Influence of working length and anatomical complexities on the apical root canal filling: a nano-CT study

Abstract The present study aimed to compare the filled volume by gutta-percha and sealer in the apical region of the main canal and ramifications, after instrumentation at two different working lengths using nano-computed tomography (nano-CT). Twenty-two premolars with apical ramifications were selected after micro-computed tomography evaluation and were randomly divided into groups for further endodontic instrumentation at two different working lengths: G1 - Root canals shaped 1 mm short of the apical foramen (n=11), and G2 - Root canals shaped at the apical foramen (n=11). After completing root treatment, nano-CT images were acquired, and the filled volume by gutta-percha and sealer in the main canal apical 0-4 mm and 0-1 mm ranges, and apical ramifications were objectively measured by an operator specialized in both radiology and endodontics, blinded for both groups. The Mann-Whitney test was applied to compare both groups regarding the filling of the main canal apical ranges and apical ramifications with a significance level of 5% (α ≤ 0.05). It was observed that root canals shaped at the apical foramen had a larger volume of the main canal filled than root canals shaped 1 mm short of the apical foramen, at both apical ranges (0-4 and 0-1 mm) (p<0.05). Regarding the filling of the apical ramifications, there was no significant difference between groups (p>0.05). In conclusion, the root canals shaped at apical foramen exhibited increased filling volume of the main canal in the apical region. However, neither of both working lengths influenced filling of the apical ramifications.

Resumo O presente estudo teve como objetivo comparar o volume preenchido por guta-percha e cimento na região apical do canal principal e ramificações, após instrumentação em dois comprimentos de trabalho diferentes, por meio de nano tomografia computadorizada (nano-TC). Vinte e dois pré-molares com ramificações apicais foram selecionados após avaliação por micro-tomografia computadorizada e foram divididos aleatoriamente em grupos para posterior instrumentação endodôntica em dois comprimentos de trabalho diferentes: G1 - Canais radiculares instrumentados 1 mm aquém do forame apical (n = 11) e G2 - Canais radiculares instrumentados até o forame apical (n = 11). Após a obturação dos canais radiculares, imagens de nano-CT foram adquiridas, e o volume preenchido por guta-percha e cimento nas faixas apicais de 0-4 mm e 0-1 mm do canal principal, e ramificações apicais, foram avaliadas objetivamente por um especialista em radiologia e endodontia, cego para ambos os grupos. O teste de Mann-Whitney foi aplicado para comparar os dois grupos quanto ao preenchimento das faixas apicais do canal principal e ramificações com nível de significância de 5% (α ≤ 0,05). Observou-se que canais radiculares instrumentados até o forame apical apresentaram maior volume do canal principal preenchido do que canais radiculares instrumentados 1 mm aquém do forame apical, em ambas as faixas apicais (0-4 e 0-1 mm) (p <0,05) Em relação ao preenchimento das ramificações apicais, não houve diferença significativa entre os grupos (p> 0,05). Em conclusão, os canais radiculares instrumentados até o forame apical mostraram um maior volume de preenchimento na região apical do canal principal. No entanto, os dois diferentes comprimentos de trabalho não influenciaram o preenchimento das ramificações apicais.

Effect of ethanol-conditioned dentine on sealer penetration into dentinal tubules: a confocal microscopy study

Aim: The aim of this study was to evaluate the effect of ethanol-conditioned dentin on endodontic sealer penetration into dentinal tubules by confocal laser scanning microscopy (CLSM). Methods: Forty human maxillary anterior teeth were instrumented and divided into four groups (n = 10) according to the drying methods: 1) wet: vacuum only, 2) paper points: vacuum + absorbent paper points, (3) 70% ethanol: 70% ethanol (1 min) + vacuum + absorbent paper points, and (4) 100% ethanol: 100% ethanol (1 min) + vacuum + absorbent paper points. All root canals were filled with resin-based endodontic sealer. Four sections from each third (cervical, middle, and apical) were examined by CLSM. Root canal wall perimeter infiltrated by sealer, maximum depth of sealer penetration, percentage of penetrated area, and fluorescence intensity of rhodamine B were measured. Statistical analysis was performed by analysis of variance and Tukey's tests (α = 0.05). Results: No statistical difference was found when percentage of root canal wall coverage infiltrated by sealer were compared. The groups in which ethanol solutions were used presented greater depth of sealer penetration, higher percentage of penetrated area, and higher fluorescence intensity of rhodamine B (p< 0.05) when compared with the wet and paper point groups. Overall, 100% ethanol produced better results than 70% ethanol, except for rhodamine B intensity (cervical third). In addition, the absorbent paper points drying method behaved better than did vacuum only group, except for rhodamine B intensity (apical third). Conclusion: Ethanol-conditioned dentin improved the penetration of resin-based sealer into dentinal tubules, especially at the concentration of 100%

Investigation of a modified hydraulic calcium silicate-based material - Bio-C Pulpo

Abstract This study evaluated the physicochemical, biological, and antimicrobial properties of a new hydraulic calcium silicate-based modified material, and compared it with MTA Repair HP and MTA Angelus. The materials were assessed regarding color luminosity (L), color change, radiopacity, setting time, and ISO 6876:2012 linear flow. Volumetric filling and volume change were evaluated using microcomputed-tomography (µCT). Chemical characterization after 28 days in Hank's Balanced Salt Solution (HBSS) and pH analysis were also assessed. Biological characterization of cytotoxicity and microbiological assessment were also undertaken. Shapiro-Wilk, ANOVA, Levene and post hoc analyses with Bonferroni correction were performed, adopting a 5% significance level (p <0.05). Bio-C Pulpo exhibited the highest L values after 90 days. All tested materials demonstrated color change during the analyses, and had radiopacity above 5 mm Al. MTA Repair HP set faster than Bio-C Pulpo, whereas the latter had the highest linear flow. MTA Repair HP had the highest volumetric filling in µCT analysis. Bio-C Pulpo showed the highest alkalinity during all tested periods, and the highest volumetric loss (above 9%), in comparison with MTA Repair HP and MTA Angelus. Bio-C Pulpo did not form calcium hydroxide after hydration. MTA Repair HP demonstrated the highest cytocompatibility, and Bio-C Pulpo, the highest cytotoxicity. No inhibition halos were observed for any material, and similar higher turbidity values were seen after direct contact. Composition additives used in Bio-C Pulpo modified its properties, and both the absence of calcium hydroxide deposition after hydration, and the related cytotoxicity of this material are of particular concern.

Avaliação do tratamento endodôntico em sessão única e retratamento não cirúrgico com alargamento foraminal de dentes com periodontite apical / Evaluation of single visit endodontic treatment and non-surgical retreatment with foraminal enlargment of teeth with apical periodontitis ?

Objective: to evaluate the root canal treatment (RCT) and non-surgical root canal retreatment (NSRCR), associated with foraminal enlargement, performed on a singlevisit. Material and Methods: 125 teeth with apical periodontitis and follow-up period ranging from 6 to 12 months were included. The success was considered by the absence of signs and symptoms and complete or incomplete periapical repair. Logistic regression analyses were used to identify factors associated with the repair (p<0.05). Results: RCT showed 71.58% of complete healing and 23.16% of acceptable healing. NSRCR showed 80% of complete healing and 20% of acceptable healing. Age, gender, type of treatment and preoperative pain were not statistically significant for the healing process (p>0.05). Premolars showed the greatest chance of periapical repair. Pulp Canal Sealer showed a greater chance of periapical repair when compared to Sealapex (p<0.05). Conclusion: RCT and NSRCR using a foraminal enlargement protocol provided a favorable prognosis of periapical healing

Objetivo: avaliar o tratamento endodôntico (TE) e o retratamento não cirúrgico do canal radicular (RNCCR), associado a ampliação foraminal, realizado em sessão única. Material e Métodos: foram incluídos 125 dentes com periodontite apical e proservação de 6 a 12 meses. O sucesso foi considerado pela ausência de sinais e sintomas e reparo periapical completo ou incompleto. Análises de regressão logística foram utilizadas para identificar fatores associados ao reparo (p<0,05). Resultados: o TE mostrou 71,58% de cicatrização completa e 23,16% de cicatrização aceitável. O RNCCR mostrou 80% e 20% cicatrização completa e aceitável, respectivamente. Idade, sexo, tipo de tratamento e dor pré-operatória não foram estatisticamente significantes para o processo de cicatrização (p>0,05). Os pré-molares apresentaram a maior chance de reparo periapical. O cimento Pulp Canal Sealer mostrou maior chance de reparo periapical quando comparado ao Sealapex (p<0,05). Conclusão: o TE e RNCCR utilizando um protocolo de alargamento foraminal, proporcionaram um prognóstico favorável da cicatrização periapical

Dental discoloration caused by Grey-MTAFlow cement: analysis of its physicochemical, biological and antimicrobial properties

Abstract Tricalcium silicate-based cement are materials used in reparative and regenerative procedures in endodontics. A recently proposed formulation aimed to enhance handling during clinical use with a versatile material applicable by syringe. Although, the use of bismuth oxide as radiopacifier and grey raw powder are drawbacks considering aesthetics. Objectives Evaluate physicochemical, biological, and antimicrobial properties of Grey-MTAFlow (Ultradent) and assess whether the addition of zinc oxide (ZnO) prevents dentinal discoloration caused by bismuth oxide. Methodology Grey-MTAFlow was manipulated in 'thin' consistency for all tests. Luminosity, color change, ion migration to dentine, radiopacity, setting time, ISO 6876:2012 linear flow, volumetric lateral flow and central filling of simulated grooves scanned using micro-computed tomography (μCT), pH, calcium release, volumetric change using μCT, chemical characterisation, cytotoxicity, and antimicrobial activity were assessed. Addition of 5% ZnO to Grey-MTAFlow and a bismuth-containing experimental composition were comparatively tested. Statistical analyses used Shapiro-Wilk, T-test, ANOVA, and Kolmogorov-Smirnov (p<0.05). Results The addition of ZnO to Grey-MTAFlow prevented dentine darkening after 90 days due to bismuth migration reduction, although no statistical difference was found (p=0.863). ZnO addition significantly enhanced Grey-MTAFlow radiopacity without differences in initial setting time. Grey-MTAFlow presented an ISO linear flow of 10.9 mm and a balanced volumetric lateral flow with central filling in μCT evaluation. All compositions presented an alkaline pH after immersion. Grey-MTAFlow had a significantly higher calcium ion release after 28 days in comparison to 24 hours (p=0.011) and volumetric expansion of 0.4±1.8% after immersion. ZnO addition altered the hydrated cement matrix once calcium hydroxide (portlandite) could not be detected in characterisation. Neither of the materials produced inhibition halos nor reduced bacterial turbidity, but all presented cytocompatibility above 100%. Conclusion Grey-MTAFlow expanded after immersion and exhibited higher luminosity values after the evaluation period when ZnO was added, but chemical modifications after this addition occurred.

Influência da técnica de preparo apical na desinfecção e modelagem dos canais radiculares: revisão de literatura / Influence of apical preparation technique on root canal disinfection and shaping: literature review

Introdução: um dos objetivos da terapia endodôntica é a redução dos fatores microbianos no interior dos canais radiculares, o que pode ser conseguido por meio do preparo químico-mecânico (PQM). O PQM tem como finalidade criar um ambiente propício à condição de reparo, por meio da limpeza e modelagem do sistema de canais radiculares (SCR), que associa a ação mecânica dos instrumentos ao uso de substâncias químicas auxiliares. Em relação ao limite apical desse preparo e ao diâmetro apical final da instrumentação, podemos observar que não há consenso entre os profissionais. Introdução: o objetivo do presente estudo foi avaliar, por meio de uma revisão de literatura, a eficiência de duas técnicas no preparo e desinfecção do terço apical do SCR: a técnica de ampliação foraminal e a técnica de batente apical com manutenção da patência foraminal. Métodos: foi realizada uma busca nas bases de dados PubMed, Medline, BBO, Lilacs e SciELO, usando os seguintes termos: canal radicular, forame apical, endodontia, lima de patência, tamanho apical, lima apical final, preparo biomecânico, ampliação foraminal, comprimento de trabalho, anatomia dental, tratamento endodôntico, patência foraminal, preparo do canal radicular e batente apical. Cada um desses termos foi combinado utilizando os operadores booleanos E/OU. Após leitura dos resumos, 65 artigos foram selecionados e incluídos nessa revisão. Resultados: os resultados demonstraram que o alargamento do terço apical, seja com ou sem ampliação foraminal, parece favorecer o prognóstico do tratamento endodôntico, devido à redução do conteúdo infeccioso em toda a extensão do SCR. A manutenção da patência foraminal é um fator essencial para um PQM adequado quando a técnica de batente apical é realizada. Conclusão: conclui-se que preparos apicais mais amplos promovem resultados mais previsíveis, e que a ampliação foraminal possibilita o melhor debridamento e desinfeção do SCR (AU).

Introduction: Endodontic therapy should reduce the microbial load within the root canals, which can be achieved during chemomechanical preparation (CMP). The purpose of CMP of the root canal system (RCS) is to create a favorable environment for healing. CMP associates the mechanical action of instruments with the use of auxiliary chemical substances. There is no consensus among professionals about what should be the diameter of the apical foramen after CMP. This literature review evaluated the efficiency of two apical preparation techniques: foraminal enlargement and apical stop with maintenance of foraminal patency. Material and methods: A literature search was conducted in PubMed, Medline, BBO, Lilacs and Scielo using the following terms: root canal, apical foramen, endodontics, patency file, apical size, master apical file, biomechanical preparation, foraminal enlargement, working length, dental anatomy, endodontic treatment, foraminal patency, root canal preparation, and apical stop. All terms were combined using the Boolean operators AND/OR. After the abstracts were analyzed, 65 full texts were selected and included in this review. Results: The enlargement of the apical third, with or without foraminal enlargement, seems to improve endodontic treatment prognosis due to the reduction of infectious contents throughout the RCS. Foraminal patency is essential for adequateCMP when the apical stop technique is performed. Conclusion: Apical preparations with a greater diameter have more predictable results, and foraminal enlargement ensures better debridement and disinfection of the RCS (AU).

Demographic profile of patients and clinical characteristics of dental emergencies at the outpatient clinic of a Brazilian Dental School / Perfil demográfico dos pacientes e características clínicas das urgências dentárias no Serviço de Plantão de uma Faculdade Brasileira de Odontologia

ABSTRACT Objective: This retrospective study evaluated the demographic profile of patients and the clinical characteristics of dental emergencies in a brazilian university outpatient clinic. Methods: During the period from June 2013 to May 2014, data were collected from 1.345 clinical records. Chief complaint, gender, age, systemic alteration, clinical inspection of the affected tooth, pulp and periapical diagnosis, the type of procedure performed and whether there was the need for post-operative systemic medication. Data were analyzed using the SAS software and chi-square test was used to verify the presence or absence of statistical significance at a level of 5%. Results: Dental pain (53.3%) was the main reason why people attended the emergency service, that is, female patients (63.1%), aged 29-48 years old (42%), patients without systemic conditions (75%), and patients with decayed teeth (25%). In addition, involvement of lower molars (29.81%) and diagnosis of irreversible pulpitis (30.42%) were the most frequent findings. Emergency endodontic treatment (45.8%) was the most performed procedure. Irreversible pulpitis (30.4%) and pulp necrosis associated with acute apical periodontitis (21.9%) were the most frequent conditions requiring emergency endodontic treatment, and in most cases, there was no need for post-operative systemic medications (95.7%). Conclusion: The prevalence of endodontic emergencies during the period of one year emphasizes the need for more accurate diagnosis and the importance of providing this service to the population.

RESUMO Objetivo: Este estudo retrospectivo avaliou o perfil demográfico dos pacientes e as características clínicas das urgências dentárias em um Serviço de Plantão de Urgências de uma Faculdade brasileira de Odontologia. Métodos: Durante o período de junho de 2013 a maio de 2014, os dados foram coletados de 1.345 registros clínicos, com informações sobre a queixa principal, gênero, idade, alteração sistêmica, inspeção clínica do dente afetado, diagnóstico pulpar e periapical, o tipo de procedimento realizado e se houve necessidade de medicação sistêmica pós-operatória. Os dados foram analisados usando o software SAS e o teste do qui-quadrado foi utilizado para verificar a presença ou ausência de significância estatística ao nível de 5%. Resultados: A dor dental (53,3%) foi a queixa principal mais encontrada. Pacientes do gênero feminino (63,1%), com idade entre 29-48 anos (42%), sem condições sistêmicas (75%) e com dentes cariados (25%) foram os mais prevalentes. Além disso, o envolvimento de molares inferiores (29,81%) e o diagnóstico de pulpite irreversível (30,42%) foram os achados mais frequentes. O tratamento endodôntico de urgência (45,8%) foi o procedimento mais realizado. A pulpite irreversível (30,4%) e a necrose pulpar associada a periodontite apical aguda (21,9%) foram as condições mais frequentes que necessitaram de tratamento endodôntico de urgência e, na maioria dos casos, não houve prescrição de medicamentos sistêmicos pós-operatórios (95,7%). Conclusão: A prevalência de urgências endodônticas durante o período de um ano enfatiza a necessidade de diagnósticos mais precisos e a importância de oferecer esse serviço à população.

Influence of ethanol on dentin roughness, surface free energy, and interaction between AH Plus and root dentin

Abstract This study aimed to evaluate the influence of different ethanol concentrations on dentin roughness, surface free energy, and contact angle between AH Plus and the root canal dentin. One hundred human maxillary anterior teeth were split longitudinally and 200 dentin specimens were polished to make the surface flatter and smoother. An acrylic bar was positioned between two dentin specimens and impression material was added to create a block, simulating an instrumented root canal space. Specimens were removed from the mold and cleaned in an ultrasonic bath for 10 min. Thereafter, dentin specimens were divided into four groups (n = 50) according to the drying methods used: a) wet: vacuum only, b) paper points: vacuum + absorbent paper points, c) 70% alcohol: 70% alcohol (1 min) + vacuum + absorbent paper points, and d) 100% alcohol: 100% alcohol (1 min) + vacuum + absorbent paper points. A rugosimeter and a goniometer were used to verify the roughness (Ra) and to measure the surface free energy and the contact angle between the AH Plus sealer and the root canal dentin. ANOVA and Tukey tests (α = 0.05) were used for statistical analysis. The 70% and 100% ethanol groups showed significantly decreased roughness as well as increased surface free energy in the root canal dentin when compared to the wet and paper point groups. In addition, ethanol significantly reduced the contact angle between the AH Plus sealer and the root canal dentin. Ethanol solutions (70% and 100%) provide better wettability of AH Plus sealer on dentin surfaces.

Relationship between Initial Attendance after Dental Trauma and Development of External Inflammatory Root Resorption

Abstract This clinical study aimed to evaluate the relationship of the delay between dental trauma and the initial attendance to the development of external inflammatory root resorption in permanent teeth affected by severe luxation. Sixty-seven patients, aged between 11 and 56 years, presenting 133 injured teeth with closed apex (56 extrusive luxation, 69 lateral luxation and 8 intrusive luxation) were followed up for a minimum of 24 months. The time elapsed between dental trauma and the initial attendance was recorded. The presence of necrotic pulp and external inflammatory resorption for each type of trauma was verified. Fisher’s exact test was used to verify the influence of the initial attendance date at the Dental Trauma Center and the development of inflammatory resorption (p<0.05). The odds ratio was used to check the risk of developing external inflammatory resorption due to delay in seeking treatment. Pulp necrosis was observed in 105 teeth (78.9%) and external inflammatory resorption was detected in 17.8% cases of extrusive luxation (10 teeth), 15.9% of lateral luxation (11 teeth) and 25% of intrusive luxation (2 teeth). For lateral luxation, extended delay between the date of injury and initial attendance influenced the occurrence of external inflammatory resorption (p=0.0174). Patients who began treatment 45 days after the injury were 3.4 times more likely to develop external inflammatory resorption than patients who sought treatment after the trauma. Treatment late after the occurrence of dental trauma can impair the prognosis and result in the development of external inflammatory resorption in luxated teeth.

Resumo O objetivo deste estudo clínico foi avaliar a relação entre a demora na procura por tratamento e o desenvolvimento de reabsorções inflamatórias externas em dentes luxados com ápice fechado. A amostra desta pesquisa foi constituída por 67 pacientes que apresentaram 133 dentes traumatizados, dos quais 56 foram acometidos por luxação extrusiva, 69 por luxação lateral e 8 por luxação intrusiva, proservados por no mínimo 24 meses. Foi registrado o tempo decorrido entre a data do trauma e o primeiro atendimento. Verificou-se a ocorrência de necrose pulpar e reabsorções inflamatórias externas em cada tipo de traumatismo. O Teste Exato de Fisher foi aplicado para verificar a influência da data do atendimento inicial e o desenvolvimento de reabsorções inflamatórias externas em cada tipo de luxação e o teste de Odds Ratio foi aplicado para verificar o risco do desenvolvimento de reabsorções inflamatórias externas em função da demora na procura por tratamento. Os resultados revelaram que a necrose pulpar foi verificada em 105 dentes luxados (78,9%) e a reabsorção inflamatória externa foi verificada em 17.8% das luxações extrusivas (10), sendo 15,9% das luxações laterais (11) e 25% das luxações intrusivas (2). A demora na procura por tratamento influenciou o desenvolvimento de reabsorções infamatórias externas nas luxações laterais (p=0,0174). Os pacientes que procuraram tratamento após 45 dias da data do trauma apresentaram 3,4 vezes mais chance de desenvolver reabsorção inflamatória externa do que os pacientes que procuraram tratamento logo após o traumatismo. Conclui-se que o tratamento tardio após a ocorrência do traumatismo pode prejudicar o prognóstico e favorecer o desenvolvimento de reabsorções inflamatórias externas em dentes luxados com ápice fechado.

Cytotoxicity Profile of Endodontic Sealers Provided by 3D Cell Culture Experimental Model

Abstract The aim of the present study was to evaluate the cytotoxic effects of five endodontic sealers (AH Plus, Endomethasone N, EndoSequence BC, MTA Fillapex and Pulp Canal Sealer EWT) using a three-dimensional (3D) cell culture model. A conventional bi-dimensional (2D) cell culture model was used as reference technique for comparison. Balb/c 3T3 fibroblasts were cultured in conventional bi-dimensional cell culture and in rat-tail collagen type I three-dimensional cell culture models. Then, both cell cultures were incubated with elutes of freshly mixed endodontic sealers for 24 h. Cell viability was measured by the methyl-thiazol-diphenyltetrazolium assay (MTT). Data were statistically analyzed using ANOVA and the Tukey test at a significance level of p<0.05. All tested sealers exhibited cytotoxic effects; however, cytotoxic effect was culture model- and sealer-dependent. Sealers showed higher cytotoxicity in 2D than in 3D cell culture model (p<0.05). In both conditions, EndoSequence BC showed the lowest cytotoxicity (p<0.05). MTA Fillapex was much more cytotoxic than the other tested endodontic sealers (p<0.05), with the exception of AH Plus in the 2D cell culture model (p>0.05). Endomethasone N and Pulp Canal Sealer EWT showed lower cytotoxic effects than AH Plus in 2D cell culture model (p<0.05); however no statistical differences was observed among these sealers in 3D cell culture model. It may be concluded that cytotoxicity was higher in 2D cell culture compared to 3D cell culture. EndoSequence BC sealer exhibited the highest cytocompatibility and MTA Fillapex the lowest cytocompatibility.

Resumo O objetivo do presente estudo foi avaliar os efeitos citotóxicos de cinco cimentos endodônticos (AH Plus, Endomethasone N, EndoSequence BC, MTA Fillapex e Pulp Canal Sealer EWT) utilizando um modelo de cultura celular tridimensional (3D). Utilizou-se um modelo convencional de cultura de células bidimensionais (2D) como técnica de referência para comparação. Os fibroblastos Balb/c 3T3 foram cultivados em culturas de células bidimensionais convencionais e em modelos de cultura de células tridimensionais de colagéno de cauda de rato do tipo I. Em seguida, ambas as culturas de células foram incubadas com eluções dos cimentos endodônticos recém manipulados, durante 24 h. A viabilidade celular foi medida pelo ensaio de MTT. Os dados foram analisados estatisticamente utilizando ANOVA e o teste de Tukey com nível de significância de p<0,05. Todos os cimentos testados exibiram efeitos citotóxicos. Contudo, o efeito citotóxico foi dependente do modelo de cultura e do cimento testado. Os cimentos apresentaram maior citotoxicidade no modelo 2D do que no modelo 3D (p<0,05). Em ambas as condições, a EndoSequence BC apresentou a menor citotoxicidade (p<0,05). MTA Fillapex foi mais citotóxico do que os outros cimentos endodônticos testados (p<0,05), com exceção do AH Plus no modelo de cultura de células 2D (p>0,05). Endomethasone N e EWT mostraram efeitos citotóxicos mais baixos do que AH Plus no modelo de cultura de células 2D (p<0,05); entretanto, não houve diferenças estatísticas entre esses cimentos no modelo de cultura de células 3D. Pode concluir-se que a citotoxicidade foi maior na cultura de células 2D em comparação com a cultura de células 3D. EndoSequence BC selante exibiu a maior citocompatibilidade e MTA Fillapex a menor citocompatibilidade.

Influence of working length and foraminal enlargement on foramen morphology and sealing ability.

Aim: The present study evaluated the influence of the working length and foraminal enlargement on the sealing ability and anatomy of the apical region of the root. Materials and Methods: Fifty‑five roots were divided into three groups: G1, instrumentation 1 mm short of the major foramen; G2, instrumentation in the limit of the apical foramen; and G3, instrumentation 1 mm beyond the foramen. All groups were prepared using nickel‑titanium rotary files and obturated with AH Plus and Gutta‑percha. Photomicrographs were taken using a scanning electron microscopy (SEM) before instrumentation, after instrumentation with each file, and after root canal filling. Moreover, bacterial microleakage with Enterococcus faecalis was performed. Results: The results were analyzed using Mann–Whitney, Friedman, Kruskal–Wallis and Kaplan– Meier tests at a significance level of 5%. The cemental canal was uninstrumented in G1. No statistical differences regarding foramen deviation was observed when compared G2 and G3 (P > 0.05). SEM analysis showed that G2 and G3 resulted in good apical foramen obturation. Microleakage showed no statistically significant differences between all of the groups tested. Conclusions: Under the conditions of this study, it can be concluded that foramen enlargement resulted in more apical deviation; however, no differences in bacterial microleakage was observed among the experimental groups.

Push-out bond strength of MTA HP, a new high-plasticity calcium silicate-based cement

Abstract This study was designed to investigate the resistance to dislodgment provided by MTA HP, a new high-plasticity calcium silicate-based cement. Biodentine and White MTA Angelus were used as reference materials for comparison. Three discs 1 ± 0.1 mm thick were obtained from the middle third of the roots of 5 maxillary canines. Three 0.8-mm-wide holes were drilled on the axial surface of each root disc. Standardized irrigation was performed. Then the holes were dried with paper points and filled with one of the three tested cements. The filled dental slices were immersed in a phosphate-buffered saline (PBS) solution (pH 7.2) for 7 days before the push-out assessment. The Kruskal-Wallis test was applied to assess the effect of each endodontic cement on the push-out bond strength. Mann-Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05. All specimens had measurable push-out values and no premature failure occurred. There were significant differences among the materials (p <0.05). The Biodentine specimens had the highest push-out bond strength values (p < 0.05). MTA HP had significantly higher bond strength than White MTA (p < 0.05). MTA HP showed better push-out bond strength than its predecessor, White MTA; however, Biodentine had higher dislodgment resistance than both MTA formulations.

The biocompatibility of a new endodontic paste used in dental trauma / Biocompatibilidade de uma nova pasta utilizada em traumatismo dentário

Objective: This study investigated the short-term subcutaneous tissue reaction of a new endodontic paste, based on the association among calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX) and zinc oxide (ZnO) in comparison with a control paste, and the individual substances alone. Material and method: Twenty-four male wistar rats were used. Polyethylene tubes containing the materials were implanted into the dorsal connective tissue of rats. Empty implanted tubes served as controls. The materials used were: Ca(OH)2+CHX+ZnO paste in two different proportions (2:1:2) and (2:1:3), a control paste, Ca(OH)2+CHX (2:1), and the substances alone. After time intervals of 2, 3, 7 and 15 days, the animals were euthanized and the specimens prepared for histological processing. Data were evaluated qualitatively according to the levels of tissue repair and the degree of inflammation. Result: On the second day all the materials were observed to cause a severe inflammatory response. On the third day, the pastes Ca(OH)2+CHX+ZnO (2:1:2) and (2:1:3) showed reduction in degree of inflammation. On seventh day the tissue was already more organized with presence of collagen fibers in all materials. After 15 days it was found that compound Ca(OH)2+CHX+ZnO (2:1:2) showed areas with no inflammatory infiltrate. Conclusion: The experimental pastes, Ca(OH)2+CHX+ZnO in two different proportions (2:1:2) and (2:1:3), showed favorable results with respect to biocompatibility, when evaluated for a short-term.

Objetivo: O presente estudo investigou a reação em tecido subcutâneo de ratos, por um curto período, de uma nova pasta endodôntica, obtida a partir da associação entre o hidróxido de cálcio [Ca(OH)2], clorexidina gel 2% (CHX) e óxido de zinco (ZnO), em comparação à pasta controle, e as substâncias isoladamente. Material e método: Foram utilizados vinte e quatro ratos wistar machos. Tubos de polietileno contendo os materiais foram implantados no tecido conjuntivo dorsal de ratos. Tubos vazios foram utilizados como controle. Os materiais utilizados foram: Pasta de Ca(OH)2 + CHX + ZnO em duas proporções diferentes (2: 1: 2) e (2: 1: 3), pasta controle, Ca(OH)2< + CHX (2:1), e as substâncias isoladas. Após intervalos de tempo de 2, 3, 7 e 15 dias, os animais foram sacrificados e as amostras preparadas para processamento histológico. Os dados foram avaliados qualitativamente de acordo com os níveis de reparo dos tecidos e do grau de inflamação. Resultado: No segundo dia observou-se que todos os materiais causaram uma resposta inflamatória grave. No terceiro dia, as pastas de Ca(OH)2 + CHX + ZnO (2: 1: 2) e (2: 1: 3) mostraram uma redução no grau de inflamação. No sétimo dia, o tecido encontrava-se mais organizado, com a presença de fibras colágenas em todos os materiais. Após 15 dias, verificou-se que a pasta de Ca(OH)2 + CHX + ZnO (2: 1: 2) mostrou áreas sem infiltrado inflamatório. Conclusão: As pastas experimentais, Ca(OH)2 + CHX + ZnO, nas duas proporções avaliadas (2: 1: 2) e (2: 1: 3), mostraram resultados favoráveis em relação à biocompatibilidade, quando avaliada por curto período de tempo.

Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants

Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer. Objectives : The purpose of this study was to compare the antimicrobial and cytotoxic effects of a 37% phosphoric acid solution to other irrigants commonly used in endodontics. Material and Methods : The substances 37% phosphoric acid, 17% EDTA, 10% citric acid, 2% chlorhexidine (solution and gel), and 5.25% NaOCl were evaluated. The antimicrobial activity was tested against Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Actinomyces meyeri, Parvimonas micra, Porphyromonas gingivalis, and Prevotella nigrescens according to the agar diffusion method. The cytotoxicity of the irrigants was determined by using the MTT assay. Results : Phosphoric acid presented higher antimicrobial activity compared to the other tested irrigants. With regard to the cell viability, this solution showed results similar to those with 5.25% NaOCl and 2% chlorhexidine (gel and solution), whereas 17% EDTA and 10% citric acid showed higher cell viability compared to other irrigants. Conclusion : Phosphoric acid demonstrated higher antimicrobial activity and cytotoxicity similar to that of 5.25% NaOCl and 2% chlorhexidine (gel and solution). .

Pulp revascularization: an alternative treatment to the apexification of immature teeth / Revascularização pulpar: tratamento alternativo à apicificação de dentes jovens com rizogênese incompleta

Pulp revascularization can be considered as a current alternative treatment to apexification, recommended for immature teeth cases, requiring endodontic treatment. Apexification involves long-term periodic exchanges of a calcium hydroxide paste into the root canal to induce the formation of a calcified barrier. Despite being the most classically therapy employed for these cases, the permanence of calcium hydroxide for long periods of time and also the successive changes may lead to a weakening of the root due to its hygroscopic properties and the proteolytic activities of calcium hydroxide, increasing the risk of fractures and contamination of the pulp space. Thus, a constant search for new treatment alternatives that provide the end of root development have been done to avoid the risk of future root fractures. So, revascularization has emerged as a new treatment option for cases of undeveloped teeth, that provides not only apical closure, as apexification, but also increase the dentin walls thickness. In the literature, there is an assortment of treatment protocols employing pulp revascularization procedure in attempt to attain the best way to achieve success. Assuming the diversity of protocols for revascularization treatment, it is important to go deep in the literature to collect, describe and discuss these protocols guiding new researches in this field and also conducting the clinicians. Therefore, this review aims to assess the literature on the different revascularization protocols.

A revascularização pulpar pode ser considerada atualmente como um tratamento alternativo à apicificação e é indicado para dentes com rizogênese incompleta e necessidade de tratamento endodôntico. A apicificação envolve a realização de trocas periódicas em longo prazo de uma pasta de hidróxido de cálcio com o objetivo de formar uma barreira calcificada. Apesar de ser a terapia mais empregada, a permanência desta medicação por longos períodos e as trocas sucessivas, podem levar à fragilização da raiz devido às propriedades higroscópicas e proteolíticas do hidróxido de cálcio, aumentando o risco de fraturas e contaminação do espaço pulpar. Desta forma, tem-se buscado novas alternativas de tratamento que possibilitem o fechamento do forame apical dos dentes imaturos sem que ocorra a fragilização dos mesmos. A revascularização pulpar tem surgido como uma nova opção de tratamento para estimular o término do desenvolvimento radicular e não apenas o fechamento apical. Há na literatura uma variedade de protocolos utilizando esta técnica, buscando sempre alcançar o sucesso no tratamento. Diante dessa variedade, é de grande importância a realização de uma revisão de literatura sobre revascularização pulpar visando reunir, descrever e discutir os diferentes protocolos, para que possam direcionar novas pesquisas e ser empregada de forma adequada pelo clínico. O objetivo desse trabalho é revisar na literatura os diferentes protocolos de revascularização pulpar.

Evaluation of foraminal transportation during foraminal enlargement with different instrumentation systems

Aim: To evaluate the foraminal transportation during foraminal enlargement after manual instrumentation with stainless steel files, preparation with the Mtwo system and Reciproc R25 file. Methods: Thirty roots were selected, divided in three groups and prepared in accordance with the different instrumentation systems: Hand Files (HF); Mtwo system (MS); and Reciproc system (RS). All groups were prepared with the instrumentation level 1 mm beyond the apex. Photomicrographs were performed using scanning electron microscopy, to record the foraminal anatomy before and after instrumentation. Data were analyzed using ANOVA followed by Tukey's test with a significance level of 5%. Results: The group instrumented with hand files showed higher foraminal transportation when compared to the Mtwo and Reciproc groups (p<0.05). Reciproc group showed lower transportation when compared to the Mtwo group (p<0.05). Conclusions: The stainless steel files caused significant foraminal transportation, while Reciproc system showed safe apical preparation, with little transportation.

Monitoring the effectiveness of root canal procedures on endotoxin levels found in teeth with chronic apical periodontitis

Objective: The aim of this study was to monitor the effectiveness of root canal procedures by using different irrigants and intracanal medication on endotoxin levels found in root canals of teeth with chronic apical periodontitis. Material and Methods: Thirty root canals of teeth with pulpal necrosis associated with periapical lesions were selected and randomly divided into groups according to the irrigants used: GI - 2.5% NaOCl, GII - 2% chlorhexidine (CHX) gel, and GIII - saline solution (SS) (all, n=10). Samples were collected with sterile/apyrogenic paper points before (S1) and after root canal instrumentation (S2), after use of 17% ethylenediaminetetraacetic acid (EDTA) (S3), and after 30 days of intracanal medication (Ca(OH)2+SS) (S4). A turbidimetric kinetic Limulus Amebocyte Lysate assay was used for endotoxin measurement. Results: Endotoxins were detected in 100% of the root canals investigated (30/30), with a median value of 18.70 EU/mL. After S2, significant median percentage reduction was observed in all groups, irrespective of the irrigant tested: 2.5% NaOCl (99.65%) (GI), 2% CHX (94.27%) (GII), and SS (96.79%) (GIII) (all p<0.05). Root canal rinse with 17% EDTA (S3) for a 3-minute period failed to decrease endotoxin levels in GI and a slight decrease was observed in GII (59%) and GIII (61.1%) (all p>0.05). Intracanal medication for 30 days was able to significantly reduce residual endotoxins: 2.5% NaOCl (90%) (GI), 2% CHX (88.8%) (GII), and SS (85.7%) (GIII, p<0.05). No differences were found in the endotoxin reduction when comparing s2 and s4 treatment groups. Conclusion: Our findings demonstrated the effectiveness of the mechanical action of the instruments along with the flow and backflow of irrigant enduring root canal instrumentation for the endotoxin removal from root canals of teeth with chronic apical periodontitis. Moreover, the use of intracanal medication for 30 days contributed for an improvement ...

Diferenciação entre granulomas e cistos periapicais por meio de imagens de tomografia computadorizada: revisão de literatura / Differentiation between granulomas and periapical cysts by computed tomography images: literature

As lesões periapicais são formadas em resposta a um processo inflamatório que envolve a região periodontal de dentes necrosados. Assim, o tratamento endodôntico frequentemente está relacionado ao tratamento dessas lesões, as quais podem se manifestar na forma de cistos ou granulomas periapicais. Entretanto, ainda restam muitas dúvidas quanto ao diagnóstico diferencial. A avaliação histopatológica de uma amostra submetida à biópsia ainda é considerada o padrão-ouro para determinação do tipo da lesão periapical. A fim não só de proporcionar um tratamento endodôntico o menos invasivo possível, como também com o objetivo de otimizá-lo, é de suma importância que seja identificado um método não cirúrgico capaz de distinguir entre cistos periapicais e granulomas. Buscando um novo método diagnóstico, tem sido proposta a utilização de Tomografias Computadorizadas de Feixe Cônico (TCFC). Apesar de elas serem capazes de identificar lesões periapicais, ainda existe discordância sobre o seu real potencial de proporcionar a distinção entre cistos e granulomas. Assim, o objetivo dessa revisão de literatura foi proporcionar uma visão abrangente e crítica sobre o potencial da utilização de TCFC para discernir lesões periapicais como cistos ou granulomas. Pôde-se concluir que ainda são necessárias mais pesquisas sobre métodos alternativos não invasivos para a realização do diagnóstico diferencial entre cistos periapicais e granulomas. Apesar disso, a partir do conhecimento transmitido pelos estudos realizados até hoje, a tomografia computadorizada pode ser considerada como uma ferramenta em potencial para realizar o diagnóstico diferencial não cirúrgico de lesões periapicais

Tratamento endodôntico de um incisivo lateral maxilar: um caso raro de dens invaginatus tipo II duplo / Endodontic treatment of a maxillary lateral incisor: a rare case of type II dens invaginatus double

Introdução: o dens invaginatus é uma má formação de desenvolvimento resultante da invaginação da coroa do dente ou da raiz, antes da calcificação, durante a odontogênese. Constitui uma condição onde é fundamental o tratamento endodôntico, uma vez que, frequentemente, o dente apresenta uma complexa anatomia interna. A ocorrência de dens invaginatus tipo II é extremamente rara. Objetivos: o presente trabalho visa relatar um caso raro de dens invaginatus tipo II com presença de extensa lesão periapical. Métodos: foi realizado tratamento endodôntico não cirúrgico. Resultados: após um ano de tratamento, ao exame clínico, o dente se apresentou assintomático e a radiografia mostrou a cicatrização da lesão periapical

Intracanal dressing paste composed by calcium hydroxide, chlorhexidine and zinc oxide for the treatment of immature and mature traumatized teeth

AIM : To evaluate clinical and radiographic aspects before and after endodontic treatment with an intracanal dressing paste composed of calcium hydroxide, chlorhexidine and zinc oxide in traumatized teeth followed-up for 1 year. METHODS : Patients (n=105) treated at the Dental Trauma Service of Piracicaba School of Dentistry, Brazil were enrolled in the study. Two groups of teeth were formed: immature (G1) (n=28) and completely developed teeth (G2) (n=174). All teeth were endodontically treated and received an intracanal dressing with a paste composed by calcium hydroxide, 2% chlorhexidine gel and zinc oxide at a 2:1:2 rate. Clinical and radiographic aspects were evaluated initially, monthly and after 1-year. RESULTS : Most of the immature teeth suffered extrusive luxation (39.3%), whereas intrusive luxation (40.8%) was more common in completely developed teeth. There was a significant reduction in pain on percussion and mobility (p=0.0001) for immature teeth. Mature teeth showed reduction of spontaneous pain, fistula, mobility and pain on percussion (p<0.0001). Radiographic examination showed decrease in all evaluated parameters for both groups, in addition to stabilization of root resorption. CONCLUSIONS : This new intracanal dressing paste for traumatized teeth showed promising results in both immature and completely developed teeth, and may prevent post-traumatic complications.