RESUMO
AIM: To evaluate in a clinical trial the efficacy of reciprocating and ultrasonic activation of 6% sodium hypochlorite (NaOCl) in the microbial composition and reduction in microbial load as well as in levels of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) in teeth with primary endodontic infections. METHODOLOGY: Samples were collected from 24 root canals with pulp necrosis and periapical lesions, before and after chemo-mechanical canal preparation. The teeth were randomly divided according to the activation protocol as follows: control group without activation (WA, n = 8), reciprocating activation group using Easy Clean tip (EC, n = 8) and ultrasonic activation group using Irrisonic insert (US, n = 8). Microbiological specimens were processed using a culture technique and microbiota composition was analysed using the checkerboard technique. The levels of LPS and LTA were quantified using limulus amebocyte lysate (LAL) and enzyme-linked immunosorbent assay (ELISA), respectively. The Fisher's exact test, Kruskal-Wallis, Dunn's and Wilcoxon's test with a significance level of P < 0.05 were used for statistical analysis. RESULTS: All initial specimens had growth of viable bacteria in fastidious anaerobe agar (FAA), with an average of 105 CFU mL-1 , whereas only one case had such growth after chemo-mechanical canal preparation. LPS and LTA were recovered in 100% of the cases. Chemo-mechanical canal preparation significantly decreased the levels of LPS and LTA (P < 0.05), but no significant differences were found between the groups (P > 0.05). Through the checkerboard technique, bacteria were found in 100% of the initial specimens with concentrations between <105 and 106 . The most frequently identified microorganisms were Prevotella nigrescens and Enterococcus hirae. After chemo-mechanical canal preparation, many species were not detected in any of the three groups tested. A significant reduction occurred in Group US, followed by Groups EC and WA. CONCLUSIONS: Activation of 6% NaOCl reduced the levels of LPS and LTA with no differences between the groups. However, ultrasonic activation was associated with a greater reduction in microbial load within root canals.
Assuntos
Infecções , Periodontite Periapical , Cavidade Pulpar , Humanos , Irrigantes do Canal Radicular , Preparo de Canal Radicular , Hipoclorito de Sódio , Ultrassom , Fatores de VirulênciaRESUMO
AIM: To compare the shaping ability of four root canal instrumentation systems in oval-shaped canals using micro-computed tomographic analysis. METHODOLOGY: Forty anatomically matched mandibular incisors were scanned and assigned to four groups (n = 10), according to the canal preparation protocol: BioRace, Reciproc, Self-Adjusting File (SAF) and TRUShape systems. After canal instrumentation, the specimens were rescanned, and the registered pre- and postoperative datasets were examined to evaluate the percentages of accumulated hard-tissue debris, untouched canal walls and dentine removed. Kruskal-Wallis and Mann-Whitney U-tests with Bonferroni correction were used to compare the variables in the groups (α = 5%). RESULTS: The preparation techniques did not affect the percentage of accumulated hard-tissue debris (P = 0.126). The percentage of untouched canal areas was significantly higher for BioRace (32.38%)compared to Reciproc (18.95%) and SAF (16.08%) systems (P < 0.05). Reciproc removed significantly more dentine (4.18%) than BioRace (2.21%) and SAF (2.56%) (P < 0.05). The TRUShape system had intermediate results for both untouched canal walls (19.20%) and dentine removed (3.77%), with no significant difference compared to BioRace, Reciproc and SAF systems. CONCLUSIONS: The preparation techniques resulted in the same level of accumulated hard-tissue debris. Compared to the other tested systems, BioRace was associated with more untouched canal walls and Reciproc produced the greatest amount of removed dentine. Although it touched more of the root canal walls, the SAF system removed less dentine, whereas TRUShape had intermediate results for these same parameters. None of the systems tested were able to provide optimal shaping ability in oval-shaped canals.
Assuntos
Cavidade Pulpar/cirurgia , Obturação do Canal Radicular/instrumentação , Cavidade Pulpar/anatomia & histologia , Cavidade Pulpar/diagnóstico por imagem , Humanos , Incisivo/anatomia & histologia , Incisivo/cirurgia , Maxila , Microtomografia por Raio-XRESUMO
AIM: This clinical study was conducted to investigate the influence of 17% ethylenediaminetetraacetic acid (EDTA) ultrasonic activation after chemomechanical preparation (CMP) on eliminating/reducing oral bacterial lipopolysaccharides (known as endotoxins) and cultivable bacteria in teeth with pulp necrosis and apical periodontitis. METHODOLOGY: Samples were taken from 24 root canals at several clinical periods: S1 - before CMP; S2 - after CMP; S3 - after EDTA: G1 - with ultrasonic activation (n = 12) and G2 - without ultrasonic activation (n = 12). Root canals were instrumented using Mtwo rotary files. Culture techniques were used to determine the number of colony-forming units (CFU). Limulus amebocyte lysate (LAL) was used to measure endotoxin levels. Friedman's and Wilcoxon signed-rank tests were used to compare the amount of bacteria and endotoxin levels in each period (P < 0.05). RESULTS: Endotoxins and cultivable bacteria were recovered in 100% of the initial samples (S1). CMP was effective in reducing endotoxins and bacterial load (all with P < 0.05). Higher values of endotoxin reduction were achieved with EDTA ultrasonic activation [G1, 0.02 EU mL-1 (range 0.01-0.75)] compared with the no activation group [G2, 1.13 EU mL-1 (range 0.01-8.34)] (P < 0.05). Regarding bacterial reduction, no statistically significant difference was found in S3, regardless of the group (G1, G2, P > 0.05). CONCLUSIONS: Chemomechanical preparation was effective in reducing bacteria and endotoxins, but could not completely eliminate them. The ultrasonic activation of EDTA was effective in further reducing endotoxin levels in the root canals of teeth with pulp necrosis and apical periodontitis.
Assuntos
Necrose da Polpa Dentária/terapia , Ácido Edético/uso terapêutico , Endotoxinas/antagonistas & inibidores , Periodontite Periapical/terapia , Preparo de Canal Radicular/métodos , Bactérias/efeitos dos fármacos , Bactérias/efeitos da radiação , Humanos , Células-Tronco/efeitos dos fármacos , Células-Tronco/efeitos da radiação , UltrassomRESUMO
BACKGROUND: This study aimed to evaluate the accuracy of cone beam computed tomography (CBCT) and periapical radiography in diagnosing root resorption and verify the influence of filling material in detecting these lesions. METHODS: Digital periapical radiographs and CBCT images of patients with root resorption and a history of dental trauma from a radiology clinic were reviewed retrospectively. The sample comprised 40 teeth with root resorption and 20 normal teeth as controls. Images were analysed by two radiologists and two endodontists. The sensitivity, specificity and accuracy were determined. The kappa coefficient assessed interobserver agreement and the t test determined significant differences between the imaging methods. RESULTS: The accuracy of CBCT in diagnosing external (P = 0.0144) and internal (P = 0.0038) inflammatory resorption was significantly higher than for periapical radiography. For replacement resorption, no statistical difference was noted (P > 0.05). In endodontically treated teeth, CBCT was statistically superior in diagnosing root resorption (P = 0.0138). CONCLUSIONS: CBCT was superior to digital periapical radiography in diagnosing external and internal inflammatory root resorption after dental trauma and can be considered in the differential diagnosis of resorptive lesions in teeth with endodontic treatment.
Assuntos
Reabsorção da Raiz/diagnóstico por imagem , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Tomografia Computadorizada de Feixe Cônico/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Radiografia Interproximal/métodos , Radiografia Dentária Digital/métodos , Materiais Restauradores do Canal Radicular , Sensibilidade e EspecificidadeRESUMO
AIM: To evaluate the cytotoxic effects of Biodentine, using a three-dimensional (3D) cell culture associated with an in situ root-end filling experimental model. White mineral trioxide aggregate (MTA) and zinc oxide cement were used as reference for comparison. IL-1α and TNF-α cytokine production were also evaluated. METHODOLOGY: The root canals of 24 human maxillary incisor teeth were prepared using a single-file reciprocating technique. After root filling, a 3-mm root-end resection was performed and 3 mm of gutta-percha was removed from the canal. The teeth were randomly distributed to receive one of the following root-end filling materials: Biodentine, white MTA or zinc oxide cement (positive control group). In the negative control group, the root canal was not retro-filled. The cytocompatibility of the materials was evaluated using the methyl-thiazol-diphenyl-tetrazolium (MTT) assay in an in situ root-end filling experimental model. Balb/c 3T3 fibroblasts, cultured in rat tail collagen type I 3D scaffold, were exposed to the root apex for 24 h, and cell viability was measured by means of reduction MTT salt. IL-1α and TNF-α production were analysed using enzyme-linked immunosorbent assay. One-way analysis of variance was performed and, when the F-ratios were significant, data were compared by Duncan's multiple-range test. The alpha-type error was set at 0.05. RESULTS: Biodentine and MTA groups had similar cell activity to the negative control group (P > 0.05), indicating low cytotoxicity for both materials. The stronger cytotoxicity effect was identified on the zinc oxide cement (P < 0.05). Zinc oxide cement caused a significant up-regulation in IL-1α and TNF-α (P < 0.05). No significant differences amongst MTA, Biodentine and the negative control group were observed for TNF-α (P > 0.05); however, both MTA and Biodentine were associated with overproduction of IL-1α when compared to the control group (P < 0.05). CONCLUSIONS: Biodentine and MTA had similar cytocompatibility in a 3D cell culture model associated with an in situ root-end filling model. The methodology could be used as an alternative to assess the cytocompatibility of endodontic cements because it is more closely related to the in vivo situation.
Assuntos
Compostos de Cálcio/farmacologia , Materiais Restauradores do Canal Radicular/farmacologia , Silicatos/farmacologia , Células 3T3 , Compostos de Alumínio/efeitos adversos , Compostos de Alumínio/farmacologia , Animais , Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/farmacologia , Compostos de Cálcio/efeitos adversos , Células Cultivadas , Citocinas/metabolismo , Combinação de Medicamentos , Humanos , Camundongos , Óxidos/efeitos adversos , Óxidos/farmacologia , Materiais Restauradores do Canal Radicular/efeitos adversos , Silicatos/efeitos adversos , Óxido de Zinco/efeitos adversos , Óxido de Zinco/farmacologiaRESUMO
Immature avulsed teeth are not usually treated with pulp revascularization because of the possibility of complications. However, this therapy has shown success in the treatment of immature teeth with periapical lesions. This report describes the case of an immature replanted tooth that was successfully treated by pulp revascularization. An 8-year-old boy suffered avulsion on his maxillary left lateral incisor. The tooth showed incomplete root development and was replanted after 30 minutes. After diagnosis, revascularization therapy was performed by irrigating the root canal and applying a calcium hydroxide paste and 2% chlorhexidine gel for 21 days. In the second session, the intracanal dressing was removed and a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate was placed as a cervical barrier at the entrance of the root canal and the crown was restored. During the follow-up period, periapical repair, apical closure and calcification in the apical 4 mm of the root canal was observed. An avulsed immature tooth replanted after a brief extra-alveolar period and maintained in a viable storage medium may be treated with revascularization.
Assuntos
Apexificação/métodos , Incisivo/lesões , Avulsão Dentária/terapia , Reimplante Dentário/métodos , Compostos de Alumínio/uso terapêutico , Compostos de Cálcio/uso terapêutico , Hidróxido de Cálcio/uso terapêutico , Criança , Clorexidina/uso terapêutico , Polpa Dentária/irrigação sanguínea , Polpa Dentária/efeitos dos fármacos , Cavidade Pulpar/efeitos dos fármacos , Combinação de Medicamentos , Seguimentos , Humanos , Masculino , Óxidos/uso terapêutico , Materiais Restauradores do Canal Radicular/uso terapêutico , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Silicatos/uso terapêutico , Ápice Dentário/efeitos dos fármacos , Calcificação de Dente/efeitos dos fármacosRESUMO
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.
Assuntos
Cavidade Pulpar/microbiologia , Necrose da Polpa Dentária/metabolismo , Necrose da Polpa Dentária/microbiologia , Endotoxinas/metabolismo , Fibroblastos/enzimologia , Gelatinases/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Periodontite Periapical/metabolismo , Periodontite Periapical/microbiologia , Preparo de Canal Radicular/métodos , Técnicas de Cultura de Células , Desinfecção/métodos , Humanos , Metaloproteinase 9 da Matriz/metabolismo , Regulação para CimaRESUMO
Objetivo: Evaluar in vitro, la efectividad del método visual y radiográfico, comparándolos con la técnica de diafanización en la detección del segundo conducto radicular de incisivos inferiores tratados endodónticamente. Material y métodos: Fueron analizados 133 dientes incisivos inferiores permanentes, tratados endodónticamente, a través de métodos visuales (con y sin auxilio de magnificación), radiográficos y de diafanización. El análisis radiográfico fue realizado en negatoscopio utilizando una lupa estereoscópica (10X). Posteriormente, fue realizada la remoción completa de la obstrucción provisional para la exploración visual con y sin auxilio de microscopio clínico (MO) en un aumento de 12X. Finalmente los dientes fueron diafanizados y almacenados en salicilato de metila para posterior análisis. Dos evaluadores calibrados registraron los datos referentes a la presencia o no del segundo conducto radicular para cada uno de los métodos utilizados. Resultados: El análisis radiográfico mostró la presencia del segundo conducto en 24 dientes (18,05%. Visualmente, fue encontrado en 4 dientes (3,00%) sin magnificación y en 16 dientes (12,03%) con ayuda del MO. A través de la diafanización, 34 dientes (25,95%) presentaron segundo conducto. Conclusiones: La asociación de técnicas radiográficas y la magnificación visual obtenida con la utilización del MO se muestran como los aliados clínicos más efectivos para la localización del segundo conducto en incisivos inferiores.
Objective: To evaluate in vitro the effectiveness of the visual, radiographic and clearing technique on detection of two root canals in mandibular incisor teeth endodontically treated. Material and methods: One hundred thirty-three human permanent lower incisors were anlyzed through visual methods (with and without magnification), radiographic and clearing technique. Radiographic analysis was performed in light box using a stereomicroscope (10X). Then, the temporary filling of al specimens was removed for visual exploration with and without clinical microscope (OM) (12X). Finally the teeth were submitted to clearing technique and stored in methyl salicylate for subsequent analysis. Two calibrated reviewers recorded data about the presence or absence of the second root canal for each of the used methods. Results: Radiographic analysis showed the presence of the second root canal in 24 teeth (18.05%). Visually, it was found in 4 teeth (3.00%) and 16 teeth (12.03%) without and with the use of OM, respectively. Through clearing technique, in 334 teeth (25.95%) it was found the second root canal. Conclusion: The association of radiographic techniques and visual magnification with the use of MO has been shown as the most effective clinical partners to locate the second root canal in mandibular incisors.
Assuntos
Humanos , Cavidade Pulpar , Cavidade Pulpar , Endodontia , Técnicas In Vitro , Incisivo , Ampliação RadiográficaRESUMO
The aim of this investigation was to identify microorganisms from root canals with periapical abscesses and assess the susceptibility of specific anaerobic bacteria to selected antimicrobials and their ß-lactamase production. Sixty root canals were microbiologically investigated. The susceptibility of Anaerococcus prevotii, Fusobacterium necrophorum, F. nucleatum, Parvimonas micra, and Prevotella intermedia/nigrescens to antimicrobials was evaluated with the Etest, whereas ß-lactamase production was assessed with nitrocefin. A total of 287 different bacterial strains were recovered, including 201 strict anaerobes. The most frequently strict isolated anaerobes were A. prevotii, P. micra, and F. necrophorum. The selected bacteria were susceptible to all the tested antibiotics, except A. prevotii and Fusobacterium species to azithromycin and erythromycin, as well as A. prevotii and F. necrophorum to metronidazole. None of the microorganisms produced ß-lactamase. Gram-positive anaerobic bacteria predominated in the root canals with periapical abscesses. All microorganisms tested were susceptible to benzylpenicillin, amoxicillin, amoxicillin + clavulanate, cefaclor, and clindamycin, producing no ß-lactamase.
Assuntos
Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/efeitos dos fármacos , Biodiversidade , Cavidade Pulpar/microbiologia , Abscesso Periapical/microbiologia , Adolescente , Adulto , Antibacterianos/farmacologia , Bactérias Anaeróbias/isolamento & purificação , Criança , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Adulto Jovem , beta-Lactamases/metabolismoRESUMO
AIM: To examine the feasibility of using the pOBCol3.6GFPtpz [3.6-green fluorescent protein (GFP)] transgenic mice as an in vivo model for studying the biological sequence of events during pulp healing and reparative dentinogenesis. METHODOLOGY: Pulp exposures were created in the first maxillary molar of 12-16-week-old 3.6-GFP transgenic mice with CD1 and C57/Bl6 genetic background. Direct pulp capping on exposed teeth was performed using mineral trioxide aggregate followed by restoration with a light-cured adhesive system (AS) and composite resin. In control teeth, the AS was placed in direct contact with the pulp. Animals were euthanized at various time points after pulp exposure and capping. The maxillary arch was isolated, fixed and processed for histological and epifluorescence analysis to examine reparative dentinogenesis. RESULTS: Analysis of teeth immediately after pulp exposure revealed absence of odontoblasts expressing 3.6-GFP at the injury site. Evidence of reparative dentinogenesis was apparent at 4 weeks in 3.6-GFP mice in CD1 background and at 8 weeks in 3.6-GFP mice with C57/Bl6 background. The reparative dentine with both groups contained newly formed atubular-mineralized tissue resembling a dentine bridge and/or osteodentine that was lined by cells expressing 3.6-GFP as well as 3.6-GFP expressing cells embedded within the atubular matrix. CONCLUSION: This study was conducted in a few animals and did not allow statistical analysis. The results revealed that the 3.6-GFP transgenic animals provide a unique model for direct analysis of cellular and molecular mechanisms of pulp repair and tertiary dentinogenesis in vivo. The study also shows the effects of the capping material and the genetic background of the mice in the sequence and timing of reparative dentinogenesis.
Assuntos
Dentina Secundária/efeitos dos fármacos , Dentina Secundária/crescimento & desenvolvimento , Regulação da Expressão Gênica , Agentes de Capeamento da Polpa Dentária e Pulpectomia/farmacocinética , Cicatrização/efeitos dos fármacos , Compostos de Alumínio/uso terapêutico , Animais , Compostos de Cálcio/uso terapêutico , Capeamento da Polpa Dentária/métodos , Exposição da Polpa Dentária/terapia , Adesivos Dentinários/farmacologia , Dentinogênese/efeitos dos fármacos , Dentinogênese/genética , Combinação de Medicamentos , Proteínas da Matriz Extracelular/fisiologia , Estudos de Viabilidade , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Odontoblastos/metabolismo , Óxidos/uso terapêutico , Fosfoproteínas/fisiologia , Cimentos de Resina/farmacologia , Sialoglicoproteínas/fisiologia , Silicatos/uso terapêutico , Cicatrização/genéticaRESUMO
This clinical study was conducted to quantify cultivable bacteria and endotoxin in root canals with post-treatment apical periodontitis by correlating their levels with clinical features and to evaluate the effect of chemo-mechanical preparation (CMP) with 2 % chlorhexidine gel + 17 % EDTA on bacterial and endotoxin removal/elimination. Moreover, target strict Gram-negative anaerobic bacteria were investigated by polymerase chain reaction (PCR). Fifteen teeth with post-treatment apical periodontitis were sampled before (s1) and after (s2) CMP. Culture techniques determined the number of colony-forming units (CFU). PCR (16S rDNA) and limulus amebocyte lysate (LAL) assay were used for bacterial and endotoxin detection, respectively. Prevotella nigrescens (4/15), Prevotella intermedia (2/15), and Tannerella forsythia (2/15) were the most frequently detected species. Endotoxin was recovered in 100 % of the samples. At s1, bacteria and endotoxin were detected at a median value of 5.14 × 10(3) CFU/mL and 3.96 EU/mL, respectively. Higher levels of endotoxin were related to a larger size of radiolucent area (>5 mm) (p < 0.05). CMP was more effective in reducing bacteria (99.61 %) than endotoxin (60.6 %) (both p < 0.05). Our findings indicated that the levels of endotoxin found in infected root canals were related to a larger size of radiolucent area in the periapical region. Moreover, CMP was effective in reducing both bacterial and endotoxin contents in post-treatment apical periodontitis.
Assuntos
Carga Bacteriana/métodos , Clorexidina/farmacologia , Endotoxinas/metabolismo , Periodontite Periapical/tratamento farmacológico , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana/métodos , Cavidade Pulpar/metabolismo , Cavidade Pulpar/microbiologia , Ácido Edético/farmacologia , Humanos , Viabilidade Microbiana , Periodontite Periapical/metabolismo , Periodontite Periapical/microbiologia , Reação em Cadeia da Polimerase/métodos , Prevotella/genética , Prevotella/crescimento & desenvolvimento , Prevotella/isolamento & purificação , Prevotella/metabolismo , RNA Bacteriano/análise , RNA Bacteriano/genética , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/genética , Resultado do Tratamento , Treponema/genética , Treponema/crescimento & desenvolvimento , Treponema/isolamento & purificação , Treponema/metabolismoRESUMO
AIM: To investigate the effects of root repair materials on the cytotoxicity and gelatinolytic activity of matrix metalloproteinases (MMPs) in 3T3 fibroblasts. METHODOLOGY: Fibroblasts (3T3, 3 × 10(5) cells per well) were incubated with elutes of calcium hydroxide (Biodinâmica, Ibiporã, PR, Brazil), EndoBinder (Binderware, São Carlos, SP, Brazil) and mineral trioxide aggregate (MTA) (Angelus, Londrina, PR, Brazil) for 24 h. The cytotoxicity of all root repair materials was determined using the MTT assay. Supernatants of cell cultures incubated with materials were collected after 24 h to determine the levels of MMP-2 and MMP-9 gelatinolytic activity by gelatin zymography. Data were analysed using anova and Tukey's test. RESULTS: Cells secreted MMP-2 after 24 h with calcium hydroxide inducing significantly greater MMP-2 expression in relation to the control and the other root repair materials (P < 0.05). The cytotoxicity results revealed that there was no significant difference in the cell viability of MTA, EndoBinder and the control group. However, there was a significantly reduced cell viability of 3T3 fibroblasts in association with calcium hydroxide (P < 0.05). CONCLUSIONS: Calcium hydroxide was associated with significantly less cell viability when compared with EndoBinder and MTA. All materials had gelatinolytic activity for MMP-2 with calcium hydroxide being associated with the greatest activity.
Assuntos
Fibroblastos/efeitos dos fármacos , Metaloproteinase 2 da Matriz/efeitos dos fármacos , Metaloproteinase 9 da Matriz/efeitos dos fármacos , Materiais Restauradores do Canal Radicular/toxicidade , Células 3T3 , Compostos de Alumínio/toxicidade , Animais , Compostos de Cálcio/toxicidade , Hidróxido de Cálcio/toxicidade , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Corantes , Combinação de Medicamentos , Fibroblastos/enzimologia , Teste de Materiais , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Óxidos/toxicidade , Silicatos/toxicidade , Sais de Tetrazólio , Tiazóis , Fatores de Tempo , Regulação para Cima/efeitos dos fármacosRESUMO
AIM: To investigate the effects of root canal sealers on the cytotoxicity and gelatinolytic activity of matrix metalloproteinases (MMPs) in human fibroblasts. METHODOLOGY: Human fibroblasts (MRC5, 3×10(5) cells per well) were incubated directly or indirectly with AH Plus, Endomethasone N, Pulp Canal Sealer EWT or Sealapex for 30 min, 1, 4 or 24 h (time-points). The cytotoxicity of all root canal sealers was determined by counting viable cells using the trypan blue exclusion assay. Supernatants of cell cultures incubated with root sealers directly or indirectly were collected after each time-point to determine the levels of MMP-2 and MMP-9 gelatinolytic activity by gelatin zymography. Data were analysed using anova and the Tukey's tests. RESULTS: Cells secreted MMP-2 after periods of 4 and 24 h; however, there were no significant differences between the sealers. Secretion of gelatinases was elevated by root canal sealers in direct contact with the cell monolayer when compared to indirect contact (P < 0.05). At the time-points tested, no gelatinolytic activity could be detected in the control group without the sealers. The cytotoxicity results revealed that all sealers were cytotoxic in both contact forms. Sealapex had the lowest cytotoxicity and AH Plus the most cytotoxicity. CONCLUSIONS: All root canal sealers induced the expression of MMP-2 in MRC5 fibroblasts. AH Plus had the highest cytotoxicity amongst the tested sealers, but all were associated with cytotoxic effects.
Assuntos
Fibroblastos/efeitos dos fármacos , Gelatinases/efeitos dos fármacos , Materiais Restauradores do Canal Radicular/toxicidade , Regulação para Cima/efeitos dos fármacos , Hidróxido de Cálcio/química , Técnicas de Cultura de Células , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Corantes , Dexametasona/química , Combinação de Medicamentos , Resinas Epóxi/química , Fibroblastos/enzimologia , Formaldeído/química , Gelatinases/análise , Humanos , Hidrocortisona/química , Teste de Materiais , Metaloproteinase 2 da Matriz/análise , Metaloproteinase 2 da Matriz/efeitos dos fármacos , Metaloproteinase 9 da Matriz/análise , Metaloproteinase 9 da Matriz/efeitos dos fármacos , Materiais Restauradores do Canal Radicular/química , Salicilatos/química , Propriedades de Superfície , Timol/análogos & derivados , Timol/química , Fatores de Tempo , Azul Tripano , Cimento de Óxido de Zinco e Eugenol/químicaRESUMO
AIM: To measure the minimum thickness of the distal (furcal) root dentine associated with the buccal and lingual canals of the mesial roots of mandibular first molars with different lengths. METHODOLOGY: The mesial roots of 285 mandibular first molars were allocated into three groups according to their length: group I - long (24.14 mm +/- 0.85), group II - medium (22.10 mm +/- 0.65) and group III - short (19.97 mm +/- 0.75). The minimum thickness of the distal (furcal) root dentine associated with the buccal and lingual canals of the mesial roots 2 mm below the furcation was measured. The distance between the buccal and lingual canals, and the depth of concavity in the distal surface of the mesial roots were also measured. anova and Tukey-Kramer were used to test for significant differences among the groups. RESULTS: The minimum thickness of the distal wall of the mesiobuccal canal was significantly different (P < 0.05) between group I (long) and III (short), with long teeth having the smallest mean values. No significant difference was found in the thickness of the distal wall of the mesiolingual canal among the groups studied (P > 0.05). The shortest distance between the mesiobuccal and the mesiolingual canals was observed in group III (P < 0.05). The distal (furcal) concavity was deeper in group I (P < 0.05) when compared with the other groups. CONCLUSION: There was a significant difference in the minimum thickness of the distal (furcal) root wall of the mesiobuccal canal of mandibular first molars 2 mm below the furcation between group I (long) and group III (short) teeth. The thinnest walls were found in the longest teeth. The deepest concavities in the distal (furcal) walls of the mesial roots were found in the longest roots.
Assuntos
Cavidade Pulpar/anatomia & histologia , Dentina/anatomia & histologia , Dente Molar/anatomia & histologia , Raiz Dentária/anatomia & histologia , Análise de Variância , Humanos , Mandíbula , Odontometria , Valores de Referência , Estatísticas não ParamétricasRESUMO
Expressed by squamous mucosal keratinocytes, calprotectin is a complex of two EF-hand calcium-binding proteins of the S100 subfamily (S100A8 and S100A9) with significant antimicrobial activity. Calprotectin-expressing cells resist invasion by Porphyromonas gingivalis, Listeria monocytogenes, and Salmonella enterica serovar Typhimurium (S. typhimurium). To understand the interactions between calprotectin and invasive bacteria, we studied the distribution of calprotectin in the cytoplasm of TR146 epithelial cells. In response to L. monocytogenes, calprotectin mobilized from a diffuse cytoplasmic distribution to a filamentous pattern and colocalized with the microtubule network. Listeria more frequently invaded cells with mobilized calprotectin. Calprotectin mobilization was listeriolysin O-dependent and required calcium (extracellular and intracellular) and an intact microtubule network. In the presence of preformed microtubules in vitro, the anti-Listeria activity of calprotectin was abrogated. To facilitate intraepithelial survival, therefore, Listeria mobilizes calprotectin to colocalize with cytoplasmic microtubules, subverting anti-Listeria activity and autonomous cellular immunity.
Assuntos
Anti-Infecciosos/metabolismo , Citoplasma/imunologia , Citoplasma/metabolismo , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Complexo Antígeno L1 Leucocitário/metabolismo , Listeria monocytogenes/imunologia , Cálcio/farmacologia , Linhagem Celular , Citoplasma/efeitos dos fármacos , Humanos , Ligação Proteica , Salmonella typhimurium/imunologia , Tubulina (Proteína)/metabolismoRESUMO
AIM: To investigate ex vivo the antimicrobial activity of a paste of sodium perborate associated with various vehicles comparing it with 37% carbamide peroxide and 35% hydrogen peroxide. METHODOLOGY: The antimicrobial activity of these agents was evaluated against three microorganisms: Enterococcus faecalis, Streptococcus mutans and Candida albicans. One millilitre of each tested substance was placed on the bottom of wells of 24-well cell culture plates. Six wells were used for each time period and group. Two millilitres of the microbial suspension was ultrasonically mixed for 10 s with the bleaching pastes and placed in contact with them for 10, 30, 45 s; 1, 3, 5, 10, 20, 30 min; and 1 and 2 h. After each period of time, 1 mL from each well was transferred to tubes containing 2 mL of freshly prepared brain heart infusion agar + neutralizers. Agar plates were inoculated in appropriate gaseous conditions. Data were analysed statistically by the Kruskal-Wallis test with the level of significance set at P < 0.05. RESULTS: In all groups containing chlorhexidine (groups 3, 5 and 7), the antimicrobial activity of the bleaching paste was significantly increased when compared with groups with other kinds of vehicle (groups 1, 2, 4, 6 and 8). For all tested groups, the most resistant microorganism was E. faecalis. CONCLUSIONS: Chlorhexidine when used as a vehicle for sodium perborate enhanced its antimicrobial activity.
Assuntos
Anti-Infecciosos/farmacologia , Boratos/farmacologia , Peróxido de Hidrogênio/farmacologia , Oxidantes/farmacologia , Peróxidos/farmacologia , Clareamento Dental/métodos , Ureia/análogos & derivados , Anti-Infecciosos Locais/farmacologia , Candida albicans/efeitos dos fármacos , Peróxido de Carbamida , Clorexidina/farmacologia , Combinação de Medicamentos , Farmacorresistência Bacteriana , Enterococcus faecalis/efeitos dos fármacos , Humanos , Teste de Materiais , Veículos Farmacêuticos , Streptococcus mutans/efeitos dos fármacos , Fatores de Tempo , Ureia/farmacologiaRESUMO
BACKGROUND/AIMS: The purpose of this study was to determine the amount of endotoxin (lipopolysaccharide) and cultivable bacteria in human necrotic root canals before (S1) and after chemo-mechanical preparation using chlorhexidine (CHX) gel as auxiliary chemical substance (S2), and after 7 days of intracanal dressing (S3) in order to evaluate the anti-endotoxin and antimicrobial effects of endodontic procedures. METHOD: Twenty-four teeth were selected for the present study. Chemo-mechanical preparation was performed using 2% CHX gel and three different intracanal medicaments [CaOH2 paste; 2% CHX gel; and CaOH2 + 2% CHX gel]. A quantitative chromogenic Limulus amoebocyte lysate assay was used to measure the amount of endotoxin. Aerobic and anaerobic techniques were used to isolate and identify bacteria, and to determine the bacterial reduction by counting colony-forming units (CFU). RESULTS: Endotoxins and bacteria were present in 100% of the initial samples, with endotoxin concentration ranging from 62.93 to 214.56 UE/ml and CFU ranging from 4 x 10(5) to 2.6 x 10(6). After chemo-mechanical preparation a mean endotoxin reduction of 44.4% was found. Eight (33.3%) root canals were still positive by culture analysis with a mean reduction of bacteria (CFU) of 99.96%. After 7 days of intracanal dressing, endotoxin concentration decreased by only 1.4% compared with S2, and residual bacteria were recovered by culture analysis in 13 cases (54.1%). No significant difference was found among different intracanal medicaments. CONCLUSION: Relatively high values of endotoxin were still present in the root canal after chemo-mechanical preparation although the majority of bacteria were eliminated. No improvement was achieved by 7 days of intracanal dressing.
Assuntos
Bactérias/classificação , Cavidade Pulpar/patologia , Necrose da Polpa Dentária/microbiologia , Endotoxinas/análise , Tratamento do Canal Radicular/métodos , Adolescente , Adulto , Idoso , Anti-Infecciosos Locais/uso terapêutico , Bactérias Aeróbias/classificação , Bactérias Anaeróbias/classificação , Técnicas de Tipagem Bacteriana , Hidróxido de Cálcio/uso terapêutico , Clorexidina/uso terapêutico , Compostos Cromogênicos , Contagem de Colônia Microbiana , Necrose da Polpa Dentária/terapia , Bactérias Gram-Negativas/classificação , Bactérias Gram-Positivas/classificação , Humanos , Lipopolissacarídeos/análise , Pessoa de Meia-Idade , Irrigantes do Canal Radicular/uso terapêuticoRESUMO
AIM: To evaluate the flow characteristics of AH Plus, Epiphany Root Canal Sealant, Endométhasone, Pulp Canal Sealer (EWT) and Sealapex and their ability to fill artificial lateral canals and prevent microleakage. METHODOLOGY: Flow of the sealers was analysed using the American Dental Association (ADA) 57 and the International Standards Organization (ISO) 6,876 specifications. Two lateral canals were produced in the middle and apical third of 64 roots using 0.1 mm cylindrical drills. Lateral condensation of gutta-percha or Resilon and one or other of the sealers were used to fill the root canals. Buccal-lingual digital radiographs were exposed. After the sealer had set, the roots were immersed in Indian ink and cleared in methyl salicylate. The extent of filling and dye penetration were measured on the buccal and lingual root surfaces under 30 x magnification with a stereoscope. RESULTS: AH Plus, Epiphany and Pulp Canal Sealer (EWT) complied with ADA 57 and ISO 6,876 specifications. Sealapex complied with the ADA 57 specification but not with ISO 6,876. Endométhasone did not comply with either specification. Filling of lateral canals was similar for the five sealers tested. Dye leakage demonstrated that AH Plus, Epiphany and Sealapex permitted less leakage than Pulp Canal Sealer (EWT) (P < 0.05). CONCLUSIONS: All the sealers flowed into the 0.1 mm artificial lateral canals. AH Plus, Epiphany and Sealapex allowed less linear leakage than Pulp Canal Sealer (EWT). The flow of Endométhasone did not comply with either ADA 57 or ISO 6,876 specifications and Sealapex did not comply with ISO 6,876.
Assuntos
Infiltração Dentária/prevenção & controle , Cavidade Pulpar/cirurgia , Materiais Restauradores do Canal Radicular/química , Cavidade Pulpar/anatomia & histologia , Humanos , Materiais Restauradores do Canal Radicular/uso terapêutico , Estatísticas não ParamétricasRESUMO
AIM: To evaluate in vivo degradation of root filling materials over time. METHODOLOGY: Thirty-six root filled teeth with or without periapical lesions were selected. Teeth with poor coronal restoration were not included. The teeth had been root filled 3-30 years previous and were scheduled for conventional retreatment. The association of root canal treatment, age, periapical lesion and root filling degradation was investigated. The filling material was removed from the root canal using files and no solvent. Trans-1,4-polyisoprene was isolated through solubilization of root filling remnants in chloroform followed by filtration and centrifugation. Gel permeation chromatography (GPC) and infrared spectroscopy (FT-IR) were utilized to study the occurrence and degree of degradation. The GPC and FT-IR data were collected for each sample and analysed statistically using the Kruskal-Wallis test. RESULTS: Degradation of trans-1,4-polyisoprene was a slow process. The process was identified as an oxidation reaction through the production of carboxyl and hydroxyl groups. Compared with the control group, significant molar mass decrease was noted after 15 years (P = 0.0146) in teeth with no periapical lesions. However, in teeth associated with periapical lesions the number of years for significant degradation was reduced to 5 (P = 0.0009). CONCLUSION: Polyisoprene degrades inside root canals as an oxidative process. The presence of periapical lesions was associated with a more rapid onset of degradation.
Assuntos
Butadienos/química , Guta-Percha/química , Hemiterpenos/química , Pentanos/química , Materiais Restauradores do Canal Radicular/química , Biotransformação , Cromatografia em Gel , Falha de Restauração Dentária , Humanos , Oxirredução , Periodontite Periapical/terapia , Retratamento , Obturação do Canal Radicular , Espectroscopia de Infravermelho com Transformada de Fourier , Estatísticas não Paramétricas , Fatores de TempoRESUMO
AIM: To investigate the antimicrobial activity of 2.5% and 5.25% sodium hypochlorite and 2.0% chlorhexidine gel and liquid as endodontic-irrigating substances against selected single-species biofilms. METHODS: Single-species biofilms of Enterococcus faecalis, Staphylococcus aureus, Candida albicans, Prevotella intermedia, Porphyromonas gingivalis, Porphyromonas endodontalis and Fusobacterium nucleatum were generated on a cellulose nitrate membrane placed on agar medium. The biofilms were then immersed in the endodontic-irrigating substances for 30 s and also for 5, 10, 15, 30 and 60 min, with and without mechanical agitation. Sterile saline was used as control. After each time period, the membrane filters were then transferred to tubes containing 2 mL of fresh broth medium plus neutralizers (in order to prevent the residual action of the tested substances). The micro-organisms were suspended using a vortex, and the inoculum was serially diluted 10-fold. Aliquots of the dilutions were plated on 5% sheep blood agar medium, and incubated under adequate gaseous conditions. Colony-forming units were calculated. The samples were compared using the Friedman and Tukey test, when necessary, at a significance level of P < 0.05. RESULTS: Mechanical agitation promoted the effectiveness of the antimicrobial agents, resulting in less time to eliminate the same micro-organisms, except for S. aureus with 2.5% NaOCl. Antimicrobial agents in liquid presentation, especially 5.25% NaOCl and 2% chlorhexidine, killed the tested micro-organisms more rapidly. Saline did not inhibit the growth of any of the tested micro-organisms, with or without agitation, being statistically different (P < 0.05) from NaOCl and chlorhexidine. P. intermedia, P. gingivalis, P. endodontalis and F. nucleatum were eliminated in 30 s by all antimicrobial agents, with our without agitation, in contrast with the facultative and aerobe strains. CONCLUSIONS: Mechanical agitation improved the antimicrobial properties of the chemical substances tested using a biofilm model, favouring the agents in liquid presentation, especially 5.25% NaOCl and 2% chlorhexidine.