Chemomechanical preparation influences the microbial community and the levels of LPS, LTA and cytokines in combined endodontic-periodontal lesions: A clinical study.

BACKGROUND: This study was conducted to compare the microbiomes, the levels of lipopolysaccharides (LPS), lipoteichoic acid (LTA), and cytokines (interleukin [IL]-1ß and tumor necrosis factor-alpha [TNF-α]), before and after chemomechanical preparation (CMP) of the root canals (RC) and their associated periodontal pockets (PP) in teeth with combined EPL. MATERIALS: Samples were taken from 10 RC and PP, before and after CMP. The microbiomes (next-generation sequencing, V3-V4 hypervariable region of the 16S rRNA gene), microbiome diversity (bioinformatics analyses), LPS (limulus amebocyte lysate), LTA, IL-1ß, and TNF-α (ELISA) were evaluated. A statistical analysis was performed with significance level set at 5%. RESULTS: The most abundant phyla in both sites were Firmicutes and Proteobacteria. Comparative studies of bacterial genera species revealed that some increased and others decreased after CMP at both sites. A 3% reduction in Gram-negative bacteria (RC) and a 4% increase in Gram-positive bacteria (PP) were detected. LPS levels were 4.4 times higher in PP than in the RC. LTA was detected in all samples investigated. Higher levels of IL-1ß and TNF-α were detected in both sites at baseline. After CMP, LPS, LTA, IL-1ß and TNF-α were reduced in both sites. CONCLUSION: The microbial community in the RC and PP in teeth with combined EPL indicated a similarity between both sites. CMP effectively reduced the microbial load and the LPS levels from teeth with EPL, and consequently diminished the cytokine levels. The reduction in LTA levels in the RC and PP proved challenging.

Neutrophils Orchestrate the Periodontal Pocket.

The subgingival biofilm attached to tooth surfaces triggers and maintains periodontitis. Previously, late-onset periodontitis has been considered a consequence of dysbiosis and a resultant polymicrobial disruption of host homeostasis. However, a multitude of studies did not show "healthy" oral microbiota pattern, but a high diversity depending on culture, diets, regional differences, age, social state etc. These findings relativise the aetiological role of the dysbiosis in periodontitis. Furthermore, many late-onset periodontitis traits cannot be explained by dysbiosis; e.g. age-relatedness, attenuation by anti-ageing therapy, neutrophil hyper-responsiveness, and microbiota shifting by dysregulated immunity, yet point to the crucial role of dysregulated immunity and neutrophils in particular. Furthermore, patients with neutropenia and neutrophil defects inevitably develop early-onset periodontitis. Intra-gingivally injecting lipopolysaccharide (LPS) alone causes an exaggerated neutrophil response sufficient to precipitate experimental periodontitis. Vice versa to the surplus of LPS, the increased neutrophil responsiveness characteristic for late-onset periodontitis can effectuate gingiva damage likewise. The exaggerated neutrophil extracellular trap (NET) response in late-onset periodontitis is blameable for damage of gingival barrier, its penetration by bacteria and pathogen-associated molecular patterns (PAMPs) as well as stimulation of Th17 cells, resulting in further neutrophil activation. This identifies the dysregulated immunity as the main contributor to periodontal disease.

Periodontal pocket and COVID-19: Could there be a possible link?

COVID-19 is the emerging health emergency ruining the well being of individuals and devastating the global economies. Sustained research focusing on the virus has been on throughout the world. However, no definitive remedies have yet been derived in the containment of the virus. Steady knowledge on the pathogenesis of the virus has revealed certain consistent features specific to the disease which includes massive destruction of the lung due to the presence of excessive angiotensin-converting enzyme receptors (ACE2) which are essential for the viral entry inside the host. Once, access is gained multiplication occurs resulting in suppressing the immune response of the body against the virus. Henceforth, the equilibrium of the host is disrupted leading to manifestation of the disease. The Periodontal pocket also presents with pathology very much similar to COVID-19 and a possibility of dual role can be thought of pertaining to aspects of Periodontal Medicine.

Characterization of the Treponema denticola Virulence Factor Dentilisin.

Treponema denticola is a potent periodontal pathogen that forms a red complex with Porphyromonas gingivalis and Tannerella forsythia. It has many virulence factors, yet there are only a few reports detailing these factors. Among them, dentilisin is a well-documented surface protease. Dentilisin is reported to be involved in nutrient uptake, bacterial coaggregation, complement activation, evasion of the host immune system, inhibition of the hemostasis system, and cell invasion as a result of its action, in addition to its original proteolysis function. Therefore, characterization of dentilisin, and clarifying the relationship between T. denticola and the onset of periodontal disease will be important to better understanding this disease. In this chapter, we explain the methods for analysis of dentilisin activity and pathogenicity.

Aberrant Periodontal and Systemic Immune Response of Overweight Rodents to Periodontal Infection.

This study aimed to explore periodontal and systemic immune response of overweight hosts to periodontitis. Forty C57 BL/6J male mice were divided into high (HF) or low fat (LF) diet groups and fed with the two diets, respectively, for 8 weeks. Each diet group was then divided into periodontitis (P) or control (C) groups (n = 10 per group) for 10-day ligation or sham-ligation. Overweight-related parameters including body weight were measured. Alveolar bone loss (ABL) was morphometrically analyzed and periodontal osteoclasts were stained. Periodontal immune response including leukocyte and macrophage number and inflammatory cytokines were analyzed by histology and quantitative PCR. Serum cytokine and lipid levels were quantified using electrochemiluminescence immunoassays, enzyme-linked immunosorbent assays, and biochemistry. It was found that HF group had 14.4% body weight gain compared with LF group (P < 0.01). ABL and periodontal osteoclast, leukocyte, and macrophage number were higher in P group than C group regardless of diet (P < 0.05). ABL and periodontal osteoclast number were not affected by diet regardless of ligation or sham-ligation. Leukocyte and macrophage number and protein level of tumor necrosis factor α (TNF-α) in periodontium and serum interleukin-6 level were downregulated by HF diet in periodontitis mice (P < 0.05). Periodontal protein level of TNF-α was highly correlated with serum interleukin-6 and low-density lipoprotein cholesterol levels (P < 0.01). These findings indicated that impaired immune response occurs both periodontally and systemically in preobesity overweight individuals. Given a well-reported exacerbating effect of obesity on periodontitis, overweight, if let uncontrolled, might place the individuals at potential risk for future periodontal tissue damage.

Periodontal Condition and Immunological Aspects of Individuals Hospitalized in the Intensive Care Unit.

There are few studies on the clinical and immunological periodontal status of intensive care unit (ICU) in-patients. The aim of the present study was to evaluate the periodontal condition among ICU in-patients through clinical and immunological periodontal parameters. From the sample of 373 hospitalized ICU patients, 182 were submitted' to a thorough clinical periodontal and immunological evaluation. Data on bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) were collected and gingival sulcular fluid samples were quantified through ELISA on IL-1, IL-6, and MMP-2 for immunological evaluation. Data was statistically analyzed by Chi-square, Fisher's exact, Mann-Whitney tests, and Sperman's correlation and multivariate logistic regression analysis. A high dental plaque index and a high prevalence of periodontitis (48.3%), mostly in moderate and localized chronic form, were observed. Individuals with periodontitis presented higher levels of IL-1 and MMP-2, while individuals with cardiovascular disease (CVD) and individuals with two or more systemic diseases (MSD) presented higher levels of IL-1; diabetes mellitus (DM) and MSD individuals presented higher levels of IL-6. A positive association was found between the severity of periodontitis and CVD (OR 2.2; CI = 1.11-4.42). This study reported a 48.3% of the prevalence of periodontitis in ICU patients and a positive association between the severity of periodontitis and CVD. Additionally, higher levels of IL-1 and MMP-2 were found in individuals with periodontitis, higher levels of IL-6 were found in individuals with DM, and higher levels of IL-1 were found in individuals with CVD.

Periodontal condition and immunological aspects of individuals hospitalized in the intensive care unit

Abstract There are few studies on the clinical and immunological periodontal status of intensive care unit (ICU) in-patients. The aim of the present study was to evaluate the periodontal condition among ICU in-patients through clinical and immunological periodontal parameters. From the sample of 373 hospitalized ICU patients, 182 were submitted' to a thorough clinical periodontal and immunological evaluation. Data on bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) were collected and gingival sulcular fluid samples were quantified through ELISA on IL-1, IL-6, and MMP-2 for immunological evaluation. Data was statistically analyzed by Chi-square, Fisher's exact, Mann-Whitney tests, and Sperman's correlation and multivariate logistic regression analysis. A high dental plaque index and a high prevalence of periodontitis (48.3%), mostly in moderate and localized chronic form, were observed. Individuals with periodontitis presented higher levels of IL-1 and MMP-2, while individuals with cardiovascular disease (CVD) and individuals with two or more systemic diseases (MSD) presented higher levels of IL-1; diabetes mellitus (DM) and MSD individuals presented higher levels of IL-6. A positive association was found between the severity of periodontitis and CVD (OR 2.2; CI = 1.11-4.42). This study reported a 48.3% of the prevalence of periodontitis in ICU patients and a positive association between the severity of periodontitis and CVD. Additionally, higher levels of IL-1 and MMP-2 were found in individuals with periodontitis, higher levels of IL-6 were found in individuals with DM, and higher levels of IL-1 were found in individuals with CVD.

Resumo Existem poucos estudos sobre o estado clínico periodontal e imunológico de pacientes em unidade de terapia intensiva (UTI). O objetivo do presente estudo foi avaliar a condição periodontal entre os pacientes internados na UTI através de parâmetros clínicos periodontais e imunológicos. De uma amostra inicial de 373 pacientes internados em UTI, 183 foram submetidos a exame periodontal completo e análise imunológica. Os dados sobre o sangramento na sondagem (BOP), profundidade de sondagem (PD) e nível clínico de inserção (CAL) foram coletados e as amostras de fluido sulcular gengival foram quantificadas para avaliação imunológica através de ELISA para IL-1, IL-6 e MMP-2. Os dados foram analisados estatisticamente pelos testes de Qui-quadrado, exato de Fischer, Mann-Whitney, correlação de Sperman e análise de regressão logística multivariada. Foi observado um alto índice de placa dental e uma alta prevalência de periodontite (48,3%), principalmente na forma crônica moderada e localizada. Os indivíduos com periodontite apresentaram níveis mais altos de IL-1 e MMP-2, enquanto indivíduos com doença cardiovascular (CVD) e com mais de duas doenças sistêmicas (MSD) apresentaram níveis mais altos de IL-1 e os com diabetes mellitus (DM) e MSD apresentaram níveis mais elevados de IL-6. Foi encontrada associação positiva entre a gravidade da periodontite e CVD (OR 2.2; IC = 1,11-4,42). Este estudo reportou uma prevalência de periodontite em 48.3% dos pacientes em UTI e uma associação positiva entre ocorrência de periodontite e CVD. Além disso, níveis mais elevados de IL-1 e MMP-2 foram encontrados em indivíduos com periodontite, de IL-6 em indivíduos com DM e de IL-1 em indivíduos com CVD.

Bacterial modulators of bone remodeling in the periodontal pocket.

The signaling network involved in the pathogenesis of periodontal disease is not yet fully understood. This review aims to describe possible mechanisms through which the bacterial modulators may be linked directly or indirectly to the process of alveolar bone loss in periodontitis. From the late 1970s to present, new paradigm shifts have been developed regarding our understanding of pathological bone remodeling in periodontal disease. Upcoming evidence suggests that in periodontal disease the local immune response is exacerbated and involves the existence of signaling pathways that have been shown to modulate bone-cell function leading to alveolar bone loss. Those complex signaling pathways have been observed not only between bacteria but also between bacteria and the gingival surface of the host. More specifically, it has been shown that bacteria, through their secretion molecules, may interact indirectly and directly with immune-type cells of the host, resulting in the production of osteolytic agents that enhance bone resorption. Further research is required to provide a clear understanding of the role of these molecules in the pathogenesis of periodontal disease, and the availability of new technologies, such as next-generation sequencing and metagenomic analysis, may be useful tools in achieving this.

The periodontal pocket: pathogenesis, histopathology and consequences.

The conversion of junctional epithelium to pocket epithelium is regarded as a hallmark in the development of periodontitis. Knowledge of factors contributing to the initiation and progression of pocket formation is important and may result in the development of better preventive measures and improve healing outcomes after therapeutic interventions. The periodontal pocket is a pathologically deepened gingival sulcus. In healthy periodontal conditions, the defense mechanisms are generally sufficient to control the constant microbiological challenge through a normally functioning junctional epithelium and the concentrated powerful mass of inflammatory and immune cells and macromolecules transmigrating through this epithelium. In contrast, destruction of the structural integrity of the junctional epithelium, which includes disruption of cell-to-cell contacts and detachment from the tooth surface, consequently leading to pocket formation, disequilibrates this delicate defense system. Deepening of the pocket apically, and also horizontal expansion of the biofilm on the tooth root, puts this system to a grueling test. There is no more this powerful concentration of defense cells and macromolecules that are discharged at the sulcus bottom and that face a relatively small biofilm surface in the gingival sulcus. In a pocket situation, the defense cells and the macromolecules are directly discharged into the periodontal pocket and the majority of epithelial cells directly face the biofilm. The thinning of the epithelium and its ulceration increase the chance for invasion of microorganisms and their products into the soft connective tissue and this aggravates the situation. Depending on the severity and duration of disease, a vicious circle may develop in the pocket environment, which is difficult or impossible to break without therapeutic intervention.

Increased levels of the T-helper 22-associated cytokine (interleukin-22) and transcription factor (aryl hydrocarbon receptor) in patients with periodontitis are associated with osteoclast resorptive activity and severity of the disease.

BACKGROUND AND OBJECTIVE: Two new T-helper (Th) phenotypes have been recently described and named Th9 and Th22 lymphocytes; however, their role in the pathogenesis of periodontitis remains unclear. This study was aimed to assess whether Th9 and Th22 lymphocytes, through interleukin (IL)-9 and IL-22 production, respectively, are associated with the severity of periodontitis and bone resorption. MATERIAL AND METHODS: Gingival crevicular fluid samples and biopsies were obtained from patients with moderate-to-advanced chronic periodontitis and gingivitis, and healthy controls. The levels for the Th9 and Th22-associated cytokines and master-switch transcription factors Spi-B and aryl hydrocarbon receptor (AhR) were quantified by enzyme-linked immunosorbent assay, real-time reverse-transcription quantitative polymerase chain reaction and flow cytometry. In addition, the osteoclast activity in response to tissue homogenates from periodontitis and healthy samples was analyzed quantifying the number of TRAP-positive cells and areas of bone resorption pits produced, in the presence or absence of recombinant human IL-22 and anti-IL-22 neutralization antibody. RESULTS: Higher levels of IL-22 and AhR were detected in patients with periodontitis compared with gingivitis and healthy individuals. In addition, higher levels of IL-9 and Spi-B were detected in gingivitis patients compared with periodontitis and healthy individuals. In patients with periodontitis, a significant positive correlation was detected between secreted levels of IL-22 and clinical attachment level of the sampled periodontal pockets. When osteoclasts were exposed to tissue homogenates obtained from patients with periodontitis, higher levels of resorptive activity were observed as compared with the same cells exposed to tissue homogenates obtained from healthy individuals, and this increment was dependent on the presence and neutralization of IL-22. CONCLUSION: Increased levels of IL-22 produced by Th22 lymphocytes are associated with the pathogenesis of periodontitis, in particular, with osteoclast resorptive activity and severity of disease.

Inverse Association of Plasma IgG Antibody to Aggregatibacter actinomycetemcomitans and High C-Reactive Protein Levels in Patients with Metabolic Syndrome and Periodontitis.

The association between clinically diagnosed periodontitis, a common chronic oral infection, and metabolic syndrome has been previously reported. The aim of this study was to investigate the association of plasma IgG levels against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia, C-reactive protein, and periodontal status with metabolic syndrome. Plasma IgG levels and C-reactive protein were measured by enzyme-linked immunosorbent assay, and salivary levels of A. actinomycetemcomitans and P. gingivalis were determined by quantitative real-time polymerase chain reaction. Among 127 individuals aged 35-76 years, 57 participants had metabolic syndrome and severe periodontitis, 25 had metabolic syndrome and an absence of severe periodontitis, 17 healthy individuals had severe periodontitis, and 28 healthy individuals were without severe periodontitis. Patients with metabolic syndrome had reduced humoral immune response to A. actinomycetemcomitans (p = 0.008), regardless of their salivary levels or periodontitis status compared with healthy participants. The IgG antibody response to P. gingivalis, regardless of their salivary levels or participants' health condition, was significantly higher in severe periodontitis patients (p<0.001). Plasma IgG titers for P. intermedia were inconsistent among metabolic syndrome or periodontal participants. Our results indicate that the presence of lower levels of IgG antibodies to A. actinomycetemcomitans (OR = 0.1; 95%CI 0.0-0.7), but not P. gingivalis, a severe periodontitis status (OR = 7.8; 95%CI 1.1-57.0), high C-reactive protein levels (OR = 9.4; 95%CI 1.0-88.2) and body mass index (OR = 3.0; 95%CI 1.7-5.2), are associated with the presence of metabolic syndrome. The role of the decreased IgG antibody response to A. actinomycetemcomitans, increased C-reactive protein levels on the association between periodontal disease and metabolic syndrome in a group of Thai patients is suggested.

Impact of heavy smoking on the clinical, microbiological and immunological parameters of patients with dental implants: a prospective cross-sectional study.

AIM: The aim of the present study was to investigate how heavy smoking influences the clinical, microbiological, and host-response characteristics in peri-implant sulcus fluid of patients with healthy dental implants. METHODS: A total of 29 individuals with 74 dental implants were included in the present study; 20 implants were in heavy smokers and 54 were in non-smokers. The modified gingival index, modified plaque index, and probing pocket depth were evaluated. Periodontopathogenic bacteria Tannerella forsythia, Treponema denticola, and Porphyromonas gingivalis were evaluated, together with the total bacterial load. Peri-implant sulcus fluid samples were analyzed for the quantification of interleukin-8, interleukin-1ß, interleukin-6, interleukin-10, and tumor necrosis factor-α. RESULTS: No significant differences in the clinical parameters evaluated were found between the groups, although smokers had poorer peri-implant parameters. Among the smokers, subgingival microbiota was composed of a greater number of periodontal pathogens; these differences were not statistically significant. Smokers showed a greater expression of interleukin-1ß, interleukin-6, interleukin-10, and tumor necrosis factor-α, but interleukin-8 was slightly higher among non-smokers, but not significantly. CONCLUSIONS: Although smokers presented deeper probing depths, bleeding on probing, and peri-implant microbiota composed of a greater number of periodontal pathogens than in non-smoking patients, these data did not show significant differences. In the present study, and in relation to the samples analyzed, smoking alone did not influence the immunological and microbiological parameters in dental implants with healthy peri-implant tissues. Further studies with larger samples are required to better evaluate the influence of smoking on dental implants.

Cytokine expression in peri-implant crevicular fluid in relation to bacterial presence.

AIM: The aim was to assess clinical inflammatory parameters, cytokine levels and bacterial counts in samples from implant crevicular fluid in cases with untreated peri-implantitis. MATERIAL AND METHODS: Several bacterial species known to up-regulate pro-inflammatory cytokines have been associated with peri-implantitis. The Luminex magnet bead technology was used to study cytokines in crevicular fluid. The checkerboard DNA-DNA hybridization method was used to study bacterial counts in samples from 41 implants (41 individuals). RESULTS: Profuse bleeding and suppuration was found in 25/41 (61.0%) of the implants. The reliability of duplicate cytokine processing was high. In the presence of profuse bleeding, higher pg/ml levels of IL-1ß (p = 0.02), IL-8 (p = 0.04), TNF-α (p = 0.03) and VEGF (p = 0.004) were found. Higher concentrations of IL-1ß were found in the presence of suppuration, and if Escherichia coli (p = 0.001) or Staphylococcus epidermidis (p = 0.05) could be detected. CONCLUSION: Profuse bleeding and/or suppuration in untreated peri-implantitis can be associated with higher concentrations of IL-1ß, IL-8, TNF-α and VEGF in peri-implant crevicular fluid. A higher concentration of IL-1ß in peri-implant crevicular fluid was found in samples that were positive for E. coli or S. epidermidis.

Clinical, microbiological, and immunological aspects of healthy versus peri-implantitis tissue in full arch reconstruction patients: a prospective cross-sectional study.

BACKGROUND: Due to the world-wide increase in treatments involving implant placement, the incidence of peri-implant disease is increasing. Late implant failure is the result of the inability to maintain osseointegration, whose most important cause is peri-implantitis. The aim of this study was to analyze the clinical, microbiological, and immunological aspects in the peri-implant sulcus fluid (PISF) of patients with healthy dental implants and patients with peri-implantitis. METHODS: PISF samples were obtained from 24 peri-implantitis sites and 54 healthy peri-implant sites in this prospective cross-sectional study. The clinical parameters recorded were: modified gingival index (mGI), modified plaque index (mPI) and probing pocket depth (PPD). The periodontopathogenic bacteria Tannerella forsythia, Treponema denticola and Porphyromonas gingivalis were evaluated, together with the total bacterial load (TBL). PISF samples were analyzed for the quantification of Interleukin (IL)-8, IL-1ß, IL-6, IL-10 and Tumor Necrosis Factor (TNF)-α using flow cytometry (FACS). RESULTS: The mGI and PPD scores in the peri-implantitis group were significantly higher than the healthy group (p < 0.001). A total of 61.5% of the patients with peri-implantitis had both arches rehabilitated, compared with 22.7% of patients with healthy peri-implant tissues; there was no implant with peri-implantitis in cases that received mandibular treatment exclusively (p < 0.05). Concentrations of Porphyromonas gingivalis (p < 0.01), association with bacteria Porphyromonas gingivalis and Treponema denticola (p < 0.05), as well as the TBL (p < 0.05) are significantly higher in the peri-implantitis group. IL-1ß (p < 0.01), IL-6 (p < 0.01), IL-10 (p < 0.05) and TNF-α (p < 0.01) are significantly higher at the sites with peri-implantitis compared to healthy peri-implant tissue, while IL-8 did not increase significantly. CONCLUSION: The results of the present study involving a limited patient sample suggest that the peri-implant microbiota and which dental arch was rehabilitated involved could contribute to bone loss in peri-implantitis. A significant relationship is observed between the concentration of cytokines (interleukins 1ß, 6 and 10 and TNF-α) and the inflammatory response in peri-implantitis tissue.

Periodontal Status and Whole Salivary Cytokine Profile Among Smokers and Never-Smokers With and Without Prediabetes.

BACKGROUND: Whole salivary interleukin (IL)-1ß and IL-6 in smokers and never-smokers with prediabetes remains uninvestigated. The aim of this study is to assess the periodontal status and whole salivary IL-1ß and IL-6 levels among smokers and never-smokers with and without prediabetes (controls). METHODS: Ninety-five males (45 with prediabetes and 50 systemically healthy controls) were included. Twenty-seven controls and 29 patients with prediabetes were smokers. Periodontal parameters (plaque index, bleeding on probing, probing depth, clinical attachment loss, and marginal bone loss) were measured, and the number of missing teeth were recorded. Fasting blood glucose (FBG) and hemoglobin A1c (HbA1c) levels were recorded. Unstimulated whole saliva samples were collected, unstimulated whole salivary flow rate (UWSFR) was determined, and IL-1ß and IL-6 levels were measured. P values <0.05 were considered statistically significant. RESULTS: FBG (P <0.05) and HbA1c (P <0.05) levels were higher among patients with prediabetes than controls. All patients with prediabetes were hyperglycemic. UWSFR was significantly higher among controls than among patients with prediabetes (P <0.05). Periodontal parameters and whole salivary IL-1ß and IL-6 levels were comparable among smokers and never-smokers with prediabetes. Among controls, periodontal parameters and whole salivary IL-1ß and IL-6 levels were higher among smokers than never-smokers (P <0.05). CONCLUSIONS: Among controls, periodontal inflammation was worse, and whole salivary IL-1ß and IL-6 levels are higher in smokers than never-smokers. Among patients with prediabetes, periodontal inflammation and whole salivary IL-1ß and IL-6 levels were comparable between smokers and never-smokers.

The complement system and its role in the pathogenesis of periodontitis: current concepts.

Periodontitis is a highly prevalent inflammatory disease in tooth supporting tissues, induced by bacteria growing in a biofilm on tooth surfaces. Components of the complement system are present in the periodontal tissue and the system is activated in periodontitis. Continuous complement activation and modulation by bacteria within the biofilm in periodontal pockets, however, may enhance local tissue destruction, providing the biofilm with both essential nutrients and space to grow. A more profound understanding of the mechanisms involved in complement-derived tissue degradation may facilitate the development of new treatment concepts for periodontitis. Further studies on the role of complement in periodontitis pathogenesis may also contribute to the understanding of why some individuals fail to resolve periodontitis. Here, we review evidence that links complement to the pathogenesis of periodontitis with an emphasis on interaction of complement with bacteria from periodontitis-associated biofilm.

Quantifying oral inflammatory load: oral neutrophil counts in periodontal health and disease.

BACKGROUND AND OBJECTIVE: Neutrophils are the primary white blood cells that are recruited to fight the initial phases of microbial infections. While healthy norms have been determined for circulating blood neutrophil counts in order to identify patients with suspected systemic infections, the levels of oral neutrophils (oPMNs) in oral health and in the presence of periodontal diseases have not been described. It is important to address this deficiency in our knowledge as neutrophils are the primary immune cell present in the crevicular fluid and oral environment and previous work has suggested that they may be good indicators of overall oral inflammation and periodontal disease severity. The objective of this study was to measure oPMN counts obtained in a standardized oral rinse from healthy patients and from those with chronic periodontal disease in order to determine if oPMN levels have clinical relevance as markers of periodontal inflammation. A parallel goal of this investigation was to introduce the concept of 'oral inflammatory load', which constitutes the inflammatory burden experienced by the body as a consequence of oral inflammatory disease. MATERIAL AND METHODS: Periodontal examinations of patients with a healthy periodontium and chronic periodontal disease were performed (n = 124). Two standardized consecutive saline rinses of 30 s each were collected before patient examination and instrumentation. Neutrophils were quantified in the rinse samples and correlated with the clinical parameters and periodontal diagnosis. RESULTS: Average oPMN counts were determined for healthy patients and for those with mild, moderate and severe chronic periodontal diseases. A statistically significant correlation was found between oPMN counts and deep periodontal probing, sites with bleeding on probing and overall severity of periodontal disease. CONCLUSIONS: oPMN counts obtained through a 30-s oral rinse are a good marker of oral inflammatory load and correlate with measures of periodontal disease severity.

The actin-bundling protein L-plastin: a novel local inflammatory marker associated with periodontitis.

BACKGROUND AND OBJECTIVE: L-plastin, an actin-bundling protein, is exclusively expressed in leukocytes and plays a crucial role in immune-mediated events. Periodontitis is a common infectious inflammatory disease that destroys the tooth-supporting tissues. Recent findings using proteomic technologies have demonstrated that L-plastin is one of the few molecules consistently present in the inflammatory exudate of the gingiva in periodontal disease, but not in health. Therefore, this study aimed to investigate in detail the local and systemic role of this molecule in different forms of periodontitis. MATERIAL AND METHODS: A total of 61 subjects who met the inclusion/exclusion criteria were recruited, including 21 with chronic periodontitis, 20 generalized aggressive periodontitis and 20 nonperiodontitis control subjects. Gingival tissue biopsies, gingival crevicular fluid, as well as serum and saliva, were obtained. Immunohistochemistry and quantitative real-time PCR were employed to evaluate the localization and mRNA expression, respectively, of L-plastin. L-plastin levels in gingival crevicular fluid, saliva and serum were measured using ELISA. Statistical analysis was performed using nonparametric methods. RESULTS: Subjects with chronic periodontitis and generalized aggressive periodontitis exhibited significantly higher tissue L-plastin gene expression and gingival crevicular fluid levels than did subjects in the control group but there was no significant difference between the two forms of periodontitis. Within gingival tissue, L-plastin was confined to the inflammatory infiltrate. There was no statistically significant difference between serum and salivary L-plastin levels among the three study groups. CONCLUSION: The elevated gingival tissue expression and gingival crevicular fluid levels of L-plastin in both forms of periodontitis may denote the localized involvement of this novel molecule in the pathogenesis of the disease.

Periodontopathogens and human ß-defensin-2 expression in gingival crevicular fluid from patients with periodontal disease in Guangxi, China.

BACKGROUND AND OBJECTIVE: Periodontal diseases are often induced by periodontopathogens, which are always exposed to certain innate immune factors in gingival crevicular fluid, including human ß-defensin-2 (hBD-2). This study aims to investigate the relationship among periodontopathogens, clinical parameters and hBD-2 expression. MATERIAL AND METHODS: Thirty-two healthy controls, 42 patients with chronic gingivitis and 95 patients with chronic periodontitis were recruited in Guangxi, China. Bleeding index, probing depth and clinical attachment level were measured for all teeth including mesiobuccal, buccal, disobuccal, mesiolingual, lingual, disolingual six sites of all patient. Gingival crevicular fluid samples were collected from the study sites. The prevalence and copy numbers (CN) of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, Tannerella forsythia and total bacteria in gingival crevicular fluid were quantified by real-time PCR. The hBD-2 concentration in gingival crevicular fluid was measured by ELISA. RESULTS: Both the prevalence and the CN of A. actinomycetemcomitans, P. gingivalis, T. denticola and T. forsythia were higher in patients with chronic periodontitis than in healthy controls and patients with chronic gingivitis; however, there was no significant difference in the prevalence of P. intermedia among the three study groups, and the highest CN was found in patients with chronic gingivitis, rather than in patients with chronic periodontitis. The loads of P. gingivalis, P. intermedia, T. denticola and total bacteria were positively related to probing depth, bleeding index and clinical attachment level. The concentration of hBD-2 in gingival crevicular fluid was higher in patients with chronic gingivitis and in patients with chronic periodontitis than in healthy controls. In addition, the hBD-2 concentration was positively related to the CN of P. gingivalis, T. forsythia and total bacteria, as well as to bleeding index and probing depth. CONCLUSION: The prevalence, composition and CN of periodontopathogens were closely related to the severity of periodontal disease, and the red complex was related to the severity of clinical symptoms of periodontal diseases. The concentration of hBD-2 in gingival crevicular fluid from periodontal disease sites was higher than that in gingival crevicular fluid from healthy sites, which suggests that hBD-2 expression might be up-regulated by periodontopathogens.

Evaluation of biochemical parameters and local and systemic levels of osteoactive and B-cell stimulatory factors in gestational diabetes in the presence or absence of gingivitis.

BACKGROUND: Gestational diabetes mellitus (GDM) is defined as varying glucose intolerance, with first onset or recognition in pregnancy. This study evaluates clinical and biochemical parameters in a possible association between GDM and gingivitis. METHODS: A total of 167 pregnant females was included in the study. There were 101 females with GDM and 66 females without GDM. Subgroups were created according to the presence or absence of gingival inflammation. Plaque index, bleeding on probing, and probing depth were recorded at four sites per tooth. Serum, saliva, and gingival crevicular fluid (GCF) levels of interleukin (IL)-6, IL-8, soluble receptor activator of nuclear factor-kappa B ligand (sRANKL), osteoprotegerin (OPG), B-cell activating factor (BAFF), and a proliferation-inducing ligand (APRIL) were determined by enzyme-linked immunosorbent assay. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests and Spearman correlation analysis. RESULTS: Age and anthropometric indices were higher in the GDM than non-GDM group (P <0.0001). Clinical periodontal recordings, serum BAFF, IL-8, and saliva sRANKL levels were higher in the GDM group (P <0.05). Saliva IL-6 level was higher in the GDM with gingivitis group than non-GDM with gingivitis group (P = 0.044). Serum and GCF BAFF (P <0.0001), serum, saliva, and GCF APRIL (P <0.0001; P <0.0001; P = 0.032, respectively), GCF OPG (P = 0.036), and serum and saliva sRANKL (P <0.0001) were higher in the GDM with gingivitis group than GDM without gingivitis group. CONCLUSIONS: The inflammatory response seems to be more pronounced in females with GDM. The observed increase in both local and systemic levels of inflammatory cytokines may suggest an interaction between gingivitis and GDM.