Comparative in vitro analysis of the antifungal activity of different calcium silicate-based endodontic sealers

Aim: This study aimed to perform an in vitro comparative analysis of the antifungal activity of different calcium silicate-based endodontic sealers against three fungal species. Methods: The antifungal properties of three calcium silicate-based sealers were tested: Bio-C Sealer, Cambiar a Sealer Plus BC, and MTA-Fillapex. Two commonly used sealers were used as controls: AH Plus and Endomethasone. An agar diffusion test was performed to analyze the antifungal activity of the sealers against Candida albicans, Candida glabrata, Candida tropicalis, and a mixed microbial culture medium. The results were analyzed using ANOVA (p <0.05). Results: Endomethasone exhibited the highest inhibition against all strains examined, maintaining a consistent level of inhibition throughout 7 days. MTA-Fillapex demonstrated the best performance among the calcium silicate-based sealers for the three fungal species (p < 0.05), maintaining stable values over the 7 days, surpassing that of Endomethasone. Nevertheless, MTA-Fillapex only exhibited antimicrobial effect against the mixed culture for the first 24 hours, and no antimicrobial activity was observed at 48 hours, being surpassed by all tested sealers (p < 0.05). Conclusion: Of all silicate-based sealers tested, only MTA-Fillapex exhibited promising antifungal activity. Nevertheless, care must be taken when extrapolating these results, as MTA-Fillapex exhibited poor antimicrobial activity when tested in mixed microbial cultures

Analysis of antimicrobial efficacy of sodium hypochlorite and ozonated water against biofilm in oval canals

Abstract This in vitro study compared the antimicrobial efficacy of 2.5% sodium hypochlorite (NaOCl) and 8 µg/mL ozonated water agitated by passive ultrasonic irrigation (PUI) or PUI combined with EndoActivator (EA) against mature multispecies biofilm. One hundred and five oval-shaped mandibular premolars were instrumented, sterilized, and inoculated with Enterococcus faecalis, Candida albicans, and Staphylococcus aureus, divided into: control group - saline; O3 group - ozonated water; O3 PUI group - ozonated water with PUI agitation; O3 PUI+EA group - ozonated water with PUI+EA agitation; NaOCl group - NaOCl; NaOCl PUI group - NaOCl with PUI agitation; and NaOCl PUI+EA group - NaOCl with PUI+EA agitation. Microbiological samples were collected before (S1) and after (S2) the disinfection procedures and the data were statistically analyzed using the Kruskal-Wallis test. In the culture method, there was significant disinfection in the O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). The combination of NaOCl with PUI+EA reduced microbial counts to zero (p˂0.05). In the qPCR method, there was a significant reduction in the total count of viable microorganisms in the O3 PUI, O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). It can be concluded that 2.5% NaOCl with and without agitation, as well as 8 µg/mL ozonated water with its action enhanced by the agitation techniques, were effective in root canal disinfection, and their antimicrobial efficacy is related to the microorganisms present in the biofilm.

Resumo Este estudo in vitro comparou a desinfecção do hipoclorito de sódio 2,5% (NaOCl) e da água ozonizada 8 µg/mL agitados pela irrigação ultrassônica passiva (PUI) e por associação da PUI com EndoActivator (EA) na redução de biofilme misto maduro. Cento e cinco pré-molares inferiores ovalados foram instrumentados, esterilizados e inoculados com Enterococcus faecalis, Candida albicans e Staphylococcus aureus, divididos em: Grupo controle: soro; Grupo O3: água ozonizada; Grupo O3 PUI: água ozonizada agitada por PUI; Grupo O3 PUI + EA: água ozonizada agitada por PUI e EA: Grupo NaOCl: hipoclorito de sódio; Grupo NaOCl PUI: hipoclorito de sódio agitado por PUI; Grupo NaOCl PUI + EA: hipoclorito de sódio agitado por PUI e EA. Amostras microbiológicas foram coletadas antes (S1) e após (S2) os procedimentos de desinfecção e os dados foram analisados estatisticamente pelo teste de Kruskal-Wallis. No método de cultura, houve desinfecção significativa nos grupos O3 PUI + EA, NaOCl, NaOCl PUI e NaOCl PUI + EA (p˂0.05), sendo que no grupo NaOCl PUI + EA não houve crescimento de microrganismo (p˂0.05). No método de qPCR, nas contagens dos microrganismos antes e após os protocolos de desinfecção, houve redução microbiana nos grupos O3 PUI, O3 PUI + EA, NaOCl, NaOCl PUI, NaOCl PUI + EA (p˂0.05). Concluiu-se que o NaOCl 2,5% com e sem agitação foi eficiente, assim como a água ozonizada 8 µg/mL potencializada pelos métodos de agitação na desinfecção e que a mesma está relacionada com os microrganismos presentes no biofilme.

Influência do hipoclorito de sódio na resistência à fadiga cíclica em instrumentos rotatórios endodônticos de memória controlada de NiTi: uma avaliação experimental / Influence of sodium hypochlorite on cyclic fatigue resistance in niti controlled memory endodontics rotary instruments: an experimental evaluation

Introdução: É importante saber se o hipoclorito de sódio (NaOCl) influencia a resistência à fadiga cíclica das limas de níquel-titânio (NiTi). Objetivo: Avaliar a influência de NaOCl 2,5% na resistência à fadiga cíclica de dois sistemas de NiTi. Material e método: 40 instrumentos rotatórios - 20 TruNatomy® (TRU, Dentsply Sirona, Maillefer, Ballaigues, Suíça) e 20 Prodesing Logic2® (PDL2, Bassi, Belo Horizonte, Minas Gerais, Brasil) - foram aleatoriamente distribuídos em 4 grupos experimentais (n = 10) imersos em água destilada (H2O) e NaOCl 2,5% em temperatura a 37°C. Foram submetidos a testes de fadiga cíclica mensurando o número de ciclos para fratura (NCF) e análise dessas superfícies pós-teste em microscópio eletrônico por varredura. Para a análise estatística entre os grupos, foi aplicada a análise de variância (ANOVA), complementada com o pós-teste de Tukey. Resultado: Houve diferença estatística em todos os grupos (P<0.05). Os instrumentos PDL2 obtiveram maior resistência à fratura nas condições em H2O e em NaOCl 2,5% comparados aos instrumentos TRU. Na análise de grupos de instrumentos nas soluções de NaOCl e H2O, foi observado que o NaOCl 2,5% diminuiu o NCF. Conclusão: A resistência à fadiga cíclica dos instrumentos TRU e PDL2 diminuiu com NaOCl 2,5%. Os instrumentos PDL2 foram mais resistentes à fratura em relação aos instrumentos TRU.

Introduction: It is important to know whether sodium hypochlorite (NaOCl) influences the cyclic fatigue resistance of nickel-titanium (NiTi) files. Objective: To evaluate the influence of NaOCl 2.5% on the cyclic fatigue resistance of two NiTi systems. Material and method: Forty rotary instruments - 20 TruNatomy® (TRU, Dentsply Sirona, Maillefer, Ballaigues, Switzerland) and 20 Prodesign Logic2® (PDL2, Bassi, Belo Horizonte, Minas Gerais, Brazil) - were distributed randomly across four experimental groups (n=10) and submerged in distilled water (H2O) or 2.5% NaOCl at 37°C according to allocation. Cyclic fatigue testing was then performed, measuring the number of cycles to fracture (NCF), and post-test surfaces were analysed by scanning electron microscopy (SEM). Statistical Analysis: Analysis of variance (ANOVA) was applied for between-group analysis, followed by Tukey's post-hoc test. Result: A significant difference was observed in all groups (P<0.05). PDL2 instruments showed higher fracture resistance under H2O and 2.5% NaOCl conditions compared to TRU. Analysis of all instrument groups showed that exposure to 2.5% NaOCl decreased the NCF compared to H2O. Conclusion: Cyclic fatigue resistance of the TRU and PDL2 instruments was decreased by exposure to 2.5% NaOCl. PDL2 instruments were more resistant to fracture than TRU instruments.

Avaliação da acurácia de quatro localizadores apicais durante o retratamento endodôntico / Evaluate the accuracy of four electronic apex locators during endodontic retreatment

Este estudo teve como objetivo avaliar a acurácia de quatro localizadores apicais eletrônicos durante o retratamento endodôntico. Quarenta pré-molares unirradiculares com apenas um canal, ápice completamente formado, foram divididos em quatro grupos e analisados: Grupo 1: Root ZX ll. Grupo 2: Mini Root. Grupo 3: Propex ll e Grupo 4: Mini Apex. Todos os elementos foram padronizados no comprimento de 22 mm, instrumentados com limas Wave One Primary (25.08), obturados e armazenados. Após um mês, foram desobturados com limas reciprocantes Wave One Primary (25.08) e, em seguida, montados em blocos de esponja vegetal, embebida em solução de cloreto de sódio a 0,9%. A acurácia eletrônica de cada elemento foi realizada, utilizando-se uma lima manual do tipo K#20, até que a mesma fosse ultrapassada pelo forame e recuada até o comprimento real do dente, onde, então, as medidas de cada elemento eram anotadas. Todas as medidas obtidas de cada grupo passaram por análise estatística. Não houve diferença estatisticamente significante entre os localizadores apicais eletrônicos analisados, quando utilizados durante o retratamento endodôntico, sendo possível concluir que, os quatro modelos de localizadores apicais analisados mostraram-se eficientes durante o retratamento endodôntico, dentro dos limites estabelecidos, não havendo diferença entre eles.

This study aimed to evaluate the accuracy of four electronic apex locators during endodontic retreatment. Forty single-rooted premolars, with a root canal, with fully formed apex, were divided into four groups and analyzed: Group 1: Root ZX II. Group 2: Mini Root. Group 3: Propex II and Group 4: Mini Apex. All elements have been standardized in the length of 22 mm, instrumented with Wave One Primary (25.08) files, sealed and stored. After a month, the desobturation with reciprocating Wave One Primaty (25.08) files off and then assembled into blocks vegetable sponge, soaked in 0.9% sodium chloride solution. Electronic accuracy of each element was performed using a manual file type K#20, until it was overtaken by the foramen and retracted to the actual length of the tooth, which then measures each element were noted. All measurements obtained from each group passed by statistical analysis. There was no statistically significant difference between the electronic apex locators analyzed when used during endodontic retreatment it is possible to conclude that the four models analyzed apex locators were effective during endodontic retreatment wirhin the established timits, there is no difference between them.

Efeito do laser de baixa potência na dor após a montagem do aparelho ortodôntico / Effect of low level laser for pain relief after the first orthodontic archwire’s placement

Objetivo: avaliar clinicamente a eficácia da Terapia de Laser de Baixa Potência (TLBP) no alívio da dor após a instalação do aparelho ortodôntico e primeiro arco. Materiais e Métodos: 90 voluntários receberam aparelho fixo e colocação do primeiro arco ortodôntico. Foram randomicamente divididos em três grupos: Grupo 1- Controle (n=30), Grupo 2 - Placebo (n=30) e Grupo 3 - Laser (n=30). Foi realizada a TLBP infravermelho (810 nm) com 100 mW de potência e dose de 6 J/cm2 divididas em quatro aplicações por dente. A dor foi avaliada utilizando Escala Visual Analógica (EVA). Os dados obtidos foram submetidos à análise estatística por meio de teste de Kruskal- Wallis (α=0,05). Resultados: Em todos os grupos analisados a dor iniciou-se após 2 horas, houve um pico de dor entre 12 horas e 48 horas e sua diminuição ocorreu em sete dias. O Grupo 3 (Laser) apresentou todos os valores de dor menores em relação aos valores observados nos outros grupos. Houve diferença estatisticamente significante (p<0,05) da dor pós-operatória entre 12 e 48 horas (momento de pico de dor) para o grupo 3 em relação aos grupos 1 e 2. Conclusão: A TLBP mostrou-se eficiente para a redução da dor após a colocação do aparelho fixo e primeiro arco ortodôntico...

Objective: The aim of this study was to clinically evaluate Low Level Laser Therapy (LLLT) as a method of reducing pain after the first orthodontic archwire placement. Materials and Methods: 90 volunteers received metal braces and the first archwire. They were randomly distributed over three different treatment groups: Group 1- (n=30) Control, patients did not received any LLLT; Group 2- (n=30) Placebo, the LLLT was simulated, the laser was turned off; Group 3- (n=30) Laser patients received LLLT, infra-red with 810 nm wave length and 100 mW power, and it was used 6 J/cm2 as total dose per tooth, divided into four times of 1.5 J/cm2 per 12 seconds per point. Pain intensity experienced was evaluated by a Visual Analogue Scale. Data were tabulated and analyzed through Biostat 4.0 software. Means and standard deviations were calculated and a Kruskal-Wallis statics test was performed (Dunn’s method) (α=0.05). Results: It was possible to observe that the pain started 2 hours after treatment was initiated in the three groups. Higher pain levels occurred between 12 and 48 hours, and pain reduction occurred in 7 days. Group 3 (Laser) presented lower pain data values than the other groups. There was a statistically significant difference (p<0.05) among post operating pain in times T3, T4 and T5 between group 3 and groups 1 and 2. Conclusion: LLLT reduced the pain after orthodontics braces and archwires placement...

Efficiency and effectiveness evaluation of three glass fiber post removal techniques using dental structure wear assessment method.

Aim: This study evaluated the efficiency and effectiveness of three glass fiber post removal techniques. Materials and Methods: Forty-five extracted maxillary teeth were endodontically treated and cross-sectioned in thirds. Presence of cementing agent and dental structure wear were assessed by analyzing images taken before luting of glass fiber post and after removal procedure. Teeth were divided into 3 groups: Group 1 - diamond bur + Largo reamer; Group 2 - ultrasonic insert; Group 3 - carbide bur + ultrasonic insert. Time spent on removal procedures, dental structure wear and amount of remaining cement agent were recorded and results submitted to ANOVA, Kruskal Wallis and Tukey-Kramer tests. Results: Group 1 - 16'46", 33.33% and 6.99%; Group 2 - 12'31", 40% and 7.86%; and Group 3 - 10'24", 80% and 8.14%. Group 3 presented the most effective removal of glass fiber posts. Conclusion: There was no significant difference in efficiency among the evaluated techniques.

Influência do tratamento e do retratamento endodóntico na resistência adesiva de pinos de fibra de vidro / Influence of endodontic treatment and retreatment on the bond strength of fiber-glass post

O espaço preparado para pino após um retratamento endodôntico pode estar sujeito a maior quantidade de smear layer, em comparação com a quantidade de resíduos produzidos no tratamento inicial, já que nenhum protocolo de retratamento é capaz de garantir completa remoção de guta-percha e cimento obturador das paredes dos canais radiculares. Este estudo avaliou a resistência adesiva in vitro de pinos de fibra de vidro cimentados em dentes submetidos ao retratamento endodôntico, em comparação aos cimentados em dentes tratados endodonticamente. Quarenta canais de raízes bovinas foram instrumentados e obturados. As amostras foram divididas aleatoriamente em 2 grupos, sendo que as raízes do Grupo I foram preparadas para pino imediatamente depois de obturadas. As raízes do Grupo II tiveram as embocaduras dos canais seladas com o cimento restaurador temporário por um período de 30 dias, com posterior retratamento endodôntico e preparo para pino imediato. Pinos de fibra de vidro foram cimentados com cimento resinoso RelyX U100 nas raízes dos dois grupos, que permaneceram armazenadas por 7 dias para posterior realização do teste push-out, com resultados submetidos à análise de variância e ao teste de Tukey. A comparação das médias de força entre os grupos testados revelou que a média de força do Grupo I foi significativamente maior que a do Grupo II (p<0,01). O padrão de fratura foi predominantemente adesivo (interface dentina-cimento resinoso) em ambos os grupos. Pode-se concluir que há diminuição na resistência adesiva de pinos de fibra de vidro cimentados em dentes submetidos ao retratamento endodôntico.

The space prepared for a post after endodontic retreatment could be subject to a greater amount of debris compared to that produced during initial treatment because no retreatment protocol is capable of ensuring complete removal of gutta-percha and sealer from the root canal walls. This study assessed the in vitro bond strength of glass fiber posts cemented in teeth submitted to endodontic treatment, in comparison to posts cemented in teeth submitted to endodontic retreatment. Fourty roots of bovine teeth were instrumented, obturated and then randomly divided into two groups. In Group I, the gutta-percha was partially removed and the roots were prepared for post placement immediately after obturation. In Group II, the roots were sealed with temporary restorative cement and stored for a period of 30 days, after which they were endodontically retreated and immediately prepared for post preparation. Glass fiber posts were cemented with RelyX U100 resin cement in the roots of both groups, which remained stored during 7 days for subsequent push-out testing a and Tukey’s test. Comparison between groups revealed that the mean bond strength for Group I was significantly higher than that for Group II (p < 0.01). The pattern of bond failure was predominantly adhesive (dentin-resin cement interface) for both groups. It could be concluded that there was a reduction in the bond strength of glass fiber posts cemented in teeth submitted to endodontic retreatment

Avaliação da radiopacidade de cimentos endodônticos através de radiografias digitais / Evaluation of radiopacity of endodontic cements using digital X-ray

A radiopacidade ‚ uma das propriedades essenciais dos cimentos obturadores endodônticos, pois permite ao profissional avaliar a qualidade da obturação de canais radiculares e, consequentemente, a previsibilidade do tratamento. As especificações de radiopacidade foram avaliadas de acordo com a norma ISO 6876/2001. Para a análise da radiopacidade, 10 placas acrílicas foram confeccionadas com seis cavidades, cada uma com 5,0 mm de diâmetro e 2,0 mm de espessura e preenchidas com os cinco cimentos estudados: AHPlus, Endofill, Fill Canal, Sealapex, Sealer 26 e, como controle, foi utilizada guta-percha. Imagens radiográficas digitais dos espécimes foram importadas do software Digora for Windows versão 1.51. Uma escala de alumínio foi utilizada como um instrumento de medição da densidade radiográfica na comparação das amostras, e o valor da radiopacidade foi determinado de acordo com essa densidade radiográfica (mm Al). Os resultados foram analisados estatisticamente por teste ANOVA e complementados por Tukey. Os cimentos testados apresentaram diferenças estatisticamente significantes entre eles (p<0,005). Os valores da radiopacidade dos cimentos em ordem decrescente foram os seguintes: AHPlus (13,456ñ 0,069); Sealer 26 (11,197ñ0,039); Endofill (11,050ñ0,016); Fill Canal (9,793ñ0,074) e Sealapex (7,604ñ0,057). A radiopacidade da guta-percha (10,912ñ0,054) foi menor que o AHPlus, Sealer 26 e Endofill, por‚m todos os materiais testados preencheram os requisitos das normas ISO 6876/2001

Radiopacity is an essential attribute of endodontic filling materials because it allows an evaluation of the root canal filling, and thus the predictability of the treatment. Radiopacity was evaluated according to ISO 6876/2001 standards. For radiopacity analysis, ten acrylic plates were made, each with six holes 10.0 mm diameter and 2.0 mm thickness which were filled with the five studied cements: AHPlus, Endofill, Fill Canal, Sealapex, Sealer 26 and, as control was used guta-percha. Digital radiographic images of the patients were imported into the software Digora for Windows version 1.51. An aluminum step wedge was used to measure the radiographic density in the comparison of the samples. The radiopacity value was determined according to radiographic density (mm Al). The studied cements have presented statistically significant differences among them (p<0.005). Radiopacity values of the cements in descending order were: AHPlus (13.456ñ0.069); Sealer 26 (11.197ñ0.039); Endofill (11,050ñ0,016); FillCanal (9,793ñ0,074); and Sealapex (7.604ñ0.057). The radiopacity of guta-percha (10.912ñ0.054) was lower than AHPlus, Sealer 26 and Endofill, however all the tested materials were in accordance with the ISO 6876 normative

Analysis of the preparation obtained by three techniques of root canal instrumentation using computed tomography / Análise do preparo obtido por três técnicas de instrumentação do canal radicular através de tomografia computadorizada

Objective: Use computed tomography to compare three methods of root canal instrumentation. Methods: Thirty mandibular molar mesiobuccal canals were divided in three groups according to instrumentation technique: Group 1 - hand instrumentation with balanced force technique; Group 2 - Protaper Universal rotary system following manufacturer's instructions; and Group 3 - Protaper Universal rotary system and Gates-Glidden drills. Teeth were evaluated by computed tomography before and after preparation at three axial cuts: 3mm, 5mm, and 7mm from the root apex. Data were subjected to statistical analysis using the F, Chi-Square, Likelihood Ratio Chi-Square, and Mantel-Haenszel Chi-Square tests. Results: Group 3 showed significantly greater dentin removal with no tendency towards mesial or distal canal transportation, compared with Groups 1 and 2. Also, Group 3 required the least amount of time for instrumentation. Conclusion: Association of rotary instrumentation and Gates-Glidden drills is a safe and effective technique for root canal preparation.

Objetivo: Comparar o preparo de canais radiculares através de tomografia computadorizada. Métodos: Trinta canais mésio-vestibulares de molares inferiores foram divididos em 3 grupos, de acordo com a técnica de instrumentação a ser utilizada: Grupo 1 - instrumentação manual, utilizando-se de movimentos de forças balanceadas; Grupo 2 - Sistema Protaper Universal de instrumentação rotatória, conforme protocolo do fabricante; Grupo 3 - Sistema Protaper Universal de instrumentação rotatória associada a brocas de Gates- Glidden para pré-alargamento cervical. Os dentes foram submetidos à tomografia computadorizada antes e após o preparo, e a análise das imagens foi feita através de cortes axiais a 3mm, 5mm e 7mm do ápice radicular. Os dados foram submetidos a análise estatística utilizando testes paramétricos (para as variáveis tempo e desgaste de dentina) e não-paramétricos (para a variável sentido do desvio). Resultados: Os resultados mostraram uma tendência significativa do grupo 3 a desgastar mais dentina quando comparado aos grupos 1 e 2. O grupo 1 desgastou significantemente mais dentina para o sentido distal e o grupo 2 desgastou significantemente mais para o sentido mesial. O grupo 3 não apresentou tendência de sentido de desgaste. O tempo despendido foi menor no grupo 3, seguido pelo grupo 1 e 2. Conclusão: Pôde-se concluir que a associação das brocas de Gates-Glidden ao Sistema Protaper Universal promoveu um preparo adequado de maneira segura e, a tomografia computadorizada foi um método adequado para a análise do preparo de canais radiculares.

In vitro study of solubilization ability of bovine pulp tissue using different irrigating solutions

Introduction and Objective: The aim of this study was to evaluate in vitro the capacity of solubilization of bovine pulp tissue, promoted by the following auxiliary chemical solutions: 2.5% sodium hypochlorite at pH 9, 5.25 % sodium hypochlorite at pH 9, 2% chlorhexidine gel at pH 6, 17% EDTA at pH 7, and Smear-Clear®. Material and methods: A total of ten specimens of bovine pulp tissue, weighing 1.65 g each, were placed into flasks connected to a device developed for the study in order to reproduce irrigation dynamics. The flasks with the specimens received a volume of 80 ml of irrigating solution and the experimental times were 15, 30, 45 and 60 minutes. Results: The results were analyzed statistically by Kruskal-Wallis test to compare the different experiment times (15, 30, 45 and 60 minutes) of each irrigating solution. To compare the variation among the times of one solution, Kolmogorov-Smirlov test (Lilliefors) was used. Conclusion: Considering the results obtained and the limitations of the study, it can be concluded that 5.25% sodium hypochlorite exhibited the greatest solubilization ability, followed by 2.5% sodium hypochlorite, Smear-Clear®, 17% EDTA and 2% chlorhexidine gel.

Comparação entre os sistemas rotatórios Pathfile + Protaper Universal e Twisted Files quanto à preservação da morfologia e ao tempo de trabalho despendido na preparação de canais curvos / Comparison of preparation time and ability to maintain canal morphology in curved canals: Pathfile + Protaper Universal versus Twisted Files

Introdução: Instrumentos rotatórios em níquel-titânio (NiTi) reduzem erros processuais e o tempo requerido para a preparação do canal radicular. Objetivo: Comparar dois sistemas de instrumentação rotatória NiTi - Pathfile + ProTaper Universal e Twisted Files - quanto à capacidade de preservação da morfologia do canal e quanto ao tempo de trabalho necessário para a preparação de canais curvos. Material e Método: Os canais mesiais de 32 molares inferiores humanos (com ângulos de curvatura entre 20 e 40 graus) foram selecionados para o estudo. As amostras foram divididas aleatoriamente em dois grupos de 16 canais. Os preparos foram realizados por um Endodontista, utilizando-se a combinação dos instrumentos rotatórios Pathfile e ProTaper Universal (grupo PT) e os instrumentos rotatórios Twisted Files (grupo TF). Três Endodontistas analisaram imagens com a técnica da dupla radiografia digital, pré e pós-instrumentação, para avaliar se ocorreu transporte apical e/ou aberrações na morfologia dos canais. Por meio de uma análise computadorizada e com o auxílio de magnificação, as imagens inicial e final do canal radicular foram comparadas por meio de sua sobreposição. O teste de odds ratio foi utilizado para a comparação dos níveis de preservação da morfologia do canal, e ANOVA, complementada pelo teste de Tukey, foi utilizada para a comparação dos tempos de preparo. O nível de significância adotado foi de 5%. Resultado: Ocorreram desvios na trajetória do canal em ambos os grupos, mas a diferença entre estes não foi significativa. O tempo de trabalho requerido pela combinação dos sistemas Pathfile + ProTaper Universal foi significativamente maior do que o requerido pelo sistema Twisted Files. Conclusão: Os dois sistemas apresentaram performances semelhantes em relação à preservação da trajetória do canal; no entanto, o tempo de trabalho requerido pelo sistema Twisted Files foi menor.

Introduction: Nickel-titanium (NiTi) rotary instruments reduce procedural errors and the time required for root canal preparation. The aim of this study was to compare two rotary NiTi instrumentation systems-Pathfile + ProTaper Universal versus Twisted Files-as to their ability to maintain original canal morphology and the time they require to prepare curved root canals. Material and Method: The mesial canals of 32 human mandibular molars (with curvature angles between 20 and 40 degrees) were selected for the study, and divided at random into two groups of 16 canals each. The canals were prepared by an endodontist using either the combination of Pathfile and ProTaper Universal instruments (Group PT) or Twisted Files (Group TF). The double digital radiograph technique, pre- and post-instrumentation, was used by three endodontists to assess whether apical transportation and/or aberration in root canal morphology occurred. The initial and final images of the root canals were compared by superimposition through computerized analysis and with the aid of magnification. The odds ratio test was used to compare root canal morphology preservation, and ANOVA complemented by Tukey's test was used to compare preparation times. The significance level was set at 5%. Result: Deviation in root canal trajectory occurred in both groups, although the differences were not significant. The preparation time required by the Pathfile + ProTaper Universal combination was significantly longer than that required by the Twisted Files system. Conclusion: Both systems showed similar performances regarding the ability to maintain original root canal morphology; however, the preparation time required by the Twisted Files system was shorter.

Radiopacidade de resinas compostas / Radiopacity of composites resins

A radiopacidade dos materiais utilizados em restaurações ou como base forradora exerce importância devido ao contraste da visualização com as estruturas do dente. A norma internacional ISO 4049:2009 qualifica o teste para a quantificação da radiopacidade das resinas compostas. Materiais restauradores devem ser mais radiopacos do que a estrutura do dente e ter exequibilidade para distinguir de lesões cariosas ou dentina descalcificada. As imagens das amostras dos materiais restauradores foram projetadas e importadas para o software Digora para Windows versão 1.51 (Orion Corporation), onde uma ferramenta relacionou tons de cinza nas diversas áreas com a densidade radiográfica. Para isso, estudos que envolvam esta propriedade devem utilizar como padrão uma escala de alumínio. Cinco matrizes de acrílico foram confeccionadas, cada uma com 6 cavidades com formato circular de tamanho 5,0 mm de diâmetro e com 2,0 mm de espessura, onde foram inseridos seis marcas de resinas compostas. A radiopacidade não depende somente da quantidade da carga, mas também do teor dos aditivos radiopacos na carga inorgânica. A maioria das resinas permite uma boa visualização no diagnóstico radiográfico. A radiopacidade da resina depende da quantidade de BaO no complexo do silicato de bário-alumínio

The radiopacity of the materials used in restorations or as a base liner is important to visualize the contrast to the structures of the tooth. ISO 4049:2009 International Standard describes the test to quantify the radiopacity of composite resins. Restorative materials should be more radiopaque than the tooth structure to distinguish easily decalcified dentin or carious lesions. The images of samples of restorative materials were designed and imported into the software Digora for Windows version 1.51 (Soredex Orion Corporation, Helsinki, Finland), where a tool related grayscale in various areas with the radiographic density. For this reason, studies involving this property should use a default scale of aluminum. Five casts were made from acrylic resin, each with 6 circular shaped cavities with a size of 5.0 mm in diameter and 2.0 mm thickness where in six brands of composite resins were inserted. The radiopacity depends not only on the amount of charge, but also on the content of the radiopaque additives in the inorganic filler. Most resins allow good visualization in radiographic diagnosis. The radiopacity of the resin depends on the quantity of BaO in the complex of barium aluminum silicate

Comparison of the effectiveness of the protaper system versus hand instrumentation in endodontic retreatment: a scanning electron microscopy study

Introduction: Several rotary systems have been evaluated for removal of endodontic filling materials from the canal. Moreover, studies focusing on the comparison of the effectiveness of rotary systems versus hand instrumentation have yielded mixed results in terms of the efficacy and amount of time required by each technique. Objective: To compare the effectiveness of a nickel-titanium rotary system and of hand instrumentation using stainless steel files and Gates-Glidden burs in the removal of gutta-percha from root canals, as well as the time required to complete the procedure by each method. Material and methods: Forty single-rooted teeth were prepared and obturated then divided in two groups, according to the method employed for removal of the gutta-percha: ProTaper Universal rotary retreatment system (rotary instrumentation) and stainless steel hand files with Gates-Glidden burs (hand instrumentation). The time required to remove gutta-percha by each method was recorded. Roots were then sectioned lengthwise and the apical, middle, and coronal thirds were analyzed by SEM under two magnifications: x400 and x1,000. Results: Rotary instrumentation promoted better cleansing compared with hand instrumentation. The apical third was less clean than the coronal and middle thirds (Kruskal-Wallis p < 0.05). Rotary instrumentation was faster than hand instrumentation (Tukey p < 0.05). Conclusion: Although none of the methods promoted complete cleanliness of the canal walls, ProTaper Universal system showed better results and was faster than hand instrumentation.

Persistent infection in root-filled tooth: an SEM morphological analysis after apical microsurgery

Introduction and Objective: Endodontic failure can be associated to well-conducted treatments due to microbial factors characterized by intra or extraradicular infections not eliminated during endodontic treatment. Case report: This report describes a case of persistent apical periodontitis of an asymptomatic maxillary lateral incisor endodontically retreated and subsequently subject to apical surgery. Conclusion: After SEM morphological analysis of the apical fragment, areas of cementum-dentin resorption that were probably responsible for the perpetuation of the disease process were observed.

Location of three canals in the mesiobuccal root of the maxillary first molar

Introduction:The knowledge on the complex anatomy of the maxillary first molar and location of extra canals are essential for diagnosis and endodontic treatment success. Objective:The purpose of this study was to report a clinical case showing a varied number of root canals in maxillary molars with the aid of the operating microscope (OM). Case report: The endodontic retreatment of the right maxillary first molar with unusual anatomical variation was performed, displaying three canals in the mesiobuccal root (MB), a root canal in the distobuccal root (DV) and a root canal in the palatal root (P). To remove the resin core inside pulp chamber with and without the aid of dental operating microscope, a high-speed drill and ultrasonic tip (diamond round) was used, respectively, for the refinement of the pulp chamber walls. The dental operating microscopewas used during the access surgery, location, negotiation of canals and checking of the completion of all stages of the retreatment. Subsequently, the cleaning, shaping and filling of the root canal system was completed. The presence of three canals in the mesiobuccal root, one in the distobuccal root and one in the palatal root was found. Conclusion: Variations in the number of canals could be confirmed during the surgery access in endodontic retreatment cases with the aid of dental operating microscope.

Evaluation of cleaning efficacy of a nickel-titanium rotary system, with or without 17% EDTA passive ultrasonic activation: a scanning electron microscopic study

Introduction: The goal of endodontic instrumentation is to promote root canal cleaning and shaping to prepare it for the subsequent three-dimensional filling. Objective: The aim of this study was to evaluate, ex vivo, root canal cleaning ability executed by nickel-titanium rotary system instrumentation and this same system plus ultrasound passive activation of 17% EDTA, through SEM. Material and methods: Seventy upper second single-rooted human bicuspids were used. All teeth presented a single root canal, flattened towards buccal-palatal direction. The teeth were randomly separated into 3 groups. Group 1 (n = 30), had the canals instrumented by using the original operative sequence of ProTaper Universal System, up to instrument #F3. In this group, 5 ml of 5.25% sodium hypochlorite was employed as irrigant, every each instrument change. After group 1 instrumentation, root canals were irrigated with 5 ml of 17% EDTA, which was kept inside the canal for 3 minutes. Next, a final irrigation with 5 ml of 5.25% NaOCl was performed to remove the smear layer in suspension. Group 2 (n = 30) had the canals instrumented by the same system and up to the same instrument size. It was used 5.0 ml of 5.25% NaOCl as irrigant substance every each instrument change. In group 2, however, 17% EDTA (5 ml) was applied through ultrasonic passive activation for 1 minute, and then leaving the substance for 2 minutes within root canal.A final irrigation and with 5.25% NaOCl was also performed. Group 3 (n = 10) was the control group, where the canals were not instrumented and irrigation was executed with saline solution. After that, the teeth were cut into their long axis, metalized and taken for SEM analysis, at x2000 magnification. Each tooth's cervical, middle and apical thirds were observed. The cleaning quality of root canal's walls was observed by the images analyzed by three examiners. Results: Data were statistically analysed by analysis of variance and Tukey test, with a significance level of 5%. The control group showed an average score of the presence of smear layer of 3.41; group 1 (ProTaper) of 2.34; and the group 2 (ProTaper+Ultrassound) of 0.60. Conclusion: None of the studied preparation techniques promoted the total cleaning of the root canal walls. The addition of the ultrasound passive activation, after rotary instrumentation, promoted an increase of the smear layer removal, improving the cleaning of root canal wall. The apical third obtained the smallest cleaning rate, regardless of the technique employed.

Comparison of MTA Fillapex radiopacity with five root canal sealers

Introduction: The endodontic sealer is a filling material whose physicochemical properties are mandatory for the achievement of endodontic therapy final goal. An ideal endodontic sealer should have some properties, including radiopacity. Objective: This study compared MTA Fillapex™ radiopacity with the radiopacity of five others endodontic sealers: Endométhasone-N™, AH Plus™, Acroseal™, Epiphany SE™ and RoekoSeal™. Material and methods: Five cylindrical samples of each sealer were used, constructed with the aid of a matrix. On an occlusal film, a sample of each sealer was placed along with an aluminum stepwedge and five radiographic shots were taken. The radiographic images were digitized and each sample's gray scales were compared with each shade of the aluminum stepwedge, by using software. Results: The results, in decreasing order of radiopacity, were: AH Plus™ was statistically the most radiopaque sealer (9.4 mm Al), followed by Epiphany SE™ (7.8 mm Al), MTA Fillapex™ (6.5 mm Al), RoekoSeal™ (5.8 mm Al), Endométhasone-N™ (4.5 mm Al), and Acroseal™, the least statistically radiopaque (3.5 mm Al). Conclusion: It can be concluded that MTA Fillapex™ was the third most radiopaque sealer among all tested sealers. Also, MTA Fillapex™ has the radiopacity degree in agreement with ADA specification No. 57 (1983).

Extrusão acidental de hipoclorito durante tratamento endodôntico de dente com raiz fraturada / Accidental extrusian oi hypachlarite during endadantic treatment oi tooth with freatured roat

Os autores fazem uma revisão da literatura sobre fraturas radiculares, acidentes com hipoclorito de sódio durante o tratamento endodôntico e o uso de clorexidina gel a 2% como substância auxiliar na limpeza e modelagem dos canais radiculares. Apresentam um caso clínico em que, durante um tratamento endodôntico de um dente com fratura radicular transversal no terço médio, ocorreu extrusão involuntária de hipoclorito de sódio a 1% no ligamento periodontal através da linha de fratura, provocando grande edema no tecido gengival e no lábio superior da paciente. Foi administrada medicação sistêmica e tratamento fisioterápico de urgência, e, posteriormente, foi feita uma contenção da unidade com sucessivas camadas de tiras de poliéster e resina, limpeza e modelagem do canal com o Sistema Rotatório NiTi, utilizando-se clorexidina gel a 2% como substância auxiliar da instrumentação, irrigação com soro fisiológico e colocação de hidróxido de cálcio por 30 dias. Após este período, o canal radicular foi obturado utilizando-se a técnica da Termoplastificação da Guta Percha com um termocampactador de McSpadden e cimento AHPlus. A contenção foi removida com noventa dias. O exame clínico radiográfico de proservação foi realizado após seis meses, sugerindo reparação tecidual do caso.

The authors make a revision of the literature over root fractures, accidents with sodium hypochlorite during endodontic treatment and the use of 2% gel chlorhexidine as a auxiliary substance in the cleaning and shaping to the root canais. Presents a clinical case under, during a endodontic treatment of a tooth with a transversal freatured root in the medium third, occur involuntary extrusion of sodium hypochlorite at 1% in the periodontalligament across the fre- acture line, provoking great edema in the gingival tissue and in the superior lip of the patient. Administrated systemic medication and urgency physioterapic treatment and after time maked a splinting of the tooth with successives stratuns of poliester bands and resins, cleaning and shaping of the root canal with the NiTi Rotary System, using 2% gel chlorexidine how auxi- liary substance of the instrumentation, irrigation with physiological serum and place calcium hydroxide at 30 days. After this time the root canal was obtured used the guta percha termo- plastification technique used a McSpadden guta condensor and AHPus sealer. The splinting was removed with 90 days. The clinical and radiographic follow up was maked after six months, suggest tissue reparation.

Radiopacidade de sete cimentos endodônticos avaliada através de radiografia digital / Radiopacity of seven endodontic sealers evaluated using digitized radiograph

Objetivo: Determinar a radiopacidade de sete cimentos endodônticos, dois à base de hidróxido de cálcio - Sealapex e Apexit, três resinosos- Sealer 26, AH Plus e EndoRez e dois cimentos à base de óxido zinco e eugenol - Intrafill e Endomethasone, através de imagens radiográficas digitais obtidas pelo método indireto. Métodos: Confeccionaram-se cinco placas de acrílico com nove cavidades cada, nas quais foram inseridos os cimentos estudados. Como controle foi utilizado a guta-percha e para se obter um parâmetro da radiopacidade fragmentos de dentina do mesmo tamanho dos corpos de prova foram utilizados. As placas foram radiografadas e as películas digitalizadas com resolução de 400 dpi no formato de tons de cinza, sendo posteriormente as imagens analisadas com o uso do software Image Tool v.3.00. Este tipo de análise determina os níveis de cinza. Resultados: Com os valores da média em pixels de radiopacidade obtidas, a ordem dos cimentos do mais radiopaco para o menos foi: AH Plus, EndoRez, Intrafill, Sealer 26, Endomethasone, Apexit e Sealapex. Conclusão: Todos os cimentos avaliados apresentaram radiopacidade maior que a da dentina e somente o AH Plus foi maior que a da guta-percha.

Objective: Determine the radiopacity of seven root canal sealers, two based on calcium hydroxide - Sealapex Apexit and three resin - Sealer 26, AH Plus and EndoRez and two cements based on zinc oxide and eugenol - Intrafill and Endomethasone through digital radiographic images obtained by the indirect method. Methods: Five-confected acrylic plates with nine holes each, which were inserted in the cements studied. As control was used gutta-percha and to obtain a parameter of the radiopacity of dentin fragments of the same size of the specimens were used. The plates were radiographed and the film scans with a resolution of 400 dpi in grayscale format, the images were later analyzed using the Image Tool v.3.00 software. This type of analysis determines the levels of gray. Results: With the values of the average pixel radiopacity obtained, the order of the most radiopaque cements to least were: AH Plus, EndoRez, Intrafill, Sealer 26, Endomethasone, Apexit and Sealapex. Conclusion: All sealers showed radiopacity greater than that of dentin and only the AH Plus was greater than that of gutta-percha.

Resposta tecidual subcutânea em ratos frente a implantes de cones de guta-percha e cones de resilon / Rat subcutaneous tissue response to resilon and gutta-percha cones

O objetivo deste estudo foi avaliar a biocompatibilidade em tecidos subcutâneos de ratos dos cones de resilon e cones de guta-percha. Para isso, foram selecionados 20 ratos adultos divididos em quatro grupos de cinco ratos cada. Em cada rato foram implantados um pedaço de cone de resilon e um de guta-percha. O Grupo I foi observado após 24 horas; o Grupo II, após 48 horas; o Grupo III, após sete dias; e o Grupo IV, após 30 dias. Na análise histológica, observou-se que, no Grupo I, os dois materiais provocaram uma reação inflamatória aguda intensa, com presença de neutrófilos. No Grupo II, ao redor da guta-percha ainda havia áreas com infiltrado inflamatório rico em neutrófilos, porém em menor extensão que ao redor do resilon. No Grupo III, tanto para a guta-percha quanto para o resilon, observou-se tecido de granulação caracterizado por proliferação fibroblástica endotelial e neovascularização, permeados por moderado a intenso infiltrado inflamatório mononuclear. No Grupo IV, observou-se, em volta dos cones de guta-percha e cones de resilon, um tecido de granulação restrito à proximidade do material, além de menor quantidade de vasos sanguíneos, e infiltrado inflamatório de discreto a moderado. Em algumas regiões ao redor dos cones de guta-percha e resilon, as análises apresentaram cápsula fibrosa delgada livre de inflamação. Assim conclui-se que os dois materiais se comportaram de forma semelhante quando implantados nos tecidos subcutâneos de ratos, mostrando-se bem toleráveis e biocompatíveis.

Objective: the aim of this study was to evaluate the tissue response of resilon and gutta-percha cones when implanted in subcutaneous tissues of rat. Method: 20 adult male rats were selected and then randomly divided into four groups (n=5, each). In each animal one piece (semelhante) of resilon cone and one of gutta-percha were implanted. The tissues surrounding the implants were removed and analyzed histologically in Group I after 24 hours; in Group II after 48 hours; in Group III after seven days; and in Group IV, after 30 days. Results: in Group I, both materiais provoked an intense sharp inflammatory reaction, with the presence of neutrofiles. In Group II, the tissues around gutta-percha still showed inflammatory infiltrate rich in neutrofiles, however in a smaller extension than of those around resilon. In Group III granulation tissues characterized by fibroblastic endothelial proliferation and neovascularization permeated with moderate to intense mononucleate inflammatory infiltrate were observed around both gutta-percha and resilon implants. In Group IV a granulation tissue was observed around the implant, restricted to the proximity of the material. In addition a small amount of blood vessels and discrete inflammatory infiltrate was present. In some areas a thin fibrous capsule free from inflammation was observed. Conclusion: Subcutaneous rat tissues behaved in a similar way when implanted with gutta-percha cones and resilon cones, which therefore can be considered very tolerable and biocompatible.