Добірка наукової літератури з теми "Periodontopathogen bacteria"

INTRODUCTION Periodontitis is an inflammatory disease of the supporting tissues of teeth and is a major cause of tooth loss in adults. The onset and progression of periodontal disease is attributed to the presence of elevated levels of a consortium of pathogenic bacteria. Gram negative bacteria, mainly strict anaerobes, play the major role. OBJECTIVE The present study aimed to assess the presence of the main types of microorganisms involved in the aetiopathogenesis of periodontal disease: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Treponema denticola, Tanerella forsythia and Prevotella intermedia in different samples collected from the oral cavity of 90 patients diagnosed with periodontitis. METHOD Bacterial DNA detection was performed in diverse biological materials, namely in dental plaque, gingival tissue and saliva, by means of multiplex PCR, a technique that allows simultaneous identification of two different bacterial genomes. RESULTS In the dental plaque of the periodontitis patients, Treponema denticola dominated. In the gingival tissue, Tannerella forsythia and Treponema denticola were the microbiota most frequently detected, whilst in saliva Treponema denticola and Eikenella corrodens were found with the highest percentage. CONCLUSION The identification of microorganisms by multiplex PCR is specific and sensitive. Rapid and precise assessment of different types of periodontopathogens is extremely important for early detection of the infection and consequently for the prevention and treatment of periodontal disease. In everyday clinical practice, for routine bacterial evaluation in patients with periodontal disease, the dental plaque is the most suitable biological material, because it is the richest in periodontal bacteria.

is a gram-negative oral pathobiont that is associated with severe form of periodontitis. This bacterium has various virulence factors which enables the bacterium to colonize the oral cavity, invade and evade the host defences. Leukotoxin and cytolethal distending toxin are the important virulence factors that causes periodontal destruction. Periodontal infections with seems to be refractory to conventional therapy and systemic antibiotics. Hence, leukotoxin represents an ideal anti-virulence target and inhibition of its immunosuppressive activity would eliminate the colonization advantage provided to the bacteria by the toxin. This review provides a comprehensive update of with an emphasis on its virulence factors leukotoxin and cytolethal distending toxin and its role in periodontal destruction and recent developments in the management.

The complexity of the periodontal microbiota resembles that of the gastro-intestinal tract, where infectious diseases are treatable via probiotics. In the oropharyngeal region, probiotic or replacement therapies have shown some benefit in the prevention of dental caries, otitis media, and pharyngitis, but their effectiveness in the treatment of periodontitis is unknown. Therefore, this study addressed the hypothesis that the application of selected beneficial bacteria, as an adjunct to scaling and root planing, would inhibit the periodontopathogen recolonization of periodontal pockets. Analysis of the data showed, in a beagle dog model, that when beneficial bacteria were applied in periodontal pockets adjunctively after root planing, subgingival recolonization of periodontopathogens was delayed and reduced, as was the degree of inflammation, at a clinically significant level. The study confirmed the hypothesis and provides a proof of concept for a guided pocket recolonization (GPR) approach in the treatment of periodontitis.

Gram-negative bacteria derived extracellular vesicles (EVs), also known as outer membrane vesicles, have attracted significant attention due to their pathogenic roles in various inflammatory diseases. We recently demonstrated that EVs secreted by the periodontopathogen Aggregatibacter actinomycetemcomitans (Aa) can cross the blood–brain barrier (BBB) and that their extracellular RNA cargo can promote the secretion of proinflammatory cytokines, such as IL-6 and TNF-α, in the brain. To gain more insight into the relationship between periodontal disease (PD) and neuroinflammatory diseases, we investigated the effect of Aa EVs in a mouse model of ligature-induced PD. When EVs were administered through intragingival injection or EV-soaked gel, proinflammatory cytokines were strongly induced in the brains of PD mice. The use of TLR (Toll-like receptor)-reporter cell lines and MyD88 knockout mice confirmed that the increased release of cytokines was triggered by Aa EVs via TLR4 and TLR8 signaling pathways and their downstream MyD88 pathway. Furthermore, the injection of EVs through the epidermis and gingiva resulted in the direct retrograde transfer of Aa EVs from axon terminals to the cell bodies of trigeminal ganglion (TG) neurons and the subsequent activation of TG neurons. We also found that the Aa EVs changed the action potential of TG neurons. These findings suggest that EVs derived from periodontopathogens such as Aa might be involved in pathogenic pathways for neuroinflammatory diseases, neuropathic pain, and other systemic inflammatory symptoms as a comorbidity of periodontitis.

ABSTRACT Directed mutagenesis of a gene coding for a membrane protein of the periodontopathogen Actinobacillus actinomycetemcomitans was achieved by conjugation. The gene was disrupted by insertion of an antibiotic cassette into a unique endonuclease restriction sequence engineered by inverse PCR. The disrupted gene was cloned into a conjugative plasmid and transferred from Escherichia colito A. actinomycetemcomitans. The allelic replacement mutation resulted in the loss of a 22-kDa inner membrane protein. The loss of this protein (ImpA) resulted in changes in the outer membrane protein composition of the bacterium. Concurrent with the mutation in impA was a change in the pattern of growth of the mutant bacteria in broth cultures. The progenitor bacteria grew as a homogeneous suspension of cells compared to a granular, autoaggregating adherent cell population described for the mutant bacteria. These data suggest that ImpA may play a regulatory role or be directly involved in protein(s) that are exported and associated with colony variations in A. actinomycetemcomitans.

Porphyromonas gingivalis(P. gingivalis) andFusobacterium nucleatum(F. nucleatum) are Gram-negative anaerobic bacteria possessing several virulence factors that make them potential pathogens associated with periodontal disease. Periodontal diseases are chronic inflammatory diseases of the oral cavity, including gingivitis and periodontitis. Periodontitis can lead to tooth loss and is considered one of the most prevalent diseases worldwide.P. gingivalisandF. nucleatumpossess virulence factors that allow them to survive in hostile environments by selectively modulating the host’s immune-inflammatory response, thereby creating major challenges to host cell survival. Studies have demonstrated that bacterial infection and the host immune responses are involved in the induction of periodontitis. The NLRP3 inflammasome and its effector molecules (IL-1βand caspase-1) play roles in the development of periodontitis. We and others have reported that the purinergic P2X7 receptor plays a role in the modulation of periodontal disease and intracellular pathogen control. Caspase-4/5 (in humans) and caspase-11 (in mice) are important effectors for combating bacterial pathogens via mediation of cell death and IL-1βrelease. The exact molecular events of the host’s response to these bacteria are not fully understood. Here, we review innate and adaptive immune responses induced byP. gingivalisandF. nucleatuminfections and discuss the possibility of manipulations of the immune response as therapeutic strategies. Given the global burden of periodontitis, it is important to develop therapeutic targets for the prophylaxis of periodontopathogen infections.

The objective of this study was to determine if the interaction between common oral commensal bacteria and oral epithelial cells would provide protective effects against the invasion of periodontopathogen Porphyromonas gingivalis. Oral epithelial OKF6/Tert cells were used in co-cultures with Streptococcus gordonii, Streptococcus oralis, Streptococcus mitis, and Streptococcus intermedius. The viability of OKF6/Tert cells following a bacterial challenge was evaluated by trypan blue exclusion. The adherence of commensal species was determined by CFU counts. P. gingivalis invasion in OKF6/Tert cells was assessed before and after exposure to commensal species according to CFU counts. Viability assays show that only S. gordonii and S. intermedius display low toxicity toward OKF6/Tert cells. Both commensals adhere to OKF6/Tert cells at an average ratio of 1 CFU to 10 cells. P. gingivalis invasion into host cells is significantly reduced by 25% or 60% after exposure to S. gordonii or S. intermedius, respectively. The results suggest that these commensal species bind to host cells and diminish P. gingivalis invasion. This is important in the context of periodontal disease since P. gingivalis primarily acts on the host by invading it. Therefore, efforts to decrease invasion will eventually lead to future therapies harnessing the mechanisms employed by oral commensal bacteria.

ABSTRACTAggregatibacter actinomycetemcomitans, a periodontopathogen, has been associated with several systemic diseases. Herein, we report the protective effect of human lactoferrin (hLF) duringA. actinomycetemcomitansbacteremia in lactoferrin knockout (LFKO−/−) mice. The prophylactic, concurrent, and therapeutic intravenous (i.v.) administrations of hLF significantly cleared the bacteria from blood and organs. Nevertheless, all modes of hLF administration significantly decreased the concentrations of serum proinflammatory cytokines, such as interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-10, and IL-12p70. Additionally, hLF administration significantly decreased hepatic and splenic proinflammatory cytokine expression levels compared to those in the non-hLF-treated group. Furthermore, administration of hLF decreased the serum C-reactive protein level, inducible nitric oxide synthase (iNOS) and myeloperoxidase (MPO) gene expression levels in liver and spleen. hLF treatment has also resulted in a 6-fold decrease in spleen weight with the migration of typical inflammatory cells in infected mice as a result of decreased inflammatory response. These results reveal that hLF protects againstA. actinomycetemcomitansbacteremia, as indicated by rapid bacterial clearance and decreased host proinflammatory mediators.

ABSTRACTPolyphosphate [poly(P)] has antibacterial activity against various Gram-positive bacteria. In contrast, Gram-negative bacteria are generally resistant to poly(P). Here, we describe the antibacterial characterization of poly(P) against a Gram-negative periodontopathogen,Porphyromonas gingivalis. The MICs of pyrophosphate (Na4P2O7) and all poly(P) (Nan+ 2PnO3n+ 1;n= 3 to 75) tested for the bacterium by the agar dilution method were 0.24% and 0.06%, respectively. Orthophosphate (Na2HPO4) failed to inhibit bacterial growth. Poly-P75 was chosen for further study. In liquid medium, 0.03% poly-P75 was bactericidal againstP. gingivalisirrespective of the growth phase and inoculum size, ranging from 105to109cells/ml. UV-visible spectra of the pigments fromP. gingivalisgrown on blood agar with or without poly-P75 showed that poly-P75 reduced the formation of μ-oxo bisheme by the bacterium. Poly-P75 increased hemin accumulation on theP. gingivalissurface and decreased energy-driven uptake of hemin by the bacterium. The expression of the genes encoding hemagglutinins, gingipains, hemin uptake loci, chromosome replication, and energy production was downregulated, while that of the genes related to iron storage and oxidative stress was upregulated by poly-P75. The transmission electron microscope showed morphologically atypical cells with electron-dense granules and condensed nucleoid in the cytoplasm. Collectively, poly(P) is bactericidal againstP. gingivalis, in which hemin/heme utilization is disturbed and oxidative stress is increased by poly(P).

Ghrelin plays a major role in obesity-related diseases which have been shown to be associated with periodontitis. This study sought to analyze the expression of the functional receptor for ghrelin (GHS-R1a) in periodontal cells and tissues under microbial conditions in vitro and in vivo. The GHS-R1a expression in human periodontal cells challenged with the periodontopathogen Fusobacterium nucleatum, in gingival biopsies from periodontally healthy and diseased individuals, and from rats with and without ligature-induced periodontitis was analyzed by real-time PCR, immunocytochemistry, and immunofluorescence. F. nucleatum induced an initial upregulation and subsequent downregulation of GHS-R1a in periodontal cells. In rat experimental periodontitis, the GHS-R1a expression at periodontitis sites was increased during the early stage of periodontitis, but significantly reduced afterwards, when compared with healthy sites. In human gingival biopsies, periodontally diseased sites showed a significantly lower GHS-R1a expression than the healthy sites. The expression of the functional ghrelin receptor in periodontal cells and tissues is modulated by periodontal bacteria. Due to the downregulation of the functional ghrelin receptor by long-term exposure to periodontal bacteria, the anti-inflammatory actions of ghrelin may be diminished in chronic periodontal infections, which could lead to an enhanced periodontal inflammation and tissue destruction.

Aim: To determine whether there was any significant difference in the antimicrobial activity of 4 herbal toothpastes against cultures of 3 primary plaque colonizers (Streptococcus mutans, Streptococcus sanguinis and a non-specific &alpha
-heamolytic streptococcus).

Cette thèse traite des problèmes d'infections des implants dentaires, telles que la péri-implantite, causées par l'adhérence de bactéries parodontopathogènes. Elle explore l'utilisation de la texturation laser femtoseconde (fs-L) pour améliorer les propriétés des surfaces d'implants en alliage de titane (Ti6Al4V).Le projet, financé par l'ANR et mené en collaboration avec divers laboratoires, a utilisé des techniques de caractérisation avancées pour analyser les surfaces texturées et évaluer leur efficacité en conditions biologiques. Les résultats montrent que la texturation par fs-L permet de créer des structures de surface périodiques (LIPSS) micro et nanométriques, modifiant la surface de contact et par conséquent l’adhérence cellulaire et bactérienne. Les surfaces ainsi texturées ont démontré une réduction significative de l'adhérence des bactéries parodontopathogènes, telles que Porphyromonas gingivalis, réduisant ainsi potentiellement les risques de péri-implantite.Les études in vitro ont également confirmé une meilleure adhérence des fibroblastes gingivaux sur les surfaces texturées, ce qui pourrait réduire les risques d’infiltration bactérienne et ainsi améliorer la stabilité et l’intégration des implants.En conclusion, la texturation laser femtoseconde des surfaces d'implants dentaires est prometteuse pour créer des implants plus durables et doublement fonctionnalisés, améliorant l'adhérence cellulaire et possédant des propriétés antibactériennes accrues. Ces avancées ouvrent la voie à des implants répondant mieux aux défis cliniques actuels tout en contribuant à la lutte contre l'antibiorésistance. Des études supplémentaires plus proches d'une situation clinique sont prévues pour valider ces résultats et explorer les interactions entre les topographies fs-L et les réponses biologiques des tissus environnants
This thesis addresses issues related to infections of dental implants, such as peri-implantitis, caused by the adhesion of periodontopathogenic bacteria. It explores the use of femtosecond laser (fs-L) texturing to enhance the properties of titanium alloy (Ti6Al4V) implant surfaces.The project, funded by the ANR and conducted in collaboration with various laboratories, employed advanced characterization techniques to analyze textured surfaces and evaluate their effectiveness under biological conditions. The results demonstrate that fs-L texturing can create micro and nanometric periodic surface structures (LIPSS), altering the contact surface and thus cellular and bacterial adhesion. Textured surfaces showed a significant reduction in the adhesion of periodontopathogenic bacteria, such as Porphyromonas gingivalis, potentially reducing the risks of peri-implantitis.In vitro studies also confirmed better adhesion of gingival fibroblasts to textured surfaces, which could reduce the risk of bacterial infiltration and thus improve implant stability and integration.In conclusion, femtosecond laser texturing of dental implant surfaces holds promise for creating more durable and dual-functionalized implants, enhancing cellular adhesion, and possessing increased antibacterial properties. These advancements pave the way for implants better suited to current clinical challenges while contributing to the fight against antibiotic resistance. Further studies closer to clinical settings are planned to validate these results and explore the interactions between fs-L topographies and the biological responses of surrounding tissues

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Periodontal infections consist of a group of inflammatory conditions caused by microorganisms that colonize the tooth surface through the formation of dental biofilm. Chronic infections such as periodontitis have been associated to the development and progression of atherosclerosis. AIM: Detect cultivatable and non-cultivatable periodontopathogenic bacteria in atheromatous plaques; search for factors associated to the presence of these bacteria in the atheromatous plaques and characterize the presence of cultivatable and non-cultivatable bacteria in these plaques. METHODOLOGY: A cross-sectional study was performed with a sample of 30 patients diagnosed with atherosclerosis in the carotid, coronary or femoral arteries and surgically treated with angioplasty and stent implant, bypass or endarterectomy. The plaques were collected during surgery and analyzed using the PCR molecular technique for the presence of the DNA of the cultivatable bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Treponema denticola and of the non-cultivatable Synergistes phylotypes. The patients were examined in the infirmary, after the surgery, where they also responded to a questionnaire aimed at determining factors associated to the presence of periodontopathogenic bacteria in the atheromatous plaques. RESULTS: All patients with tooth (66,7%) possessed disease periodontal, being 95% severe and 65% widespread. No periodontopathogenic bacteria were found in the atheromatous plaques. However, four samples (13.3%) were positive for the presence of bacteria. Of these, three participants were dentate, being two carriers of widespread severe chronic periodontite and one of located severe chronic periodontitis. None of them told the accomplishment of procedures associated to possible bacteremia episodes, as treatment endodontic, extraction the last six months or some procedure surgical dental. CONCLUSION: The periodontopathogenic bacteria studied were not found in the atheromatous plaques, making it impossible to establish the prevalence of these pathogens or the factors associated to their presence in plaques, the detection of positive samples for bacteria suggests that other periodontal and non-periodontal pathogens be studied in an attempt at discovering the association or not between periodontal disease and/or others infections and atherosclerosis, from the presence of these bacteria in atheromas
As infec??es periodontais compreendem um grupo de condi??es inflamat?rias, causadas por microrganismos que colonizam a superf?cie dent?ria, atrav?s da forma??o do biofilme dent?rio. Atualmente, infec??es cr?nicas como as periodontais t?m sido associadas ao desenvolvimento e progress?o da aterosclerose. OBJETIVOS: Detectar bact?rias periodontopatog?nicas cultiv?veis e n?o cultiv?veis em placas ateromatosas; buscar fatores associados ? presen?a destas bact?rias nas placas ateromatosas e caracterizar a presen?a de bact?rias cultiv?veis e n?o cultiv?veis em placas ateromatosas. METODOLOGIA: Foi realizado um estudo seccional, utilizando uma amostra de 30 pacientes que apresentaram o diagn?stico de aterosclerose nas art?rias car?tidas, coronarianas ou femorais, e foram tratados cirurgicamente atrav?s da realiza??o dos procedimentos de angioplastia com implante de stent, bypasse ou endartarectomia. As placas foram coletadas durante as cirurgias realizadas e analisadas atrav?s da t?cnica molecular de PCR para a presen?a de DNA das bact?rias periodontais cultiv?veis Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis e Treponema denticola e o filotipo n?o-cultiv?vel Synergistes species. Os pacientes foram examinados no leito da enfermaria, ap?s as cirurgias, onde tamb?m responderam a um question?rio cujo objetivo foi buscar fatores associados ? presen?a de bact?rias periodontopatog?nicas nas placas ateromatosas. RESULTADOS: Todos os pacientes dentados (66,7%) possu?am doen?a periodontal, sendo 95% severa e 65% generalizada.Nenhuma bact?ria periodontopatog?nica pesquisada foi encontrada nas placas ateromatosas. No entanto, quatro amostras (13,3%) foram positivas para a presen?a de bact?rias. Destas, tr?s participantes eram dentados, sendo dois portadores de periodontite cr?nica severa generalizada e um de periodontite cr?nica severa localizada. Nenhum deles relatou a realiza??o de procedimentos associados a poss?veis epis?dios de bacteremia, como tratamento endod?ntico, exodontia nos ?ltimos seis meses ou algum procedimento cir?rgico odontol?gico. CONCLUS?O: As bact?rias periodontopatog?nicas estudadas n?o foram encontradas nas placas ateromatosas, n?o pudendo ser estabelecida a preval?ncia destes pat?genos e nem os fatores associados ? presen?a deles nas placas, mas, a detec??o das amostras positivas para bact?rias abre caminhos para que outros pat?genos periodontais e n?o periodontais sejam estudados na tentativa de elucidar de maneira definitiva a associa??o ou n?o entre a doen?a periodontal e/ou outras infec??es e a aterosclerose, atrav?s da presen?a destas bact?rias nos ateromas

Empregando a técnica de biologia molecular Checkerboard DNA-DNA Hybridization e o teste Limulus Amebocyte Lysate, os objetivos do presente estudo clínico randomizado in vivo foram avaliar, em bráquetes ortodônticos metálicos: 1) A presença de 16 espécies de microrganismos periodontopatogênicos Gram-negativos pertencentes aos complexos laranja e vermelho, por meio de sondas de DNA; 2) A quantidade de endotoxina bacteriana presente; e 3) A eficácia da utilização do gluconato de clorexidina a 0,12%, sob a forma de bochechos, na redução da contaminação pelas 16 espécies de microrganismos periodontopatogênicos Gram-negativos e na redução da quantidade de endotoxina bacteriana. Participaram do estudo 33 pacientes de 11 a 33 anos de idade, em tratamento com aparelho ortodôntico fixo, nos quais foram colocados randomicamente 3 bráquetes metálicos novos nos pré-molares. Os pacientes do Grupo Controle (n=17) fizeram 2 bochechos semanais com solução placebo, durante 30 dias. Os pacientes do Grupo Experimental (n=16) fizeram bochechos com solução à base de gluconato de clorexidina a 0,12% (Periogard®), da mesma forma que o grupo Controle. Decorridos 30 dias, os 3 bráquetes foram removidos de cada paciente e processados para a detecção dos microrganismos, pela técnica Checkerboard DNA-DNA Hybridization, e para a quantificação da endotoxina bacteriana por meio do teste Limulus Amebocyte Lysate. Os resultados obtidos foram analisados por meio dos testes não-paramétricos de Kruskal-Wallis, Mann-Whitney e pós-teste de Dunn, utilizando os softwares SAS e Graphpad Prism. O nível de significância adotado foi de 5%. De acordo com os resultados obtidos, observou-se que todos os bráquetes dos pacientes do Grupo Controle encontravam-se densamente contaminados pelos microrganismos avaliados. Nesse grupo, as espécies bacterianas do complexo laranja apresentaram-se em maiores quantidades, em relação às espécies do complexo vermelho (p<0,01). A mediana da quantidade de endotoxina para este grupo foi de 0,6673 EU/ml. Quando comparado ao grupo Controle, observou-se que o número total de microrganismos no grupo Experimental foi estatisticamente menor, com mediana de 29.150.000 no grupo Controle e de 13.130.000 no grupo Experimental (p=0,01). Quando os microrganismos foram avaliados por complexos, foi observada diferença estatisticamente significante entre os grupos Controle e Experimental para o complexo laranja (p=0,04), com contagens menores de bactérias após os bochechos com clorexidina. Por outro lado, observou-se que a quantidade de endotoxina no grupo Experimental foi maior, com mediana de 1,2199 EU/ml (p=0,02). Concluiu-se que os bochechos com solução de gluconato de clorexidina a 0,12% podem ser úteis, na prática clínica, com a finalidade de reduzir os níveis de microrganismos periodontopatogênicos Gram-negativos, em pacientes portadores de aparelhos ortodônticos fixos. No entanto, em função do aumento da quantidade de endotoxina bacteriana após o uso dos bochechos com clorexidina, estudos adicionais são necessários com a finalidade de desenvolver procedimentos clínicos ou agentes antimicrobianos que tenham ação sobre a endotoxina presente nos bráquetes metálicos.
Using the biomolecular technique Checkerboard DNA-DNA Hybridization and the Limulus Amebocyte Lysate (LAL) assay, the purposes of the present randomized clinical study were to evaluate in orthodontic metallic brackets: 1) The presence of 16 Gram-negative periodontopathogenic microbial species of the orange and red complexes by using DNA probes; 2) The amount of bacterial endotoxin; and 3) The efficacy of 0.12% chlorhexidine gluconate mouthwashes in reducing the contamination by the evaluated microbial species and the amount of bacterial endotoxin. Thirty-three 11-33-year-old patients undergoing orthodontic treatment with fixed appliances were enrolled in the study and all subjects had 3 new metallic brackets bonded to different premolars in a randomized manner. The patients in the Control group (n=17) were instructed to use a placebo mouthwash twice a week, while those in the Experimental group (n=16) were instructed to use a 0.12% chlorhexidine gluconate mouthwash (Periogard®) in the same way. After 30 days, the 3 brackets were removed from each patient and processed for detection of the microorganisms by the Checkerboard DNADNA hybridization technique, and for quantification of bacterial endotoxin by the LAL assay. The data were analyzed statistically by the non-parametric Mann-Whitney, Kruskal-Wallis and Dunn\'s post tests using SAS and GraphPad Prism softwares. A significance level of 5% was set for all analyses. The brackets of the patients in the Control group were densely contaminated by the evaluated microbial species. In this group, the number of bacterial species of the orange complex was larger compared to the number of bacterial species of the red complex (p<0.01). The median of the amount of bacterial endotoxin for this group was 0.6673 EU/ml. The Experimental group had a significantly smaller number of microorganisms than the Control group (median 13,130,000 versus 29,150,000; p=0.01). When the microorganisms were analyzed by complex, there was statistically significant difference between the Control and Experimental groups for the orange complex (p=0.04) with smaller counts of bacteria after use of chlorhexidine oral rinses. On the other hand, there was a greater amount of bacterial endotoxin in the Experimental (median of 1,2199 EU/ml; p=0.02). In conclusion, 0.12% chlorhexidine oral rinse can be useful in the clinical practice to reduce the levels of Gram-negative periodontopathogenic microorganisms in patients with fixed orthodontic appliances. Considering the increase in the amount of bacterial endotoxin after use of chlorhexidine oral rinses, further research is necessary to develop clinical procedures or antimicrobial agents with action against the endotoxin in the metallic brackets

碩士
中山醫學大學
口腔生物暨材料科學研究所
99
Periodontal disease is an inflammatory process in the periodontal tissue that is initiated by the microorganisms in the subgingival plaque. If left untreated, it will cause periodontal tissue breakdown and alveolar bone resorption. Porphyromonas gingivalis （Pg）、Tannerella forsythia （Tf） and Treponema denticola （Td） are among the anaerobic species frequently associated with periodontal disease, which possess a trypsin-like enzyme that can be detected by the hydrolysis of N-benzoyl-DL-arginine-2-naphthylamide （BANA）. The purpose of the study is using the BANA test to detect the presence of trypsin-like enzyme releasing periodontopathogenic bacteria from patients. For each qualified periodontal patients, two samples were taken from advanced lesion （pocket depth （PD） > 5 mm）, two from mild lesion （PD < 5 mm）, and one was saliva sample. Endodontic paper points were inserted into the periodontal pockets to collect microbiological samples. One hundred μl Wilkins Chalgren medium and 100 μl BANA solution then were incubated with each sample overnight at 37 °C. The color was developed by the addition of 10 μl fast garnet solution and read with an enzyme linked immunosorbent assay reader with a 490 nm filter within 30 min. The data showed that the optical density values for samples collected from advanced lesions were significantly higher than those from less serious lesions. The results suggest that the advanced periodontal lesion may harbor higher numbers of periodontal pathogenic bacteria （ie, red complex）, which produce high titers of trypsin-like enzyme in gingival fluid and can be detected by BANA test. The BANA test may useful in quick detecting the severity and activity of periodontal pathogenic bacteria in patients.

Review question / Objective: The aim of this systematic review and meta-analysis of case-control studies is to find out the association of IL-1 RN intron 2 (VNTR) rs2234663 Gene Polymorphism and the occurrence and progression of periodontitis(including chronic periodontitis, aggressive periodontitis and early-onset periodontitis). Condition being studied: Periodontitis is one of the most common ailments affecting the teeth, leading to the destruction of the supporting and surrounding tooth structure. Periodontitis is originally a disease originating from the gingival tissue which if left untreated results in penetration of inflammation to the deeper tissues, altering the bone homeostasis causing tooth loss. Periodontal disease has a multifactorial origin. The main culprit identified in periodontitis is the bacterial biofilm growing on the tooth surfaces. The deleterious effects of periodontopathogens are not limited to the periodontium, but they also exude their ill effects on the systemic health of the patients. While the host response determines the progression of the disease, genetics, environmental factors, systemic health of the patient, lifestyle habits and various social determinants also play a role. Interleukin-1 receptor antagonist encoded by this gene IL-1RN is a member of the interleukin 1 cytokine family. This protein inhibits the activities of interleukin 1, alpha (IL1A) and interleukin 1, beta (IL1B), and modulates a variety of interleukin 1 related immune and inflammatory responses, particularly in the acute phase of infection and inflammation. We aim to study their association by conducting a meta-analysis.