Host responses in maintaining periodontal health and determining periodontal disease

Prevalence and Risk Factors of Bone and Dental Lesions in Neotropical Deer

Bone and dental lesions have been documented in various deer species globally, affecting the efficiency of ingestion and digestion, consequently influencing their general health and leading to a decline in survival and reproductive performance. The present study aimed to characterize bone and dental lesions in the dry skulls of individual deer, estimate the prevalence of these lesions, and assess potential risk factors associated with the development of bone and dental alterations. This study assessed bone and dental lesions in 180 dry skulls of eleven neotropical deer species, originating from both captivity and wildlife conditions, through direct visual inspection. A high prevalence of bone and dental lesions was observed in all analyzed species. Dental calculus was the most common alteration (96.7%), followed by dental wear (71.1%). Animal age positively correlated with most bone and dental alterations, indicating that older animals showed more lesions. Additionally, the prevalence of these alterations was similar between sexes. Moreover, all lesions were more common in captive-bred animals, likely attributed to their older age and a less diverse diet. Blastocerus dichotomus and Mazama americana were most affected by bone resorption and dental trauma and had the highest dental calculus prevalence, along with Subulo gouazoubira and Passalites nemorivagus. All eleven species evaluated in the present study were susceptible to the occurrence of bone and dental lesions. Therefore, monitoring oral health and diet in captivity are fundamental practices for the conservation of these species.

Assessment of the Antibacterial Effect of Vitamin D3 against Red Complex Periodontal Pathogens: A Microbiological Assay

AIM

The study aims is to evaluate the antibacterial effect of vitamin D3 against the red complex bacteria, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia in chronic periodontitis patients.

MATERIALS AND METHODS

The study comprised 98 participants with chronic periodontitis. All clinical parameters including plaque index (PI), gingival bleeding index (GBI), probing pocket depth (PPD), clinical attachment level (CAL), and a microbiological assay of P. gingivalis, T. denticola, T. forsythia were assessed at the baseline. All study participants who underwent scaling and root planning were divided into two groups, A and B, each with 49 patients and only group B patients were advised to take vitamin D supplementation of 60,000 IU granules, once daily for 2 months. All the patients of both the groups were recalled at the end of 2nd month and all the clinical and microbiological parameters were reassessed.

RESULTS

After two months, there was a reduction in all the clinical markers in both groups, but the group B patients showed more improvement following non-surgical treatment vitamin D intake. There was also a statistical reduction in P. gingivalis, T. denticola, and T. forsythia following administration of vitamin D in group B patients compared to group A.

CONCLUSION

These discoveries proposed that vitamin D has a superb antimicrobial impact against red complex periodontal microbes and might be considered a promising compound in the counteraction of periodontal disease.

CLINICAL SIGNIFICANCE

Vitamin D is considered to possess anti-inflammatory and antimicrobial activity, which may help to delay the progression of periodontitis. So, vitamin D3 can be used as a potential supplement that could be employed to stop the advancement of periodontal disease. How to cite this article: Govindharajulu R, Syed NK, Sukumaran B, et al. Assessment of the Antibacterial Effect of Vitamin D3 against Red Complex Periodontal Pathogens: A Microbiological Assay. J Contemp Dent Pract 2024;25(2):114-117.

Gallic acid induces osteoblast differentiation and alleviates inflammatory response through GPR35/GSK3β/β-catenin signaling pathway in human periodontal ligament cells

BACKGROUND AND OBJECTIVE

Gallic acid (GA) possesses various beneficial functions including antioxidant, anticancer, anti-inflammatory as well as inhibiting osteoclastogeneis. However, effects on osteogenic differentiation, especially in human ligament periodontal (hPDL) cells, remain unclear. Thus, the aim of this study was to evaluate the function of GA on osteogenesis and anti-inflammation in hPDL cells and to explore the involved underlying mechanism.

METHODS

Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) treatment was used as a model for periodontitis. ROS production was determined by H2DCFDA staining. Trans-well and wound healing assays were performed for checking the migration effect of GA. Alizarin red and alkaline phosphatase activity (ALP) assays were performed to evaluate osteogenic differentiation. Osteogenesis and inflammatory-related genes and proteins were measured by real-time PCR and western blot.

RESULTS

Our results showed that GA-treated hPDL cells had higher proliferation and migration effect. GA inhibited ROS production-induced by Pg-LPS. Besides, GA abolished Pg-LPS-induced inflammation cytokines (il-6, il-1β) and inflammasome targets (Caspase-1, NLRP3). In addition, GA promoted ALP activity and mineralization in hPDL cells, lead to enhance osteoblast differentiation process. The effect of GA is related to G-protein-coupled receptor 35 (GPR35)/GSK3β/β-catenin signaling pathway.

CONCLUSION

GA attenuated Pg-LPS-induced inflammatory responses and periodontitis in hPDL cells. Taken together, GA may be targeted for therapeutic interventions in periodontal diseases.

Gastric adenocarcinoma and periodontal disease: A systematic review and meta-analysis

BACKGROUND

The oral cavity is a link between of external environment with gastrointestinal tract. Studies are controversial on the presence of Periodontal Disease (PD) and its association with Gastric Adenocarcinoma (GAC).

METHODS

The authors performed a systematic review and meta-analysis to verify the association between PD and GAC. Six electronic databases were evaluated between 1961 and 2022. Titles and abstracts were reviewed independently according to the eligibility criteria, assessing full texts of selected studies. The quality of the included research was verified using the Newcastle-Ottawa Scale for case-control and cohort studies. Statistical analyses were performed based on fixed and/or random effects models to calculate the summarized Relative Risk (RR) and its 95 % Confidence Interval (95 % CI).

RESULTS

There were 639 studies, of which nine articles were included (3 case-controls and 6 cohorts). Overall, the authors identified 1,253 cases of GAC 2,501 controls in case-control studies, and 1,631 patients with GAC enrolled in cohort studies. Patients presenting PD increased the risk of developing GAC by 17 % (RR=1.17; 95 % CI 1.03‒1.32), which remained regardless of the diagnostic method for PD, i.e., clinical examination (RR = 1.19; 95 % CI 1.14‒1.24) and self-report (RR = 1.34; 95 % CI 1.06‒1.69). Moreover, Asian patients (RR=1.17; 95 % CI 1.00‒1.36) with PD had a higher risk of having GAC than American and European patients (RR = 1.18; 95 % CI 0.84‒1.66).

CONCLUSIONS

The presence of PD the risk of GAC suggesting that its infectious-inflammatory process of PD may be related to GAC development. Further investigations on the oral-gastric microbiota and its role in the carcinogenesis of gastric cancer should be carried out, and the screening of patients with potential risk for GAC should be considered in the clinical practice of dentists.

Mineral contents in bone and liver of sheep with or without periodontitis

ABSTRACT Due to the supposed involvement of minerals in cases of ruminant periodontitis, this study aimed to analyze the concentrations of phosphorus (P) in bone, and cobalt (Co), copper (Co), iron (Fe), zinc (Zn) and selenium (Se) in liver of a cohort of sheep affected or not by periodontitis. From an outbreak of the disease in 2011 in Pará state, Brazil, rib and liver samples were obtained from 22 sheep with periodontitis and seven samples from healthy animals. Based on the concentrations of the different minerals in the tissues, we concluded that there was no relationship between periodontal disease in sheep with any mineral deficiency status. In contrast, most of the minerals in the tissues were above or within the recommended concentrations in bone and liver. Within the various aspects which until now have been studied regarding periodontitis in ruminants, the results obtained here corroborate the fact that periodontal disease in sheep is an infectious disease and it is not a consequence of the deficiency or excess of mineral elements in the diet.

Express Diagnostics of Proteolytic Activity of Periodontopathogens-Methodological Approach

The species spectrum of the oral microbiome is considered to be the key factor in the development and progression of periodontal inflammatory disorders. The “red complex” including Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola has the highest pathogenic potential. These bacteria have several biochemical mechanisms that allow them to colonize and destroy periodontal tissues. Proteolytic enzymes play a crucial role in this process. Early diagnosis of pathological conditions induced by microbial contamination allows for the timely treatment of periodontitis. Otherwise, the development of the disease may lead to tooth loss. A total of 48 patients aged 18 to 65 years old who required professional oral hygiene were recruited for this clinical study. Microbial content analysis of dental plaque from the interdental space and the back of the tongue was performed using real-time PCR. To determine the proteolytic activity of oral bacteria, the new express diagnostic method was applied (diagnostic sensitivity, 0.875; specificity, 0.928). The results demonstrate a strong and significant correlation between the new method and the PCR analysis (r = 0.785, p < 0.001). These results show that the new express method can be valuable as an early diagnostic method for periodontal inflammatory disorders caused by the “red complex” bacteria.

Rodent Gingival Tissue Culture in an Aging Experimental Model: A Pilot Study

Background:

Gingiva acts as a barrier to prevent further invasion of pathogens in periodontitis. The gingival structure consists of epithelial tissue and connective tissue. As the aging process continues, there are several changes in the periodontium. Previous studies have tried to investigate the complex interaction between the host immune system and bacteria by using animal models, especially rodents.

Objective:

The aim of the study was to evaluate the effectiveness of collecting gingival tissue from the palate and retromolar pad.

Materials and Methods:

The aging experimental model had two age categories of male rodents of 18 and 58 weeks. Tissue was collected from the mandible retromolar pad and palate with full-thickness excision. Tissues were transferred to a complete medium at 4°C. Gingival tissue was cultured in a 37°C culture incubator at 5% CO2. Tissue proliferation was observed on the first, third, and fifth days using the hemocytometer. The cell metabolism rate between the two age categories was checked using the MTT Assay. Two-way ANOVA was used for statistical analysis.

Results:

Gingival tissues obtained from the experimental models of two age categories were alive, and proliferation was observed. The old rodent group showed no significant result in terms of cell morphology on the first vs. third day (p>0.05), but significant results were found on the first vs. fifth day and third day vs. the fifth day (p<0.05). The young rodent group showed the most significant morphology changes between days. In both young and old categories, no significant difference was observed in the cell metabolism.

Conclusion:

Rodent gingival tissue collection from the retromolar pad and palate was found suitable for tissue culture in the aging experimental study.

Neutrophils in homeostasis and tissue repair

Neutrophils are the most abundant innate immune cell and are equipped with highly destructive molecular cargo. As such, these cells were long thought to be short-lived killer cells that unleash their full cytotoxic programs on pathogens following infection and on host bystander cells after sterile injury. However, this view of neutrophils is overly simplistic and as a result is outdated. Numerous studies now collectively highlight neutrophils as far more complex and having a host of homeostatic and tissue-reparative functions. In this review, we summarize these underappreciated roles across organs and injury models.

Periodontal ligament stem cells promote polarization of M2 macrophages

Macrophages are widely distributed in a variety of tissues, and the different state of macrophages polarization is closely related to the occurrence, development, and prognosis of inflammation, including periodontitis, a chronic inflammatory disease leading to tooth loss worldwide. Periodontal ligament stem cells (PDLSCs) play a key role in immune regulation and periodontal tissues regeneration, contributing to cell-based therapy of periodontitis. However, the interactions between PDLSCs and macrophages are still elusive. The purpose of present study is to investigate the effect of PDLSCs conditioned medium (PDLSCs-CM) on the macrophage polarization and the possible mechanism. PDLSCs were isolated using tissue explant methods and characterized via multipotent differentiation test and examination of expression profiles of mesenchymal stem cells (MSCs) markers. The supernatant of PDLSCs was collected, centrifuged, filtered, and used as PDLSCs-CM. Then, PDLSCs-CM was cocultured with M0 macrophages or IL-4- and IL-13-induced M2 macrophages. The level of surface markers of M1/M2 macrophages and production of several proinflammatory or anti-inflammatory factors were evaluated by flow cytometric analysis and enzyme-linked immunosorbent assay, respectively. The associated genes and proteins involved in the JNK pathway were investigated to explore the potential mechanism that may regulate PDLSCs-CM-mediated macrophage polarization. PDLSCs expressed MSCs markers, including STRO-1, CD146, CD90, and CD73, and were negative for CD34 and CD45, could undergo osteogenic and adipogenic differentiation when cultured in defined medium. After incubation with PDLSCs-CM, no significant increase of CD80+ and HLA-DR+ M1 macrophages was shown while evaluated CD209+ and CD206+ M2 macrophages were observed. In addition, the levels of anti-inflammatory factors such as IL-10, TGF-β, and CCL18 were increased instead of proinflammatory factors such as IL-1β, TNF-α with PDLSC-CM treatment. There was a decrease of JNK expression on M0 macrophages by qRT-PCR analysis and an increase of protein phosphorylation on M0 macrophages after incubation with PDLSCs-CM. Furthermore, as for the enhancement of IL-4- and IL-13-mediated M2 polarization by PDLSCs-CM, the mRNA level of JNK decreased, and the protein phosphorylation level of JNK increased. In addition, the treatment of JNK pathway inhibitor, SP600125, could inhibit the expression and secretion level of anti-inflammatory factor such as IL-10 in M2 polarization induced by PDLSCs-CM. Collectively, PDLSCs were able to induce M2 macrophage polarization instead of M1 polarization, and capable of enhancing M2 macrophage polarization induced by IL-4 and IL-13. The JNK pathway was involved in the promotion of M2 macrophage polarization.

Distinct Microbial Signatures between Periodontal Profile Classes

Precise classification of periodontal disease has been the objective of concerted efforts and has led to the introduction of new consensus-based and data-driven classifications. The purpose of this study was to characterize the microbiological signatures of a latent class analysis (LCA)-derived periodontal stratification system, the Periodontal Profile Class (PPC) taxonomy. We used demographic, microbial (subgingival biofilm composition), and immunological data (serum IgG antibody levels, obtained with checkerboard immunoblotting technique) for 1,450 adult participants of the Dental Atherosclerosis Risk in Communities (ARIC) study, with already generated PPC classifications. Analyses relied on t tests and generalized linear models with Bonferroni correction. Men and African Americans had higher systemic antibody levels against most microorganisms compared to women and Caucasians (P < 0.05). Healthy individuals (PPC-I) had low levels of biofilm bacteria and serum IgG levels against most periodontal pathogens (P < 0.05). Subjects with mild to moderate disease (PPC-II to PPC-III) showed mild/moderate colonization of multiple biofilm pathogens. Individuals with severe disease (PPC-IV) had moderate/high levels of biofilm pathogens and antibody levels for orange/red complexes. High gingival index individuals (PPC-V) showed moderate/high levels of biofilm Campylobacter rectus and Aggregatibacter actinomycetemcomitans. Biofilm composition in individuals with reduced periodontium (PPC-VI) was similar to health but showed moderate to high antibody responses. Those with severe tooth loss (PPC-VII) had significantly high levels of multiple biofilm pathogens, while the systemic antibody response to these microorganisms was comparable to health. The results support a biologic basis for elevated risk for periodontal disease in men and African Americans. Periodontally healthy individuals showed a low biofilm pathogen and low systemic antibody burden. In the presence of PPC disease, a microbial-host imbalance characterized by higher microbial biofilm colonization and/or systemic IgG responses was identified. These results support the notion that subgroups identified by the PPC system present distinct microbial profiles and may be useful in designing future precise biological treatment interventions.

Influence of the treatment with the antineoplastic agents 5-fluorouracil and cisplatin on the severity of experimental periodontitis in rats

PURPOSE

The determination on how antineoplastic agents interfere on the progression of periodontitis is critical for improvement and even development of novel therapeutic approaches for periodontal management. This study evaluated the influence of chemotherapy with 5-fluorouracil (5-FU) or cisplatin (CIS) on healthy periodontal tissues and on the progression of experimental periodontitis (EP).

METHODS

One hundred forty-four male rats were divided into six groups (n = 24). Each group was treated with physiological saline solution (PSS) 0.9%, 5-FU, or CIS. Experimental periodontitis (EP) was induced by ligature placement. Animals were euthanized at 7, 15, and 30 days after treatment. Data were statistically analyzed (p ≤ 0.05).

RESULTS

The groups with EP and treated with 5-FU or CIS showed lower percentage of bone volume in the furcation region and higher percentage of alveolar bone loss, higher number of TRAP-positive cells, and lower number of PCNA-positive cells when compared group with EP and treated with PSS (p ≤ 0.05). Groups with EP and treated with 5-FU or CIS showed high immunolabelling pattern of RANKL, TNF-α, and IL-1β, moderate of BAX, and low of HIF-1α. Histological analysis showed severe tissue breakdown in the groups with EP and treated with 5-FU or CIS.

CONCLUSIONS

Chemotherapy with antineoplastic agents 5-FU and CIS increased the intensity and duration of the inflammation and compromised tissue repair by reduction in cellular and vascular turnover. The more severe periodontal breakdown was caused by 5-FU.

B cell activating factor regulates periodontitis development by suppressing inflammatory responses in macrophages

Background

B cell activating factor (BAFF) is a member of the tumor necrosis factor (TNF) superfamily with immunomodulatory effects on both innate and adaptive immune responses. Periodontitis is an inflammatory disease characterized by periodontal soft tissue inflammation and the progressive loss of periodontal ligament and alveolar bone. Macrophages are closely related to periodontitis progression. However, the role of BAFF in periodontitis development and macrophage polarization and the underlying mechanism remain unknown.

Methods

In vivo, a ligation-induced mouse model of periodontitis for BAFF blockade was established to investigate the expression of inducible nitric oxide synthase (iNOS) through real-time PCR (RT-PCR) and immunohistochemistry. In addition, the level of TNF-α in the periodontium, the number of osteoclasts, and alveolar bone resorption were observed. In vitro, RAW 264.7 macrophage cells were treated with 100 ng/mL Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS) in either the presence or absence of 50 nM small interfering RNA (siRNA) targeting BAFF, followed by further incubation for 24 h. These cells and supernatants were collected and stored for RT-PCR, enzyme-linked immunosorbent assay, western blotting and immunofluorescence microscopy.

Results

In vivo, BAFF blockade decreased the levels of TNF-α in the periodontium in a ligature-induced mouse periodontitis model. Reduced osteoclast formation and lower alveolar bone loss were also observed. In addition, BAFF blockade was related to the expression of polarization signature molecules in macrophages. In vitro, BAFF knockdown notably suppressed the production of TNF-α in RAW 264.7 cells stimulated by P. gingivalis LPS. Moreover, BAFF knockdown attenuated the polarization of RAW 264.7 cells into classically activated macrophages (M1), with reduced expression of iNOS.

Conclusions

Based on our limited evidence, we showed BAFF blockade exhibits potent anti-inflammatory properties in mice experimental periodontitis in vivo and in P. gingivalis LPS-treated RAW 264.7 cells in vitro, and macrophage polarization may be responsible for this effect.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01788-6.

Proportion and severity of periodontitis and correlation of periodontal inflamed surface area with glycemic status in patients with type 2 diabetic neuropathy with and without diabetic foot

BACKGROUND

The association between diabetic neuropathy with and without diabetic foot and periodontitis remains unaddressed in the literature. The present study was conducted to evaluate the frequency of patients with periodontitis and its severity, and to correlate clinical attachment loss (AL) and periodontal inflamed surface area (PISA) with HbA1c in Type 2 Diabetic Neuropathy (T2DN) patients with and without diabetic foot.

METHODS

In this cross-sectional study 310 patients with type 2 diabetic neuropathy (T2DN) were randomly selected, and the study comprised of 120 patients with T2DN with diabetic foot and 155 patients with T2DN without diabetic foot. All patients were assessed for periodontal parameters (bleeding on probing, probing depth, clinical AL, oral hygiene index-simplified), plaque index, and PISA) and systemic parameters (HbA1c, fasting blood glucose, post prandial blood glucose, urinary albumin creatine ratio, erythrocyte sedimentation rate, and high-sensitivity C-reactive protein).Unpaired t-test and Chi-Square test were used to analyze quantitative data and qualitative data, respectively.

RESULTS

The frequency of patients with periodontitis in patients with T2DN with and without diabetic foot was 91.7% and 88.4%, respectively. The severity of periodontitis, PISA, and clinical AL were higher in the diabetic foot group. Clinical AL and PISA were significantly related with HbA1c in patients with T2DN with and without diabetic foot.

CONCLUSIONS

Percentage of patients with periodontitis and the severity of periodontal destruction were high in type 2 diabetic neuropathy with diabetic foot. A significant correlation of PISA, clinical AL with glycemic status was found in patients with T2DN with and without diabetic foot.

The Marine-Derived Natural Product Epiloliolide Isolated from Sargassum horneri Regulates NLRP3 via PKA/CREB, Promoting Proliferation and Anti-Inflammatory Effects of Human Periodontal Ligament Cells

Currently, periodontitis treatment relies on surgical operations, anti-inflammatory agents, or antibiotics. However, these treatments cause pain and side effects, resulting in a poor prognosis. Therefore, in this study, we evaluated the impact of the compound epiloliolide isolated from Sargassum horneri on the recovery of inflammatory inhibitors and loss of periodontal ligaments, which are essential treatment strategies for periodontitis. Here, human periodontal ligament cells stimulated with PG-LPS were treated with the compound epiloliolide, isolated from S. horneri. In the results of this study, epiloliolide proved the anti-inflammatory effect, cell proliferation capacity, and differentiation potential of periodontal ligament cells into osteoblasts, through the regulation of the PKA/CREB signaling pathway. Epiloliolide effectively increased the proliferation and migration of human periodontal ligament cells without cytotoxicity and suppressed the protein expression of proinflammatory mediators and cytokines, such as iNOS, COX-2, TNF-α, IL-6, and IL-1β, by downregulating NLRP3 activated by PG-LPS. Epiloliolide also upregulated the phosphorylation of PKA/CREB proteins, which play an important role in cell growth and proliferation. It was confirmed that the anti-inflammatory effect in PG-LPS-stimulated large cells was due to the regulation of PKA/CREB signaling. We suggest that epiloliolide could serve as a potential novel therapeutic agent for periodontitis by inhibiting inflammation and restoring the loss of periodontal tissue.

Latency, thermal stability, and identification of an inhibitory compound of mirolysin, a secretory protease of the human periodontopathogen Tannerella forsythia

Mirolysin is a secretory protease of Tannerella forsythia, a member of the dysbiotic oral microbiota responsible for periodontitis. In this study, we show that mirolysin latency is achieved by a “cysteine-switch” mechanism exerted by Cys23 in the N-terminal profragment. Mutation of Cys23 shortened the time needed for activation of the zymogen from several days to 5 min. The mutation also decreased the thermal stability and autoproteolysis resistance of promirolysin. Mature mirolysin is a thermophilic enzyme and shows optimal activity at 65 °C. Through NMR-based fragment screening, we identified a small molecule (compound (cpd) 9) that blocks promirolysin maturation and functions as a competitive inhibitor (K_i = 3.2 µM), binding to the S1′ subsite of the substrate-binding pocket. Cpd 9 shows superior specificity and does not interact with other T. forsythia proteases or Lys/Arg-specific proteases.

Management of Risk Factors Associated with Chronic Oral Lesions in Sheep

Oral disorders constitute a significant cause of weight loss in sheep. In a study of disorders of the oral cavity of 36,033 sheep from 60 meat sheep flocks in Spain, we looked for management risk factors associated with chronic oral lesions. Mandibular and maxillary disorders were assessed as an external manifestation of oral lesions by palpation, searching for tissue swellings, fistulae, or open wounds. The prevalence of flocks containing sheep with jaw disorders was 98.3%, with an average individual prevalence of 5.5%. The majority of lesions were located in in the mid-region of the mandible, and the most relevant risk factor was increasing age. Use of acidic diets based on silage and inclusion of hard foods, such as maize straw or hay, was associated with the occurrence of jaw inflammation. It was concluded that hard diets containing plant material with edges and sharp areas, plus acidic foods including silage, are more likely to cause lesions of the gingiva, enabling entry of pathogens to the oral mucosa that eventually establish locally in bony tissues, usually as mandibular osteomyelitis. It was also observed that mineral supplementation appears to prevent the occurrence of these lesions.

Evaluation of the efficacy of subgingival irrigation in patients with moderate-to-severe chronic periodontitis otherwise indicated for periodontal flap surgeries

Background:

In certain medically and physically compromised; and terminally ill patients, periodontal surgery may not be feasible. They need special attention and assistance for their daily plaque control regimens for the management and maintenance of periodontal conditions. Subgingival irrigation home care devices with antiplaque agents may serve as useful tools in such specific patient populations.

Aims:

The aim of this study was to evaluate of the efficacy of sub-gingival irrigation in patients with moderate-to-severe chronic periodontitis otherwise indicated for periodontal flap surgeries.

Settings and Design:

Randomized comparative parallel group interventional clinical trial.

Materials and Methods:

Forty adults with moderate-to-severe periodontitis, divided inot Group A and B, were subjected to the use of subgingival home irrigations using 0.06% chlorhexidine (CHX) and mouth-rinsing with 15 ml of 0.12% CHX twice daily, respectively after Phase I therapy. Clinical parameters, i.e., gingival index, oral hygiene index simplified, and bleeding on probing scores were assessed at baseline, 2 weeks, 4 weeks, and 12 weeks’ postphase I therapy, whereas clinical attachment level (CAL), probing depth (PD), and stain assessment at baseline and 12 weeks following Phase I therapy.

Statistical Analysis Used:

Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, USA version 15.0 for Windows).

Results:

A statistically significant difference was seen with the use of 0.06% CHX irrigations in PD (P = 0.004) and CAL (P = 0.002) as compared to the use of mouth rinsing with 0.12% CHX. Similar differences were observed in both intensity (P = 0.014) and area (P = 0.034) of lingual surface staining with greater staining with CHX mouth rinsing.

Conclusion:

The adjunctive use of subgingival home irrigations using 0.06% CHX has a promising potential to maintain the oral health and results in lesser staining compared to CHX mouth rinsing. The regimen may further obviate the need of periodontal surgery in medically compromised subjects.

Further evidence on the relationship between abdominal aortic aneurysm and periodontitis: A cross-sectional study

BACKGROUND

Periodontitis is a chronic inflammatory disease characterized by Gram-negative bacteria responsible for the degradation of tissues surrounding tooth. Moreover, periopathogens can invade the bloodstream, disseminate and promote cardiovascular disease, such as the link between Porphyromonas gingivalis and atherosclerosis. The aim of this study was to explore the relationship between the severity of periodontitis and of abdominal aortic aneurysm (AAA).

METHODS

This cross-sectional study compared patients with stable AAA (n = 30) and patients with unstable AAA (n = 31) based on aortic diameter, growth rate, and eligibility for surgical intervention. Periodontal clinical parameters were recorded as well as the Periodontal Inflamed Surface Area and the Periodontal Index for Risk of Infectiousness (PIRI). Microbiological analyses were performed on saliva and supragingival and subgingival plaque. Quantification of Tannerella forsythia (Tf), Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), and Prevotella intermedia (Pi) was done by quantitative polymerase chain reaction.

RESULTS

The two AAA groups were homogeneous for age, sex, and most risk factors except hypertension and chronic obstructive pulmonary disease. Periodontal parameters were comparable but the proportion of patients with high PIRI scores was greater in those with unstable AAA (51.6% versus 23.3%). The probing depth (PD) and the proportion of PD >6 mm were positively correlated with AAA size and thrombus volume. Several associations were found between periopathogens such as Pg and AAA diameters and volumes, but no difference could be evidenced between stable and unstable AAA groups.

CONCLUSIONS

Periodontitis was highly prevalent in both stable and unstable AAA patients. Severe and progressive periodontitis (stage IV and grade C) tended to be more frequent in the group of patients with unstable AAA. Moreover, Pg was observed in all the samples (saliva, supragingival, and subgingival plaque) and was correlated with AAA diameters and volumes. The study evidenced potential relationships between periodontitis severity and size of AAA.

Salivary Total Protease Activity Based on a Broad-Spectrum Fluorescence Resonance Energy Transfer Approach to Monitor Induction and Resolution of Gingival Inflammation

OBJECTIVE

Salivary total protease and chitinase activities were measured by a broad-spectrum fluorescence resonance energy transfer approach as predictors of induction and resolution of gingival inflammation in healthy individuals by applying an experimental human gingivitis model.

METHODS

Dental biofilm accumulated (21 days, Induction Phase) by omitting oral hygiene practices followed by a 2-week Resolution Phase to restore gingival health in an experimental gingivitis study. Plaque accumulation, as assessed by the Turesky Modification of the Quigley-Hein Plaque Index (TQHPI), and gingival inflammation, assessed using the Modified Gingival Index (MGI), scores were recorded and unstimulated saliva was collected weekly. Saliva was analysed for total protein, albumin, total protease activity and chitinase activity (n = 18).

RESULTS

The TQHPI and MGI scores, as well as total protease activity, increased until day 21. After re-establishment of oral hygiene, gingival inflammation levels returned to values similar to baseline (day 0). Levels of protease activity decreased significantly, but not to baseline values. Furthermore, 'fast' responders, who responded immediately to plaque, exhibited significantly higher proteolytic activity throughout the experimental course than 'slow' responders, who showed a lagged inflammatory response.

CONCLUSION

The results indicate that differential inflammatory responses encompass inherent variations in total salivary proteolytic activities, which could be further utilised in contemporary diagnostic, prognostic and treatment modalities for periodontal diseases.

Correlations between the Peptide Hormone Ghrelin and Proinflammatory Cytokines in Experimental Periodontitis Models of Female Rats at Different Stages of the Life Cycle

OBJECTIVE

The aim of this study was to examine the correlations between the levels of ghrelin and inflammatory and bone metabolism markers in rats with periodontitis.

DESIGN

Thirty female Wistar rats (6 trial rats and 4 control rats in each group) were divided into pubertal, adult and postmenopausal groups. Periodontitis was induced by ligatures. On the 21 st day, blood was collected and all rats were then sacrificed. The levels of osteocalcin, osteoprotegerin, alkaline phosphatase, tumour necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), acylated ghrelin, total ghrelin and soluble receptor activator of nuclear factor-kB ligands in the blood samples were measured using enzyme-linked immunosorbent assays. The jaws were decalcified in a Tris-EDTA solution and embedded in paraffin and 4-5 μm sections were cut for IL-β, TNF -α and ghrelin staining.

RESULTS

Significantly higher serum alkaline phosphatase levels were detected in the trial rats in the pubertal group than in the control rats (p = 0.033). In the postmenopausal group, ghrelin levels positively correlated with interleukin 1 beta levels (r = 0.708, p < 0.05). Among all trial rats, the postmenopausal group exhibited significantly higher levels of acylated ghrelin than the other groups (p = 0.001). Significantly higher osteoprotegerin levels were observed in the control rats than in the trial rats in the postmenopausal group (p = 0.012). Inflammation scores were significantly higher in adult trial rats than in controls (p = 0.024); significantly higher TNF-α levels were detected in postmenopausal experimental rats than in the adult experimental group (p = 0.025).

CONCLUSIONS

We concluded that total ghrelin levels in serum only correlated with IL-β levels in postmenopausal rats.

Interdisciplinary Approach for Oral Rehabilitation in a Young Type 1 Diabetes Patient

Introduction. The most frequent oral complications of diabetes are periodontal disease and caries. If left untreated, these may lead to tooth loss, with a significant psychological impact, especially in young patients. Case report. This case report presents a type 1 diabetes young female patient with periodontal disease, poor decay control and tooth loss, that create functional and esthetic issues. After consulting the diabetes specialist, an interdisciplinary dental treatment plan which comprise surgical, periodontal, endodontic and prosthetic rehabilitation was initiated. Long-term provisional computer-aided design and computer-aided manufacturing (CAD-CAM) fixed partial dentures were fabricated to stabilize the occlusion and to obtain in short term an optimal functional and esthetic rehabilitation. Conclusion. This case reveals a consistent collaboration between the prosthodontist, periodontist and endodontist, with an effective monitoring from the diabetes specialist, that conduct to a successful oral rehabilitation for a young female patient with type I diabetes.

Periodontal ligament fibroblasts migration injury via ROS/TXNIP/Nlrp3 inflammasome pathway with Porphyromonas gingivalis lipopolysaccharide

Inflammasomes serve as an intracellular machinery to initiate inflammatory response to various danger signals. However, the chronic periodontitis pathological relevance of this inflammasome activation, particularly in periodontal ligament fibroblasts, remains largely unknown. The present study demonstrated that Nlrp3 inflammasome components abundantly expressed in cultured mouse periodontal ligament fibroblasts (mPDLFs). In addition, our data demonstrated that P.g-LPS (Porphyromonas gingivalis Lipopolysaccharide), a major injurious factor during chronic periodontitis, could induce the mPDLFs migration dysfunction and the inhibition of Nlrp3 inflammasome by Isoliquiritigenin (ISO) markedly recovered the migration dysfunction in mPDLFs. And Nlrp3 inflammasome components could be aggregated to form an inflammasome complex on stimulation of P.g-LPS, as shown by fluorescence confocal microscopy. Correspondingly, P.g-LPS induced Nlrp3 inflammasome activation, caspase-1 activation, IL-1β and HMGB1 release, which were blocked by Nlrp3 inflammasome inhibitor (ISO). Interestingly, reactive oxygen species, TXNIP protein and TXNIP binding to Nlrp3 were markedly increased in mPDLFs with P.g-LPS. Furthermore, ROS generation inhibitor (Apocynin; APO) significantly reduced Nlrp3 inflammasome formation and IL-1β production in mPDLFs with P.g-LPS. And APO attenuated P.g-LPS-induced TXNIP protein expression and mPDLFs injury. In conclusion, our results demonstrate that ROS/TXNIP/Nlrp3 Inflammasome pathway is a key initiating mechanism necessary for P.g-LPS-induced subsequent mPDLFs inflammatory response leading to chronic periodontitis.

Study of association between interleukin-8 - 845 T/C and + 781 C/T polymorphisms with periodontitis disease among population from Western Iran

Periodontitis is a chronic inflammatory disease that influences the protective tissues of teeth. IL-8, a member of the chemokine super-family, plays vital roles in the pathogenesis of periodontitis with activation and migration of neutrophils in inflammatory regions. The purpose of present study was to evaluate the association of interleukin-8 - 845 T/C and + 781 C/T polymorphisms with periodontitis in an Iranian population. A total of 65 patients with periodontitis including 18 patients with chronic periodontitis and 47 patients with aggressive periodontitis and 55 controls were enrolled into our study. Interleukin-8 - 845 T/C and + 781 C/T polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. For + 781C/T locus, in the dominant genetic model there was a significant difference between TT vs. CC + CT genotypes that significantly had a protective role against periodontitis disease with a value of 0.38 (95% CI 0.16-0.90, p = 0.02). Also, the analysis of results showed a significant positive association between the distribution of IL-8 - 845 T/C alleles and the risk of periodontitis disease (χ² = 6.2, p = 0.01) that presence of C allele of IL-8 - 845 increased the risk of periodontitis disease by 9.08-fold [OR 9.08 (95% CI 1.14-72.12, p = 0.03)]. In conclusion, our results demonstrate a positive association between distribution of IL-8 - 845 T/C alleles and risk of periodontitis disease.

Patients with chronic periodontitis are more likely to develop upper urinary tract stone: a nation-wide population-based eight-year follow up study

Background

The purpose of this study was to investigate the relationship between chronic periodontitis (CP) and upper urinary tract stone (UUTS) in Taiwan by using a population-based data set.

Methods

A total of 16,292 CP patients and 48,876 randomly-selected controls without chronic periodontitis were selected from the National research database and studied retrospectively. Subjects selected have not been diagnosed with UUTS previously. These subjects were prospectively followed for at least eight years. Cox regression models were used to explore the connection between risk factors and the development of UUTS.

Results

The CP patients have a greater chance of developing UUTS compared to controls (1761/16292, 10.8% vs. 4775/48876, 9.8%, p-values < 0.001). Conditioned logistic regression suggested CP increases the risk of UUTS development (HR 1.14, 95% CI [1.08–1.20], p < 0.001). After respective adjustment for age, gender, hypertension and diabetes, results showed that CP still increases the risk of developing UUTS (HR 1.14, 95% CI [1.08–1.20], p < 0.001).

Conclusion

By using a population-based database with a minimum eight 8 follow-up of CP in Taiwan, we discovered patients with CP are more likely to develop UUTS.

Revisiting the Page & Schroeder model: the good, the bad and the unknowns in the periodontal host response 40 years later

In their classic 1976 paper, Page & Schroeder described the histopathologic events and the types of myeloid cells and lymphocytes involved in the initiation and progression of inflammatory periodontal disease. The staging of periodontal disease pathogenesis as 'initial', 'early', 'established' and 'advanced' lesions productively guided subsequent research in the field and remains fundamentally valid. However, major advances regarding the cellular and molecular mechanisms underlying the induction, regulation and effector functions of immune and inflammatory responses necessitate a reassessment of their work and its integration with emerging new concepts. We now know that each type of leukocyte is actually represented by functionally distinct subsets with different, or even conflicting, roles in immunity and inflammation. Unexpectedly, neutrophils, traditionally regarded as merely antimicrobial effectors in acute conditions and protagonists of the 'initial' lesion, are currently appreciated for their functional versatility and critical roles in chronic inflammation. Moreover, an entirely new field of study, osteoimmunology, has emerged and sheds light on the impact of immunoinflammatory events on the skeletal system. These developments and the molecular dissection of crosstalk interactions between innate and adaptive leukocytes, as well as between the immune system and local homeostatic mechanisms, offer a more nuanced understanding of the host response in periodontitis, with profound implications for treatment. At the same time, deeper insights have generated new questions, many of which remain unanswered. In this review, 40 years after Page & Schroeder proposed their model, we summarize enduring and emerging advances in periodontal disease pathogenesis.

Type 1 Diabetes and Periodontal Health

It is well established that hyperglycemia affects periodontal outcomes. A body of evidence, predominantly over the past 20 years supports significant independent associations between periodontal disease and glycemic control or complications of diabetes. Association between periodontal tissue and hyperglycemia is possible through altered cellular immunity, increased proliferation of bacteria, microangiopathy, and formation of the advanced glycation end products. However, most studies focus solely on patients with type 2 diabetes or diabetes in general. There is still the paucity of data concerning patients with type 1 diabetes (T1D). Here, the authors consider the possible mechanisms linking periodontal disease with diabetes, focusing mainly on T1D and discuss possible diagnostic and therapeutic approaches.

Does periodontal inflammation affect glycosylated haemoglobin level in otherwise systemically healthy individuals? - A hospital based study

BACKGROUND AND OBJECTIVES

Microbial biofilm and host susceptibility play an important role in the initiation and progression of periodontitis. Periodontitis is considered the sixth complication of diabetes mellitus and a bidirectional relationship exists between diabetes and periodontitis. This cross-sectional observational study was undertaken to evaluate the glycosylated haemoglobin (HbA1c) level in chronic periodontitis.

METHODS

The study involved 100 subjects. The case group consisted of 50 subjects with chronic periodontitis and the control group consisted of 50 periodontally healthy subjects. Periodontal parameters including plaque index, oral hygiene index, modified gingival index, probing pocket depth, and clinical attachment level were measured and recorded. Systemic parameters like Body Mass Index (BMI), Waist Hip Ratio (WHR), C- Reactive Protein (CRP), Glycosylated haemoglobin (HbA1c), lipid profile, fasting blood sugar, post prandial blood sugar and serum albumin were assessed in all subjects.

RESULTS

The mean HbA1C for the case group was 6.27±1.5 and for the control was 5.36±0.4 and the difference was statistically significant (p = 0.001). The mean FBS, PPBS, LDL, WHR, CRP was statistically significant between groups (p ≤0.05). Periodontal parameters like PI, OHI, MGI, PD and CAL were significantly higher in the case group than the control group (p value ≤ 0.05). The multivariate linear regression model with the dependent variable HbA1c showed chronic periodontitis was significantly associated with HbA1c level.

CONCLUSION

In chronic periodontitis patients (otherwise systemically healthy) the presence of periodontal inflammation affected the glycosylated haemoglobin level and they were in prediabetes stage. Therefore, it is plausible that the prediabetes stage might be reduced via appropriate periodontal therapy.

The role of 5-lipoxygenase in Aggregatibacter actinomycetemcomitans-induced alveolar bone loss

AIM

Leukotrienes (LTs) are pro-inflammatory lipid mediators formed by the enzyme 5-lipoxygenase (5-LO). The involvement of 5-LO metabolites in periodontal disease (PD) is not well defined. This study aimed to assess the role of 5-LO in experimental PD induced by Aggregatibacter actinomycetemcomitans (Aa).

MATERIAL AND METHODS

In vivo experiments were carried out using SV129 wild-type (WT) and 5-LO-deficient (5lo^-/- ) mice inoculated with Aa. Osteoclasts were stimulated in vitro with AaLPS in the presence or not of selective inhibitors of the 5-LO pathway, or LTB4 or platelet-activating factor (PAF), as PAF has already been shown to increase osteoclast activity.

RESULTS

In 5lo^-/- mice, there were no loss of alveolar bone and less TRAP-positive osteoclasts in periodontal tissues, after Aa inoculation, despite local production of TNF-α and IL-6. The differentiation and activity of osteoclasts stimulated with AaLPS were diminished in the presence of BLT1 antagonist or 5-LO inhibitor, but not in the presence of cysteinyl leukotriene receptor antagonist. The osteoclast differentiation induced by PAF was impaired by the BLT1 antagonism.

CONCLUSION

In conclusion, LTB4 but not CysLTs is important for Aa-induced alveolar bone loss. Overall, LTB4 affects osteoclast differentiation and activity and is a key intermediate of PAF-induced osteoclastogenesis.

Salivary Levels of NLRP3 Inflammasome-Related Proteins as Potential Biomarkers of Periodontal Clinical Status

BACKGROUND

Emerging evidence suggests that activation of inflammasomes plays a central mechanism in pathogenesis of periodontitis. This study aims to compare salivary levels of nod-like receptor family pyrin domain containing protein (NLRP) 3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cysteine aspartase (caspase)-1, and interleukin (IL)-1β from individuals with aggressive (AgP) or chronic periodontitis (CP) and healthy controls (HC), as well as elucidate its association with periodontal clinical status.

METHODS

Saliva samples from individuals with CP (n = 75), AgP (n = 20), and HC (n = 69) were collected. Periodontal status was assessed by measurement of probing depth, clinical attachment level, and extent and severity of disease. Salivary levels of analytes were analyzed by enzyme-linked immunosorbent assay. Association between biomarkers with CP or AgP was analyzed using multivariate binary logistic regression models.

RESULTS

Significantly higher levels of NLRP3, ASC, and IL-1β were detected in periodontitis groups in comparison to the periodontally HC group. However, no significant differences were observed for caspase-1 levels between clinical groups, and only NLRP3 salivary concentration was significantly higher in AgP compared with CP patients. Also, positive significant correlations among NLRP3, ASC, and IL-1β salivary concentrations and clinical parameters were observed. Logistic regression analyses revealed a strong/independent association of NLRP3, ASC, and IL-1β salivary levels with CP and AgP.

CONCLUSION

Although the concentration of caspase-1 in saliva samples makes its determination useless for detection of periodontal disease and/or its severity, salivary levels of NLRP3, ASC, and IL-1β may act as strong/independent indicators of amount and extent of periodontal breakdown in both CP and AgP and could potentially be used for prevention and therapy of this group of diseases.

Low-level laser and antimicrobial photodynamic therapy on experimental periodontitis in rats submitted to chemotherapy by 5-fluorouracil

PURPOSE

The aim of this study was to evaluate the effects of low-level laser therapy (LLLT) and antimicrobial photodynamic therapy (aPDT) as adjuvant to mechanical treatment of experimental periodontitis (EP) in adult rats submitted to 5-fluorouracil (5-FU) chemotherapy.

METHODS

EP was induced through ligature around the left mandibular first molar for 7 days. The ligature was removed and the animals separated into groups: EP, no treatment; 5FU, systemic administration of 5-FU (80 and 40 mg/kg); 5FU/scaling and root planing (SRP), systemic application of 5-FU and SRP; 5FU/SRP/LLLT, systemic application of 5-FU, SRP, and LLLT (660 nm, 0.035 W; 29.4 J/cm²); and 5FU/SRP/aPDT, systemic application of 5-FU, SRP, and aPDT (methylene blue irrigation and LLLT). The animals were euthanized 7, 15, and 30 days after treatments. Histological sections from mandibles were processed for histomorphometric and immunohistochemical analysis (TRAP, RANKL, OPG, TNF-α, IL-6, IL-10). The alveolar bone loss (BL) area in the furcation region of the mandibular first molar was analyzed histometrically.

RESULTS

There was less bone loss in 5FU/SRP/aPDT compared with 5FU at 7 days (p < 0.05). The immunohistochemical analysis showed no significant difference for TRAP and osteoprotegerin, but lower RANKL immunolabeling was observed in the 5FU/SRP/LLLT and 5FU/SRP/aPDT groups compared with the 5FU group at 15 days. There was lower TNF-α and IL-6 immunolabeling in the 5FU/SRP/LLLT and 5FU/SRP/aPDT groups and higher IL-10 immunolabeling in 5FU/SRP/aPDT at 30 days.

CONCLUSION

LLLT and aPDT adjuvant to SRP minimized the effects of 5-FU on periodontal disease. Furthermore, aPDT promoted greater benefits in bone loss control and inflammatory response.

Periodontitis and bone metabolism in patients with advanced heart failure and after heart transplantation

AIMS

Heart failure (HF) is a multi-organ, pro-inflammatory syndrome that impairs bone metabolism. Pro-inflammatory cytokines and bone catabolism enhance periodontal disease, a local inflammatory, bacteria-induced disease that causes bone loss and periodontal soft tissue destruction.

METHODS AND RESULTS

Medical and dental examinations were performed on patients with HF (n = 39), following heart transplantation (post-HTx, n = 38) and controls (n = 32). Blood, saliva, and gingival crevicular fluid were analysed for bone metabolism and inflammation markers. HF average New York Heart Association classification was III. Average time since HTx was 1414 days. Pro-inflammatory tumour necrosis factor-alpha was higher in HF and HTx as compared with controls (P < 0.05). Both HF and HTx participants had higher levels of bone resorption marker C-terminal telopeptide and parathyroid hormone with subjects in the HF group having the highest serum levels of all groups (P ≤ 0.05). In contrast, 25-hydroxyvitamin D was lowest in HF. HF patients had greater clinical attachment loss, cumulative pockets depth (greater than 3 mm) and probing depth (P < 0.05) as compared with controls. Cumulative pockets depth correlated significantly with measures of the inflammatory burden, β-glucuronidase in saliva (r = 0.4863, P < 0.01), interleukin-1b in saliva (r = 0.5149, P < 0.01), and gingival crevicular fluid (r = 0.6056, P < 0.001) in HF. However, adjustment of periodontal results for measures of oral hygiene (plaque, bleeding on probing), systemic 25-hydroxyvitamin D, and race attenuated significant differences between groups.

CONCLUSIONS

Patients with HF exhibit more severe periodontal disease associated with increased bone turnover markers when compared with control patients. However, local and systemic factors may account for this association and should be evaluated in future studies.

Epidemiological, clinical and pathological aspects of an outbreak of periodontitis in sheep

ABSTRACT: The objective of this study was to describe the epidemiological, clinical and pathological aspects of an outbreak of periodontitis in sheep that occurred on a rural property in Benevides, in the state of Pará, Brazil. The first clinical signs of this disease in the herd - visible nodular swollen mandible - were observed about one month after the sheep began grazing on a recently renovated Panicum maximum cv. Massai pasture; the animals were also supplemented with elephant grass (Pennisetum purpureum). From the 545 adult Santa Ines, Dorper, Texel and crossbred sheep, 20 (3.7%) showed facial bulging, particularly of the mandible. These 20 sheep, which were generally over 36 months of age, had low body condition scores as well as dull and ruffled coats; many of them had loose or missing pre, upper or lower molars, showed the formation of abscesses and fistulas, exhibited pain upon palpation and had difficulty chewing. In the same herd, the prevalence of periodontal lesions at the premolars and molar teeth was evaluated via post-mortem examination of 39 young and 17 adult sheep. In 51.3% (20/39) of adolescents and in 100% of adults, periodontal lesions were found at least at one tooth of the dental arch, with unilateral or bilateral periodontal lesions at the maxillary and mandibular teeth. Histopathological analysis of 13 sheep revealed pyogranulomatous inflammation. The second and third maxillary premolars were the teeth that were most affected in young animals, whereas the third pre-molar and the molars, of the maxilla and mandible, were most often affected in adults. These lesions led to severe bone destruction, alterations in the dental arch, occlusion, tooth loss and periodontal abscesses. The epidemiological and clinic-pathological characteristics of this periodontitis outbreak, described here for the first time in sheep in Brazil, were similar to those for bovine periodontitis (“cara inchada”).

Immunologic environment influences macrophage response to Porphyromonas gingivalis

Macrophages adapt both phenotypically and functionally to the cytokine balance in host tissue microenvironments. Recent studies established that macrophages contribute an important yet poorly understood role in the development of infection-elicited oral bone loss. We hypothesized that macrophage adaptation to inflammatory signals encountered before pathogen interaction would significantly influence the subsequent immune response of these cells to the keystone oral pathobiont Porphyromonas gingivalis. Employing classically activated (M1) and alternatively activated (M2) murine bone-marrow-derived macrophage (BMDMø), we observed that immunologic activation of macrophages before P. gingivalis challenge dictated phenotype-specific changes in the expression of inflammation-associated molecules important to sensing and tuning host response to bacterial infection including Toll-like receptors 2 and 4, CD14, CD18 and CD11b (together comprising CR3), major histocompatibility complex class II, CD80, and CD86. M2 cells responded to P. gingivalis with higher expression of tumor necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, regulated on activation normal T cell expressed and secreted, and KC than M1 cells. M1 BMDMø expressed higher levels of interleukin-10 to P. gingivalis than M2 BMDMø. Functionally, we observed that M2 BMDMø bound P. gingivalis more robustly than M1 BMDMø. These data describe an important contribution of macrophage skewing in the subsequent development of the cellular immune response to P. gingivalis.

The expression of gingival epithelial junctions in response to subgingival biofilms

Periodontitis is an infectious inflammatory disease that destroys the tooth-supporting tissues. It is caused by the formation of subgingival biofilms on the surface of the tooth. Characteristic bacteria associated with subgingival biofilms are the Gram-negative anaerobes Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, collectively known as the “red complex” species. Inter-epithelial junctions ensure the barrier integrity of the gingival epithelium. This may however be disrupted by the biofilm challenge. The aim of this in vitro study was to investigate the effect of subgingival biofilms on the expression of inter-epithelial junctions by gingival epithelia, and evaluate the relative role of the red complex. Multi-layered human gingival epithelial cultures were challenged with a 10-species in vitro subgingival biofilm model, or its variant without the red complex, for 3 h and 24 h. A low-density array microfluidic card platform was then used for analyzing the expression of 62 genes encoding for tight junctions, gap junctions, adherens junctions, and desmosomes. Although there was a limited effect of the biofilms on the expression of tight, adherens and gap junctions, the expression of a number of desmosomal components was affected. In particular, Desmoglein-1 displayed a limited and transient up-regulation in response to the biofilm. In contrast, Desmocollin-2, Desmoplakin and Plakoglobin were down-regulated equally by both biofilm variants, after 24 h. In conclusion, this subgingival biofilm model may down-regulate selected desmosomal junctions in the gingival epithelium, irrespective of the presence of the “red complex.” In turn, this could compromise the structural integrity of the gingival tissue, favoring bacterial invasion and chronic infection.

Enzyme-labeled Antigen Method: Development and Application of the Novel Approach for Identifying Plasma Cells Locally Producing Disease-specific Antibodies in Inflammatory Lesions

In chronic inflammatory lesions of autoimmune and infectious diseases, plasma cells are frequently observed. Antigens recognized by antibodies produced by the plasma cells mostly remain unclear. A new technique identifying these corresponding antigens may give us a breakthrough for understanding the disease from a pathophysiological viewpoint, simply because the immunocytes are seen within the lesion. We have developed an enzyme-labeled antigen method for microscopic identification of the antigen recognized by specific antibodies locally produced in plasma cells in inflammatory lesions. Firstly, target biotinylated antigens were constructed by the wheat germ cell-free protein synthesis system or through chemical biotinylation. Next, proteins reactive to antibodies in tissue extracts were screened and antibody titers were evaluated by the AlphaScreen method. Finally, with the enzyme-labeled antigen method using the biotinylated antigens as probes, plasma cells producing specific antibodies were microscopically localized in fixed frozen sections. Our novel approach visualized tissue plasma cells that produced 1) autoantibodies in rheumatoid arthritis, 2) antibodies against major antigens of Porphyromonas gingivalis in periodontitis or radicular cyst, and 3) antibodies against a carbohydrate antigen, Strep A, of Streptococcus pyogenes in recurrent tonsillitis. Evaluation of local specific antibody responses expectedly contributes to clarifying previously unknown processes in inflammatory disorders.

Avian leukosis virus subgroup J triggers caspase-1-mediated inflammatory response in chick livers

Many pathogens trigger caspase-1-mediated innate immune responses. Avian leukosis virus subgroup J (ALV-J) causes serious immunosuppression and diverse tumors in chicks. The caspase-1 inflammasome mechanism of response to ALV-J invading remains unclear. Here we investigated the expression of caspase-1, the inflammasome adaptor NLRP3, IL-1β and IL-18 in response to ALV-J infection in the liver of chick. We found caspase-1 mRNA expression was elevated at 5 dpi and peaked at 7 dpi in ALV-J infected animals. Corresponding to this, the expressions of NLRP3 and proinflammatory cytokines IL-1β and IL-18 were significantly increased at 5 or 7 dpi. In addition, caspase-1 protein expression and inflammatory cell infiltration were induced after virus infection. These results indicated that ALV-J infection could trigger the caspase-1- mediated inflammatory response in chicks. Thus, an understanding of the inflammatory responses can provide a better insight into the pathogenicity of ALV-J and a possible anti-virus target for ALV-J infection.

The B Cell-Stimulatory Cytokines BLyS and APRIL Are Elevated in Human Periodontitis and Are Required for B Cell-Dependent Bone Loss in Experimental Murine Periodontitis

B-lineage cells (B lymphocytes and plasma cells) predominate in the inflammatory infiltrate of human chronic periodontitis. However, their role in disease pathogenesis and the factors responsible for their persistence in chronic lesions are poorly understood. In this regard, two cytokines of the TNF ligand superfamily, a proliferation-inducing ligand (APRIL) and B-lymphocyte stimulator (BLyS), are important for the survival, proliferation, and maturation of B cells. Thus, we hypothesized that APRIL and/or BLyS are upregulated in periodontitis and contribute to induction of periodontal bone loss. This hypothesis was addressed in both human and mouse experimental systems. We show that, relative to healthy controls, the expression of APRIL and BLyS mRNA and protein was upregulated in natural and experimental periodontitis in humans and mice, respectively. The elevated expression of these cytokines correlated with increased numbers of B cells/plasma cells in both species. Moreover, APRIL and BLyS partially colocalized with κ L chain-expressing B-lineage cells at the epithelial-connective tissue interface. Ligature-induced periodontitis resulted in significantly less bone loss in B cell-deficient mice compared with wild-type controls. Ab-mediated neutralization of APRIL or BLyS diminished the number of B cells in the gingival tissue and inhibited bone loss in wild-type, but not in B cell-deficient, mice. In conclusion, B cells and specific cytokines involved in their growth and differentiation contribute to periodontal bone loss. Moreover, APRIL and BLyS have been identified as potential therapeutic targets in periodontitis.

Relationship of Bone Metabolism Biomarkers and Periodontal Disease: The Osteoporotic Fractures in Men (MrOS) Study

CONTEXT

Periodontitis is an inflammatory disease of tooth-supporting tissue leading to bone destruction and tooth loss. Periodontitis affects almost 50% of adults greater than 30 years of age.

OBJECTIVE

This study evaluated the association between biomarkers linked to bone formation and resorption with the occurrence and progression of periodontal disease in older men (≥ 65 y).

DESIGN

The Osteoporotic Fractures in Men (MrOS) study is a prospective, observational study among men 65 years of age and older.

SETTING

This ancillary study, Oral and Skeletal Bone Loss in Older Men, was conducted at two of the six MrOS study sites (Birmingham, AL and Portland, OR).

PATIENTS

Patients underwent medical and dental evaluation. Diagnoses of periodontitis were based on clinical attachment loss, pocket depth, calculus, plaque, and bleeding on a random half-mouth. Bone metabolism biomarkers included serum levels of calcium, phosphate (Pi), alkaline phosphatase, albumin, carboxy-terminal collagen crosslinks (CTX), N-terminal propeptides of type I procollagen, isoform 5b of tartrate-resistant acid phosphatase, and urine alpha- carboxy-terminal collagen crosslinks (alpha-CTX) and beta-CTX and serum levels of calciotropic hormones vitamin D (25(OH)D) and PTH.

MAIN OUTCOME MEASURES

The aim of this study is to correlate bone metabolism biomarkers with prevalence and progression of periodontal disease in older men.

RESULTS

Patients with more severe periodontitis had significantly higher levels of PTH (P trend = .0004), whereas 25(OH)D was lower (P trend = .001). In a subset of men reevaluated at a second dental visit, improvement of periodontitis was associated with lower alpha-CTX, beta-CTX, and CTX levels at baseline after adjusting for age, site, and body mass index.

CONCLUSION

This study suggests that a distinct set of biomarkers of bone metabolism are associated with more severe periodontal disease (PTH, 25(OH)D) and periodontal progression (alpha-CTX, beta-CTX, and CTX) over time.

KLIKK proteases of Tannerella forsythia: putative virulence factors with a unique domain structure

Comparative genomics of virulent Tannerella forsythia ATCC 43037 and a close health-associated relative, Tannerella BU063, revealed, in the latter, the absence of an entire array of genes encoding putative secretory proteases that possess a nearly identical C-terminal domain (CTD) that ends with a -Lys-Leu-Ile-Lys-Lys motif. This observation suggests that these proteins, referred to as KLIKK proteases, may function as virulence factors. Re-sequencing of the loci of the KLIKK proteases found only six genes grouped in two clusters. All six genes were expressed by T. forsythia in routine culture conditions, although at different levels. More importantly, a transcript of each gene was detected in gingival crevicular fluid (GCF) from periodontitis sites infected with T. forsythia indicating that the proteases are expressed in vivo. In each protein, a protease domain was flanked by a unique N-terminal profragment and a C-terminal extension ending with the CTD. Partially purified recombinant proteases showed variable levels of proteolytic activity in zymography gels and toward protein substrates, including collagen, gelatin, elastin, and casein. Taken together, these results indicate that the pathogenic strain of T. forsythia secretes active proteases capable of degrading an array of host proteins, which likely represents an important pathogenic feature of this bacterium.

Secretome of gingival epithelium in response to subgingival biofilms

Periodontitis is the chronic inflammatory destruction of periodontal tissues as a result of bacterial biofilm formation on the tooth surface. Proteins secreted by the gingival epithelium challenged by subgingival biofilms represent an important initial response for periodontal inflammation. The aim of this in vitro study was to characterize the whole secreted proteome of gingival epithelial tissue challenged by subgingival biofilms, and to evaluate the differential effects of the presence of the red-complex species in the biofilm. Multi-layered human gingival epithelial cultures were challenged with a 10-species in vitro biofilm model or its seven-species variant excluding the red complex. Liquid chromatography-tandem mass spectrometry for label-free quantitative proteomics was applied to identify and quantify the secreted epithelial proteins in the culture supernatant. A total of 192 proteins were identified and quantified. The biofilm challenge resulted in more secreted proteins being downregulated than upregulated. Even so, presence of the red complex in the biofilm was responsible for much of this downregulatory effect. Over 24 h, the upregulated biological processes were associated with inflammation and apoptosis, whereas the downregulated processes were associated with the disruption of epithelial tissue integrity and impairment of tissue turnover. Over 48 h, negative regulation of several metabolic processes and degradation of various molecular complexes was further intensified. Again, many of these biological regulations were attributed to the presence of the red complex. In conclusion, the present study provides the secreted proteome profile of gingival epithelial tissue to subgingival biofilms, and identifies a significant role for the red-complex species in the observed effects.

Bacterial profile of aggressive periodontitis in Morocco: a cross-sectional study

Background

Aggressive periodontitis (AgP) is one of the most severe forms of periodontal diseases. In Morocco, Aggregatibacter actinomycetemcomitans has been strongly associated with AgP, however limited knowledge is available about the implication of other periodontal pathogens in this entity. Therefore, the main aim of this study was to evaluate the composition of the subgingival microbiota in Moroccan patients with AgP.

Methods

Subgingival plaque samples were collected from 50 aggressive, 13 localized and 37 generalized periodontitis patients. Samples from 20 chronic periodontitis (ChP) patients were taken as controls. Samples collected from the four deepest periodontal pockets in each patient were pooled in pre-reduced transport fluid and examined by culture.

Results

A. actinomycetemcomitans was significantly more frequent (p = 0.004) in generalised AgP compared to ChP, and Porphyromonas gingivalis was less prevalent in localized AgP, when compared with generalized AgP (p = 0.040) or ChP (p = 0.016). Prevotella intermedia, Fusobacterium nucleatum and Tannerella forsythia were also frequently detected in all groups. Mean proportions of A. actinomycetemcomitans were significantly higher in AgP groups, when compared to ChP, and generalized AgP patients harbored significantly higher proportions of P. gingivalis and T. forsythia, when compared to localized AgP or ChP.

Conclusions

A. actinomycetemcomitans, P. gingivalis, T. forsythia, P. intermedia and F. nucleatum were frequently detected in this Moroccan population with AgP. Differences in frequency of detection, counts and proportions of A. actinomycetemcomitans, P. gingivalis and T. forsythia suggests the presence of distinct microbiological profiles for localized AgP, generalized AgP and ChP patients.