Bond Strength of Resin Cements Fixing Fiber Posts to Human and Bovine Teeth of Different Ages.

PURPOSE: To evaluate the effect of human and bovine root dentin age on the bond strength of fiber posts fixed with resin cements. The degree of conversion (DC) of the resin cements in different root thirds also was evaluated. MATERIALS AND METHODS: Ninety-six single-rooted teeth were divided into groups according to the origin and age: young human (20-30 years), old human (over 60 years), young bovine (24-36 months) and adult bovine (over 48 months). The teeth were endodontically treated, and fiber posts were cemented with resin cements (RelyX Ultimate and RelyX U200). After 24 h, the teeth were sectioned perpendicularly and the push-out test was performed in a universal testing machine at a speed of 0.5 mm/min, until failure. One specimen from each third from each group (n = 6) was selected, and the DC of the resin cements was analyzed by FT-Raman spectroscopy. RESULTS: For both resin cements, the young human root dentin group presented the highest bond strengths and the old human root dentin group presented the lowest (p < 0.05). The bond strengths of bovine root dentin groups were not affected by aging (p > 0.05). For the DC of resin cements, there were differences among the root thirds (p < 0.05), with the lowest values observed in the apical third. CONCLUSIONS: The bond strengths were higher in the young human root canal than in the bovine substrate, with a negative effect of aging in the human substrate. The DC of dual-curing resin cements decreased from the coronal to apical root thirds.

Estudo piloto da análise comparativa da atividade antimicrobiana da PDT e agentes irrigantes em canais radiculares inoculados com Enterococcus faecalis "in vitro" / A pilot study of the comparative analysis of the antimicrobial activity of PDT and irrigating agents in root canals inoculated with Enterococcus faecalis "in vitro"

Objetivo:O presente estudo piloto "in vitro" avaliou o efeito antimicrobiano do hipoclorito de sódio, clorexidina, terapia fotodinâmica e do óleo de girassol ozonizado utilizados como agentes irrigantes na eliminação do Enterococcus faecalis em canais radiculares de dentes humanos extraídos.Métodos:Sessenta raízes de dentes unirradiculares (n = 60) foram selecionadas e autoclavadas para realização do experimento em fluxo laminar. Para a realização do teste de infiltração, confeccionou-se um dispositivo para cada denteque permitiu a contaminação por Enterococcus faecalis e posterior preparo químico-mecânico. As amostras foram submetidas ao preparo biomecânico com diâmetro cirúrgico correspondente à lima #45 e mesma conicidade nos terços médio e cervical e receberam protocolo de desinfecção com hipoclorito de sódio a 2,5% (NaOCl), Clorexidina a 2% (CHX), óleo de girassol ozonizado a 2400ppm (OGO), PDT após irrigação com soro fisiológico (PDT+S) e PDT após irrigação com hipoclorito de sódio a 2,5% (PDT+H). As dez raízes restantes constituíram os controles positivo e negativo, sendo cinco dentes para cada grupo. Os controles positivos foram infectados e não foi utilizado nenhum agente irrigante. Os controles negativos foram compostos por dentes não contaminados pelo E. faecallis. Resultados: Os resultados da contagem de UFC/mL total e análise descritiva foram realizados. NaOCl e PDT+H apresentaram crescimento bacteriano inferiores aos valores de referência e foi considerado nulo. CHX e PDT+S apresentaram crescimento bacteriano baixo e OGO apresentou crescimento bacteriano moderado. Conclusão: NaOCl e PDT+H apresentaram melhor desempenho em relação aos demais protocolos de desinfecção utilizados. OGO apresentou crescimento bacteriano moderado sugerindo inviabilidade de sua utilização isolada em protocolos de desinfecção em endodontia. (AU)

Aim: The present "in vitro" pilot study evaluated the antimicrobial effects of sodium hypochlorite, chlorhexidine, photodynamic therapy, and ozonated sunflower oil, which were used as irrigating agents in the elimination of Enterococcus faecalis in the root canals of extracted human teeth. Methods: Sixty roots of single-root teeth (n = 60) were selected and autoclaved to perform the laminar flow experiment. To perform the infiltration test, a device was constructed for each tooth, which allowed for contamination by Enterococcus faecalis, and the tooth's subsequent chemical-mechanical preparation. The samples were submitted to biomechanical preparation with surgical diameter, corresponding to file #45 and the same taper in the middle and cervical thirds, and received a disinfection protocol with 2.5% sodium hypochlorite (NaOCl), chlorhexidine 2% (CHX), ozonized sunflower oil at 2400ppm (OGO), PDT after irrigation with saline solution (PDT+S), and PDT after irrigation with 2.5% sodium hypochlorite (PDT + H). The remaining ten roots were positive and negative controls, with five teeth in each group. Positive controls were infected, and no irrigating agent was used. Negative controls consisted of teeth that were not contaminated by E. faecallis. Results: The results of the total CFU count and descriptive analysis were performed. NaOCl and PDT+H presented a bacterial growth of much lower t than the reference values and was considered null. CHX and PDT+S presented low bacterial growth, while OGO presented moderate bacterial growth. Conclusion: NaOCl and PDT + H presented better performance in relation to the other disinfection protocols used in this study. OGO presented moderate bacterial growth, suggesting its unviable use in endodontic disinfection protocols. (AU)

Evaluation of chemokines and receptors in gnotobiotic root canal infection by F. nucleatum and E. faecalis.

The present study aims to evaluate the longitudinal effects of induced experimental infections in gnotoxenic animals on the expression of inflammatory chemokines and their receptors in periradicular tissues. The null hypothesis tested was that Enterococcus faecalis and Fusobacterium nucleatum had no effect on CCR5, CCL5, CXCL10, CCL2/MCP-1, CXCR2 and CCR1 expression. Two groups of five animals (n = 5) aged between 8 and 12 weeks were used in this study. The animals were anaesthetized, and coronary access was performed in the first molar on the right and left sides. Microorganisms were inoculated into the left molar, and the right molar was sealed without contamination to function as a control. Animals were sacrificed 7 and 14 days after infection, and periapical tissues were collected. The cytokine mRNA expression levels were assessed using real-time PCR. The chemokine mRNA expression levels demonstrated that the experimental infection was capable of inducing increased chemokine expression on day 7 compared to that on day 14, except for CCR5 and CCL5, which showed no changes. The gnotoxenic animal model proved to be effective and allowed evaluation of the immune response against a known infection. Additionally, this study demonstrates that gene expression of chemokines and their receptors against the experimental infection preferentially prevailed during the initial phase of induction of the periradicular alteration (i.e., on day 7 post-infection).

Evaluating the cutting efficiency of NiTi instruments with reciprocating motions / Avaliação da eficiência de corte de instrumentos NiTi com movimento reciprocante

Aim:This study tested a setup for in vitro experimental analysis of axial forces and torque during the preparation of artificial canals using nickel-titanium reciprocating endodontic files.Methods: The cutting efficiency of Reciproc (RC) and WaveOne (WO) reciprocating size 25/.08 instruments (n = 10) was evaluated, taking into account their dimensional and geometrical features. Measurements of the diameter at each millimeter from the tip, pitch length, helical angle, and cross-sectional design and area were assessed. Cutting efficiency tests were carried out on a specific bench device by measuring the torque and axial force required during artificial canal shaping. Statistical analysis was performed using one-way ANOVA (α = 0.05). Results:The WO samples showed larger A3 mean values than did the RC instruments (p < 0.0001), despite having equal diameters at 3mm from the tip (D3) (p = 0.521). The mean values of pitch length were higher for RC than for WO instruments (p< 0.0001), with consequently smaller helical angles (p < 0.0001). For the cutting efficiency tests, the required torque was lower for the RC group when compared to the WO group, but it was significant only in the first stage of insertion in the artificial canals (p = 0.008). Regarding the apical force, the RC instruments reached higher values when compared to the WO instruments (p = 0.04) in the second stage of cutting action. Conclusion: Reciproc instruments demonstrated statistically higher cutting efficiency when compared to WaveOne instruments.

Objetivo: Este estudo testa uma configuração para análise experimental in vitro de forças axiais e torque durante o preparo de canais artificiais usando instrumentos endodônticos reciprocantes de níquel-titânio. Métodos: Foi avaliada a eficiência de corte dos instrumentos reciprocantes tamanho 25 / 0,08 (n = 10) Reciproc (RC) e WaveOne (WO), levando em consideração suas características dimensionais e geométricas. Medidas do diâmetro a cada milímetro a partir da ponta, comprimento de pitch, ângulo helicoidal e desenho da área transversal e área foram avaliados. Testes de eficiência de corte foram realizados em um dispositivo de bancada específico, medindo-se o torque e a força axial exigidos durante a modelagem de canais artificiais. A análise estatística foi feita com ANOVA one-way (α = 0,05). Resultados: As amostras de WO mostraram valores médios A3 maiores do que os instrumentos RC (p <0,0001), apesar de terem diâmetros iguais a 3 mm da ponta (D3) (p = 0,521). Os valores médios do comprimento do pitch foram maiores para o RC do que para os instrumentos do WO (p < 0,0001), com consequentemente menores ângulos helicoidais (p < 0,0001). Para os testes de eficiência de corte, o torque necessário foi menor para o grupo RC em comparação com o grupo WO, mas significativo apenas no primeiro estágio de inserção nos canais artificiais (p = 0,008). Em relação à força apical, os instrumentos RC alcançaram valores maiores em relação aos instrumentos WO (p = 0,04) no segundo estágio de corte. Conclusão: Os instrumentos Reciproc demonstraram uma eficiência de corte estatisticamente superior em comparação com os instrumentos WaveOne.

Avaliação da expressão apical de fatores pró-angiogênicos e citocinas em reposta à infecção endodôntica / Evaluation of apical expression of pro-angiogenic factors and cytokines in response to endodontic infection

A progressão e desenvolvimento de patologias pulpares e periapicais estão intimamente relacionados à presença de microrganismos e seus subprodutos nos sistema de canais radiculares (SCR), que induzem uma resposta de defesa adjacente ao ápice radicular. A angiogênese é apontada como fator essencial na patogênese das alterações periapicais crônicas, estando relacionada ao seu estabelecimento e manutenção, por ser fonte constante de citocinas, quimiocinas e proteases. A angiogênse também está relacionada ao reparo tecidual que segue à resolução das alterações perirradiculares após a realização da terapia endodôntica. Neste estudo, avaliou-se a expressão de fatores pró-angiogêncios e citocinas relacionadas, em amostras coletadas de pacientes (n=20) com dentes portadores de Periodontite Apical Crônica imediatamente após a instrumentação dos SCR e 7 dias após os procedimentos de desinfecção. As amostras foram analisadas por meio de reação em cadeia da polimerase em tempo real (PCR-RT). Verificou-se a expressão gênica de fatores pró-angiogênicos e citocinas Angiopoetina-1 (AGT1), Fator de crescimento endotelial vascular-A (VEGF-A), Fator de crescimento fibroblástico básico (FGF-ß), Proteína quimiotática de monócitos (CCL2/MCP-1), Proteína inflamatória de macrófagos-1ß (CCL4), C-X-C Receptor de quimiocina tipo 4 (CXCR4), C-C Receptor de quimiocina tipo 6 (CCR6), TNF-α, IFN-γ, IL-17, IL-10, IL6, RANK-L e MMP-9. A expressão do mRNA dos mediadores avaliados revelou aumento significativo nos níveis de AGT1, CCL2/MCP-1, CCL4, CCR6, TNF-α, IFN- γ, IL-10, RANK-L e MMP-9 no dia 7 quando comparado com o dia 0 (P <0,05). Para VEGF-A, FGF-ß, CXCR4, IL-17 e IL-6 as expressões de mRNA foram semelhantes em ambos tempos mensurados (P> 0,05). Pode-se concluir que, após desinfecção do SCR, houve aumento nos níveis de expressão de mRNA de importantes mediadores envolvidos nos fenômenos angioproliferativos e osteogênicos.(AU)

The progression and development of pulpal and periapical pathologies are closely related to the presence of microorganisms and their by-products in the infected root canal system (RCS), which induces a defense response adjacent to the root apex. Angiogenesis has been identified as an essential factor in the pathogenesis of chronic periapical alterations, being related to its establishment and maintenance, being a constant source of cytokines, chemokines and proteases. Angiogenesis is also related to the tissue repair that follows the resolution of the periradicular alterations after the implementation of endodontic therapy. In this study, was evaluated the expression of pro-angiogenic factors and correlated cytokines in samples collected from patients (n = 20) on teeth with Chronic Apical Periodontitis immediately after RCS instrumentation and 7 days after disinfection procedures. Samples were analyzed by real-time polymerase chain reaction (RT-PCR). The gene expression of pro-angiogenic factors and cytokines Angiopoetin-1 (AGT1), Vascular endothelial growth factor-A (VEGF-A), Basic fibroblast growth factor (FGF-ß), Monocyte Chemoattractant Protein-1 (CCL2/MCP-1), Macrophage inflammatory protein-1ß (CCL4), C-X-C chemokine receptor motif 4 (CXCR4), C-C chemokine receptor motif 6 (CCR6), TNF-α, IFN-γ, IL-17, IL-10, IL-6, RANK-L and MMP-9. The mRNA expression of the mediators evaluated revealed a significant increase in levels of AGT1, CCL2/MCP-1, CCL4, CCR6, TNF-α, IFN-γ, IL-10, RANK-L and MMP-9 on day 7 when compared to day 0 (P <0.05). As for VEGF-A, FGF-ß, CXCR4, IL-17 and IL-6 their mRNA expressions was similar at both observed times (P> 0.05). In conclusion, after cleaning and shaping procedures of the RCS, there was an increase in mRNA expression levels of important mediators involved in angioproliferative and osteogenic phenomenon.(AU)

The need for endodontic treatment and systemic characteristics of hematopoietic stem cell transplantation patients.

The aim of this study is to investigate the relationship between the epidemiological and clinical profiles of patients before and after hematopoietic stem cell transplantation (HSCT) and the need for endodontic treatment. The subjects included 188 individuals enrolled in the dental care program for transplanted patients of the School of Dentistry, Federal University of Minas Gerais (Faculdade de Odontologia da Universidade Federal de Minas Gerais, FO-UFMG) from March 2011 through March 2016. The patients were subjected to an HSCT conditioning dental regimen based on a thorough clinical and radiographic evaluation. Intraoral periapical and bite-wing X-rays were obtained, and after evaluation, specific dental treatment was planned and performed. The following demographic and clinical data were collected from the patients' medical records: age, gender, transplantation stage, primary disease, transplant type, medication used, complete blood count at the time of visit, and need for endodontic treatment. The Kolmogorov-Smirnov and the chi-square tests were used. Leukemia (31.3%) and multiple myeloma (17.9%) were the most prevalent primary diseases. Most patients were subjected to allogeneic-related transplantation (83.6%). Most patients exhibited platelet counts and hemoglobin concentrations below the reference values in the pre-transplantation stage, while the neutrophil and platelet counts and the hemoglobin levels were within the reference ranges in the post-transplantation stage. The proportions of individuals requiring endodontic treatment were similar between the pre- and post-transplantation groups: 24.3% and 24.7%, respectively. The systemic conditions of the patients referred for dental treatment were compromised.

The need for endodontic treatment and systemic characteristics of hematopoietic stem cell transplantation patients

Abstract The aim of this study is to investigate the relationship between the epidemiological and clinical profiles of patients before and after hematopoietic stem cell transplantation (HSCT) and the need for endodontic treatment. The subjects included 188 individuals enrolled in the dental care program for transplanted patients of the School of Dentistry, Federal University of Minas Gerais (Faculdade de Odontologia da Universidade Federal de Minas Gerais, FO-UFMG) from March 2011 through March 2016. The patients were subjected to an HSCT conditioning dental regimen based on a thorough clinical and radiographic evaluation. Intraoral periapical and bite-wing X-rays were obtained, and after evaluation, specific dental treatment was planned and performed. The following demographic and clinical data were collected from the patients' medical records: age, gender, transplantation stage, primary disease, transplant type, medication used, complete blood count at the time of visit, and need for endodontic treatment. The Kolmogorov-Smirnov and the chi-square tests were used. Leukemia (31.3%) and multiple myeloma (17.9%) were the most prevalent primary diseases. Most patients were subjected to allogeneic-related transplantation (83.6%). Most patients exhibited platelet counts and hemoglobin concentrations below the reference values in the pre-transplantation stage, while the neutrophil and platelet counts and the hemoglobin levels were within the reference ranges in the post-transplantation stage. The proportions of individuals requiring endodontic treatment were similar between the pre- and post-transplantation groups: 24.3% and 24.7%, respectively. The systemic conditions of the patients referred for dental treatment were compromised.

Análise da eficiência de corte de instrumentos de NiTi em movimento recíproco / Evaluating the cutting efficiency of NiTi instruments in reciprocating motion

A habilidade de corte de instrumentos endodônticos é complexa e está relacionada a parâmetros como geometria da seção transversal, ângulos de corte, comprimento de pitch, ângulo helicoidal, propriedades metalúrgicas e tratamento de superfície dos instrumentos. Este trabalho tem como objetivo, avaliar a eficiência de corte, bem como as características dimensionais e geométricas de instrumentos endodônticos, por meio dos parâmetros diâmetro a cada milímetro da ponta, comprimento de pitch, ângulo helicoidal, geometria e área da seção transversal e ângulo de corte dos instrumentos Reciproc - RC (VDW, Munich, Germany) e WaveOne - WO (Dentsply Maillefer, Ballaigues, Switzerland) de calibre de ponta 25 e conicidade .08. Dez instrumentos de cada sistema foram fotografados de forma padronizada utilizando uma câmera digital Canon EOS 20D e a análise das imagens foi realizada utilizando o software ImagePro Plus 6.0. Os ensaios de eficiência de corte foram realizados em dispositivo de bancada, consistindo na peça de mão de um motor X-SmartR Plus , presa à uma base de acrílico fixado na base da máquina de teste NA8032. Blocos de acrílico pré-fabricados, foram previamente explorados. Cada bloco foi fixado em outra base menor, também acrílica, presa à máquina de testes, que se movimentava no sentido vertical a uma velocidade constante de 0,09 mm/seg. Para simular a condição clínica, a formatação do canal foi realizada em dois momentos: os instrumentos prepararam inicialmente 13,5 mm do canal, e em seguida, os 3 mm finais. Foi observado que o diâmetro aumentou progressivamente ao longo da parte ativa nos dois sistemas analisados e que o diâmetro a 3mm da ponta (D3) não apresentou diferença estatisticamente significativa entre os instrumentos (p = 0,521). Os valores médios dos comprimentos de pitch nos instrumentos RC foram superiores àqueles nos WO, embora a variação não tenha apresentado diferença significativa (p = 0,489). Os instrumentos WO apresentaram maiores valores médios de ângulos helicoidais na parte ativa que os RC, mas também sem diferença significativa entre eles (p = 0,135). A geometria da seção transversal, bem como a área a 3 mm da ponta (A3) variou entre os instrumentos analisados...

The cutting ability of endodontic instruments is complex and related to parameters such as cross-sectional geometry, cutting angles, pitch length, helical angle, metallurgical properties in addition to surface treatment. This study aimed to evaluate the cutting efficiency taking into account dimensional and geometric features of Reciproc - RC (VDW , Munich, Germany ) and WaveOne - WO ( Dentsply Maillefer , Ballaigues , Switzerland ), 25/.08 size instruments. Measurements of diameter at each millimeter from the tip, pitch length, helical angle, cross-sectional area and cutting angles were assessed. Samples of each system (n = 10) were photographed in a standardized manner using a Canon EOS 20D digital camera and image analysis was performed using ImagePro Plus 6.0 software. The cutting efficiency tests were carried out on a specific bench device by measuring the torque required during shaping of artificial canals. Ten instruments of each type were tested in prefabricated acrylic blocks containing an artificial canal previously explored with manual K-files. The motor was set at a speed of 300 rpm and torque 5 Ncm and the instruments were inserted into the canal at a constant speed of 0.09 mm/sec. In order to simulate the clinical condition, the shaping of the artificial canal was performed in two stages: initial instrument penetration through 13.5 mm, and then a second penetration until reach the full length, i.e., 16.5 mm. Statistical analysis was done with one-w y AN VA (α . ). A increase in diameter throughout the active part was observed in the two systems analyzed showing no statistically significant difference between RC and WO instruments (P = 0.521) in relation to the diameter at 3 mm from the tip (D3). The mean values of pitch lengths for RC were higher than those presented by WO instruments, although the difference was not statistically significant (P = 0.489). WO instruments had higher mean values of helical angles in comparison to RC instruments, but without statistically significant difference (P = 0.135). The cross section geometry as well as the area at 3 mm from the tip (A3) varied between the analyzed instruments. The RC samples showed slightly larger A3 mean value than WO instruments, but also without statistically significant difference (P = 0.521). The average of the two cutting angles on RC and WO instruments were similar. However, the five WO cutting angles were all significantly different when compared with each other. WO instruments in the first insertion depth and RC in the second stage of insertion required higher torque values respectively. The Reciproc and WaveOne instruments analyzed showed similar dimensional characteristics with RC presenting higher torque values in the second shaping stage.