Comparative antibacterial efficacies of hydrodynamic and ultrasonic irrigation systems in vitro

INTRODUCTION To ensure root canal treatment success, endodontic microbiota should be efficiently reduced. The in vitro bactericidal effects of a hydrodynamic system and a passive ultrasonic irrigation system were compared. METHODS Single-rooted extracted teeth (n = 250) were contaminated with suspensions of Enterococcus faecalis ATCC 29212, mixed aerobic cultures, or mixed anaerobic cultures. First, the antibacterial effects of the hydrodynamic system (RinsEndo), a passive ultrasonic irrigation system (Piezo smart), and manual rinsing with 0.9% NaCl (the control) were compared. Colony-forming units were counted. Second, the 2 systems were used with 1.5% sodium hypochlorite (NaOCl) alone or NaOCl + 0.2% chlorhexidine (CHX). The colony-forming units in the treated and untreated roots were determined during a period of 5 days. RESULTS Both irrigation systems reduced bacterial numbers more effectively than manual rinsing (P < .001). With NaCl, ultrasonic activated irrigation reduced bacterial counts significantly better than hydrodynamic irrigation (P = .042). The NaOCl + CHX combination was more effective than NaOCl alone for both systems (P < .001), but hydrodynamic irrigation was more effective with NaOCl + CHX than the passive ultrasonic irrigation system. CONCLUSIONS Both irrigation systems, when combined with NaOCl + CHX, removed bacteria from root canals.

Effect of Rotary Instrument Associated with Different Irrigation Techniques on Removing Calcium Hydroxide Dressing

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Radiographic evaluation of root canal cleaning, main and laterals, using different methods of final irrigation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of passive ultrassonic instrumentation as a final irrigation protocol on debris and smear layer removal

This study sought to evaluate the efficacy of passive ultrasonic irrigation (PUI) on removing the smear layer and debris from root dentin using scanning electron microscopy (SEM). Twenty-five bovine incisors were manually prepared and divided into three groups according to the final irrigation protocol: EDTA, final irrigation with 12 mL of 17% EDTA for 3 minutes followed by 5 mL of 2.5% NaOCl; EDTA=PUI, final flush with 4 mL of 17% EDTA and PUI for 30 seconds. These procedures were repeated three times to standardize the volume of the irrigant. Control group, after preparation, the specimens were irrigated only with 17 mL of 2.5% NaOCl. The roots were fractured and analyzed using SEM. The intragroup analysis revealed that the EDTA=PUI protocol removed a higher amount of debris at the cervical third (P 5 0.03). The intergroup analysis revealed that EDTA=PUI presented the lowest amount of debris at the cervical third (P 5 0.007). Smear layer scores were higher in the control group compared with the EDTA and EDTA=PUI groups, but only at the cervical third (P 50.02). None of the final irrigant protocols completely removed the smear layer and debris. EDTA=PUI only improved the removal of debris at the cervical third.

Eficácia da irrigação ultrassônica passiva na limpeza e eliminação de Enterococcus faecalis dos canais radiculares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do veículo na remoção da pasta tri antibiótica do canal radicular

Pós-graduação em Ciência Odontólogica - FOA

Debris and smear removal in flattened root canals after use of different irrigant agitation protocols

Scanning electron microscopy (SEM) can be used to analyze the presence of debris and smear layer on the internal walls of root canal. This study evaluated the debris and smear removal in flattened root canals using SEM after use of different irrigant agitation protocols. Fifty mandibular incisors were distributed into five groups (n = 10) according to the irrigant agitation protocol used during chemomechanical preparation: conventional syringe irrigation with NaviTip needle (no activation), active scrubbing of irrigant with brush-covered NaviTip FX needle, manual dynamic irrigation, continuous passive ultrasonic irrigation, and apical negative pressure irrigation (EndoVac system). Canals were irrigated with 5 mL of 2.5% NaOCl at each change of instrument and received a final flush with 17% EDTA for 1 min. After instrumentation, the roots were split longitudinally and SEM micrographs at x 100 and x 1,000 were taken to evaluate the amount of debris and smear layer, respectively, in each third. Data were analyzed by KruskalWallis and Dunn's post-hoc tests (a = 5%). Manual dynamic activation left significantly (p < 0.05) more debris inside the canals than the other protocols, while ultrasonic irrigation and EndoVac were the most effective (p < 0.05) for debris removal. Regarding the removal of smear layer, there was no statistically significant difference (p > 0.05) either among the irrigant agitation protocols or between the protocolcanal third interactions. Although none of the irrigant agitation protocols completely removed debris and smear layer from flattened root canals, the machine-assisted agitation systems (ultrasound and EndoVac) removed more debris than the manual techniques. Microsc. Res. Tech. 75:781790, 2012. (C) 2011 Wiley Periodicals, Inc.

Sistemas auxiliares de desinfeção em Endodontia

Introdução: O objetivo da terapia endodôntica é eliminar a infeção presente nos canais radiculares e prevenir a reinfeção dos mesmos, criando assim as condições para a manutenção da peça dentária em função e livre de patologia pulpar ou peri-apical. A complexa anatomia dos canais faz com que seja impossível uma limpeza completa dos mesmos. Para se conseguir um bom resultado clínico é de extrema importância utilizarmos técnicas e procedimentos que visem uma utilização combinada de instrumentação mecânica e desinfeção com soluções de irrigação. Objetivo: Revisão bibliográfica sobre sistemas auxiliares de desinfeção em Endodontia, abordando as suas principais vantagens e limitações e apresentando estudos que provam a sua importância para o sucesso do tratamento endodôntico. Materiais e métodos: Realizou-se uma pesquisa eletrónica nos principais motores de busca online tais como PubMed, B-On, Scielo e Science Direct e em livros científicos sobre a temática, utilizando palavras-chave em inglês tais como “irrigation techniques”, “sonic irrigation”, “EndoVac”, “EDTA”, “hypoclorite sodium”, “passive ultrasonic irrigation”, “apical negative pressure irrigation”, “root canal irrigation”, “EndoAtivator”, e ainda alguns termos em português tais como “insucesso em endodontia”, “hipoclorito de sódio” “ácido cítrico” e “irrigação sónica e ultrasónica”. Da pesquisa efectuada entre Junho e Novembro de 2015 e cujo critério de inclusão foram artigos datados de 2001 a 2015, escolheu-se 65 artigos em inglês, 4 em português e 1 em espanhol, dos quais se utilizaram 44 artigos. Além dos artigos analisou-se 2 livros, dos quais se utilizou 1. Resultados: Os artigos analisados apresentam como principais resultados que a combinação de instrumentação mecânica e a irrigação reduz mas não elimina totalmente as bactérias. Até à data não existem soluções de irrigação ideais. Têm-se desenvolvido técnicas capazes de combater as dificuldades encontradas e aumentar as potencialidades da irrigação, cada uma apresentando suas vantagens e desvantagens. Dos resultados constatados, a literatura científica aparenta reconhecer o Sistema EndoVac como o melhor em termos de biossegurança e o sistema de irrigação ultrasónica passiva como o melhor em termos de desinfecção e limpeza. Conclusão: Uma combinação de soluções com uma sequência específica é aparentemente necessária para atingir o sucesso endodôntico, bem como uma escolha adequada da técnica. As novas técnicas desenvolvidas tais como a ativação dinâmica manual, irrigação ultrasónica passiva, ativação sónica e sistemas de pressão apical negativa apresentam melhores resultados quando associados a irrigantes adequados como o hipoclorito, EDTA, ácido cítrico, clorohexidina e álcool. No entanto, concluiu-se que mais investigação é necessária para melhorar o sucesso do tratamento endodôntico não-cirúrgico.

Soluções irrigadoras em Endodontia

O principal objetivo do tratamento endodôntico não cirúrgico reside na limpeza e desinfeção do sistema tridimensional de canais radiculares, removendo os microrganismos existentes e conseguindo restituir a função do dente, em vez de o extrair. É fácil compreender que o insucesso deste tratamento deve-se, essencialmente, à sobrevivência dos microrganismos nos canais radiculares. Por isso, a irrigação e a desinfeção são essenciais para alcançar o sucesso do tratamento. Devido à morfologia do canal e à incapacidade de determinar a localização exata do ápice, as soluções irrigadoras têm de alcançar as ramificações dos canais radiculares e outras áreas inacessíveis à instrumentação. Após a pesquisa efetuada, concluiu-se que o irrigante mais utilizado universalmente é o hipoclorito de sódio. Para além disso, o hipoclorito de sódio, o EDTA e o ácido cítrico ajudam na instrumentação e no alargamento do canal, devido à desmineralização dentinária que provocam. Já a clorexidina, apesar de não provocar qualquer desmineralização, ao ser associada ao hipoclorito de sódio, origina um precipitado que vai interferir no selamento dos canais radiculares. Assim, com o presente trabalho, pretende-se realizar uma revisão bibliográfica sobre os diversos irrigantes e sistemas auxiliares de irrigação, que se encontram associados à desinfeção endodôntica.

Influence of ultrasonic activation in association with different final irrigants on intracanal smear layer removal

Aim: To evaluate the influence of ultrasonic activation (US) with different irrigant regimens in smear layer removal. Methods: One hundred bovine incisors were instrumented and divided into ten groups (n=10) according to final irrigation protocols: distilled water (DW); DW+US; 17% EDTA; QMix; 10% citric acid; 37% phosphoric acid; 17% EDTA+US; QMix+US; 10% citric acid+US; 37% phosphoric acid+US. The samples were then submitted to scanning electron microscopy where a score system was used to evaluate the images and effectiveness of proposed treatments. The data were statistically analyzed by Kruskal-Wallis and Mann-Whitney U tests for intergroup comparisons as well as the Wilcoxon and Friedman tests for intragroup comparisons at 5% significance level. Results: In the cervical third, groups 17% EDTA, QMix, 10% citric acid, 17% EDTA+US, QMix+US and 10% citric acid+US were more effective in smear layer removal (p<0.05); in the middle third, groups 17% EDTA+US and QMix+US were more effective in smear layer removal (p<0.05); in the apical third, groups 17% EDTA,17% EDTA+US and QMix+US were more effective in smear layer removal (p<0.05). Conclusions: US can aid 17% EDTA and QMix in smear layer removal at the middle third and QMix at the apical third, contributing to the cleaning of root canal system.

Analysis of root canal organic tissue dissolution capacity according to the type of irrigation solution and agitation technique

Aim: To analyze the root canal organic tissue dissolution capacity promoted by irrigating solutions, with or without the use of different agitation techniques. Methods: Bovine pulp tissue fragments were initially weighed. The following irrigating solutions were tested: 2.5% sodium hypochlorite, 2% chlorhexidine digluconate solution, and distilled water. The irrigating protocols were: immersion, mechanical agitation with endodontic files, and ultrasonic or sonic systems (Endoactivactor® and Easy Clean®). At the end of the protocols, the pulps were weighed to determine their final weight. For comparison, the average percentage of tissue dissolution in relation to the groups was analyzed using the Kruskal-Wallis nonparametric test complemented by multiple comparisons test. The significance level was set at 5%. Results: Among the irrigation solutions, 2.5% sodium hypochlorite showed a higher dissolving power than 2% chlorhexidine digluconate and distilled water. Furthermore, ultrasonic and sonic systems were more effective irrigating protocols than immersion and mechanical agitation with endodontic files. Conclusions: The combination of sodium hypochlorite with an agitation system promotes a greater degree of tissue degradation.

Effect of sonic and ultrasonic activation on organic tissue dissolution from simulated grooves in root canals using sodium hypochlorite and EDTA

Aim: To compare soft-tissue dissolution by sodium hypochlorite, with an EDTA intermediate rinse, with or without activation with passive ultrasonic activation (PUI) or sonic activation using the Endoactivator (EA) or Eddy tips (ED). Methodology: The root canals of eighty-three human maxillary central incisors were chemo-mechanically prepared and the teeth split. A standardized longitudinal intracanal groove was created in one of the root halves. Eighty-three porcine palatal mucosa samples were collected, adapted to fit into the grooves and weighed. The re-assembled specimens were randomly divided into four experimental groups (n = 20), based on the final rinse: no activation; EA; PUI; ED, using 2.5% sodium hypochlorite, with an EDTA intermediate rinse. A control group (n = 3) was irrigated with distilled water without activation. The solutions were delivered using a syringe and needle 2 mm from working length. Total irrigation time was 150 s, including 60 s of activation in the specific groups. The study was carried out at 36 ± 2 °C. The porcine palatal mucosa samples were weighed after completion of the assays. Student paired t-test and anova were used to assess the intra- and intergroup weight changes. The multiple comparisons were evaluated using Bonferroni correction (α = 0.05). Results: Weight loss occurred in all experimental groups. Irrigant activation resulted in greater weight loss when compared to the nonactivated group [vs. EA (P = 0.001); vs. PUI (P < 0.001); vs. ED (P < 0.001)]. No significant differences were found amongst the different activation systems. Conclusions: Activation increased the tissue-dissolving activity of irrigants from artificial grooves in root canals of maxillary central incisors. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

The measurement of broadband ultrasonic attenuation in cancellous bone-a review of the science and technology

The measurement of broadband ultrasonic attenuation (BUA) in cancellous bone at the calcaneus was first described in 1984. The assessment of osteoporosis by BUA has recently been recognized by Universities UK, within its EurekaUK book, as being one of the “100 discoveries and developments in UK Universities that have changed the world” over the past 50 years, covering the whole academic spectrum from the arts and humanities to science and technology. Indeed, BUA technique has been clinically validated and is utilized worldwide, with at least seven commercial systems providing calcaneal BUA measurement. However, a fundamental understanding of the dependence of BUA upon the material and structural properties of cancellous bone is still lacking. This review aims to provide a science- and technology-orientated perspective on the application of BUA to the medical disease of osteoporosis.

Ultrasonic measurement of fine head movements in a standard ophthalmic headrest

We aimed to investigate the naturally occurring horizontal plane movements of a head stabilized in a standard ophthalmic headrest and to analyze their magnitude, velocity, spectral characteristics, and correlation to the cardio pulmonary system. Two custom-made air-coupled highly accurate (±2 μm)ultrasound transducers were used to measure the displacements of the head in different horizontal directions with a sampling frequency of 100 Hz. Synchronously to the head movements, an electrocardiogram (ECG) signal was recorded. Three healthy subjects participated in the study. Frequency analysis of the recorded head movements and their velocities was carried out, and functions of coherence between the two displacements and the ECG signal were calculated. Frequency of respiration and the heartbeat were clearly visible in all recorded head movements. The amplitude of head displacements was typically in the range of ±100 μm. The first harmonic of the heartbeat (in the range of 2–3 Hz), rather than its principal frequency, was found to be the dominant frequency of both head movements and their velocities. Coherence analysis showed high interdependence between the considered signals for frequencies of up to 20 Hz. These findings may contribute to the design of better ophthalmic headrests and should help other studies in the decision making of whether to use a heavy headrest or a bite bar.