Association of dental and maxillary sinus pathologies with ear, nose, and throat symptoms.

OBJECTIVES: To investigate the correlation between cone-beam computerized tomography (CBCT) findings in the maxillary sinus, ear-nose-throat (ENT) symptoms and dental pathologies in asymptomatic patients. MATERIALS AND METHODS: A total 81 patients were referred for CBCT and filled a standard ENT visual analog scale (VAS) questionnaire. CBCT images were analyzed for sinus ostium obstruction, Schneiderian membrane thickening, sinus floor turbidity, and the presence of polyps. Dental pathologies were evaluated with the aid of CBCT images, periapical X-rays, and clinical examination. A possible correlation between the CBCT findings and the ENT/dental parameters was examined by applying Student's t test and the chi-squared test. RESULTS: Despite being asymptomatic, most of the 81 patients reported ENT symptoms in the questionnaire, thereby indicating that these symptoms were mainly subclinical. A significant correlation was found between the presence of polyps in the sinus and a decrease in smell/taste. Obstruction of the sinus meatus was associated with coughing; turbidity was associated with ear congestion. Thickening of the Schneiderian membrane showed an association with both coughing and ear congestion. The mean number of missing posterior teeth correlated with postnasal drip and nasal congestion. Periapical pathology was associated with nasal discharge/runny nose. CONCLUSION: The results emphasize the need to evaluate ENT symptoms when radiographic findings are identified in CBCT.

Vaccination with recombinant RgpA peptide protects against Porphyromonas gingivalis-induced bone loss.

OBJECTIVE: Following Porphyromonas gingivalis infection in mice, the efficacy of vaccination by recombinant and native RgpA in modulating the early local anti-inflammatory and immune responses and periodontal bone loss were examined. MATERIAL AND METHODS: Using the subcutaneous chamber model, exudates were analyzed for cytokines after treatment with native RgpA and adjuvant (test), or adjuvant and saline alone (controls). Mice were also immunized with recombinant RgpA after being orally infected with P. gingivalis. After 6 wk, serum was examined for anti-P. gingivalis IgG1 and IgG2a titers and for alveolar bone resorption. RESULTS: Immunization with native RgpA shifted the immune response toward an anti-inflammatory response as demonstrated by decreased proinflammatory cytokine IL-1ß production and greater anti-inflammatory cytokine IL-4 in chamber exudates. Systemically, immunization with recombinant RgpA peptide prevented alveolar bone loss by 50%, similar to immunization with heat-killed whole bacteria. Furthermore, recombinant RgpA shifted the humoral response toward high IgG1 and low IgG2a titers, representing an in vivo anti-inflammatory response. CONCLUSIONS: The present study demonstrates the potential of RgpA to shift the early local immune response toward an anti-inflammatory response while vaccination with recRgpA protected against P. gingivalis-induced periodontitis.

Implant dentistry in postgraduate university education. Present conditions, potential, limitations and future trends.

INTRODUCTION: In recent years, opportunities for postgraduate university education in implant dentistry have increased significantly, with an increase in both the number but also the complexity of available postgraduate programmes. However, there appears to be a lack of standards directing the learning outcomes of such programmes. METHODS: A scientific literature search was conducted for publications reporting on university programmes within implant dentistry, including description of programmes and evaluation of learning outcomes. A separate Internet search was conducted to collect information on existing university programmes as presented on university websites. RESULTS: Implant dentistry has reached a critical mass of an independent, multidisciplinary and vibrant domain of science, which combines knowledge and discovery from many clinical and basic sciences. Many university programmes conclude with a master's or equivalent degree, but there appears to be a great diversity with regard to duration and learning objectives, as well as targeted skills and competences. The importance of implant dentistry has also increased within established specialist training programmes. There was little indication, however, that the comprehensive aspects of implant dentistry are present in all specialist training programmes where implants are being covered. CONCLUSIONS: Although universities should maintain the options of designing academic programmes as they best see fit, it is imperative for them to introduce some form of transparent and comparable criteria, which will allow the profession and the public to relate the degree and academic credentials to the actual skills and competences of the degree holder. With regard to established specialist training programmes, the interdisciplinary and comprehensive nature of implant dentistry needs to be emphasised, covering both surgical and restorative aspects. Finally, implant dentistry is not, at present, a dental specialty. The profession has not reached a consensus as to whether the introduction of a new recognised specialist field is either necessary or desired.

The Prevalence of Gingival Dendritic Cell Subsets in Periodontal Patients.

As the most potent cells activating and polarizing naive T cells, dendritic cells (DCs) are of major importance in the induction of immunity and tolerance. DCs are a heterogeneous population of antigen-presenting cells that are widely distributed in lymphoid and nonlymphoid tissues. Murine studies have highlighted the important role of oral DCs and Langerhans cells (LCs) in orchestrating the physiological homeostasis of the oral mucosa. DCs are also critically involved in pathological conditions such as periodontal diseases, in which gingival DCs appear to have special localization and function. While the characterization of human DCs in health and disease has been extensively investigated in various tissues, this topic was rarely studied in human gingiva. Here, we employed an up-to-date approach to characterize by flow cytometry the gingival DCs of 27 healthy subjects and 21 periodontal patients. Four distinct subsets of mononuclear phagocytes were identified in healthy gingiva: conventional DC type 1 (cDC1), cDC2, plasmacytoid DCs (pDCs), and LCs. In periodontitis patients, the frequencies of gingival LCs and pDCs were dysregulated, as LCs decreased, whereas pDCs increased in the diseased gingiva. This shift in the prevalence of DCs was accompanied by increased expression of the proinflammatory cytokines interleukin (IL)-1ß, interferon (IFN)-α, and IFN-γ, while the anti-inflammatory cytokine IL-10 was suppressed. We further found that smoking, a known risk factor of periodontitis, specifically reduces gingival LCs in healthy individuals, indicating a possible role of LCs in the elevated severity of periodontitis in smokers. Collectively, this work reveals the various DC subsets residing in the human gingiva and the impact of periodontitis, as well as smoking, on the prevalence of each subset. Our findings provide a foundation toward understanding the role of human DCs in orchestrating physiological oral immunity and set the stage for the evaluation and modulation of shifts in immunity associated with periodontitis.

[The pathogenesis of periodontal disease: a paradigm shift].

Periodontitis is a family of related diseases that differ in etiology, natural history, disease progression and response to therapy, but have a common underlying chain of events, thatareinfluenced by disease modifiers. The clinical manifestations observed are a result of the complex interplay of these factors. The pathogenesis of human periodontitis was placed on a rational footing for the first time by Page & Schroeder in 1976 and the general principles and the overall conclusions reached in that article are still largely acceptable today. Still, an enormous amount has been learned about all aspects of human periodontitis, including its pathogenesis, since 1976. A critical evaluation of the literature regarding the complex relationship between the microbial factor, the host factor and the occurrence of a disease, might be leading us over a surge of a paradigm shift in our understanding the pathogenesis of the disease. It is well acknowledged that while the etiology of periodontitis is bacterial, the pathogenesis is inflammatory. The understanding of regulation of inflammation in periodontitis is far from complete; however, as the understanding of periodontal inflammation increases, the current understanding of the microbiology of periodontitis becomes less clear. While we think we know that bacteria initiate the disease, the role of specific bacteria is still unknown. The current knowledge of the microbiology of periodontitis is based on large cross-sectional and association studies. Periodontitis is seen as the direct consequence of bacterial invasion and is regarded as an infectious disease. It is however, not possible to draw cause and- effect inferences from these studies. One might state that the inflammation precedes the overgrowth of the bacteria. In this scenario, the initiator of the disease might be early, gram-positive colonizers that elicit a profound inflammatory response in the susceptible host. The implication of that paradigm shift outlined above is that periodontitis is an inflammatory disease, and in that case the primary target of pharmacotherapy should be the inflammation, rather than the bacteria. Still, the question to be asked and investigated is whether dampening of the inflammatory response in certain individuals susceptible to periodontitis might prevent development of disease. This is a question yet to be answered.

Niche Specific Microbiota-Dependent and Independent Bone Loss around Dental Implants and Teeth.

Oral mucosal homeostasis is achieved by complex immunologic mechanisms, orchestrating host immunity to adapt to the physiologic functions of the various specialized niches in the oral cavity. Dental implants introduce a novel mucosal niche to the immune system to deal with. Nevertheless, the immune mechanisms engaged toward implants and whether they have broader effects are not well defined. Using a murine model, we found an accumulation of neutrophils and RANKL-expressing T and B lymphocytes in the implant-surrounding mucosa, accompanied by local bone loss. Surprisingly, the presence of implants had an impact on remote periodontal sites, as elevated inflammation and accelerated bone loss were detected in intact distant teeth. This was due to microbial dysbiosis induced by the implants, since antibiotic treatment prevented bone loss around teeth. However, antibiotic treatment failed to prevent the loss of implant-supporting bone, highlighting the distinct mechanisms mediating bone loss at each site. Further analysis revealed that implants induced chronic lymphocyte activation and increased mRNA expression of IFN-α and accumulation of IFN-α-producing plasmacytoid dendritic cells, which we previously reported as bone-destructive immune responses. Collectively, this study demonstrates that implants have a strong and broad impact on oral mucosal homeostasis, inducing periodontal bone loss in a niche-specific manner that is both microbiota dependent and independent.

Periodontitis and Cardiovascular Diseases. Consensus Report.

Background: In Europe cardiovascular disease (CVD) is responsible for 3.9 million deaths (45% of deaths), being ischaemic heart disease, stroke, hypertension (leading to heart failure) the major cause of these CVD related deaths. Periodontitis is also a chronic non-communicable disease (NCD) with a high prevalence, being severe periodontitis, affecting 11.2% of the world's population, the sixth most common human disease. Material and Methods: There is now a significant body of evidence to support independent associations between severe periodontitis and several NCDs, in particular CVD. In 2012 a joint workshop was held between the European Federation of Periodontology (EFP) and the American Academy of Periodontology to review the literature relating periodontitis and systemic diseases, including CVD. In the last five years important new scientific information has emerged providing important emerging evidence to support these associations. Results and Conclusions: The present review reports the proceedings of the workshop jointly organised by the EFP and the World Heart Federation (WHF), which has updated the existing epidemiological evidence for significant associations between periodontitis and CVD, the mechanistic links and the impact of periodontal therapy on cardiovascular and surrogate outcomes. This review has also focused on the potential risk and complications of periodontal therapy in patients on anti thrombotic therapy and has made recommendations for dentists, physicians and for patients visiting both the dental and medical practices.

IL-10 gene transfer attenuates P. gingivalis-induced inflammation.

IL-10 is an anti-inflammatory cytokine secreted by stimulated Th2 lymphocytes that can down-regulate inflammatory responses to bacterial challenge. We hypothesized that local delivery of IL-10 using gene-transfer will down-regulate inflammatory responses. We examined the effect of IL-10 plasmid injection on the local cytokine response. Two weeks after the implantation of chambers, either IL-10 plasmid or vector was injected into the mice. Four days later, they were challenged with an intra-chamber injection of P. gingivalis. The intra-chamber levels of IL-10, IFNgamma, TNFalpha, and IL-1beta were evaluated after 2 and 24 hrs. The results showed that local IL-10 gene delivery elevated the levels of IL-10 at both time periods. It attenuated the levels of IFNgamma (656 +/- 154 to 218 +/- 144 pg/mL) and TNFalpha (23 +/- 2.0 to 12.5 +/- 2.9 ng/mL) at 2 hrs, and of IL-1beta (21.5 +/- 5.7 to 12.4 +/- 3.0 ng/mL) at 24 hrs. The results suggest the possibility of modulating the local inflammatory response to P. gingivalis by direct IL-10 gene transfer.

Cloning and characterization of human TNF alpha promoter region.

We report the sequence of a 1.2-kb human tumor necrosis factor alpha (TNF alpha) promoter region, which was cloned using PCR. The sequence has several variations from two previous reports and exhibits many potential DNA-binding sites specific to mammalian gene regulatory proteins inducible by lipopolysaccharides.

Rapid fluorometric quantification of monocyte attachment in tissue culture wells.

A simple fluorometric assay that permits rapid quantification of attachment of monocytes or macrophages in tissue culture wells is described. Using 4,6-diamidino-2-phenylindole (DAPI) as a specific fluorochrome marker for DNA, we observed a dose-dependent increase with strong linear correlation in fluorescent emission over a broad range of DNA concentrations. Measurements of the DNA content of the human monocytic cell line THP-1 demonstrated a linear correlation between fluorescence intensity and cell number from 5 x 10(4) to 1 x 10(6) cells, with an estimated average DNA content of 7.5 pg DNA per cell. While untreated THP-1 cells were not detectably adherent, PMA induction for 24 h results in 57-76% adherence to plastic surface. This method was found to be useful for measuring the number of peripheral blood monocytes separated from lymphocytes by attachment. 16 subjects were sampled and the standard deviation of each individual did not exceed 10%. The number of attached cells was between 10-16% of the total mononuclear cells. Fluorescence measurement of DNA with DAPI permits rapid and accurate determination of cell numbers and appears useful in the quantification of adherent populations such as myelocytic cells and cell lines.

HLA polymorphism in Moroccan Jewry.

The Moroccan Jewish community living in Israel shows a relatively large genetic distance from other North African Jewish communities. In this work the polymorphism of HLA class I and class II determinants, as defined by serology and oligotyping, is analyzed in 113 healthy unrelated Jews of Moroccan stock. The class I antigens HLA-A1, -B44, and -Cw7 showed the highest frequency, while the most prevalent class II variants were DRB1*0701 and *1104, DQA1*0501, and DQB1*0201 and *0301. HLA A1-B13-DR7, A2-B51-DR10, and A1-B44-DR13 were the most typical three-locus haplotypes. Although the antigen frequency distribution of the Moroccan Jews falls within the Caucasian diversity range, this community has a unique pattern in terms of antigen, gene, and haplotype frequencies. Thus, in the Moroccan Jews DRB1*1305, an allele believed to be the result of a recombination event between DRB1*1301-1302 and DRB1*1101, is represented to a much larger extent than in all the other population groups studied at the 11th IHWS. This allele may therefore be a typical Jewish variant. A particular finding was the high frequencies of HLA-B13, B52, and DR10, alleles common among some Oriental populations. The answer to this enigmatic phenomenon probably must be sought in the tortuous history of this community.

The interactions of human neutrophils with the constituents of an experimental dental biofilm.

Despite the antibacterial properties of neutrophils, their ability to prevent colonization of the dental biofilm by pathogenic bacteria is limited. The present study examined the ability of human neutrophils to attach to an experimental dental biofilm and tested their antibacterial functions following adhesion. Neutrophil adhesion was greatest to hydroxyapatite (HA) in the absence of biofilm. Among the biofilms, glucosyltransferase or fructosyltransferase adsorbed onto saliva-coated HA showed the highest adhesion of cells. The adhesion of neutrophils was directly related to their initial concentration in the solution and to the duration of incubation. Plasma was found to reduce neutrophil attachment significantly, while stimulation of the cells had no effect. Stimulation of attached neutrophils induced superoxide secretion with levels significantly lower than that secreted by suspended cells. The presence of neutrophils on the biofilm reduced the number and the viability of Streptococcus mutans attached to the beads. The present findings suggest that neutrophils are able to attach to dental biofilms and that the attached neutrophils retained their antibacterial activity.

Effect of amine and stannous fluoride on human neutrophil functions in vitro.

Amine fluoride (AmF)- and stannous fluoride (SnF2)-containing products were found to have a therapeutic effect on gingivitis and periodontitis. This effect was suggested to correlate with the antibacterial activity of the fluoride compounds. However, their effect on inflammatory cell function can also play a role in the therapeutic effect on gingival inflammation. The present study was designed to test the effects of AmF, SnF2, and an AmF/SnF2 combination on the function of human peripheral blood neutrophils, as compared with effects of chlorhexidine and salicylic acid. Neutrophils were isolated from human blood by ficoll centrifugation followed by dextran sedimentation. The neutrophils were pre-incubated with AmF, SnF2, or AmF/SnF2, followed by stimulation with fMLP. Cell vitality was verified by trypan-blue exclusion (> 95% vitality at all tested concentrations). Superoxide production was measured by cytochrome C reduction and the enzymatic activity of lysozyme and beta-glucoronidase by optical density measurement of substrate conversion. The results showed that AmF, SnF2, or AmF/SnF2 enhanced by two- to three-fold the superoxide release from fMLP-stimulated human neutrophils. Furthermore, the effective concentration of the AmF/SnF2 combination was several-fold lower than that of AmF or SnF2 alone (10 nM for AmF, 0.5 microM for SnF2, and 3 pM for SnF2/AmF). On the other hand, chlorhexidine and salicylic acid were found to reduce superoxide production by the cells. All the tested compounds had no effect on granular enzyme release by the stimulated neutrophils. The results suggest that AmF and SnF2 enhance the oxygen-dependent antibacterial activity of neutrophils. This effect may contribute to a more efficient elimination of bacteria from the periodontal environment, resulting in improvement in gingival health.

Interferon-gamma deficiency attenuates local P. gingivalis-induced inflammation.

Infection with the periodontal pathogen Porphyromonas gingivalis causes a strong local inflammatory reaction. Using IFNgamma-deficient mice, we tested the hypothesis that the absence of IFNgamma would result in a reduction of the local pro-inflammatory response to P. gingivalis. Cytokine secretion by macrophages from IFNgamma(-/-) animals was significantly attenuated. Addition of IFNgamma restored cytokine secretion. In vivo injection of P. gingivalis into subcutaneous chambers increased the intra-chamber leukocyte counts and TNFalpha and IL-1beta levels. This increase was significantly lower in the IFNgamma(-/-) mice. Local reconstitution of IFNgamma(-/-) mice at the site of inflammation with the IFNgamma gene increased the levels of TNFalpha and decreased the IL-10 levels. Anti-P. gingivalis IgG1 levels, a marker of Th2 response, were higher in immunized IFNgamma(-/-) than in IFNgamma(+/+) mice. The results suggest that lack of IFNgamma reduced the amplitude of the local pro-inflammatory response without decreasing the humoral protective response. The higher IgG1/IgG2a ratio observed supports the possibility of a Th2-dominant response in IFNgamma-deficient animals.

Lipopolysaccharide priming of superoxide release by human neutrophils: role of membrane CD14 and serum LPS binding protein.

Previous studies have suggested that lipopolysaccharide (LPS) interactions with neutrophils and monocytes are mediated via the CD14 receptor, in the presence of serum factors such as LPS-binding protein (LBP) and septin. The present study was designed to test if CD14-mediated LPS priming of human neutrophils is dependent upon the presence of serum proteins and to evaluate the contribution of serum factors in LPS-neutrophil interactions. The results demonstrate that CD14 mediates the priming of neutrophil superoxide release by LPS both in the presence and in the absence of serum. However, priming by LPS is greatly enhanced in the presence of human serum, and the factor responsible for this phenomenon is LBP and not heat-sensitive proteins, such as septin.

Neutrophil defects as risk factors for periodontal diseases.

There are several hypotheses proposed for the etiologic mechanisms causing periodontal diseases. These include a paradigm in which all individuals are equally susceptible to one or several pathogenic bacteria; a second paradigm that holds that all bacteria are equally virulent and that host susceptibility determines onset of disease; or a combination of the above. In this review, we analyze the role of neutrophil dysfunction as a risk factor for the onset of periodontitis. Both intrinsic or genetically inherited abnormalities of neutrophils and acquired neutrophil abnormalities are considered. While a large body of data implicates neutrophil dysfunction, either intrinsic or acquired (bacterially or extrinsically induced), as a significant risk factor for the periodontal diseases, clear, prospective, longitudinal epidemiologic studies to evaluate this association remain to be performed.

The role of the host response in periodontal disease progression: implications for future treatment strategies.

In this paper, we review the relevant aspects of host responses in periodontal diseases as we understand them today. Discussion will focus on neutrophil function, lymphocytes and the immune response, macrophage function, cytokines and complement, fibroblasts and growth factors, and regeneration. Recent literature and concepts will be presented with an emphasis on future directions and application to treatment regimens.

Priming effect of Porphyromonas gingivalis lipopolysaccharide on superoxide production by neutrophils from healthy and rapidly progressive periodontitis subjects.

Pre-incubation of neutrophils from rapidly progressive periodontitis (RPP) patients with lipopolysaccharide (LPS) extracted from Porphyromonas gingivalis was found to prime the neutrophils for enhanced FMLP-stimulated superoxide production in a dose-dependent manner. The priming effect of P. gingivalis LPS on neutrophils from control subjects was scanty or without effect at all. Inclusion of human serum in the experimental priming conditions increased the control and RPP neutrophil response by 2 to 3 fold. Blocking of the CD14 receptor on the neutrophil surface with monoclonal antibody eliminated the priming effect. Furthermore, incubation of control neutrophils with P. gingivalis LPS in the presence of serum from RPP patients generated a higher response as compared to incubation with control serum. The data suggest that neutrophil priming described in RPP patients is dependent on a serum factor which alters the neutrophil response to priming agents such as LPS.

HLA A9 and B15 are associated with the generalized form, but not the localized form, of early-onset periodontal diseases.

HLA proteins are genetically determined, and account in part for individual immune response. Several studies have been performed seeking an association between HLA antigens and various forms of periodontitis with no conclusive results. The aim of the present study was to determine the frequency of HLA antigens of patients suffering from the localized (LJP) and the generalized (SGP) forms of early-onset periodontitis (EOP). Twenty-six EOP patients from the same ethnic group were studied in comparison to 113 race-matched controls. The EOP group included 11 LJP and 15 SGP patients. HLA-A9 and B15 antigens were found to be significantly elevated in the patient group. These differences were found to be due to the high frequency of A9 and B15 antigens in the SGP patients, with the LJP patient group showing no significant difference from the control group. The results are in agreement with previous studies in which A9 and B15 were found to be associated with EOP. However, previous studies did not differentiate between the localized and the generalized form of EOP. These results support the hypothesis that the generalized and the localized forms of EOP are under different genetic control.

Experimental stress suppresses recruitment of macrophages but enhanced their P. gingivalis LPS-stimulated secretion of nitric oxide.

BACKGROUND: Epidemiological studies have suggested that stress can alter the onset and progression of periodontal disease. However, the mechanisms involved are not clear. The present study was designed to examine whether the functional response of mouse macrophages stimulated by Porphyromonas gingivalis lipopolysaccharide (LPS) is affected by experimental stress, and to investigate the role of corticosterone (CS) in the stress-related effects. METHODS: Two models of stress were used: emotional (isolation) and physical (cold). We measured thioglycollate-induced macrophage recruitment in vivo, and LPS-induced nitric oxide (NO) secretion by the macrophages in vitro. Two groups of mice were exposed to the stress conditions: isolation or cold. A third group was injected daily with CS, and a fourth group was used as a control (no stress). After 3 days of stress conditions, thioglycollate was injected into the peritoneal cavity. Four days later, peritoneal macrophages were isolated, counted, and cultured. The secretion of NO by the cultured cells was evaluated with and without P. gingivalis LPS stimulation. RESULTS: The number of cells in the peritoneal lavage of stressed mice was significantly reduced in comparison to macrophages isolated from non-stressed animals. The number of macrophages from CS-treated mice did not differ from controls. NO secretion from unstimulated macrophages did not differ between the stressed and control groups. Stimulation of the macrophages with P. gingivalis LPS significantly enhanced NO secretion by macrophages from the control and stressed animals, but not by the CS-treated group. NO levels secreted by P. gingivalis-stimulated cells from the two stressed groups were significantly higher than the levels secreted by controls, and the isolation group released significantly higher levels than the cold group. Stimulation of the macrophages with P. gingivalis LPS and interferon (IFN)-gamma resulted in enhanced NO secretion in the 4 groups compared to LPS alone, with no significant differences between the groups. CONCLUSIONS: The results suggest that experimental stress modulates the response of macrophages to inflammatory stimulants, and that CS is not the sole mediator involved. The presence of IFN-gamma in the culture may mask the functional differences induced by stress. The stress-induced upregulation of NO secretion might be involved in the accelerated periodontal destruction in stressed subjects.