Efficiency of a digital electrofulguration system in contaminated root canals in vitro

Abstract Decontamination of the root canal (RC) system is essential for successful endodontic therapy. In this in vitro study, it was evaluated the disinfection potential of an electrofulguration device, the Endox® Endodontic System (EES), in RC infected with Enterococcus faecalis. Sixty-five human lower premolars were instrumented with MTwo® system. The specimens were distributed into six experimental groups (n = 10), according to the irrigation protocol: 2% chlorhexidine gel (CHX); CHX + EES; 5.25% sodium hypochlorite (NaOCl); NaOCl + EES; saline solution (SS); and SS + EES. Five specimens were untreated (control). RC samples were collected before (C1) and after EES treatment (C2), after chemo-mechanical preparation (CMP) (C3), and after final EES treatment (C4). All samples were plated for colony forming units (CFU/mL) onto solid media. The data were analyzed by Wilcoxon and Friedman tests for intragroup comparisons and by Kruskal Wallis test followed by Dunn's test for intergroup comparisons (α = 0.05). Treatment with the EES did not significantly reduce the number of CFU/mL as compared to baseline levels (C1 vs. C2, p> 0.05). After CMP (C3), all groups showed a significantly reduced amount of CFU/mL (p <0.05), with no difference between CHX- and NaOCl-treated samples (p >0.05). Lastly, treatment with the EES following CMP (C4) did not significantly reduce the amount of CFU/mL (C3 vs. C4, p> 0.05). To conclude, the use of the Endox® Endodontic System did not result in considerable bacterial reduction at all operative times, while treatment with NaOCl and CHX was equally efficient for this purpose.

Resumo A descontaminação do sistema do canal radicular (CR) é essencial para o sucesso da terapia endodôntica. Neste estudo in vitro, foi avaliado o potencial de desinfecção de um dispositivo de eletrofulguração, o Endox® Endodontic System (EES), em CR infectado com Enterococcus faecalis. Sessenta e cinco pré-molares inferiores humanos foram instrumentados com o sistema MTwo®. As amostras foram distribuídas em seis grupos experimentais (n = 10), de acordo com o protocolo de irrigação: clorexidina gel a 2% (CHX); CHX + EES; Hipoclorito de sódio 5,25% (NaOCl); NaOCl + EES; solução salina (SS); e SS + EES. Cinco amostras não foram tratadas (controle). As amostras de CR foram coletadas antes (C1) e após o tratamento com EES (C2), após preparo químico-mecânico (PQM) (C3) e após o tratamento final com EES (C4). Todas as amostras foram plaqueadas para unidades formadoras de colônias (CFU / mL) em meio sólido. Os dados foram analisados pelos testes de Wilcoxon e Friedman para comparações intragrupos e pelo teste de Kruskal Wallis, seguidos pelo teste de Dunn para comparações intergrupos (α = 0,05). O tratamento com o EES não reduziu significativamente o número de CFU / mL em comparação com os níveis basais (C1 vs. C2, p> 0,05). Após PQM (C3), todos os grupos apresentaram uma quantidade significativamente reduzida de CFU / mL (p <0,05), sem diferença entre as amostras tratadas com CHX e NaOCl (p> 0,05). Por fim, o tratamento com o EES após PQM (C4) não reduziu significativamente a quantidade de CFU / mL (C3 vs. C4, p> 0,05). Concluindo, o uso do Endox® Endodontic System não resultou em redução bacteriana considerável em todos os momentos operatórios, enquanto os tratamentos com NaOCl e CHX foram igualmente eficientes para esse fim.

Efficacy of ethylene-diamine-tetra-acetic acid associated with chlorhexidine on intracanal medication removal: a scanning electron microscopy study.

The aim of this study was to evaluate the effectiveness of 17% ethylene-diamine-tetra-acetic acid (EDTA) used alone or associated with 2% chlorhexidine gel (CHX) on intracanal medications (ICM) removal. Sixty single-rooted human teeth with fully formed apex were selected. The cervical and middle thirds of each canal were prepared with Gates Glidden drills and rotary files. The apical third was shaped with hand files. The specimens were randomly divided into two groups depending on the ICM used after instrumentation: calcium hydroxide Ca(OH)(2) +CHX or Ca(OH)(2) +sterile saline (SS). After seven days, each group was divided into subgroups according to the protocol used for ICM removal: instrumentation and irrigation either with EDTA, CHX+EDTA, or SS (control groups). All specimens were sectioned and processed for observation of the apical thirds by using scanning electron microscopy. Two calibrated evaluators attributed scores to each specimen. The differences between the protocols for ICM removal were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Friedman and Wilcoxon signed rank tests were used for comparison between the score of debris obtained in each root canal third. Remains of Ca(OH)(2) were found in all specimens independently of the protocol and ICM used (P > 0.05). Seventeen percent EDTA showed the best results in removing ICM when used alone (P < 0.05), particularly in those associated with CHX. It was concluded that the chelating agent 17% EDTA significantly improved the removal of ICM when used alone. Furthermore, the type of the vehicle associated with Ca(OH)(2) also plays a role in the ICM removal.

Infuence of irrigation and obturation techniques on artificial lateral root canal filling capacity

The aim of this study was to evaluate the influence of two dif-ferent irrigation protocols on artificial lateral root canalfilling capacity using different obturation techniques. Sixtysingle-root human teeth were used. Two artificial lateralcanals were created in the apical third. Root canals wereinstrumented up to a 45 K-file to the working length. Beforeeach file, root canals were irrigated either with 2 mL of 2.5%NaOCl or 2% chlorhexidine gel with further irrigation withsaline solution and 3 mL of 17% EDTA. Specimens were ran-domly divided into three groups according to the obturationtechnique: (1) lateral compaction technique; (2) Taggerhybrid technique; and (3) thermoplasticized technique usingBeeFill 2 in 1. All groups used AH Plus as the root canal seal-er. The specimens were decalcified and cleared in methylsalicylate. The total length of lateral canals was observedunder X30 magnification with a stereomicroscope and meas-ured on the buccal and lingual root surfaces using Leica IM50software. The data were submitted to ANOVA and Tukey test(p<0.05). Among the obturation techniques, BeeFill 2 in 1showed deeper penetration into all lateral canals than the lat-eral compaction or Tagger hybrid techniques (p<0.05). Thelateral compaction group showed the worst results (p<0.05).Irrigants did not affect the outcome; there was no differencebetween NaOCl and chlorhexidine when the same obturationtechnique was used (p>0.05). Regardless of the irrigant usedduring endodontic procedures, the thermoplasticized tech-niques showed higher penetration behavior for filling artificiallateral canals than the lateral compaction technique.

O objetivo do presente estudo foi avaliar a influência de doisdiferentes protocolos de irrigação na capacidade de penetraçãode canais artificiais, utilizando diferente técnicas de obturação.Sessenta dentes humanos unirradiculares foram utilizados. Doiscanais laterais artificiais foram confeccionados no terço apicaldo dente. Os canais foram instrumentados até uma lima K 45 nocomprimento de trabalho. Antes do uso de cada lima, os canaisradiculares foram irrigados com 2 mL de NaOCl 2.5% ou comClorexidina gel 2% seguido de solução salina. Ambos os gruposreceberam no final da instrumentação 3 mL de EDTA 17%. Osespecimes foram randomicamente separados em 3 subgrupos deacordo com a técnica de obturação utilizada: (1) técnica de com-pactação lateral; (2) técnica híbrida de Tagger; e (3) técnicatermoplástica utilizando o BeeFill 2 em 1. Em todos os grupos ocimento utilizado foi o AH Plus. Depois, os elementos foramdiafanizados utilizando metil salicilato. As extensões de pe -netração dos cimentos nos canais laterais foram realizadas uti-lizando estereomicroscópio (X30). Os dados de cada grupoforam analizados utilizando ANOVA e o teste de Tukey (p<0.05).Dentre as técnicas de obturação, a técnica termoplástica uti-lizando o BeeFill 2 em 1 mostrou a maior penetração em canaislaterais (p<0.05). A técnica de compactação lateral apresentouos piores resultados dentes os grupos testados (p<0.05). Os irri-gantes não afetaram a penetração dos canais laterais; não foramobservados diferenças entre NaOCl e clorexidina, quando amesma técnica de obturação foi utilizada (p>0.05). Pode-se con-cluir que independente da substância química auxiliar utilizada,as técnicas termoplásticas de obturação demonstraram maiorpenetração de canais laterais do que a técnica de compactação lateral.