RESUMO
Human histology provides critical information on the biological potential of various regenerative protocols and biomaterials, which is vital to advancing the field of periodontal regeneration, both in research and clinical practice. Outcomes of histologic studies are particularly valuable when interpreted considering additional evidence available from pre-clinical and clinical studies. One of the best-documented growth factors areproven to have positive effects on a myriad of oral regenerative procedures is recombinant human platelet-derived growth factor-BB (rhPDGF-BB). While a systematic review of clinical studies evaluating rhPDGF in oral regenerative procedures has been recently completed, a review article that focuses on the histologic outcomes is needed. Hence, this communication discusses the histologic effects of rhPDGF-BB on oral and periodontal regenerative procedures, including root coverage and soft tissue augmentation, intrabony defects, furcation defects, peri-implant bone augmentation, and guided bone regeneration. Studies from 1989 to 2022 have been included in this review.
Assuntos
Defeitos da Furca , Peptídeos e Proteínas de Sinalização Intercelular , Humanos , Becaplermina/uso terapêutico , Proteínas Proto-Oncogênicas c-sis/farmacologia , Proteínas Proto-Oncogênicas c-sis/uso terapêutico , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêuticoRESUMO
Extensive research in humans and animal models has begun to unravel the complex mechanisms that drive the immunopathogenesis of periodontitis. Neutrophils mount an early and rapid response to the subgingival oral microbiome, producing destructive enzymes to kill microbes. Chemokines and cytokines are released that attract macrophages, dendritic cells, and T cells to the site. Dendritic cells, the focus of this review, are professional antigen-presenting cells on the front line of immune surveillance. Dendritic cells consist of multiple subsets that reside in the epithelium, connective tissues, and major organs. Our work in humans and mice established that myeloid dendritic cells are mobilized in periodontitis. This occurs in lymphoid and nonlymphoid oral tissues, in the bloodstream, and in response to Porphyromonas gingivalis. Moreover, the dendritic cells mature in situ in gingival lamina propria, forming immune conjugates with cluster of differentiation (CD) 4+ T cells, called oral lymphoid foci. At such foci, the decisions are made as to whether to promote bone destructive T helper 17 or bone-sparing regulatory T cell responses. Interestingly, dendritic cells lack potent enzymes and reactive oxygen species needed to kill and degrade endocytosed microbes. The keystone pathogen P. gingivalis exploits this vulnerability by invading dendritic cells in the tissues and peripheral blood using its distinct fimbrial adhesins. This promotes pathogen dissemination and inflammatory disease at distant sites, such as atherosclerotic plaques. Interestingly, our recent studies indicate that such P. gingivalis-infected dendritic cells release nanosized extracellular vesicles called exosomes, in higher numbers than uninfected dendritic cells do. Secreted exosomes and inflammasome-related cytokines are a key feature of the senescence-associated secretory phenotype. Exosomes communicate in paracrine with neighboring stromal cells and immune cells to promote and amplify cellular senescence. We have shown that dendritic cell-derived exosomes can be custom tailored to target and reprogram specific immune cells responsible for inflammatory bone loss in mice. The long-term goal of these immunotherapeutic approaches, ongoing in our laboratory and others, is to promote human health and longevity.
Assuntos
Perda do Osso Alveolar , Periodontite , Animais , Citocinas , Células Dendríticas , Suscetibilidade a Doenças , Humanos , Imunoterapia , Camundongos , Porphyromonas gingivalisRESUMO
Periodontitis (PD) is a common dysbiotic inflammatory disease that leads to local bone deterioration and tooth loss. PD patients experience low-grade bacteremias with oral microbes implicated in the risk of heart disease, cancer, and kidney failure. Although Th17 effectors are vital to fighting infection, functional imbalance of Th17 effectors and regulatory T cells (Tregs) promote inflammatory diseases. In this study, we investigated, in a small pilot randomized clinical trial, whether expansion of inflammatory blood myeloid dendritic cells (DCs) and conversion of Tregs to Th17 cells could be modulated with antibiotics (AB) as part of initial therapy in PD patients. PD patients were randomly assigned to either 7 d of peroral metronidazole/amoxicillin AB treatment or no AB, along with standard care debridement and chlorhexidine mouthwash. 16s ribosomal RNA analysis of keystone pathogen Porphyromonas gingivalis and its consortium members Fusobacterium nucleatum and Streptococcus gordonii confirmed the presence of all three species in the reservoirs (subgingival pockets and blood DCs) of PD patients before treatment. Of the three species, P. gingivalis was reduced in both reservoirs 4-6 wk after therapy. Further, the frequency of CD1C+CCR6+ myeloid DCs and IL-1R1 expression on IL-17A+FOXP3+CD4+ T cells in PD patients were reduced to healthy control levels. The latter led to decreased IL-1ß-stimulated Treg plasticity in PD patients and improvement in clinical measures of PD. Overall, we identified an important, albeit short-term, beneficial role of AB therapy in reducing inflammatory DCs and Treg-Th17 plasticity in humans with PD.
Assuntos
Amoxicilina/administração & dosagem , Bactérias , Infecções Bacterianas , Células Dendríticas , Metronidazol/administração & dosagem , Periodontite , Linfócitos T Reguladores , Células Th17 , Bactérias/imunologia , Bactérias/metabolismo , Infecções Bacterianas/sangue , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/imunologia , Infecções Bacterianas/patologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Periodontite/sangue , Periodontite/tratamento farmacológico , Periodontite/imunologia , Periodontite/patologia , Linfócitos T Reguladores/metabolismo , Linfócitos T Reguladores/parasitologia , Linfócitos T Reguladores/patologia , Células Th17/imunologia , Células Th17/metabolismo , Células Th17/patologiaRESUMO
Mucosal health and disease is mediated by a complex interplay between the microbiota ("spark") and the inflammatory response ("flame"). Pathobionts, a specific class of microbes, exemplified by the oral microbe Porphyromonas gingivalis, live mostly "under the radar" in their human hosts, in a cooperative relationship with the indigenous microbiota. Dendritic cells (DCs), mucosal immune sentinels, often remain undisturbed by such microbes and do not alert adaptive immunity to danger. At a certain tipping point of inflammation, an "awakening" of pathobionts occurs, wherein their active growth and virulence are stimulated, leading to a dysbiosis. Pathobiont becomes pathogen, and commensal becomes accessory pathogen. The local inflammatory outcome is the Th17-mediated degenerative bone disease, periodontitis (PD). In systemic circulation of PD subjects, inflammatory DCs expand, carrying an oral microbiome and promoting Treg and Th17 responses. At distant peripheral sites, comorbid diseases including atherosclerosis, Alzheimer's disease, macular degeneration, chronic kidney disease, and others are reportedly induced. This review will review the immunobiology of DCs, examine the complex interplay of microbes and DCs in the pathogenesis of PD and its comorbid inflammatory diseases, and discuss the role of apoptosis and autophagy in this regard. Overall, the pathophysiological mechanisms of DC-mediated chronic inflammation and tissue destruction will be summarized.
Assuntos
Células Dendríticas/patologia , Inflamação/patologia , Microbiota , Doenças da Boca/microbiologia , Mucosa Bucal/microbiologia , Mucosa Bucal/patologia , Animais , Autofagia , HumanosRESUMO
OBJECTIVE: To compare the myeloid and plasmacytoid DC counts and maturation status among subjects with/without generalized periodontitis (GP) and type 2 diabetes mellitus (T2DM). METHODS: The frequency and maturation status of myeloid and plasmacytoid blood DCs were analyzed by flow cytometry in four groups of 15 subjects: healthy controls, T2DM with generalized CP (T2DM + GP), prediabetes with GP (PD + GP), and normoglycemics with GP (NG + GP). RT-PCR was used to determine levels of Porphyromonas gingivalis in the oral biofilms and within panDCs. The role of exogenous glucose effects on differentiation and apoptosis of healthy human MoDCs was explored in vitro. RESULTS: Relative to controls and to NG + GP, T2DM + GP showed significantly lower CD1c + and CD303 + DC counts, while CD141 + DCs were lower in T2DM + GP relative to controls. Blood DC maturation required for mobilization and immune responsiveness was not observed. A statistically significant trend was observed for P. gingivalis levels in the biofilms of groups as follows: controls Assuntos
Células Dendríticas/imunologia
, Diabetes Mellitus Tipo 2
, Periodontite
, Estado Pré-Diabético
, Adulto
, Idoso
, Brasil
, Humanos
, Pessoa de Meia-Idade
, Porphyromonas gingivalis
RESUMO
OBJECTIVES: Vitamin D deficiency/insufficiency is a worldwide public health issue that has been linked to numerous inflammatory disorders, including periodontitis. There is increasing support for a role for adequate vitamin D levels in overall health. Populations with darker skin color have a higher prevalence of vitamin D deficiency/insufficiency and periodontitis. The purpose of this small pilot study was to investigate the influence of 12 weeks of 25(OH)D vitamin D supplementation (VDS) on mediators of systemic inflammation in dark-skinned, periodontitis patients. MATERIALS AND METHODS: A total of 23 patients with moderate to severe periodontitis were randomly assigned to the vitamin D group or placebo group and received intensive single visit scaling and root planning to elicit a systemic inflammatory response. RESULTS: Vitamin D supplementation increased serum 25(OH)D levels approximately 2-fold over baseline levels; moreover, VDS group had reduced peripheral blood CD3 and CD3+CD8+ cytotoxic T lymphocyte (CTLs) counts and reduced pro-inflammatory salivary cytokines. In contrast, VDS group had higher levels of the autophagy-related proteins and other proteins crucial for anti-microbial autophagy in whole blood PBMCs. CONCLUSION: In conclusion, VDS has multiple benefits for reducing systemic inflammation and promoting induction of autophagy-related proteins related to anti-microbial functions.
Assuntos
Mediadores da Inflamação/sangue , Inflamação/etiologia , Periodontite , Deficiência de Vitamina D , Vitamina D/administração & dosagem , Suplementos Nutricionais , Humanos , Inflamação/sangue , Projetos Piloto , Vitamina D/uso terapêutico , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/imunologia , Vitaminas/uso terapêuticoRESUMO
Visceral adipose tissue (VAT) inflammation and metabolic dysregulation are key components of obesity-induced metabolic disease. Upregulated arginase, a ureahydrolase enzyme with two isoforms (A1-cytosolic and A2-mitochondrial), is implicated in pathologies associated with obesity and diabetes. This study examined A2 involvement in obesity-associated metabolic and vascular disorders. WT and globally deleted A2(-/-) or A1(+/-) mice were fed either a high fat/high sucrose (HFHS) diet or normal diet (ND) for 16 weeks. Increases in body and VAT weight of HFHS-fed WT mice were abrogated in A2-/-, but not A1+/-, mice. Additionally, A2-/- HFHS-fed mice exhibited higher energy expenditure, lower blood glucose, and insulin levels compared to WT HFHS mice. VAT and adipocytes from WT HFHS fed mice showed greater A2 expression and adipocyte size and reduced expression of PGC-1α, PPAR-γ, and adiponectin. A2 deletion blunted these effects, increased levels of active AMPK-α, and upregulated genes involved in fatty acid metabolism. A2 deletion prevented HFHS-induced VAT collagen deposition and inflammation, which are involved in adipocyte metabolic dysfunction. Endothelium-dependent vasorelaxation, impaired by HFHS diet, was significantly preserved in A2-/- mice, but more prominently maintained in A1+/- mice. In summary, A2 is critically involved in HFHS-induced VAT inflammation and metabolic dysfunction.
Assuntos
Tecido Adiposo/metabolismo , Arginase/metabolismo , Dieta Hiperlipídica/efeitos adversos , Metabolismo Energético , Ácidos Graxos/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Adipócitos/metabolismo , Adipócitos/patologia , Tecido Adiposo/patologia , Animais , Arginase/genética , Biomarcadores , Modelos Animais de Doenças , Fibrose , Deleção de Genes , Hipertrofia , Camundongos , Obesidade/patologia , Oxirredução , Estresse Oxidativo , Consumo de Oxigênio , Sacarose/metabolismoRESUMO
The active form of vitamin D is the hormonally active 1,25(OH)2D3 (Vit D) vitamin, which plays an important role in bone biology and host immunity. The vitamin D receptor (VDR) is a nuclear ligand-dependent transcription factor expressed by many cells. Ligation of VDR by VitD regulates a wide plethora of genes and physiologic functions through the formation of the complex Vit D-VDR signaling cascade. The influence of Vit D-VDR signaling in host immune response to microbial infection has been of interest to many researchers. This is particularly important in oral health and diseases, as oral mucosa is exposed to a complex microbiota, with certain species capable of causing disruption to immune homeostasis. In this review, we focus on the immune modulatory roles of Vit D in the bone degenerative oral disease, periodontitis.
RESUMO
BACKGROUND: Partial edentulism in growing children due to aplasia or trauma poses a difficult situation to manage. We present a case of horizontal ridge augmentation in a growing patient who had trauma in childhood when it was too early to place implants. METHODS AND RESULTS: This patient had a history of trauma, at age 13, that resulted in mandibular fracture and loss of teeth #23-27. The definitive restorative treatment plan was postponed due to the patient's continued growth. At age 18, horizontal bone augmentation was performed in a severely resorbed anterior mandible. After 7 months of healing, 7-8 mm ridge augmentation was achieved, and three implants were placed. Soft tissue augmentation by free gingival graft was performed at implant second stage surgery 4 months later. CONCLUSIONS: When considering the timing of implant placement in adolescents, the clinician walks a fine line between waiting as long as possible to place the implants and racing against continued resorption of the edentulous alveolar ridge. 70/30 mineralized/demineralized cortical bone allograft and injectable platelet-rich fibrin mix combined with tenting screws and resorbable membranes are useful measures for horizontal ridge augmentation in growing patients. KEY POINTS: Why is this case new information? There are insufficient data available when considering implant treatment in younger patients. The present case was managed with a variation of the sausage technique described by Urban. The use of allograft, I-PRF, and tenting screws replaced the use of autogenous bone and resulted in exceptional results. What are the keys to the successful management of this case? Delaying treatment until after the critical growth period has passed. Adequate flap release, tension-free primary flap closure, and space maintenance through the use of tenting screws and tacking the membranes using tacking pins provided support for the grafted site. What are the primary limitations to success in this case? The continued growth may cause infra occlusion of the implant-supported bridge.
Assuntos
Aumento do Rebordo Alveolar , Implantes Dentários , Fibrina Rica em Plaquetas , Adolescente , Criança , Humanos , Implantação Dentária Endóssea , Aumento do Rebordo Alveolar/métodos , CicatrizaçãoRESUMO
Periodontitis is the most common chronic, inflammatory oral disease that affects more than half of the population in the United States. The disease leads to destruction of the tooth-supporting tissue called periodontium, which ultimately results in tooth loss if uncured. The interaction between the periodontal microbiota and the host immune cells result in the induction of a non-protective host immune response that triggers host tissue destruction. Certain pathogens have been implicated periodontal disease formation that is triggered by a plethora of virulence factors. There is a collective evidence on the impact of periodontal disease progression on systemic health. Of particular interest, the role of the virulence factors of the periodontal pathogens in facilitating the evasion of the host immune cells and promotion of carcinogenesis has been the focus of many researchers. The aim of this review is to examine the influence of the periodontal pathogens Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P. gingivalis), and Fusobacterium nucleatum (F. nucleatum) in the modulation of the intracellular signaling pathways of the host cells in order to evade the host immune response and interfere with normal host cell death and the role of their virulence factors in this regard.
RESUMO
OBJECTIVE: Although a standard treatment guideline has not been established to date, various treatment modalities have been described in the literature based on the staging of medication-related osteonecrosis of the jaw (MRONJ). The aim of this case series was to describe the outcomes of surgical intervention of MRONJ cases with the adjunctive use of platelet-rich fibrin (PRF). MATERIALS AND METHODS: Thirteen patients under therapy with zoledronic acid, seven of them underwent surgical removal of necrotic bone with debridement, followed by placement of three to four PRF membranes and achieving primary closure. In six patients, PRF was used preventively to avoid MRONJ. RESULTS: The surgical treatment outcomes were successful in all patients, with a follow-up range of 12-48 months. In the presented cases, the intraoral evaluation showed excellent soft tissue healing except for one patient secondary wound healing was reported. Additionally, there was no recurrence of bone exposure in all cases. PRF membranes were comparatively effective in postsurgical pain control. CONCLUSION: The use of PRF could represent a valuable adjunct in the surgical management for advanced stages of MRONJ cases. CLINICAL RELEVANCE: This clinical case series describes the use of PRF membranes as a valuable adjunct in the surgical management of MRONJ patients, especially when treating advanced MRONJ cases. Moreover, PRF demonstrates usefulness in preventing such difficult complications from occurring.
Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Fibrina Rica em Plaquetas , Humanos , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/prevenção & controle , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/cirurgia , Estudos de Viabilidade , Ácido Zoledrônico , Arcada OsseodentáriaRESUMO
Porphyromonas gingivalis (P. gingivalis) is a unique pathogen implicated in severe forms of periodontitis (PD), a disease that affects around 50% of the US population. P. gingivalis is equipped with a plethora of virulence factors that it uses to exploit its environment and survive. These include distinct fimbrial adhesins that enable it to bind to other microbes, colonize inflamed tissues, acquire nutrients, and invade cells of the stroma and immune system. Most notable for this review is its ability to invade dendritic cells (DCs), which bridge the innate and adaptive immune systems. This invasion process is tightly linked to the bridging functions of resultant DCs, in that it can disable (or stimulate) the maturation function of DCs and cytokines that are secreted. Maturation molecules (e.g., MHCII, CD80/CD86, CD40) and inflammatory cytokines (e.g., IL-1b, TNFa, IL-6) are essential signals for antigen presentation and for proliferation of effector T-cells such as Th17 cells. In this regard, the ability of P. gingivalis to coordinately regulate its expression of major (fimA) and minor (mfa-1) fimbriae under different environmental influences becomes highly relevant. This review will, therefore, focus on the immunoregulatory role of P. gingivalis fimbriae in the invasion of DCs, intracellular signaling, and functional outcomes such as alveolar bone loss and immune senescence.
RESUMO
(1) Background: The aim of this study was to test whether matrix-bound zoledronate (zol) molecules enhanced the oral biofilm colonization of a mineralized matrix, rendering the alveolar bone more susceptible to medication-related osteonecrosis of the jaw (MRONJ) following invasive dental procedures. (2) Methods: We tested the effect of matrix-bound zol on the growth and attachment of Porphyromonas gingivalis (Pg), Fusobacterium nucleatum (Fn) and Actinomyces israelii (Ai), and whether the nitrogen-containing component of zol contributed to such effect. The role of oral bacteria in the induction of osteonecrosis was then tested using an extra-oral bone defect model. (3) Results: The attachment of biofilm to hydroxyapatite discs increased when the discs were pre-treated with zol. Bacterial proliferation was not affected. Matrix-bound zol was more potent than non-nitrogen-containing etidronate in enhancing the colonization. Stimulation was dampened by pre-treating the bacteria with histidine. The delivery of oral biofilm to a tibial defect caused osteonecrosis in zol-treated rats. (4) Conclusions: We conclude that matrix-bound zol enhances the oral biofilm colonization of hydroxyapatite. This enhancement depended on the presence of the nitrogen-containing group. The oral biofilm rendered the extra-oral bone susceptible to medication-related osteonecrosis, suggesting that it has an important role in the induction of MRONJ.
RESUMO
Chronic bone degenerative diseases represent a major threat to the health and well-being of the population, particularly those with advanced age. This study isolated exosomes (EXO), natural nano-particles, from dendritic cells, the "directors" of the immune response, to examine the immunobiology of DC EXO in mice, and their ability to reprogram immune cells responsible for experimental alveolar bone loss in vivo. Distinct DC EXO subtypes including immune-regulatory (regDC EXO), loaded with TGFB1 and IL10 after purification, along with immune stimulatory (stimDC EXO) and immune "null" immature (iDCs EXO) unmodified after purification, were delivered via I.V. route or locally into the soft tissues overlying the alveolar bone. Locally administrated regDC EXO showed high affinity for inflamed sites, and were taken up by both DCs and T cells in situ. RegDC EXO-encapsulated immunoregulatory cargo (TGFB1 and IL10) was protected from proteolytic degradation. Moreover, maturation of recipient DCs and induction of Th17 effectors was suppressed by regDC EXO, while T-regulatory cell recruitment was promoted, resulting in inhibition of bone resorptive cytokines and reduction in osteoclastic bone loss. This work is the first demonstration of DC exosome-based therapy for a degenerative alveolar bone disease and provides the basis for a novel treatment strategy.
RESUMO
As fundamental processes of immune homeostasis, autophagy, and apoptosis must be maintained to mitigate risk of chronic inflammation and autoimmune diseases. Periodontitis is a chronic inflammatory disease characterized by oral microbial dysbiosis, and dysregulation of dendritic cell (DC) and T cell responses. The aim of this study was to elucidate the underlying mechanisms by which the oral microbe Porphyromonas gingivalis (P. gingivalis) manipulates dendritic cell signaling to perturb both autophagy and apoptosis. Using a combination of Western blotting, flow cytometry, qRT-PCR and immunofluorescence analysis, we show a pivotal role for the minor (Mfa1) fimbriae of P. gingivalis in nuclear/cytoplasmic shuttling of Akt and FOXO1 in human monocyte-derived DCs. Mfa1-induced Akt nuclear localization and activation ultimately induced mTOR. Activation of the Akt/mTOR axis downregulated intracellular LC3II, also known as Atg8, required for autophagosome formation and maturation. Use of allosteric panAkt inhibitor MK2206 and mTOR inhibitor rapamycin confirmed the role of Akt/mTOR signaling in autophagy inhibition by P. gingivalis in DCs. Interestingly, this pathway was also linked to induction of the anti-apoptotic protein Bcl2, decreased caspase-3 cleavage and decreased expression of pro-apoptotic proteins Bax and Bim, thus promoting longevity of host DCs. Addition of ABT-199 peptide to disrupt the interaction of antiapoptotic Bcl2 and its proapoptotic partners BAK/BAX restored apoptotic death to P. gingivalis-infected DC cells. In summary, we have identified the underlying mechanism by which P. gingivalis promotes its own survival and that of its host DCs.
Assuntos
Apoptose , Autofagia , Infecções por Bacteroidaceae/imunologia , Células Dendríticas/imunologia , Porphyromonas gingivalis , Infecções por Bacteroidaceae/virologia , Células Cultivadas , Células Dendríticas/microbiologia , Fímbrias Bacterianas , Proteína Forkhead Box O1/imunologia , Homeostase , Humanos , Proteínas Proto-Oncogênicas c-akt , Receptor 1 Toll-Like/imunologia , Receptor 2 Toll-Like/imunologiaRESUMO
Years of human microbiome research have confirmed that microbes rarely live or function alone, favoring diverse communities. Yet most experimental host-pathogen studies employ single species models of infection. Here, the influence of three-species oral microbial consortium on growth, virulence, invasion and persistence in dendritic cells (DCs) was examined experimentally in human monocyte-derived dendritic cells (DCs) and in patients with periodontitis (PD). Cooperative biofilm formation by Streptococcus gordonii, Fusobacterium nucleatum and Porphyromonas gingivalis was documented in vitro using growth models and scanning electron microscopy. Analysis of growth rates by species-specific 16s rRNA probes revealed distinct, early advantages to consortium growth for S. gordonii and F. nucleatum with P. gingivalis, while P. gingivalis upregulated its short mfa1 fimbriae, leading to increased invasion of DCs. F. nucleatum was only taken up by DCs when in consortium with P. gingivalis. Mature consortium regressed DC maturation upon uptake, as determined by flow cytometry. Analysis of dental plaques of PD and healthy subjects by 16s rRNA confirmed oral colonization with consortium members, but DC hematogenous spread was limited to P. gingivalis and F. nucleatum. Expression of P. gingivalis mfa1 fimbriae was increased in dental plaques and hematogenous DCs of PD patients. P. gingivalis in the consortium correlated with an adverse clinical response in the gingiva of PD subjects. In conclusion, we have identified polymicrobial synergy in a three-species oral consortium that may have negative consequences for the host, including microbial dissemination and adverse peripheral inflammatory responses.
Assuntos
Biofilmes/crescimento & desenvolvimento , Coinfecção/microbiologia , Células Dendríticas/microbiologia , Gengiva/microbiologia , Consórcios Microbianos , Periodontite/microbiologia , Fímbrias Bacterianas/genética , Fusobacterium nucleatum/genética , Fusobacterium nucleatum/fisiologia , Humanos , Inflamação , Microbiota , Porphyromonas gingivalis/genética , Porphyromonas gingivalis/fisiologia , RNA Ribossômico 16S/genética , Streptococcus gordonii/genética , Streptococcus gordonii/fisiologiaRESUMO
OBJECTIVE: To evaluate the efficacy of EDDY, a new sonic-powered irrigation system, in reducing intracanal bacteria load. METHODS: Thirty-eight instrumented, autoclaved single-rooted human premolars were inoculated with Enterococcus faecalis (ATCC-29212) for 21 days. Two teeth were used as negative control without bacterial contamination. For the bacteria-inoculated teeth, 6 were used as positive control without irrigation. The remaining 30 teeth were randomly divided into 2 groups (Nâ¯=â¯15), using 3% NaOCl as irrigant: (A) 30-gauge syringe needle irrigation (SNI), (B) EDDY (VDW, Munich, Germany). Twelve teeth per group and 4 teeth in the positive control were evaluated for bacterial reduction using MTT assay. The remaining teeth were split for BacLight LIVE/DEAD staining to examine the percentages of live/dead bacteria present in the dentinal tubules from different canal locations (coronal, mid-root and apical portions of the canal space) using confocal laser scanning microscopy (CLSM). RESULTS: MTT assay indicated that both SNI and EDDY significantly reduced overall intracanal bacterial load compared with the positive control, with no significant difference between the two techniques. CLSM indicated that EDDY had better intratubular bacterial killing efficacy than SNI in the coronal and mid-root portions of the canal space only but not in the apical portion. In all canal locations (coronal, mid-root apical), both systems failed to eliminate bacteria that proliferated deep within the dentinal tubules. CONCLUSION: With the use of 3% NaOCl, sonic-powered irrigant activation with EDDY tips did not provide additional advantage over SNI in killing Enterococcus faecalis from deep intraradicular dentin. CLINICAL SIGNIFICANCE: Both the sonic-powered root canal irrigant activation system and syringe needle irrigation can reduce intracanal bacteria load but are incapable of completely killing all bacteria that resided deep within the dentinal tubules of root canals infected with Enterococcus faecalis.
Assuntos
Cavidade Pulpar , Irrigação Terapêutica , Antibacterianos , Enterococcus faecalis , Alemanha , Humanos , Irrigantes do Canal Radicular , Preparo de Canal Radicular , Hipoclorito de SódioRESUMO
OBJECTIVE: Secondary caries and degradation of hybrid layers are two major challenges in achieving durable resin-dentin bonds. The objectives of the present study were to investigate the effects of a 2% quaternary ammonium silane (QAS) cavity cleanser on bacteria impregnated into dentin blocks and the gelatinolytic activity of the hybrid layers. METHODS: Microtensile bond strength was first performed to evaluate if the 2% QAS cavity cleanser adversely affected bond strength. For antibacterial testing, Streptococcus mutans and Actinomyces naeslundii were impregnated into dentin blocks, respectively, prior to the application of the cavity cleanser. Live/dead bacterial staining and colony-forming unit (CFU) counts were performed to evaluate their antibacterial effects. Gelatinolytic activity within the hybrid layers was directly examined using in-situ zymography. A double-fluorescence technique was used to examine interfacial permeability immediately after bonding. RESULTS: The cavity cleanser did not adversely affect the bond strength of the adhesives tested (p>0.05). Antibacterial testing indicated that 2% QAS significantly killed impregnated bacteria within the dentin blocks compared with control group (p<0.05), which was comparable with the antibacterial activity of 2% chlorhexidine (p>0.05). Hybrid layers pretreated with 2% QAS showed significant decrease in enzyme activity compared with control group. With the use of 2% QAS, relatively lower interfacial permeability was observed, compared with control group and 2% chlorhexidine (p<0.05). SIGNIFICANCE: The present study developed a 2% QAS cavity cleanser that possesses combined antimicrobial and anti-proteolytic activities to extend the longevity of resin-dentin bonds.
Assuntos
Antibacterianos/farmacologia , Desinfetantes/farmacologia , Inibidores de Proteases/farmacologia , Compostos de Amônio Quaternário/farmacologia , Silanos/farmacologia , Actinomyces/efeitos dos fármacos , Antibacterianos/química , Colagem Dentária , Materiais Dentários/química , Materiais Dentários/farmacologia , Dentina/enzimologia , Adesivos Dentinários/química , Adesivos Dentinários/farmacologia , Desinfetantes/química , Humanos , Técnicas In Vitro , Teste de Materiais , Inibidores de Proteases/química , Compostos de Amônio Quaternário/química , Células-Tronco , Streptococcus mutans/efeitos dos fármacos , Resistência à TraçãoRESUMO
OBJECTIVE: To investigate the anti-biofilm efficacy of root canal irrigants in canal spaces, isthmi and dentinal tubules of root canals ex vivo. METHODS: Fifty-one single-rooted premolars, each containing an isthmus, were instrumented, autoclaved and inoculated with Enterococcus faecalis for 4 weeks. One specimen was sectioned for bacteria-specific staining to confirm the presence of biofilms using light microscopiy. The remaining specimens were randomly divided to five groups: (1) 0.9% NaCl, (2) SilverSol/H2O2, (3) HYBENX, (4) QMix 2 in1, (5) 6% NaOCl. Bacterial sampling was performed before (S1) and after (S2) canal irrigation. Diluted bacteria suspension was cultured for 48 h for counting the colony forming units (CFU). Percentages of dead bacteria and biofilm thickness were evaluated by confocal laser scanning microscopy (CLSM). Metabolic activity, lactic acid and polysaccharide synthesis of E. faecalis derived from S2 samples were analysed. RESULTS: The percentages of dead bacteria were significantly affected by the factor "irrigant" (p < 0.001) and the factor "location" (p = 0.017). The percentages of dead bacteria in the isthmi and canals were both in the ordor: NaCl < SilverSol/H2O2 < HYBENX < QMix 2 in1â¯<â¯NaOCl (p < 0.05). Only 6% NaOCl disrupted biofilms and significantly reduced their thickness. The CFU, metabolic activity, polysaccharide and lactic acid production of E. faecalis were all reduced by the disinfecting solutions. CONCLUSIONS: SilverSol/H2O2 and HYBENX were less adept than QMix 2 in1 at killing biofilm bacteria in root canals. None of these antibacterial irrigants were effective, compared with 6% NaOCl, in disrupting biofilms. CLINICAL SIGNIFICANCE: There is advantage in using HYBENX or QMix 2 in1 to kill intratubular bacteria biofilms because of their capability in removing the inorganic component of the smear layer. SilverSol/H2O2 requires extra time to eradicate intratubular biofilms upon removal of the organic and inorganic components of the smear layer by other root canal irrigants.
Assuntos
Enterococcus faecalis , Irrigantes do Canal Radicular , Biofilmes , Cavidade Pulpar , Peróxido de Hidrogênio , Hipoclorito de SódioRESUMO
BACKGROUND: Lip repositioning is a conservative surgical method for the correction of excess gingival display (EGD) by limiting the upward retraction of the lips. Lip repositioning presents a simple method for the treatment of gummy smile. The aim of this randomized clinical trial (RCT) was to assess lip repositioning, compared to lip repositioning with muscle severance for efficacy in treatment of EGD and resultant stability. METHODS: A single-blinded, controlled, parallel-group RCT was performed. Twenty patients with EGD were enrolled in the study, treated with lip repositioning with and without muscle severance. Participants were assessed for EGD reduction, changes in lip length and result stability at 3, 6 and 12 months. Additionally, pain, swelling and satisfaction, were assessed. RESULTS: Classic lip repositioning was found capable of reducing EGD by 2.73 mm (SD ± 1.281), while lip repositioning with muscle severance offered an improved reduction in EGD with a mean reduction of 3.57mm (SD ± 1.62). Lip length, swelling and pain scores were found comparable between the two techniques. CONCLUSION: Lip repositioning is an effective method for treating EGD, however, muscle severance provides a more stable result at 12 months when compared to the classical technique. More studies are necessary to fully assess this procedure.