RESUMEN
AIM: To evaluate the association between the presence of selected bacterial species/groups in the apical root canal and expression of mediators of soft and bone tissue destruction in apical periodontitis lesions. Relationships between bacteria and some other features of apical periodontitis were also investigated. METHODOLOGY: Seventeen freshly extracted teeth with pulp necrosis and apical periodontitis were included. The apical root segment was sectioned and cryopulverized; DNA was extracted and evaluated for the presence of 9 bacterial species/groups using real-time polymerase chain reaction. Lesions were processed for histopathological and immunohistochemical analyses, which targeted matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9), receptor activator of NFκB (RANK), RANK ligand (RANKL) and osteoprotegerin (OPG). Associations of the target bacteria with expression of these mediators, presence of symptoms, lesion size and histopathological diagnosis were evaluated. Data were analysed using the chi-square, Fisher's exact, Mann-Whitney and Pearson tests. P values lower than 0.05 were considered significant. RESULTS: All pulverized apical root samples were positive for bacteria. The most prevalent taxa were Actinobacteria (53%), Streptococcus species (35%), Fusobacterium species and Parvimonas micra (18%). The target mediators exhibited a high mean expression in the lesions (MMP-2: 82%; MMP-9: 73%; RANK: 78%; RANKL; 81%; OPG; 83%). Mean RANKL:OPG ratio was significantly higher in granulomas than cysts (P < 0.05, Mann-Whitney test). Actinobacteria were associated with granulomas, higher MMP-2 expression, lower OPG expression, and higher RANKL:OPG ratio (P < 0.05 for all, Fisher's exact test or Mann-Whitney test). No other significant associations were found. CONCLUSION: Actinobacteria may play an important role in the active phase of soft and bone tissue destruction in apical periodontitis.
Asunto(s)
Cavidad Pulpar/microbiología , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Osteoprotegerina/metabolismo , Periodontitis Periapical/microbiología , Ligando RANK/metabolismo , Receptor Activador del Factor Nuclear kappa-B/metabolismo , Ápice del Diente/microbiología , Adulto , Anciano , Cavidad Pulpar/metabolismo , Necrosis de la Pulpa Dental/metabolismo , Necrosis de la Pulpa Dental/microbiología , Femenino , Fusobacterium , Humanos , Masculino , Persona de Mediana Edad , Periodontitis Periapical/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Streptococcus , Ápice del Diente/metabolismoRESUMEN
AIM: To investigate endotoxin levels from primary endodontic infections before and after chemomechanical preparation (CMP) and to determine their antigenicity against 3T3 fibroblasts through gelatinolytic activity of matrix metalloproteinases (MMPs). METHODOLOGY: Twenty-four root canals with primary endodontic infection and apical periodontitis were selected. Samples were collected using paper points before (S1) and after chemomechanical preparation (CMP) (S2). The limulus amebocyte lysate assay was used for endotoxin measurement. Fibroblasts were stimulated with root canal contents for 24 h. Supernatants of cell cultures stimulated with root canal contents were collected after 24 h to determine the levels of MMP-2 and MMP-9 gelatinolytic activity using the zymography technique. Friedman and Wilcoxon tests were used to compare the amount of endotoxin before (S1) and after CMP (S2) (P < 0.05). Data obtained from gelatinolytic activity were analysed using anova and Tukey's tests (P < 0.05). RESULTS: Endotoxin was recovered in 100% of the samples. There was a significant reduction in endotoxin levels after CMP (P < 0.05). A correlation was found between the levels of endotoxins and MMP-2 expression (P < 0.05). Root canal contents of initial samples (S1) induced significantly greater MMP-2 expression by fibroblasts when compared to S2 and the nonstimulated group (P < 0.05). No gelatinolytic activity of MMP-9 was observed in S1, S2 and control group. CONCLUSIONS: Root canal contents from primary endodontic infections had gelatinolytic activity for MMP-2. Moreover, CMP was effective in reducing endotoxin levels and their antigenicity against fibroblasts on gelatinolytic activity.
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Cavidad Pulpar/microbiología , Necrosis de la Pulpa Dental/metabolismo , Necrosis de la Pulpa Dental/microbiología , Endotoxinas/metabolismo , Fibroblastos/enzimología , Gelatinasas/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Periodontitis Periapical/metabolismo , Periodontitis Periapical/microbiología , Preparación del Conducto Radicular/métodos , Técnicas de Cultivo de Célula , Desinfección/métodos , Humanos , Metaloproteinasa 9 de la Matriz/metabolismo , Regulación hacia ArribaRESUMEN
OBJECTIVE: To assess histological features and the expression of STRO-1 and BMP-4 in dental pulp and periapical tissues in vital or necrotic rat immature teeth. DESIGN: The lower left first molars of male Wistar rats ageing four weeks (n=24) had their pulps exposed to the oral environment for 3, 6, 9 and 12 weeks (animals ageing 7, 10, 13 and 16 weeks-old, respectively; n=24). The right lower first molars served as control untouched teeth. After sample harvesting the jaws were dissected and processed for histology and immunodetection of STRO-1 and BMP-4. RESULTS: Necrotic teeth had root development arrested, while control animals showed development of dental tissues. Immunohistochemistry showed that detection of BMP-4 was restricted to vital pulps. For both groups, STRO-1 expression was evident around blood vessels walls. Neither BMP-4 nor STRO-1 was observed in the apical papilla region. CONCLUSION: STRO-1-positive precursor cells were not detected in the apical papilla. BMP-4 expression has not been detected during infection.
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Antígenos de Superficie/metabolismo , Proteína Morfogenética Ósea 4/metabolismo , Necrosis de la Pulpa Dental/inducido químicamente , Pulpa Dental/metabolismo , Células Madre Mesenquimatosas/metabolismo , Tejido Periapical/metabolismo , Ápice del Diente/patología , Animales , Pulpa Dental/citología , Necrosis de la Pulpa Dental/metabolismo , Inmunohistoquímica , Masculino , Tejido Periapical/citología , Ratas , Ratas WistarRESUMEN
INTRODUCTION: The use of calcium hydroxide is an effective step in killing bacteria that remain after cleaning and shaping procedures. It also induces hard-tissue formation and is effective for stopping inflammatory exudates. METHODS: The aim of this study was to assay and to compare the influence of calcium hydroxide on periapical interstitial fluid from human root canals. The mRNA expression levels of the cytokines interferon (IFN)-γ, tumor necrosis factor-α, interleukin (IL)-1ß, IL-17A, and IL-10 as well as the chemokine MCP-1 were assayed by real-time polymerase chain reaction immediately after root canal cleaning and 15 days later. RESULTS: Levels of IL-1ß, IFN-γ, IL-10, and the chemokine CCL2/MCP-1 were increased in teeth without endodontic dressings. With calcium hydroxide interappointment dressings, no statistically significant changes were observed in cytokine mRNA expression. However, when comparing teeth that received the medication with those that did not, expression levels of IL-1ß, IFN-γ, and IL-10 were statistically lower in those teeth that received calcium hydroxide. CONCLUSIONS: Analyses of cytokines and the chemokine CCL-2/MCP-1 demonstrated the benefits of calcium hydroxide as a root canal dressing because it impedes the increase of all mediators during the experimental time.
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Hidróxido de Calcio/uso terapéutico , Citocinas/biosíntesis , Necrosis de la Pulpa Dental/tratamiento farmacológico , Necrosis de la Pulpa Dental/metabolismo , Irrigantes del Conducto Radicular/uso terapéutico , Quimiocina CCL2/biosíntesis , Humanos , Interferón gamma/biosíntesis , Interleucina-10/biosíntesis , Interleucina-1beta/biosíntesis , ARN Mensajero/biosíntesis , Reacción en Cadena en Tiempo Real de la Polimerasa , Estadísticas no ParamétricasRESUMEN
Endodontic irrigating solutions may have different effects, one of which is dissolving pulp tissue. The capacity of different irrigants to dissolve vital and necrotic pulp tissue was evaluated in vitro by means of a quantitative and qualitative study of total soluble pulp protein. Vital pulps and pulps with induced necrosis from young bovine teeth were used. Pulp was cut into smaller pieces, weighed and placed in 1 ml of 1% and 2.5% sodium hypochlorite, 1% and 5% calcium hydroxide, 0.2% chlorhexidine gluconate, 1% tea and distilled water as a control, and kept at 37 degrees. Samples of 20 microl were taken at 30 and 90 minutes and 20 hours. Total protein was dosed using the Lowry method and soluble protein bands were determined by electrophoresis (12% SDS-Page). The results were analyzed using Anova. Chemical analysis of the electrophoretic runs of bovine pulp protein showed that both concentrations of sodium hypochlorite and calcium hydroxide produce denaturation of proteins. No solvent action was found with chlorhexidine, tea or distilled water.