host cells inhibit the cyclooxygenase pathway, reduce the activity of metalloproteinases, or inactivate bone resorptive cells (see Table 1). Although these drugs offer great potential to modulate a variety of mammalian cells, a notable and consequential limitation of these agents is a lack of specificity. Inflammation, bone metabolism, and connective tissue metabolism are two-edged swords; all are necessary for the homeostasis of the tissue, but some or all may also be involved in the pathologic destruction of that same tissue. Hence, drugs that inhibit destruction of the connective tissue in one site of the periodontium also interfere with wound healing at another. As a result of these limitations, the efficacy, safety, and cost-effectiveness of the long-term use of these agents is unknown. Preliminary results of treatment with these drugs are promising, and future generations of host-modulating drugs will provide clinicians with additional agents to help improve the success rate of periodontal treatment for patients. Antibiotics remain an important adjunctive therapy in the treatment of periodontal diseases, and the use of host modulating drugs as supplemental agents in the management of periodontal diseases continues to grow. As more knowledge is gained about the causes of periodontal diseases, new drugs that are potent, effective, site specific, and safe can be delivered at optimal times by simply having the patient take a few tablets. Considering the dramatic progress in the past decade in understanding the cause and pharmacologic management of periodontal diseases, the twenty-first century holds great promise for the development of magic bullets.

Adult↗

Immune response: the key to bone resorption in periodontal disease.

Periodontal disease infection with oral biofilm microorganisms initiates host immune response and signs of periodontitis, including bone resorption. This review delineates some mechanisms underlying the host immune response in periodontal infection and alveolar bone resorption. Activated T lymphocytes have been historically implicated in experimental periodontal bone resorption. An experimental rat adoptive transfer/gingival challenge periodontal disease model has been demonstrated to require antigen-specific T lymphocytes and gingival instillation of antigen and LPS for bone resorption. Interference with costimulatory interactions between T cells and antigen-presenting cells abrogated bone resorption, further emphasizing the significance of immune response in periodontal disease. Receptor activator of nuclear factor kappaB ligand (RANKL), a critical osteoclast differentiation factor, is expressed on T lymphocytes in human periodontal disease as determined by immunohistochemical and confocal microscopic analyses. Interference with RANKL by systemic administration of osteoprotegerin (OPG), the decoy receptor for (and inhibitor of) RANKL, resulted in abrogation of periodontal bone resorption in the rat model. This finding indicated that T cell-mediated bone resorption is RANKL-dependent. In additional experiments, treatment of T cell-transferred rats with kaliotoxin (a scorpion venom potassium channel inhibitor) resulted in decreases in T-cell RANKL expression, diminished induction of RANKL-dependent osteoclastogenesis, and abrogation of bone resorption, implicating an important role of immune response/RANKL expression in osteoclastogenesis/bone resorption. In other experiments, adoptive transfer of antigen-specific, RANKL-expressing B cells, and infection with the antigen-bearing Actinobaccillus actinomycetemcomitans gave rise to periodontal bone resorption, indicating that B cells also have the capacity to mediate bone resorption, probably via RANKL expression. In humans, prominent T lymphocytes have been identified in periodontal disease, and diseased tissues showed elevated RANKL mRNA expression, as well as decreased OPG mRNA expression. Mononuclear cells from periodontal lesions involving T cells and B cells of patients induced osteoclastogenesis in vitro. In summary, a biofilm interface initiates immune cell infiltration, stimulating osteoclastogenesis/bone resorption in periodontal disease. This resorption can be ameliorated by inhibition of RANKL activity or by diminishing immune cell stimulation. These two procedures, if localized, have the potential to lead to the prevention or therapeutic management of periodontal disease and therefore require further study.

Aggregatibacter actinomycetemcomitans↗

Oral Chlamydia trachomatis in patients with established periodontitis.

Periodontitis is considered a consequence of a pathogenic microbial infection at the periodontal site and host susceptibility factors. Periodontal research supports the association of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Bacteroides forsythus, and periodontitis; however, causality has not been demonstrated. In pursuit of the etiology of periodontitis, we hypothesized that the intracellular bacteria Chlamydia trachomatis may play a role. As a first step, a cross-sectional study of dental school clinic patients with established periodontitis were assessed for the presence of C. trachomatis in the oral cavity, and in particular from the lining epithelium of periodontal sites. C. trachomatis was detected using a direct fluorescent monoclonal antibody (DFA) in oral specimens from 7% (6/87) of the patients. Four patients tested positive in specimens from the lining epithelium of diseased periodontal sites, one patient tested positive in healthy periodontal sites, and one patient tested positive in the general mucosal specimen. In conclusion, this study provides preliminary evidence of C. trachomatis in the periodontal sites. Planned studies include the use of a more precise periodontal epithelial cell collection device, the newer nucleic acid amplification techniques to detect C. trachomatis, and additional populations to determine the association of C. trachomatis and periodontitis.

Adult↗

Actinobacillus actinomycetemcomitans serotype e--biotypes, genetic diversity and distribution in relation to periodontal status.

Actinobacillus actinomycetemcomitans isolates from 356 individuals were screened for identification of serotype e in order to investigate its distribution in relation to periodontal status. From subjects with serotype e, 1-6 isolates per subject (n = 61) were genotyped using arbitrarily primed-polymerase chain reaction (AP-PCR) and apaH gene polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) analysis to determine the genetic heterogeneity within the serotype. Furthermore, one serotype e strain per subject was tested for fermentation of 8 carbohydrates for biotyping. Among patients with adult periodontitis (n = 219), localized juvenile periodontitis (n = 55) and other forms of early-onset periodontitis (n = 18) serotypes b, a and c, respectively, were the most frequently detected serotypes. Non-periodontitis subjects (n = 64) were predominantly colonized with serotype c. Serotype e was found in 30 (14%) adult periodontitis patients, 2 (11%) early-onset periodontitis patients and in 5 (8%) non-periodontitis individuals, but in none of the 55 localized juvenile periodontitis patients. AP-PCR distinguished 3 and apaH gene PCR-RFLP analysis 2 genotypes among the 61 A. actinomycetemcomitans serotype e isolates, one genotype per subject. The AP-PCR genotypes 1 and 3 represented the apaH genotype 1 and the AP-PCR genotype 2 the apaH genotype 2. On the basis of variable fermentation of galactose and xylose, 3 biotypes among A. actinomycetemcomitans serotype e were established. Contrary to the absence of A. actinomycetemcomitans serotype e in localized juvenile periodontitis patients, its detection frequency was comparable among other forms of periodontitis and periodontal health. Clinical serotype e isolates form at least 2 genetic types and 3 biotypes.

Adolescent↗

Herpesviruses: a unifying causative factor in periodontitis?

Human cytomegalovirus and Epstein-Barr virus type 1 are discussed in this review as they relate to destructive periodontal disease in humans. Genomes of the two herpesviruses occur frequently in severe adult periodontitis, localized and generalized juvenile periodontitis, Papillon-Lefèvre syndrome periodontitis, Down's syndrome periodontitis, HIV-associated periodontitis and acute necrotizing ulcerative gingivitis. Herpesvirus infections generally involve a mild or asymptomatic primary phase followed by an asymptomatic latent phase interrupted sporadically by periods of activation, where viral replication and possibly clinical disease become manifest. Herpesvirus reactivation is triggered by a number of immunosuppressing factors, some of which have also been shown to be risk indicators of periodontal disease. Available evidence argues for the involvement of active cytomegalovirus infection in the initiation and progression of localized juvenile periodontitis and possibly other types of periodontal disease. In periodontal disease, herpesviruses may cause release of tissue-destructive cytokines, overgrowth of pathogenic periodontal bacteria, and initiation of cytotoxic or immunopathogenic events. Understanding the significance of herpesviruses in the causation and pathogenesis of destructive periodontal diseases may have important implications in future prevention and treatment of the diseases.

Adult↗

The presence of local and circulating autoreactive B cells in patients with advanced periodontitis.

AIM: The aim of the present investigation was to study the local (gingival) and systemic occurrence of autoreactive B cells (CD5+CD19 positive) in subjects with a high or low susceptibility to periodontitis. MATERIAL AND METHODS: 2 groups of subjects (Group A and B) susceptible to periodontitis were included. Group A consisted of 22 adult patients (7 females and 15 males, aged 24-66 years) with advanced and generalized chronic periodontitis and group B comprised 7 children (4 girls and 3 boys aged 9-13 years) with localized aggressive periodontitis. 26 periodontally healthy subjects, Group C (aged 23-80 years, mean 49.6+/-16.3), were also recruited. Assessment of clinical and radiographical characteristics of periodontal disease was performed. Gingival biopsies and peripheral blood samples were obtained and prepared for immunohistochemical analysis. Blood samples only were obtained from the periodontally healthy subjects (group C). RESULTS: The proportion of autoreactive B cells (CD5+CD19 positive) of peripheral blood lymphocytes was about 6 times higher in group A and 4 times higher in group B than in the samples from the control subjects (group C). About 40-50% of the B cells in the peripheral blood of the periodontitis susceptible individuals expressed markers for autoreactive features while less than 15% of the circulating B cells in the subjects of group C exhibited such markers. The periodontitis lesion in the adult periodontitis patients contained a substantial number of B cells out of which about 30% demonstrated autoreactive features. CONCLUSION: It is suggested that both circulating and local B cells in periodontitis susceptible individuals have a higher propensity to autoreactive properties than B cells of patients with a low susceptibility to periodontitis.

Adolescent↗