Summary
Periodontitis is a chronic inflammatory disease of the periodontium, which is caused by pathogenic bacteria in combination with other risk factors. The bacteria induce an immunoinflammatory ...host response, which can lead to irreversible matrix degradation and bone resorption. Periodontitis can be successfully treated. To achieve regenerative periodontal healing, bioactive molecules, such as enamel matrix derivative (EMD), are applied during periodontal surgery. Recently, it has been shown that obesity is associated with periodontitis and compromised healing after periodontal therapy. The mechanisms underlying these associations are not well understood so far, but adipokines may be a pathomechanistic link. Adipokines are bioactive molecules that are secreted by the adipose tissue, and that regulate insulin sensitivity and energy expenditure, but also inflammatory and healing processes. It has also been demonstrated that visfatin and leptin increase the synthesis of proinflammatory and proteolytic molecules, whereas adiponectin downregulates the production of such mediators in periodontal cells. In addition, visfatin and leptin counteract the beneficial effects of EMD, whereas adiponectin enhances the actions of EMD on periodontal cells. Since visfatin and leptin levels are increased and adiponectin levels are reduced in obesity, these adipokines could be a pathomechanistic link whereby obesity and obesity‐related diseases enhance the risk for periodontitis and compromised periodontal healing. Recent studies have also revealed that adipokines, such as visfatin, leptin and adiponectin, are produced in periodontal cells and regulated by periodontopathogenic bacteria. Therefore, adipokines may also represent a mechanism whereby periodontal infections can impact on systemic diseases.
Cathepsin S is a cysteine protease and regulator of autophagy with possible involvement in periodontitis. The objective of this study was to investigate whether cathepsin S is involved in the ...pathogenesis of periodontal diseases. Human periodontal fibroblasts were cultured under inflammatory and infectious conditions elicited by interleukin-1β and Fusobacterium nucleatum, respectively. An array-based approach was used to analyze differential expression of autophagy-associated genes. Cathepsin S was upregulated most strongly and thus further studied in vitro at gene and protein levels. In vivo, gingival tissue biopsies from rats with ligature-induced periodontitis and from periodontitis patients were also analyzed at transcriptional and protein levels. Multiple gene expression changes due to interleukin-1β and F. nucleatum were observed in vitro. Both stimulants caused a significant cathepsin S upregulation. A significantly elevated cathepsin S expression in gingival biopsies from rats with experimental periodontitis was found in vivo, as compared to that from control. Gingival biopsies from periodontitis patients showed a significantly higher cathepsin S expression than those from healthy gingiva. Our findings provide original evidence that cathepsin S is increased in periodontal cells and tissues under inflammatory and infectious conditions, suggesting a critical role of this autophagy-associated molecule in the pathogenesis of periodontitis.
Nonsurgical periodontal therapy with adjunctive use of systemic antimicrobials (for 7-14 days) showed improved clinical, microbiological and immunological results over the mechanical protocol alone. ...Considering the increasing risk for antimicrobial resistance with longer antibiotic regimes, it is important to establish the optimal antibiotic protocol with a maximum antimicrobial benefit and minimum risk for adverse effects. The aim of the study was to evaluate the microbiological and inflammatory outcomes 12-months after a 3-/7-day systemic antibiotic protocol amoxicillin (AMX) + metronidazole (MET) adjunctive to subgingival debridement in severe periodontitis compared to mechanical treatment alone. From the initially treated 102 patients, 75 subjects (Placebo group: n = 26; 3-day AMX + MET group: n = 24; 7-day AMX + MET group: n = 25) completed the 12-month examination. Clinical parameters, eight periodontal pathogens and inflammatory markers were determined at baseline and 3-, 6-, 12-months after therapy using real-time PCR and ELISA respectively. After 6 months, several periodontopathogens were significantly more reduced in the two antibiotic groups compared to placebo (p < 0.05). After 1 year, both antibiotic protocols showed significant reductions and detection of the keystone pathogen P. gingivalis compared to placebo. Antibiotic protocols, smoking, disease severity, baseline-BOP, -CAL and -IL-1β, as well as detection of T. denticola at 12-months significantly influenced the residual number of deep sites. The present data indicate that the systemic use of both short and longer antibiotic protocols (AMX + MET) adjunctive to nonsurgical periodontal therapy lead to higher microbiological improvements compared to subgingival debridement alone. The two investigated antibiotic protocols led to comparable microbiological and inflammatory results.
Aim: We aimed to assess caries experience and microbiota in systemically healthy children with black stain (BS) and non-discoloured plaque. Methods: Forty-six children with BS and 47 counterparts ...with non-discoloured plaque aged 7.9 ± 1.3 years were clinically examined. Dental caries was scored using WHO criteria. Samples of BS and non-discoloured dental plaque were collected from tooth surfaces. The DNA of the samples was extracted and real-time PCR was performed to determine the total number of bacteria and the species Streptococcus mutans, S. sobrinus, Lactobacillus sp., Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum. Results: Children with BS had lower DMFT (p = 0.013), lower DT values (p = 0.005) and a tendency to lower caries prevalence (p = 0.061) than children with non-discoloured plaque. Plaque samples of the BS group contained higher numbers of A. naeslundii (p = 0.005) and lower numbers of F. nucleatum (p = 0.001) and Lactobacillus sp. (p = 0.001) compared to the non-discoloured plaque samples of the control group. Comparing the children with BS and non-discoloured plaque, higher counts for A. naeslundii (p = 0.013) were observed in caries-free children with BS while in caries-affected children with BS, lower counts of F. nucleatum (p = 0.007) were found. Counts of Lactobacillus sp. were higher in non-discoloured plaque samples than in BS of caries-free and caries-affected children. Conclusion: Results suggest that the different microbial composition of BS might be associated with the lower caries experience in affected subjects. The role of black-pigmented bacteria associated with periodontitis needs further studies.
Summary
Porphyromonas gingivalis and Tannerella forsythia secrete proteases, gingipains and KLIKK‐proteases. In addition, T. forsythia produces a serpin (miropin) with broad inhibitory spectrum. The ...aim of this pilot study was to determine the level of expression of miropin and individual proteases in vivo in periodontal and peri‐implant health and disease conditions. Biofilm and gingival crevicular fluid (GCF)/ peri‐implant sulcular fluid (PISF) samples were taken from healthy tooth and implant sites (n = 10), gingivitis and mucositis sites (n = 12), and periodontitis and peri‐implantitis sites (n = 10). Concentration of interleukin‐8 (IL‐8), IL‐1β and IL‐10 in GCF was determined by enzyme‐linked immunosorbent assay. Loads of P. gingivalis and T. forsythia and the presence of proteases and miropin genes were assessed in biofilm by quantitative PCR, whereas gene expression was estimated by quantitative RT‐PCR. The presence of P. gingivalis and T. forsythia, as well as the level of IL‐8 and IL‐1β, were associated with disease severity in the periodontal and peri‐implant tissues. In biofilm samples harboring T. forsythia, genes encoding proteases were found to be present at 72.4% for karilysin and 100% for other KLIKK‐protease genes and miropin. At the same time, detectable mRNA expression of individual genes ranged from 20.7% to 58.6% of samples (for forsylisin and miropsin‐1, respectively). In comparison with the T. forsythia proteases, miropin and the gingipains were highly expressed. The level of expression of gingipains was associated with those of miropin and certain T. forsythia proteases around teeth but not implants. Cumulatively, KLIKK‐proteases and especially miropin, might play a role in pathogenesis of both periodontal and peri‐implant diseases.
Background and Objective
Nutrition and body weight are modifying factors for periodontitis. The purpose of this study was to quantify two molecules (ghrelin and chemerin), released in association ...with food intake and obesity, in periodontally healthy and diseased individuals with respect to different body mass categories.
Material and Methods
The two main groups (patients with chronic periodontitis and periodontally healthy/gingivitis volunteers) were subdivided into groups of subjects with normal weight body mass index (BMI) <25 and groups of overweight/obese subjects (BMI ≥25). Subgingival bacteria were analysed and the levels of acylated and total ghrelin, chemerin and interleukin‐1β (IL‐1β) were assessed in saliva, gingival crevicular fluid and serum.
Results
The amount of Treponema denticola present subgingivally was significantly higher in the groups of patients with chronic periodontitis as well as in periodontally healthy/gingivitis individuals with BMI ≥25 than in periodontally healthy/gingivitis individuals with BMI <25. The amount of total ghrelin in gingival crevicular fluid differed significantly between the groups, with the lowest levels found in the group of patients with chronic periodontitis and BMI ≥25. The levels of chemerin in gingival crevicular fluid were significantly higher in each chronic periodontitis group than in periodontally healthy/gingivitis individuals with BMI <25. However, the level of IL‐1β in the gingival crevicular fluid was most differentiating between the groups, with the highest levels found in the group of patients with chronic periodontitis and BMI <25 and the lowest levels in periodontally healthy/gingivitis individuals with BMI <25. No significant differences between any groups were seen for chemerin or for acylated ghrelin in the stimulated whole saliva, or for acylated and total ghrelin in peripheral blood serum. The BMI correlated with the serum level of chemerin.
Conclusion
Low ghrelin and high chemerin levels in the gingival crevicular fluid might be linked to periodontal disease and overweight/obesity. However, unlike IL‐1β, the levels of chemerin and ghrelin in gingival crevicular fluid are not reliable indicators of periodontal destruction.
Objectives
Damage-regulated autophagy modulator (DRAM) 1 is a p53 target gene with possible involvement in oral inflammation and infection. This study sought to examine the presence and regulation of ...DRAM1 in periodontal diseases.
Material and methods
In vitro, human periodontal ligament fibroblasts were exposed to interleukin (IL)-1β and
Fusobacterium nucleatum
for up to 2 days. The DRAM1 synthesis and its regulation were analyzed by real-time PCR, immunocytochemistry, and ELISA. Expressions of other autophagy-associated genes were also studied by real-time PCR. In vivo, synthesis of DRAM1 in gingival biopsies from rats and patients with and without periodontal disease was examined by real-time PCR and immunohistochemistry. For statistics, ANOVA and post-hoc tests were applied (
p
< 0.05).
Results
In vitro, DRAM1 was significantly upregulated by IL-1β and
F. nucleatum
over 2 days and a wide range of concentrations. Additionally, increased DRAM1 protein levels in response to both stimulants were observed. Autophagy-associated genes ATG3, BAK1, HDAC6, and IRGM were also upregulated under inflammatory or infectious conditions. In vivo, the DRAM1 gene expression was significantly enhanced in rat gingival biopsies with induced periodontitis as compared to control. Significantly increased DRAM1 levels were also detected in human gingival biopsies from sites of periodontitis as compared to healthy sites.
Conclusion
Our data provide novel evidence that DRAM1 is increased under inflammatory and infectious conditions in periodontal cells and tissues, suggesting a pivotal role of DRAM1 in oral inflammation and infection.
Clinical relevance
DRAM1 might be a promising target in future diagnostic and treatment strategies for periodontitis.
Objectives: This study examined differences in the efficacy of antibiotics against a single strain of three periodontal pathogens grown in an artificial biofilm.
Methods: Single species biofilms were ...established with artificial saliva and one of the following bacterial strains: Actinobacillus actinomycetemcomitans Y4, Streptococcus constellatus 384b (a clinical isolate) and Porphyromonas gingivalis ATCC 33277. The efficacy of the antibiotics clindamycin, doxycycline, metronidazole, and moxifloxacin to these bacteria was determined using concentrations up to 100‐fold minimal inhibitory concentration (MIC) to planctonic bacteria over 48 h.
Results: The ability of the bacteria to form a biofilm varied. The biofilms of S. constellatus 384b and A. actinomycetemcomitans Y4 contained more viable bacteria and showed a larger thickness in SEM photographs than those of P. gingivalis ATCC 33277. The antibiotics tested showed different efficacy for the different strains. Moxifloxacin was the most efficient antibiotic: onefold MIC was sufficient to eliminate A. actinomycetemcomitans Y4 and P. gingivalis ATCC 33277 after 48 h. However, only the 50‐fold MIC completely eradicated S. constellatus 384b. SEM photographs underlined the damaging effect of moxifloxacin on the biofilm structure.
Conclusion: The complete removal of bacteria by the use of antibiotics alone seems to be impossible when taking into account MIC values and the level of antibiotics in gingival fluid.
Summary
In periodontitis, an effective host‐response is primarily related to neutrophils loaded with serine proteases, including elastase (NE) and protease 3 (PR3), the extracellular activity of ...which is tightly controlled by endogenous inhibitors. In vitro these inhibitors are degraded by gingipains, cysteine proteases produced by Porphyromonas gingivalis. The purpose of this study was to determine the level of selected protease inhibitors in gingival crevicular fluid (GCF) in relation to periodontal infection. The GCF collected from 31 subjects (nine healthy controls, seven with gingivitis, five with aggressive periodontitis and 10 with chronic periodontitis) was analyzed for the levels of elafin and secretory leukocyte protease inhibitor (SLPI), two main tissue‐derived inhibitors of neutrophil serine proteases. In parallel, activity of NE, PR3 and arginine‐specific gingipains (Rgps) in GCF was measured. Finally loads of P. gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola were determined. The highest values of elafin were found in aggressive periodontitis and the lowest in controls. The quantity of elafin correlated positively with the load of P. gingivalis, Ta. forsythia and Tr. denticola, as well as with Rgps activity. In addition, NE activity was positively associated with the counts of those bacterial species, but not with the amount of elafin. In contrast, the highest concentrations of SLPI were found in periodontally healthy subjects whereas amounts of this inhibitor were significantly decreased in patients infected with P. gingivalis. Periodontopathogenic bacteria stimulate the release of NE and PR3, which activities escape the control through degradation of locally produced inhibitors (SLPI and elafin) by host‐derived and bacteria‐derived proteases.
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