Specific Periodontal Pathogens Research Articles

Periodontitis in Patients Undergoing Coronary Angiography: A Cross-Sectional Study.

Background Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide, with coronary artery disease (CAD) being the primary contributor. Periodontitis, a common non-communicable disease, has been associated with an increased risk of CVD. Previous studies have suggested a link between the severity of periodontitis and the degree of coronary artery obstruction. Objective This study aims to investigate the correlation between the severity of periodontitis and coronary artery stenosis, as measured by the SYNTAX score I (Synergy Between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery), and to examine the association between severe periodontitis and other coronary pathologies, such as diffuse coronary disease and coronary thrombosis. Materials and methods An observational cross-sectional study was conducted at the Second Cardiology Clinic, University Multiprofile Hospital for Active Treatment "St. Marina", Varna, Bulgaria, from December 2021 to January 2024. A total of 199 patients aged 45-64 years, indicated for coronary angiography, were included. Periodontal assessment included measuring probing pocket depth (PPD), clinical attachment loss (CAL), bleeding on probing (BoP), and plaque index (PI). Subgingival plaque samples were analyzed for periodontal pathogens. Coronary angiography was performed, and the SYNTAX score I was calculated to assess the severity of coronary artery stenosis. Statistical analyses, including chi-square tests and Spearman's correlation, were conducted to evaluate the associations. Results Among the 199 participants, 74.9% had severe periodontitis (stage III and IV). A weak but statistically significant correlation was found between mean CAL, periodontitis stage, and the SYNTAX score I (p < 0.01 and p < 0.05, respectively), indicating that more severe forms of periodontitis were associated with greater coronary artery stenosis. No correlation was observed between the presence of periodontal pathogens or the total microbial count and the SYNTAX score I. Additionally, no association was found between severe periodontitis and other coronary conditions, such as diffuse coronary disease and thrombosis. Conclusion This study provides new insights into the relationship between periodontal infection and coronary artery disease. Our findings suggest that severe periodontitis is significantly associated with a higher frequency and more complex coronary lesions, as indicated by the SYNTAX score I. However, no link was observed between specific periodontal pathogens and coronary stenosis. These results underscore the importance of early diagnosis and management of periodontal infections in patients with CAD, highlighting the potential benefits of an integrated approach to managing cardiovascular and periodontal health. Further studiesare needed to explore these associations in more depth.

Clinical and microbial evaluation of mouthwash containing Achyranthes aspera and Trachyspermum ammi: A randomized controlled non-inferiority trial

ObjectivesAchyranthes aspera (Apamarga) and Trachyspermum ammi (Ajwain) have been used in many clinical conditions, and it displays valuable properties as an alternative to Chlorhexidine (CHX) in the management of gingivitis. Therefore, this study aims to assess the effect of Achyranthes aspera and Trachyspermum ammi (AA + TA) based herbal mouthwash, 0.2 % CHX, and placebo mouthwash on gingival health, plaque control and antibacterial activity against specific periodontal pathogens (Porphyromonas gingivalis and Tannerella forsythia) using quantitative real-time PCR (RT-PCR). MethodsThis was a randomized controlled non-inferiority trial involving 108 children with plaque-induced gingivitis who were randomly assigned to three groups of 36 children each: Group A, AA + TA mouthwash; Group B, CHX mouthwash; and Group C, placebo mouthwash. Gingival index and plaque index were recorded at baseline, 7th and 21st day. RT-PCR was employed to determine the bacterial counts of each plaque sample at baseline and after 21 days. ResultsAll three groups exhibited a gradual and significant reduction in both gingival and plaque scores from baseline to days 7 and 21. However, the placebo group did not demonstrate a significant difference in scores between days 7 and 21. Furthermore, a significant reduction in bacterial counts of P. gingivalis and T. forsythia was observed in the groups receiving CHX and AA + TA mouthwash after 21 days of intervention compared to the placebo group. ConclusionAA + TA mouthwash demonstrated non-inferiority in anti-gingivitis and anti-plaque properties compared to CHX, suggesting its potential suitability as an alternative to CHX when used in conjunction with mechanical plaque control measures.

Periodontal Health in Children with Juvenile idiopathic arthritis.

To investigate gingival inflammation and prevalence of four specific periodontal associated pathogens in Juvenile idiopathic arthritis (JIA) in relation to orofacial pain, jaw function and systemic inflammatory activity in JIA. Forty-five children with JIA and 16 healthy children as controls, were enrolled. Subjects were examined and classified according to the diagnostic criteria for temporomandibular disorders (DC/TMD). Pain, pain-related disability and jaw function were also assessed. A clinical periodontal examination was performed. Subgingival plaque samples were collected and analyzed for semiquantitative levels of the following periodontal pathogens; Aggregatibacter actinomycetemcomintans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola. This study suggests that the periodontal disease-associated bacteria P. gingivalis and T. forsythia do not contribute to neither periodontal disease, systemic inflammatory activity nor orofacial pain and jaw dysfunction, including TMJ arthritis, in JIA patients in Sweden.

Silver-deposited titanium as a prophylactic 'nano coat' for peri-implantitis.

Dental implant failures caused by bacterial infections are a significant concern for dental implantologists. We modified the titanium surface by depositing silver (Ti-Ag) using direct current (DC) sputtering and confirmed the formation of a 'nano coat' by X-ray photoelectron spectroscopy (XPS), surface profilometry and energy dispersive spectroscopy (EDS). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed the deposition of a uniform nano Ag thin film. A gradual increase in thickness was observed, and the film thickness (530 nm) at 5 min deposition time (Ti-Ag5) resulted in a reduction of the water contact angle (WCA, 15%) and an increase in surface energy (SFE, 22%) in comparison to the uncoated Ti surface. Using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), the slow, steady release of Ag from the coating was observed over 21 days. The Ti-Ag5 surface exhibited excellent antibacterial activity against Streptococcus oralis, Streptococcus sanguinis, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis, which belonged to the yellow, purple, and red complexes, representing specific periodontal pathogens. Furthermore, we observed excellent cytocompatibility of Ag-deposited Ti towards MG-63 osteoblasts with no inhibitory effect on their proliferative potential. Quantitation of alkaline phosphatase (ALP) activity, mineralization efficiency, and osteogenesis-related gene expression of MG-63 cells over 21 days was suggestive of rapid osseointegration. Overall, the 'nano coat' of Ag on Ti is indeed a prophylactic against peri-implantitis, ensuring increased implant success.

Virulent Porphyromonas gingivalis as the root cause of chronic inflammation‐a Chronic Oral Health Perspective

AbstractOral health professionals are the forefront of preventing and treating not only dental and periodontal diseases, but also a growing list of systemic conditions associated with specific periodontal pathogens such as P. gingivalis (Pg). The oral‐systemic connection offers dental professionals an opportunity to positively influence patients’ overall health. Armed with the ability to transform its own environment and the entire periodontal microbiome, as well as modify the host response, the influence of Pg extends beyond the oral cavity. Beyond the neuroinflammatory effects discussed in this session it is capable of both releasing complex virulence factors/toxins and translocating and invading distant tissues and organs and is involved in the pathogenesis of systemic diseases including cardiovascular disease, atherosclerosis, hypertension, myocarditis, and myocardial infarction. This periodontal pathogen also impacts autoimmune diseases including rheumatoid arthritis; neurodegenerative diseases such as Alzheimer’s disease and AD‐related brain atrophy; several cancers‐oral, esophageal, and pancreatic; and metabolic diseases such as diabetes mellitus. Pg by limiting the complement cascade and restraining leukocyte death by activating and exploiting the C5a‐receptor signaling pathway. Another viable conduit in systemic dysbiosis and immune dysfunction is the translocation of Pg with its microbiome‐altering abilities and its coaggregation pathobiont actions found in the gut flora. Studies on murine models that introduced Pg into the gut demonstrated an altered intestinal microflora and increased manifestation or aggravation of liver disease, arthritis, including an increase in the production of proinflammatory cytokines observed at both the intestinal and extra‐intestinal levels. Dental professionals will most likely be one of the major healthcare delivery systems to bring a paradigm shift in healthcare and medicine using novel companion diagnostics and treatments to early screening and treatment of virulent Pg infections in the general population thereby greatly reducing the onset of multiple major systemic inflammatory driven chronic diseases. Dental professionals will most likely be one of the major healthcare delivery systems to bring a paradigm shift in healthcare and medicine by using novel companion diagnostics and treatments to early screening and treatment of virulent Pg infections in the general population thereby greatly reducing the onset of multiple major systemic inflammatory driven chronic diseases.

The Relationship between Dietary Habits and Periodontal Pathogens in a Sample of Romanian Children and Adolescents: A Cross-Sectional Study.

The role of diet in shaping oral microbiota and its potential contribution to the development of periodontal pathogens cannot be understated. This study aimed to explore the correlation between dietary habits and the prevalence of 11 periodontal pathogens among children and adolescents in Oradea, Romania. The identification of these pathogens was performed using the micro-IDent test kit, capable of detecting 11 specific periodontal pathogens. Bacterial sampling was conducted from the crevicular fluid in the morning, prior to brushing, followed by the completion of a brief questionnaire by parents. The questionnaire captured various aspects of the children's eating habits, including meal frequency, consumption of sweets, and hydration levels. The collected samples were dispatched to the laboratory for analysis, which provided insights into the abundance of microorganisms. The study encompassed 60 participants aged between 2 and 18 years, with the majority reported by their parents to have regulated meal timings, frequent sugar intake, and adequate hydration. The findings revealed significant associations between certain dietary factors and the presence of specific periodontal pathogens. Notably, the absence of breastfeeding was linked with the detection of Tannerella forsythia and Campylobacter rectus. Furthermore, frequent consumption of sweets corresponded with the presence of Capnocytophaga spp., which was particularly observed in individuals consuming sweets 2-3 times a day. Insufficient age-appropriate hydration showed an association with the prevalence of T. forsythia, Peptostreptococcus micros, and Capnocytophaga spp. In this sample, it became evident that eating habits and diet influenced the presence of several periodontal pathogens. The lack of breastfeeding was predominantly associated with positive results for T. forsythia and C. rectus, while inadequate hydration correlated more frequently with the presence of T. forsythia and P. micros. Moreover, frequent consumption of sweets was linked to the presence of Capnocytophaga spp.

Abstract 4238: Specific oral microbiome is closely associated with oral potentially malignant disorders and oral squamous cell carcinoma

Abstract Background: Bacterial and virus infection may cause pre-malignant and malignant disorder such as hepatocellular carcinoma and cervical cancer. Recent studies reported that oral bacterium is associated with gastric and colon cancer. However, it is not clear yet if the oral microbiome affects the development of pre-malignant disorder in oral cavity and oral cancer. Thus, this study aims to identify the periodontal pathogen candidates involved in the onset and progression of oral squamous cell carcinoma (OSCC). Materials and Methods: Saliva was collected from 112 patients without oral mucosal diseases (OMDs) as control, 36 patients with oral potentially malignant disorders (OPMDs), and 104 patients with OSCC, and DNA was extracted in each sample. Periodontal examinations were performed on all patients. Endpoint-PCR was performed on seven species of oral pathogens using the extracted DNA. 16S ribosomal RNA (rRNA) was utilized for analysis of oral microbiome with 20 samples in each group. 4-nitroqquinoline-1-oxide (4-NQO)-induced tongue tumor model in mice was analyzed with or without endotoxin of one of the oral bacteria, Porphyromonas gingivalis (P. gingivalis). Results: From the statistical analysis of the clinical parameters, periodontal disease tended to worsen in the OMPD and OSCC groups compared to the control group. The number of oral bacteria was significantly higher in the OSCC group than those in other groups. From PCR results, the detection rates of P. gingivalis, Aggregatibacter actinomycetemcomitans, and Treponema denticola were significantly higher in the OSCC group than those in the control group. From 16S rRNA analysis, the relative abundance of Prevotella buccae and intermedia was significantly higher in OSCC groups than in the control group. Furthermore, the relative abundance of P. gingivalis was higher in the OSCC group compared to other groups, regardless of age and the number of teeth. In mouse model, mice treated with P. gingivalis-derived endotoxin developed oral leukoplakia at earlier time points and tumors significantly higher lesions compared to control group. Conclusion: These results suggest that specific periodontal pathogens are present in the oral cavity of OPMDs and OSCC patients and those changes in the bacterial flora due to their presence may contribute to the onset and progression of OMDs. Citation Format: Mitomu Kioi, Hiroshi Isono, Shintaro Nakajima. Specific oral microbiome is closely associated with oral potentially malignant disorders and oral squamous cell carcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4238.

Clinico-microbiologic impact of photodynamic therapy in periodontal pocket as an adjunct to mechanical debridement for the management of halitosis

Background: Halitosis associated with periodontitis shelters specific periodontal pathogens, especially at sites such as periodontal pockets and the dorsal surface of the tongue; antimicrobial photodynamic therapy (aPDT) has shown an antimicrobial effect against them. Materials and Methods: A total of 24 participants with a clinical diagnosis of halitosis and stage II grade B periodontitis were divided into two groups. Scaling and root planing (SRP) plus aPDT was given to one group of 12 patients (group I), while SRP alone was performed in another. aPDT was performed using a 660 nm diode laser, in continuous contact mode. Clinical parameters such as halitosis score, plaque index, and probing depth were measured. Subgingival plaque samples were collected on 0, 3rd, 7th, and 14th day after treatment for microbiological analysis of Porphyromonas gingivalis, Fusobacterium nucleatum, and Treponema denticola using real-time polymerase chain reaction. Results: Both groups have shown improvements in all clinical parameters, and statistically significant results were observed in group I compared with group II with a P &lt; 0.05 from 0 day to 14 days. Conclusion: Within the scope of this study, the results have shown improvement in halitosis from a single sitting of aPDT, for a shorter duration and it can be recommended as adjunctive management for halitosis in patients with periodontal pockets.

The influence of diabetes mellitus on the peri-implant microflora: A cross-sectional study

BackgroundType 2 diabetes mellitus (T2DM) is an important systemic disease, predisposing patients to inflammatory conditions including periodontitis and peri-implantitis and negatively affects dental implant success through various mechanisms. This study aimed to compare clinical and microbiological findings of individuals with dental implants with or without T2DM. MethodsA total of 82 dental implants which were in function >3 years, were involved. The participants were divided into 2 groups; T2DM (n: 45 implants) and systemically healthy controls (n:37 implants). Periodontal indexes (Bleeding on probing (BOP), plaque index (PI), pocket depth (PD), and radiographic bone loss were recorded around implants in function >3 years. Subgingival microbiological samples were also collected from the peri-implant sites. Pathogens include Fusobacterium nucleatum, Camphylobacter rectus, Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans, Treponema denticola, Prevotella intermedia, Peptostreptococcus micros, Eikinella corrodens, Prevotella nigrescens were evaluated. ResultsPeri-implant heatlh was determined in systemically healthy (54.1%) and type 2 diabetes patients (24.4%). Peri-implantitis was also evident in systemically healthy (8.1%) and T2DM (35.6%) groups. No differences was found in shallow peri-implant pockets in both groups in terms of the prevelance of all evaluated bacteria (p > 0.05). However, C. rectus, P. gingivalis, A. actinomycetemcomitans and T. forsythia were isolated more frequently in deep peri-implant pockets in systemically healthy patients compared to T2DM patients (p < 0.05). ConclusionsEvaluted periodontal pathogens may not be affected by the presence of T2DM in implants. T2DM may not significantly alter the levels of specific periodontal pathogens in shallow and deep peri-implant pockets. C. rectus, P. gingivalis, A. actinomycetemcomitans and T. forsythia may be affected by T2DM in implants in deep pockets.

Assessment of Serum IgG Titers to Various Periodontal Pathogens Associated with Atrial Fibrillation in Acute Stroke Patients

ObjectivesThere is accumulating evidence that periodontal disease is associated with atrial fibrillation (AF) or stroke, but it is unclear which causative species of periodontal disease are present in stroke patients with AF. We aimed to investigate the associations between AF and specific periodontal pathogens using serum titers of IgG antibodies of bacteria in acute stroke patients. Materials and methodsAcute stroke patients were registered at two hospitals. Serum samples were evaluated for titers of antibodies against 9 periodontal pathogens (16 genotypes) using ELISAs. We identified AF in patients according to the following criteria: (1) a history of sustained or paroxysmal AF or (2) AF detection upon arrival or during admission. We carried out propensity score matching to categorize the patients as those with AF and those without. ResultsOf the 664 acute stroke patients, 123 (18.5%) had AF. After propensity score matching, 234 patients were selected. Patients with AF had a higher prevalence of positive serum titers of antibodies against Porphyromonas gingivalis (FimA type III) and Porphyromonas gingivalis (FimA type V) than those without AF (59.0% vs. 39.3%, p=0.004 and 58.2% vs. 40.2%, p=0.009, respectively). ConclusionsPorphyromonas gingivalis, especially FimA type III and type V, might be associated with AF in stroke patients.

A cross-sectional study of periodontal pathogens in saliva of edentulous patients

Objective: To investigate the prevalence of five specific periodontal pathogens in the saliva of edentulous patients and to compare the differences in the saliva of dentulous individuals with various periodontal conditions. Methods: All the subjects were patients who received regular care at the Beijing Hypertension Prevention and Management Institute. Twenty-seven edentulous patients (edentulous group) were included. According to age (age gap≤5 years), gender, smoking status, diabetes status and hypertension status, each edentulous patient was paired with dentulous individuals suffering from various severity of periodontitis in the same cohort. Then, we selected 3 groups of patients (n=27 in each group) with no or mild periodontitis (mild group), moderate periodontitis (moderate group) and severe periodontitis (severe group). The whole unstimulated saliva was collected before the periodontal examination. Questionnaire survey and periodontal parameters, including plaque index (PLI), probing depth (PD), bleeding index (BI) and clinical attachment loss (CAL), were examined at mesial-buccal and distal-lingual sites of each tooth respectively. DNA was extracted from each sample of the salivary deposition. Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Campylobacter rectus (Cr) and Prevotella nigrescens (Pn) were detected by using PCR method based on 16SrRNA. The prevalence and quantity of the pathogens under various severity of periodontitis were compared. Results: One or more periodontal pathogens could be detected from the 78% (21/27) of the salivary samples in edentulous group. Thereinto, the prevalences of the five periodontal pathogens were ranked as (from high to low): Cr [56% (15/27)], Tf [44% (12/27)], Pn [26% (7/27)], Pg [22% (6/27)] and Td [11% (3/27)]. All five pathogens' prevalences and Pg, Tf, Td and Pn's quantities showed statistical differences among the four groups. The numbers of detected bacterial species in the mild, moderate and severe groups were significantly higher than that in the edentulous group (P<0.01). Furthermore, the prevalences of the red complex in three dentulous groups [96% (26/27) in each group] were significantly higher than the edentulous group [48% (13/27)] (P<0.05). The proportions of the red complex among all five pathogens (83%) in moderate and severe groups were significantly higher than that in the edentulous group (37%) (P<0.01). Conclusions: All five periodontal pathogens could be detected in most of the saliva samples from edentulous individuals. Nevertheless, the prevalence and quantity were lower than dentulous individuals.

Antibacterial Efficacy of E. Jambolana (Syzygium Cumini) Seeds Extracts against Periodontal Pathogens: an In-Vitro Study

Background: Periodontal disease is progressive, inflammation of dento-gingival complex caused by specific periodontal pathogens. Objective: To evaluate the minimum inhibitory concentration and zone of inhibition of E. Jambolana (S.cumini) seed extract (aqueous, ethanol and acetone extracts) against P.Gingivalis, F.Nucleatum and A. Actinomycetemcomitans by tube dilution and disc diffusion tests. Methods: Aqueous, ethanol and acetone extract of E. Jambolana seeds were prepared. Blood agar media with Hemin, Vitamin K and Kanamycin was used to culture P gingivalis. Crystal violet Erythromycin Blood Agar and Thioglycolate broth with 1% horse serum were used to culture F. nucleatum and A. actinomycetemcomitans respectively. The antibacterial activity of extracts was evaluated by using the disc diffusion method and the Minimum Inhibitory Concentration (MIC) of the test solutions was determined by Tube dilution method. Results: E. Jambolana seed extracts exhibited antibacterial effect against all three tested periodontal pathogens. Acetone extract of E. Jambolana exhibited more potent activity than the aqueous and ethanol extracts. Minimum Inhibitory concentration of E. Jambolana seed extract against P. gingivalis, was found to be 6.25µl/ml (acetone), against F. nucleatum it was 25µl/ml (acetone) and against A. actinomycetemcomitans it was 12.5µl/ml (acetone). Conclusion: Syzygium cumini seeds extracts exhibited antibacterial property against P. gingivalis, A. actinomycetemcomitans and F. nucleatum.

Presence of Specific Periodontal Pathogens in Prostate Gland Diagnosed With Chronic Inflammation and Adenocarcinoma.

BackgroundIntraprostatic inflammation is frequently observed in the prostate and linked to prostatic diseases, including prostatitis, benign prostatic hyperplasia (BPH), and cancer. The etiology of prostate diseases is unclear. Periodontal diseases are associated with an increased risk of prostate diseases. In men, chronic prostatitis and moderate/severe periodontitis have significantly elevated serum prostate-specific antigen (PSA) levels. Treatment of periodontal disease reduced PSA levels in men. The presence of periodontal pathogens deoxyribonucleic acid (DNA) was identified in the prostate fluid of prostatitis patients. These pathogenic bacteria might have the potential to trigger prostatitis progressing to prostatic adenocarcinoma. The mechanism(s) explaining the etiology of association between periodontal disease and prostate cancer remains unclear. However, the presence of periodontal pathogens has not been analyzed in the prostate gland.ObjectiveTo identify and compare the presence of specific periodontal pathogens in the areas of BPH, inflammation, and cancer of the prostate glands diagnosed with malignancy.Materials and methodsWhole-mount radical prostatectomy sections from men (n=30) were identified for BPH, inflammation, and cancer areas and marked for tissue procurement. The tissues were subjected to DNA isolation and analysis of microbial DNA and total bacterial load for the following pathogens, including Porphyromonas gingivalis strain ATCC 33277, Prevotella intermedia strain B422, Treponema denticola strain 35405, Fusobacterium nucleatum subsp. fusiform strain, Tannerella forsythia strain ATCC 43037, and Campylobacter​​​​​​​ rectus strain ATCC 33238performed real-time PCR. The universal bacterial primer pairs were used to detect genomic DNA (gDNA) from the total bacteria present in the samples. All species-specific primers were designed to target the variable regions of the 16S ribosomal RNA (rRNA). Data were analyzed using the 2-ΔΔCT method, statistically validated using unpaired t-test and ANOVA test.ResultsA total of 90 samples of prostate tissue specimens were analyzed for periodontal pathogens; only one pathogen (F. nucleatum subsp. fusiform strain ATCC 51190) showed a significant difference compared to the expression of S. epidermidis (internal control). In particular, F. nucleatum expression was 9, 11.9, and 10.3-fold higher in BPH, inflammation, and cancer, respectively, at p-value <0.05. Moreover, the bacterial load abundance/expression was almost similar in BPH (46.8-fold), inflammation (40.9 fold), and cancer (41.5 fold) higher. There was no significant difference in bacterial load (folder change) among the three areas of BPH, inflammation, and cancer (p-valve>0.05). Similarly, there was no significant difference between F. nucleatum (folder change) among the three areas (p-valve>0.05).Conclusion Fusobacterium nucleatum is identified in the prostates that harbor cancer, chronic inflammation, and BPH.

Development of Metronidazole-loaded In situ Thermosensitive Hydrogel for Periodontitis Treatment

Periodontal treatment focuses on the thorough removal of specific periodontal pathogens, mainly anaerobic Gram-negative bacteria, by mechanical scaling and root planning. In case the periodontal abscess is detected after treatment, a high dose of antimicrobial agents is commonly applied via oral administration. However, this approach increases the risk of antibiotic resistance and systemic side effects and decreases efficacy. To overcome the aforementioned issues, this study focused on the development of thermosensitive hydrogel to deliver the antibiotic drug metronidazole (MTZ) directly and locally to the oral infection site. The thermosensitive hydrogels were prepared by blending 28% w/v Pluronic F127 with various concentrations of methylcellulose (MC) and silk fibroin (SF). The gel properties, such as sol-gel transition time, viscosity, and gel strength, were investigated. The drug dissolution profiles, together with their theoretical models and gel dissolution characteristics, were also determined. All hydrogel formulations exhibited sol-gel transitions at 37°C within 1 min. An increase in MC content proportionally increased the viscosity but decreased the gel strength of the hydrogel. By contrast, the SF content did not significantly affect the viscosity but increased the gel strength of the hydrogel. The thermosensitive hydrogels also showed prolonged MTZ release characteristics for 10 days in phosphate-buffered saline (PBS) at pH 6.6, which followed the Higuchi diffusion model. Moreover, MTZ-thermosensitive hydrogel exhibited delayed dissolution in PBS at 37°C for more than 9 days. MTZ-thermosensitive hydrogels could be considered a prospective local oral drug delivery system to achieve efficient sustained release and improve the drug pharmacological properties in periodontitis treatment.

Alzheimer disease and the periodontal patient: New insights, connections, and therapies.

Loss of cognitive function in the aging population, particular those with Alzheimer disease, presents unique challenges to health practitioners. For the dental practitioner these include management of periodontal diseases, caries, and other dental conditions in this special population. It is well established in the cognitively impaired patient that a lack of adherence to dental hygiene routines and professional care leads to increases in the prevalence and severity of these dental conditions, leading to increased loss of teeth. More recent evidence has indicated a possible role of the microbiota of dental plaque associated with periodontal diseases in the development and progression of Alzheimer disease, thereby supporting a two-way interaction of these two diseases. New therapies are needed to address the potential upstream events that may precede overt signs of Alzheimer disease. One of these approaches would be to target these various bacterial, viral, and other microbial pathogens associated with periodontal disease that can translocate into the bloodstream and then to distal sites, such as the brain. Such microbial translocation would lead to local inflammation and buildup of the hallmark signs of Alzheimer disease, including amyloid beta deposits, tau fragmentation and tangles, breakdown of host protective molecules, such as the apolipoproteins, and neuron toxicity. In this review, evidence for the biological basis of the role of the periodontal disease microflora on the initiation and progression of Alzheimer disease will be presented with a focus on the potential role of the keystone pathogen Porphyromonas gingivalis with its family of gingipain enzymes. The various mechanisms for which P.gingivalis gingipains may contribute to the initiation and progression of Alzheimer disease are presented. Small-molecule inhibitors of these gingipains and their effects on reducing biological markers of Alzheimer disease may have beneficial effects for the initiation and progression of loss of cognitive function in Alzheimer disease. In addition to these targeted therapies for specific periodontal pathogens, considerations for the dental practitioner in applying more general approaches to reducing the periodontal plaque microflora in the management of the cognitively impaired patient are discussed for this special population.

MICRO BIOLOGY OF PERIODONTAL DISEASE- A REVIEW

Periodontal diseases are inflammatory and destructive diseases of the dentogingival complex associated with specific periodontal pathogens inhabiting periodontal pockets. Periodontal diseases lead to damage of the periodontal tissues supporting the teeth (bone and connective tissue) and affect the quality of life of the affected individuals: poor alimentation, tooth loss, social and financial problems. Although it is generally considered that the disease has multifactorial etiology, data show that some specific Gram-negative microorganisms in the subgingival plaque biofilm play a major role in the initiation and progression of periodontitis. Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia form a consortium in the subgingival biofilm and are regarded as the principal periodontopathogenic bacteria. Other microorganisms that have been implicated as predominant species in the disease process are: Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, Peptostreptococcus migros, Eikenella corrodens. In periodontitis, the initiation of the disease is the colonization of the tissues by these pathogenic species. The next step is bacterial invasion or invasion by pathogenic products into the periodontal tissues, interactions of bacteria or their substances with host cells, and this directly/indirectly causes degradation of the periodontium, resulting in tissue destruction.&#x0D; Keywords: periodontal disease, periodontal pathogens, microbiology.

Microbiologic Profiles of Patients with Dental Prosthetic Treatment and Periodontitis before and after Photoactivation Therapy-Randomized Clinical Trial.

Fixed prosthodontic dental restorations can potentially affect the periodontal tissues and vice versa, the periodontium can influence the longevity and esthetic appearance of dental restorations. We proposed an investigation on total bacterial load, specific periodontal pathogens, and periodontal clinical parameters in patients with dental fixed prosthesis and different degrees of periodontal tissue loss that followed photoactivation therapy (PDT) adjunctive to scaling and root planing. The study was conducted on 160 subjects, which were randomly assigned to scaling and root planing (SRP) alone (52 subjects, 256 sites), SRP and chlorhexidine rinsing (58 subjects, 276 sites), and SRP plus PDT (50 subjects, 318 sites). Periodontal parameters (plaque index, bleeding on probing, probing depth, and clinical attachment loss), followed by total bacterial load and specific periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) were examined in each patient at baseline, one and six months after. PDT exerted significant improvements both in clinical and microbiological load after one month, and these results were maintained 6 months after when compared to chlorhexidine rinsing or SRP alone, especially in severe periodontitis cases. Photoactivation therapy as an adjunctive periodontal therapeutic method was efficient in offering supplementary periodontal improvements in the clinical and microbiological parameters of patients with fixed dental prosthesis, particularly in severe periodontitis cases.

Abstract MP43: Paradoxical Response to Antibodies in Periodontal Microbes in Subjects With Intracranial Atherosclerotic Stenosis

Introduction: Previously we have shown that periodontal disease and systemic inflammation are related to intracranial atherosclerosis (ICAS) in Atherosclerosis Risk In Communities study (ARIC). In this study we evaluated the relationship between serum antibodies against periodontal pathogens and ICAS. Methods: In this ongoing, prospective, longitudinal community-based cohort study, participants were assessed for antibodies to periodontal organisms including Porphyrmonas gingivalis (PG), Prevotella intermedia (PI), Prevotella nigrescens (PN), Bacteriodes forsythensis (BF), Treponema denticola (TD), Actinobacillus actinomycetemcomitans (AA), Campylobacter rectus (CR), Eikenella corrodens (EC), Fusobacterium nucleatum (FN), Peptostreptococcus micros (PM), Selenomonas noxia (SN), Capnocytophaga ochracea (CO), Veillonella parvula (VP), Streptococcus sanguinis (SS), Streptococcus intermedius (SI), Streptococcus oralis (SO), Actinomycosis viscosis (AV) and Helicobacter pylori (HP). These participants underwent 3D time-of-flight magnetic resonance angiography (MRA) to evaluate ICAS. Log mean antibody (IgG), CRP and IL-6 levels were compared using t-test between groups with and without ≥50% ICAS. Results: In this ARIC cohort, 1066 participants were assessed by MRA for ICAS. Serum CRP and IL-6 data were available for all and IgG levels were available for 772 participants. The log mean IgG level was significantly lower for patients with ≥50% ICAS versus patients with &lt;50% ICAS in four organisms: PN (1.69 vs 1.80, p= 0.03 ), BF (1.30 vs 1.38, p=0.05 ), CO (1.23 vs 1.33, p= 0.04 ), FN (0.87 vs 1.01, p=0.02 ). The log mean IgG was also lower for CR, EC, SN, VP, SI, SO and AV though not significant. Log mean CRP was higher in the ≥50% ICAS group versus the &lt;50% ICAS group (0.58 vs. 0.47, p &lt; 0.001 ). Log mean IL-6 levels were also higher but not significant (0. 17 vs. 0.11, p= 0.07 ). Conclusion: Higher levels of systemic inflammatory markers (CRP, IL-6) are associated with significant ICAS, but we report a significantly lower level of IgG antibodies to specific periodontal pathogens (PN, BF, CO and FN) in patients with ≥50% ICAS. This paradoxical finding may represent the effect of systemic inflammation and oxidative stress on IgG levels to periodontal bacteria.

IL-1B(3954) polymorphism and red complex bacteria increase IL-1β (GCF) levels in periodontitis.

The aim of this study was to compare IL-1β levels in gingival crevicular fluid (GCF) from healthy and periodontitis sites of IL-1B(3954)-Single Nucleotide Polymorphism (SNP) positive and IL-1B(3954)-SNP negative periodontitis subjects in association with their bacterial profiles. Susceptibility to periodontitis has been associated with several risk factors, including allelic variants at multiple gene loci. Variations in the IL-1 gene cluster have been linked with increased risk for periodontitis. IL-1B(3954)-SNP has been previously associated with increased levels of IL-1β in GCF or periodontal tissues in chronic periodontitis patients, as well as higher levels of specific periodontal pathogens. There is insufficient evidence to conclude if IL-1B gene polymorphisms affect the susceptibility to periodontitis by ultimately modulating the levels of IL-1β in GCF, the subgingival microbial profile or both. GCF, subgingival plaque, and buccal epithelial cells were collected from 32 individuals with periodontitis. GCF IL-1β levels were measured by an enzyme-linked immunosorbent assay (ELISA). Bacterial plaque samples were analyzed for 11 periodontal pathogens using polymerase chain reaction (PCR) analysis with specific primers for the 16SrRNA gene of each bacterium. IL-1B(3954)-SNP status was determined by identifying the carriers of the polymorphic T allele. A significant association was shown between IL-1B(3954)-SNP and IL-1β GCF levels (amount and concentration). The concomitant presence of two or three red complex bacterial species was associated with increased IL-1β GCF levels in periodontitis sites (site-level analysis). The concurrent presence of all three red complex periodontal pathogens and IL-1B(3954)-SNP was associated with the highest IL-1β GCF levels in periodontitis sites. Our results indicate an independent association of both IL-1B(3954)-SNP and red complex bacterial species with increased IL-1β levels in GCF of periodontitis sites. A better understanding of the interaction between genetics, bacteria, and inflammation is essential to develop more effective diagnostic, prognostic, and therapeutic tools for periodontitis.

ASSESSMENT OF THE MICROBIAL CONTENT OF PERIODONTAL POCKETS IN PATIENTS WITH CHRONIC GENERALIZED PERIODONTITIS AND CORONARY ARTERY DISEASE

The aim: To study the rate of detection of specific periodontopathogenic microbiota in patients with chronic generalized periodontitis (CGP) and coronary artery disease (CAD) and assessment of the risk of periodontal pathogens in the development of CAD. Materials and methods: A microbiological study of the content of periodontal pockets was carried out in 64 patients with CGP and CAD of the study group (mean age – 56.9±7.9 years) and 20 patients of the comparison group (mean age – 45.2±11,8 years) who were not burdened with CAD. Results: It was established that in patients with CGP and CAD the following periodontal pathogens were found more frequently than in the comparison group: Aggregatibacter actinomycetemcomitans (56.3±6.20% vs 25.0±9.68%; p=0.01), Prevotella intermedia (54.7±6.22% vs. 20.0±8.94%; p=0.01), and Fusobacterium spp. (34.4±5.94 vs. 10.0±6.71%; p=0.04). The increase in the percentage of the association of the periodontal pathogens was revealed in patients with CAD, which increased with the severity of the pathological process in periodontal tissues. The results of the study indicate the association of A. actinomycetemcomitans, P. intermedia, Fusobacterium spp. with CAD: A. actinomycetemcomitans: OR=3.86 (95% CI: 1.25-11.90), p=0.015; P. intermedia: OR=4.83 (95% CI: 1.45-16.05), p=0.007; Fusobacterium spp.: OR=4.71 (95% CI: 1.00-22.20), p=0.035. Conclusions: Analysis of the microbiological study indicates a high rate of detection of specific periodontal pathogens in patients with CGP and CAD. It can be assumed that the presence of such periodontal pathogens as A. actinomycetemcomitans, P. intermedia, Fusobacterium spp., significantly increases the risk of CAD.