Antibacterial effect of low-temperature plasma on Enterococcus faecalis in dentinal tubules in vitro / 北京大学学报(医学版)

OBJECTIVE@#To construct a model of Enterococcus faecalis (E. faecalis) infection in dentinal tubules by gradient centrifugation and to evaluate the antibacterial effect of low-temperature plasma on E. faecalis in dentinal tubules.@*METHODS@#Standard dentin blocks of 4 mm×4 mm×2 mm size were prepared from single root canal isolated teeth without caries, placed in the E. faecalis bacterial solution, centrifuged in gradient and incubated for 24 h to establish the model of dentinal tubule infection with E. faecalis. The twenty dentin blocks of were divided into five groups, low-temperature plasma jet treatment for 0, 5 and 10 min, calcium hydroxide paste sealing for 7 d and 2% chlorhexidine gel sealing for 7 d. Scanning electron microscopy and confocal laser scanning microscope were used to assess the infection in the dentinal tubules and the antibacterial effect of low-temperature plasma.@*RESULTS@#The results of scanning electron microscopy and confocal laser scanning microscopy showed that after 24 h of incubation by gradient centrifugation, E. faecalis could fully enter the dentinal tubules to a depth of more than 600μm indicating that this method was time-saving and efficient and could successfully construct a model of E. faecalis infection in dentinal tubules. Low-temperature plasma could enter the dentinal tubules and play a role, the structure of E. faecalis was still intact after 5 min of low-temperature plasma treatment, with no obvious damage, and after 10 min of low-temperature plasma treatment, the surface morphology of E. faecalis was crumpled and deformed, the cell wall was seriously collapsed, and the normal physiological morphology was damaged indicating that the majority of E. faecalis was killed in the dentinal tubules. The antibacterial effect of low-temperature plasma treatment for 10 min exceeded that of the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d. These two chemicals had difficulty entering deep into the dentinal tubules, and therefore only had a few of antibacterial effect on the bacterial biofilm on the root canal wall, and there was also no significant damage to the E. faecalis bacterial structure.@*CONCLUSION@#Gradient centrifugation could establish the model of E. faecalis dentin infection successfully. Low-temperature plasma treatment for 10 min could kill E. faecalis in dentinal tubules effectively, which is superior to the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d.

Comparação da propriedade antimicrobiana da clorexidina e do hipoclorito de sódio como irrigantes endodônticos: revisão integrativa / Comparison between the antimicrobial properties of chlorhexidine and sodium hypochlorite as endodontic irrigants: an integrative review / Comparación de la propiedad antimicrobiana de la clorhexidina y el hipoclorito de sodio como irrigantes endodónticos: revisión integradora

Introdução:Durante o tratamento endodôntico, devido às complexidades anatômicas dos canais radiculares, a ação mecânica dos instrumentos não é suficiente para a completa desinfecção dos condutos. Dessa forma, se faz necessário o uso de soluções irrigadoras que possampotencializar a desinfecção do sistema de canais radiculares. Objetivo:Realizar uma revisão integrativa da literatura para comparar as propriedades antimicrobianas da clorexidina com o hipoclorito de sódio.Metodologia:A busca na literatura foi realizada no período de setembro de 2019 a agosto de 2021, nas seguintes bases de dados: PUBMED/MEDLINE, LILACS e SCIELO. Utilizando os descritores: clorexidina, hipoclorito de sódio, irrigante do canal radicular e limpeza. Utilizou-se como critérios de busca, trabalhos experimentais laboratoriais in vitro, publicados entre os anos de 2017 e 2021.Resultados:Foram encontrados 165 artigos, dos quais 15 foram selecionados ao final do processo. 8 trabalhos não encontraram diferença estatisticamente significativa entre a clorexidina e o hipoclorito,5 artigos apresentaram resultados superiores dohipoclorito de sódioem 2 a clorexidina foi superior. Conclusões:Após análise da literatura, observamos semelhança entre a ação antimicrobiana do hipoclorito de sódioe da clorexidina, e podemos concluir que ambas apresentam boa ação antimicrobiana, justificando seu uso clinicamente (AU).

Introduction:During endodontic treatment, due to the anatomical complexities of the root canals, the mechanical action of the instruments is not sufficient for the complete disinfection of the canals. Thus, it is necessary to use irrigating solutions that can makethe disinfection of the root canal system.Objective:Conduct an integrative literature review to compare the antimicrobial properties of chlorhexidine with sodium hypochlorite.Methodology:The literature search was carried out from September 2019 to August 2021, in the following databases: PUBMED/MEDLINE, LILACS and SCIELO. Using the descriptors: chlorhexidine, sodium hypochlorite, root canal irrigant and cleaning. As search criteria, in vitro laboratory experimental works published between 2017 and 2021 were used.Results:A total of 165 articles were found, of which 15 were selected at the end of the process. 8 studies did not find a statistically significant difference between chlorhexidine and hypochlorite, 5 articles showed superior results for NaOCl and in 2 chlorhexidine was superior.Conclusions:After analyzing the literature, we observed a similarity between the antimicrobial action of sodium hypochlorite and chlorhexidine, and we can conclude that both have good antimicrobial action, justifying their clinical use (AU).

Introducción:Durante el tratamiento endodóntico, debido a las complexidades anatómicas de los conductos radiculares, la acción mecánica de los instrumentos no es suficiente para la desinfección completa de los conductos. Por lo tanto, es necesario utilizar soluciones de irrigación que puedan mejorar la desinfección del sistema de conductos radiculares.Objetivo: Realice una revisión integradora de la literatura para comparar las propiedades antimicrobianas de la clorhexidina con el hipoclorito de sodio.Metodología: La búsqueda bibliográfica se realizó desde septiembre de 2019 hasta agosto de 2021, en las siguientes bases de datos: PUBMED/MEDLINE, LILACS y SCIELO. Usando los descriptores: chlorhexidine, sodium hypochlorite, root canal irrigant and cleaning. Como criterio de búsqueda se utilizaron trabajos experimentales de laboratorio in vitro publicados entre 2017 y 2021.Resultados: Se encontraron un total de 165 artículos, de los cuales 15 fueron seleccionados al final del proceso. 8 estudios no encontraron diferencia estadísticamente significativa entre clorhexidinae hipoclorito, 5 artículos mostraron resultados superiores para NaOCl y en 2 la clorhexidina fue superior.Conclusiones: Después de analizar la literatura, observamos una similitud entre la acción antimicrobiana del hipoclorito de sodio y la clorhexidina,y podemos concluir que ambos tienen una buena acción antimicrobiana, lo que justifica su uso clínico (AU).

Alcohol (70%) versus alcoholic chlorhexidine solution (0. 5%) in skin antisepsis for neuraxial blocks: a randomized clinical trial / Álcool 70% versus solução alcoólica de clorexidina 0, 5% na antissepsia da pele para bloqueios do neuroeixo: ensaio clínico randomizado

ABSTRACT Objective: to compare the use of 0.5% alcoholic chlorhexidine and 70% alcohol in skin antisepsis for neuraxial blocks. Method: this is a non-inferiority randomized clinical trial, with two parallel arms. Seventy patients who were candidates for neuraxial block were randomly allocated to group A (n = 35), in whom antisepsis was performed with 0.5% alcoholic chlorhexidine, or to group B (n = 35), in whom we used 70% hydrated ethyl alcohol. Swabs were harvested for culture at three times: before antisepsis, two minutes after application of the antiseptic, and immediately after puncture. The samples were sown in three culture media and the number of colony forming units (CFU) per cm² was counted. Results: there was no difference between the groups regarding age, sex, body mass index, time to perform the block or type of block. There were no differences between groups in the CFU/cm² counts before antisepsis. There was less bacterial growth in group B two minutes after application of the antiseptic (p = 0.048), but there was no difference between the groups regarding the number of CFU/cm² at the end of the puncture. Conclusion: 70% alcohol was more effective in reducing the number of CFU/cm² after two minutes, and there was no difference between the two groups regarding skin colonization at the end of the procedure. These results suggest that 70% alcohol may be an option for skin antisepsis before neuraxial blocks. Trial registration: ClinicalTrials.gov, NCT02833376.

RESUMO Objetivo: comparar o uso de solução alcoólica de clorexidina 0,5% e de álcool 70% na antissepsia da pele para bloqueios do neuroeixo. Método: ensaio clínico randomizado de não inferioridade, com dois braços paralelos. Foram selecionados 70 pacientes candidatos à bloqueio do neuroeixo, randomicamente alocados para o grupo A (n=35), em que a antissepsia foi realizada com clorexidina alcoólica 0,5%, ou para o grupo B (n=35), em que se utilizou álcool etílico hidratado 70%. Foram coletadas, com swab, amostras para cultura em três momentos: antes da antissepsia, dois minutos após aplicação do antisséptico, e imediatamente após a punção. As amostras foram semeadas em três meios de cultura e foi contabilizado o número de unidades formadoras de colônias (UFC) por cm². Resultados: não houve diferença entre os grupos quanto à idade, ao sexo, ao índice de massa corporal, ao tempo para realização do bloqueio ou tipo de bloqueio. Também não houve diferenças entre os grupos na contagem de UFC/cm² antes da antissepsia. Constatou-se menor crescimento bacteriano no grupo B dois minutos após aplicação do antisséptico (p=0,048), mas não houve diferença entre os grupos quanto ao número de UFC/cm² ao final da punção. Conclusão: o álcool 70% mostrou-se mais efetivo em reduzir o número de UFC/cm² após dois minutos, e não houve diferença entre os dois grupos quanto à colonização da pele ao final do procedimento. Esses resultados sugerem que o álcool 70% pode ser opção para antissepsia da pele antes de bloqueios do neuroeixo. Registro ensaio clínico: ClinicalTrials.gov, NCT02833376.

Ação inibitória de dentifrícios sobre Streptococcus mutans e Candida albicans: estudo in vitro / Inhibitory effect of dentifrices on Streptococcus mutans and Candida albicans: in vitro study

Introdução: este estudo avaliou a ação antimicrobiana de sete dentifrícios nacionais com ação antiplaca ou antimicrobiana, conforme os fabricantes, sobre os patógenos orais Streptococcus mutans e Candida albicans. Métodos: a avaliação dos dentifrícios foi realizada pelo teste de difusão em ágar. Placas de Petri com meios de cultura ágar cérebro coração e ágar Sabourad foram semeadas com suspensão microbiana padronizada de S. mutans e C. albicans. Poços foram confeccionados no ágar semeado e preenchidos com as soluções dos dentifrícios diluídas em 1:1, 1:2, 1:4 e 1:8, além dos controles positivo (solução de clorexidina 2%) e negativo (dentifrício sem princípios ativos). Após incubação por 48h/37°C, os halos de inibição do crescimento microbiano foram medidos com paquímetro e régua milimetrada, e os resultados finais dos halos obtidos em milímetros. Resultados e conclusão: verificou-se que todos os dentifrícios, na diluição de 1:1, foram efetivos sobre C. albicans e S. mutans, exceto o composto de bicarbonato de sódio e extratos vegetais, o qual não inibiu S. mutans. Na diluição de 1:2, somente o dentifrício contendo triclosan inibiu C. albicans, enquanto todos mostraram algum potencial de inibição ao S. mutans. Nas demais diluições, não foram observados halos de inibição de ambos os microrganismos. A C. albicans demonstrou ser mais resistente à ação inibitória dos antimicrobianos dos dentifrícios testados neste estudo. S. mutans demonstrou ser mais sensível à ação dos dentifrícios, no entanto, a diluição durante a escovação dentária reduz a ação inibitória esperada, indicando a importância da remoção mecânica do biofilme.(AU)

Introduction: this study analyzed the antimicrobial activity in seven national dentifrices with antiplaque or antimicrobial substances in their composition, according the manufacturer, on the oral pathogens Streptococcus mutans and Candida albicans. Methods: the dentifrices antimicrobial effect evaluation was carried out by agar diffusion test. S. mutans and C. albicans. Padronized microbial suspension was cultured on Petri dishes containing Brain Hearth Agar and Sabourad Agar, respectively. Wells were prepared in the cultured agar and filled with 1:1, 1:2, 1:4 and 1:8 dilutions of dentifrice solutions, and besides positive (2% chlorhexidine solutions) and negative controls (dentifrices without active ingredients). After 48h/37°C incubation, the microbial growing inhibition zones were measured with a paquimeter and a millimeter rule, being the final zone results obtained in millimeters. Results and conclusion: on 1:1 dilution, all dentifrices were effective on C. albicans and S. mutans, except one with vegetal extract and sodium bicarbonate composition, which did not inhibit S. mutans. In 1:2 dilution, only tricolsan-containing dentifrice inhibited C. albicans, while all dentifrices presented some inhibition potential on S. mutans. There were no inhibition zones for both microorganims in other dilutions. We concluded that C. albicans showed to be more resistant to antimicrobial agents tested in the dentifrices, in this study. S. mutans showed to be more sensitive to tested dentifrices, however, the product dilution during toothbrushing reduces the expected inhibitory action, strengthening the importance of the mechanical removal of dental biofilm.(AU)

Decontamination of Gutta-percha Cones employed in Endodontics / Descontaminação de cones de guta-percha empregados em endodontia

ABSTRACT The guttapercha cones used in endodontic treatment are produced in aseptic conditions and their composition includes zinc oxide, which is responsible for antibacterial activity. However, there is the possibility of microbial contamination by manipulation, aerosol or during storage. Although several chemical agents have been tested for their decontamination, there is no consensus on the best disinfection protocol to be used. The aim of this study was to evaluate the decontamination of guttapercha cones contaminated with the bacteria Enterococcus faecalis, by using chlorhexidine digluconate (CHX) and sodium hypochlorite (NaClO) at different concentrations for short exposure times. For this purpose, guttapercha cones (size 40) were selected at random from a sealed box and immersed for 1 min in a microbial suspension. Then they were immersed in specific Petri dishes for different groups containing: CHX 2%, NaClO 1% or NaClO 2.5% for 30 s or 1 min, and subsequently placed in tubes containing BHI broth. After incubating the tubes for 48 h, it was observed that 1% and 2.5% NaClO and 2% CHX were effective for decontaminating the cones at those exposure time intervals. Microbial growth was detected in one of the replicates of the group with CHX applied for 30 s. To prevent the possibility of failures at this stage, the exposure time of guttapercha cones to the decontaminating agent should not be reduced.

RESUMO Os cones de gutapercha utilizados no tratamento endodôntico são produzidos em condições assépticas e possuem óxido de zinco em sua composição, responsável pela atividade antibac te riana. No entanto, existe a possibilidade de contaminação microbiana por manipulação, aerossol ou seu armazenamento. Embora vários agentes químicos já tenham sido testados para sua descontaminação, não há consenso sobre o melhor proto colo de desinfecção a ser usado. Nosso objetivo foi avaliar a descontaminação de cones de gutapercha contaminados com a bactéria Enterococcus faecalis, utilizando digluconato de clorexidina (CHX) e hipoclorito de sódio (NaClO) em diferentes concentrações e tempos de exposição curtos. Para esse fim, 40 cones de gutapercha foram selecionados aleatoriamente, de uma caixa selada e imersos por 1 min em uma suspensão microbiana. Em seguida, foram imersos em placas de Petri específicas para diferentes grupos contendo: CHX 2%, NaClO 1% ou 2,5%, nos tempos de exposição de 30s e 1min e subseqüentemente imersos em tubos contendo caldo BHI. Após incubação dos tubos por 48 h, observouse que NaClO 1% e 2,5% e CHX 2% foram eficazes para a descontaminação dos cones nesses intervalos de tempo de exposição. Em uma das réplicas do grupo com CHX aplicado por 30s foi detectado crescimento microbiano. O tempo de exposição dos cones de gutapercha ao agente de desconta minação não deve ser reduzido para evitar a possibilidade de falhas nesse estágio.

Efeito do extrato da própolis e do digluconato de clorexidina sobre a formação de biofilme por Candida albicans em resina acrílica / Effect of propolis extract and chlorhexidine digluconate on the biofilm formation by Candida albicans in acrylic resin

Objetivo: avaliar in vitro a ação antimicrobiana do extrato da própolis (EP) e do digluconato de clorexidina (DCHX) na formação de biofilme por Candida albicans em resina acrílica termopolimerizada. Métodos: o efeito do EP e DCHX em biofilmes de C. albicans foi avaliado pela quantificação de Unidades Formadoras de Colônias (UFCs), pela quantificação da biomassa por cristal violeta e de polissacarídeos por safranina. Para tanto, C. albicans foram pré-aderidas em corpos de prova e somente em microplacas de poliestireno, posteriormente foi realizado o tratamento com diferentes concentrações de EP (221 µg/mL e 443 µg/mL) e DCHX (0,25% e 0,5%). Resultados: foi demonstrada uma redução significativa na formação de biofilme por C. albicans com ambas as substâncias testadas e em todas as concentrações. Conclusão: de acordo com os resultados, observou-se que ambos os tratamentos foram eficazes na redução do biofilme e que o EP, por ser um produto natural, de baixo custo e sem afeitos colaterais, representa uma alternativa inovadora para o tratamento da candidose oral em usuários de próteses removíveis.(AU)

Objective: to evaluate in vitro the antimicrobial action of propolis extract (EP) and chlorhexidine digluconate (DCHX) in the biofilm formation by Candida albicans in thermopolymerized acrylic resin. Methods: the effect of EP and DCHX on C. albicans biofilms were evaluated through the quantification of Colony Forming Units (CFU's), the quantification of biomass by violet crystal and polysaccharides by safranin. For this purpose, C. albicans were pre-adhered to specimens and only on polystyrene microplates and subsequently the treatment was performed with different concentrations of EP (221 µg/mL and 443 µg/mL) and DCHX (0.25% and 0,5%). Results: a significant reduction in the biofilm formation by C. albicans was demonstrated, with both substances tested and in all concentrations. Conclusion: according to the results, it was observed that both treatments were effective in reducing biofilm and EP, being a natural product, low cost and without side effects, represents an innovative alternative for the treatment of oral candidiasis in users removable dentures.(AU)

Antimicrobial activity of intracanal dressings composed by natural products associated to chlorhexidine and its influence on dentinal colour change / Avaliação da ação antimicrobiana de medicações intracanais à base de produtos fitoterápicos associados à clorexidina e sua influência na alteração de cor da estrutura dentinária

Purpose: evaluate the antimicrobial activity of intracanal dressings and their influence on dentinal colour changes. Material and methods: eighty single-rooted human extracted teeth were decoronated and divided into eight groups (n=10) according to intracanal dressing protocols inserted into the root canals: G1­distilled water (DW); G2­2% chlorhexidine gel (CHX); G3­calcium hydroxide (Ca[OH]2)+DW; G4­grape seed extract (GSE)+DW; G5­ginger extract (GE)+DW; G6­Ca(OH)2+CHX; G7­GSE+CHX; and G8­GE+CHX. The antimicrobial activity was evaluated by colony-forming units (CFUs) counting and dentinal colour changes was evaluated by digital spectrophotometry. Data were statistically analysed by One-way ANOVA followed by Tukey´s post hoc test (antimicrobial evaluation) and non-parametric Wilcoxon followed by the Mann- Whitney-U test (colour change evaluation) (α=0.05). Results: the highest bacterial reduction was observed in groups 4, 6, 7 and 8, with no significant difference between them (p<0.05). Groups 4 and 7 showed the highest medians of dentinal colour change (p<0.05). Conclusion: the addition of CHX improved the antimicrobial activity of GE-based intracanal dressing, with no effect in GSE-based intracanal dressing; moreover, these protocols induced significant dentinal colour changes. (AU)

Objetivo: avaliar a atividade antimicrobiana de medicações intracanais e sua influência na alteração da cor dentinária. Materiais e métodos: oitenta dentes humanos extraídos unirradiculares foram seccionados e divididos em oito grupos (n = 10), de acordo com os protocolos de medicação intracanal inseridos nos canais radiculares: água destilada G1 (DW); G2-2% de gel de clorexidina (CHX); hidróxido de cálcio G3 ­ (Ca [OH] 2) + DW; extrato de semente de uva G4 (GSE) + DW; extrato de gengibre G5 (GE) + DW; G6- Ca (OH) 2 + CHX; G7 ­ GSE + CHX; e G8-GE + CHX. A atividade antimicrobiana foi avaliada por contagem de unidades formadoras de colônias (UFCs) e as alterações de cor dentinária foram avaliadas por espectrofotometria digital. Os dados foram analisados estatisticamente por ANOVA one-way, seguida pelo teste post hoc de Tukey (avaliação antimicrobiana) e Wilcoxon não paramétrico, seguido pelo teste de Mann- Whitney-U (avaliação da mudança de cor) (α = 0,05). Resultados: a maior redução bacteriana foi observada nos grupos 4, 6, 7 e 8, sem diferença significativa entre eles (p < 0,05). Os grupos 4 e 7 apresentaram as maiores medianas da alteração da cor dentinária (p < 0,05). Conclusão: a adição de CHX melhorou a atividade antimicrobiana da medicação intracanal baseado em GE, sem efeito na medicação intracanal baseado em GSE; além disso, esses protocolos induziram alterações significativas na cor dentinária.(AU)

Essential Oil from Psidium cattleianum Sabine (Myrtaceae) Fresh Leaves: Chemical Characterization and in vitro Antibacterial Activity Against Endodontic Pathogens

Abstract Endodontic infections result from oral pathogenic bacteria which reach and infect dental pulp, as well as surrounding tissues, through cracks, unrepaired caries and failed caries restorations. This study aims to determine the chemical composition of essential oil from Psidium cattleianum leaves (PC-EO) and to assess its antibacterial activity against endodontic bacteria. Antibacterial activity of PC-EO was evaluated in terms of its minimum inhibitory concentration (MIC) values by the broth microdilution method on 96-well microplates. Bacteria Porphyromonas gingivalis (MIC = 20 µg/mL), Prevotella nigrescens (MIC = 62.5 µg/mL), Fusobacterium nucleatum (MIC = 12.5 µg/mL), Actinomyces naeslundii (MIC = 50 µg/mL), Bacteroides fragilis (MIC = 12.5 µg/mL), Aggregatibacter actinomycetemcomitans (MIC = 6.25 µg/mL) and Peptostreptococcus anaerobius (MIC = 62.5 µg/mL) were evaluated and compared to chlorhexidine dihydrochloride (CDH), the positive control. PC-EO was obtained by hydrodistillation with the use of a Clevenger-type apparatus whereas its chemical composition was analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Viridiflorol (17.9%), β-caryophyllene (11.8%), 1,8-cineole (10.8%) and β-selinene (8.6%) were the major constituents found in PC-EO, which exhibited high antibacterial activity against all endodontic pathogens under investigation. Therefore, PC-EO, a promising source of bioactive compounds, may provide therapeutic solutions for the field of endodontics.

Safety alert for hospital environments and health professional: chlorhexidine is ineffective for coronavirus

SUMMARY An alarming fact was revealed by recent publications concerning disinfectants: chlorhexidine digluconate is ineffective for disinfecting surfaces contaminated by the new coronavirus. This is a finding that requires immediate disclosure since this substance is widely used for the disinfection of hands and forearms of surgeons and auxiliaries and in the antisepsis of patients in minimally invasive procedures commonly performed in hospital environments. The objective of this study is to compare the different disinfectants used for disinfection on several surfaces, in a review of worldwide works. Scientific studies were researched in the BVS (Virtual Health Library), PubMed, Medline, and ANVISA (National Health Surveillance Agency) databases. The following agents were studied: alcohol 62-71%, hydrogen peroxide 0.5%, sodium hypochlorite 0.1%, benzalkonium chloride 0.05-0.2%, povidone-iodine 10%, and chlorhexidine digluconate 0.02%, on metal, aluminum, wood, paper, glass, plastic, PVC, silicone, latex (gloves), disposable gowns, ceramic, and Teflon surfaces. Studies have shown that chlorhexidine digluconate is ineffective for inactivating some coronavirus subtypes, suggesting that it is also ineffective to the new coronavirus.

RESUMO Um dado alarmante revelado por publicações a respeito dos agentes desinfetantes: o digluconato de clorexidina é ineficaz para desinfecção de superfícies contaminadas por coronavírus. Trata-se de uma constatação que reclama imediata divulgação, uma vez que essa substância é amplamente usada para degermação de mãos e antebraços dos cirurgiões e auxiliares e na antissepsia dos pacientes, em procedimentos minimamente invasivos, comumente em ambientes hospitalares. O objetivo deste trabalho foi comparar os diferentes desinfetantes usados para desinfecção em diversas superfícies em revisão de trabalhos mundiais. Foram pesquisados trabalhos científicos na BVS (Biblioteca Virtual de Saúde), PubMed, Medline e Anvisa (Agência Nacional de Vigilância Sanitária). Foram estudados os seguintes agentes: álcool 62-71%, peróxido de hidrogênio 0,5%, hipoclorito de sódio 0,1%, cloreto de benzancônio 0,05-0,2%, iodo povidina 10% e digluconato de clorexidina 0,02%, em superfícies de metal, alumínio, madeira, papel, vidro, plástico, PVC, silicone, látex (luvas), avental descartável, cerâmica e teflon. Os estudos demonstraram que o digluconato de clorexidina é ineficaz para a inativação de alguns subtipos de coronavírus, sugerindo que também seja ineficaz contra o novo coronavírus.

Evaluation of the physical and antifungal effects of chlorhexidine diacetate incorporated into polymethyl methacrylate

Abstract This study aimed to evaluate the physical properties and antifungal activities of polymethyl methacrylate (PMMA) acrylic resins after the incorporation of chlorhexidine diacetate salt (CDA). Methodology: First, acrylic resin specimens were fabricated with Vipi Cor® and DuraLay® resins with and without the incorporation of 0.5%, 1.0% or 2.0% CDA. The residual monomer and CDA release were measured at intervals ranging from 2 hours to 28 days using ultraviolet spectrometry combined with high-performance liquid chromatography. The antifungal activity against C. albicans was evaluated with the agar diffusion method. Fourier transform infrared spectroscopy was used to analyze the degree of resin conversion. Finally, the water sorption values of the resins were also measured. Results: The incorporated CDA concentration significantly changed the rate of CDA release (p<0.0001); however, the brand of the material appeared to have no significant influence on drug release. Subsequently, the inhibition zones were compared between the tested groups and within the same brand, and only the comparisons between the CDA 2% and CDA 1% groups and between the CDA 1% and CDA 0.5% groups failed to yield significant differences. Regarding the degrees of conversion, the differences were not significant and were lower only in the CDA 2% groups. Water sorption was significantly increased at the 1.0% and 2.0% concentrations. Conclusions: We concluded that the incorporation of CDA into PMMA-based resins enabled the inhibition of C. albicans growth rate, did not alter the degrees of conversion of the tested resins and did not change the release of residual monomers.

In vitro evaluation of Eugenia dysenterica in primary culture of human gingival fibroblast cells

Abstract: Eugenia dysenterica is a Brazilian tree investigated for its properties and bioactive compounds, which are believed to have both pharmacological and phytochemical therapeutic effects. The leaves of this tree contain tannins, flavonoids, terpenes, and saponins, with reportedly beneficial effects to the human body. Despite these therapeutic applications, its effects have never been tested on oral tissues. Therefore, the aim of the present study was to evaluate the cytotoxic and antioxidant effects and the anti-inflammatory and repair properties of the acetone fraction of E. dysenterica on primary culture of human gingival fibroblasts and on the immortalized murine macrophage cell line (RAW 264.7). For this purpose, a metabolic activity assay, a wound healing assay, a nitric oxide assay, and RT-qPCR were performed. The assays revealed a cytoprotective effect of this plant, suggested by the increase in the expression of SOD1 and NRF2. An antioxidant potential effect was observed in the DPPH• assay. However, the fraction of E. dysenterica did not show anti-inflammatory activity. In conclusion, Eugenia dysenterica may promote cytoprotection when associated with chlorhexidine digluconate because of its antioxidant effect. However, additional studies are necessary on other human dental tissues using other parts of the plant in order to develop a possible mouthwash to assist patients with oral disorders.

Os efeitos das Metaloproteinases da matriz extracelular - MMPS e clorexidina no mecanismo de adesão dentária / The effects of metaloproteinases of the extracellular matrix - MMPs and chlorexidine in the dental adhesion mechanism

Introdução: A adesão da resina composta à dentina ocorre pela formação da camada híbrida. Assim, sua degradação ocasiona a perda da resistência de união na interface resina/dentina, influenciando na longevidade da restauração. Após o condicionamento ácido e aplicação do sistema adesivo na dentina desmineralizada, fibras colágenas não envolvidas por sistema adesivo ficam desprotegidas e suscetíveis ao ataque das metaloproteinases (MMPs). Objetivos: Esta revisão buscou esclarecer o efeito das MMPs na degradação da camada híbrida e os efeitos da clorexidina no processo de adesão. Materiais e métodos: Foi realizada uma revisão da literatura por meio de uma busca bibliográfica nas bases de dados Pubmed/ Medline, Scielo e Google Acadêmico, utilizados estudos publicados nos anos de 2005 a 2018. Foi realizada a busca pelos seguintes descritores: Dentistry, MMPs, Chlorhexidine. Resultados: Estas enzimas, presentes na própria dentina, são reativadas pelo ácido fosfórico ou pelos monômeros ácidos dos adesivos autocondicionantes e iniciam a degradação. A aplicação da clorexidina (CHX) na dentina, após o condicionamento ácido, impede ou retarda a degradação das fibras de colágeno da camada híbrida. Conclusão: Concluiu-se que a ligação adesiva à dentina diminui com o passar dos anos devido à ação das MMPs que degradam o colágeno não infiltrado por monômeros adesivos na parte mais profunda da camada híbrida. Além disso, a clorexidina como inibidor terapêutico em sistemas adesivos convencionais é capaz de inibir as MMPs e assim a ligação adesiva à dentina pode ser mantida estável por um período de tempo mais longo.

Introduction: The adhesion of the composite resin to the dentin occurs by the formation of the hybrid layer. Thus, its degradation causes loss of union resistance on interface resin / dentin interface, directly influencing the longevity of the restoration. After the acid etching and the application of the adhesive system into demineralized dentin, collagen fibers not involved by adhesive system get unprotected and susceptibles to attack by metalloproteinases (MMPs). The enzymes, present in the dentin itself, are rehabilitated by phosphoric acid or by the acids monomers of the self-etching adhesives initiating degradation. The application of chlorhexidine (CHX) in the dentin, after acid conditioning, prevents or slows down the degradation of the collagen fibers of the hybrid layer. This literature review sought to clarify the effect of MMPs on the degradation of the hybrid layer and the effects of chlorhexidine on the adhesion process. It was concluded that the adhesive bonding to dentin decreases with the passage of years due in part to the action of MMPs, which degrade collagen not infiltrated by adhesive monomers in the deepest part of the hybrid layer. In addition, the use of chlorhexidine as a therapeutic inhibitor in conventional adhesive systems is capable of inhibiting the MMPs and thus the adhesive bonding to the dentin can be kept stable for a longer period of time.

Eficácia de um dentifrício sem flúor no controle de Streptococcus mutans in vitro / Effectiveness of a non-fluoridated dentifrice in control of Streptococcus mutans in vitro

Objetivo: avaliar a eficácia de um dentifrício, que contém em sua composição extratos vegetais e xilitol para inibição de Streptococcus mutans (UA159). Materiais e método: para verificação da atividade antimicrobiana, foram realizados ensaios in vitro de difusão de ágar, baseados na metodologia da norma M2A8 Anvisa. O estudo foi feito utilizando inóculo de 108 UFC/mL da cepa de S. mutans. O princípio básico foi a difusão de uma solução de dentifrício na superfície do ágar a partir de um disco impregnado. O ensaio foi realizado utilizando como controle negativo água deionizada estéril e como controle positivo clorexidina 0,12%, e foram comparados aos dentifrícios Orgânico Natural® e Colgate Total 12®. O resultado foi analisado a partir da medição dos halos de inibição (mm). Resultados: a clorexidina 0,12% teve maior halo de inibição (21,08 ± 1,02), seguida do dentifrício Orgânico Natural® (11,33 ± 4,35) e do dentifrício Colgate Total 12 (3,93 ± 4,67) P<0,05. Conclusão: a inibição da cepa de S. mutans evidenciada neste ensaio in vitro demonstra o potencial antimicrobiano do dentifrício Orgânico Natural®, mesmo como um possível auxiliar no controle do biofilme dental cariogênico. (AU)

Objective: the goal was to evaluate the effectiveness of a dentifrice that has a chemical composition of plant extracts and xylitol to inhibit the Streptococcus mutans (UA159). Materials and methods: based on the methodology of the M2A8 Anvisa standard, in vitro agar diffusion assays were performed to verify antimicrobial activity. The study was carried out using inoculum of 108 CFU / mL of S. mutans strain. The principle was the diffusion of a dentifrice solution on the agar surface, from a disc impregnated therewith. The assay was performed using as a negative control the sterile deionized water, 0.12% chlorhexidine as a positive control compared to Orgânico Natural® and Colgate Total 12® toothpastes. The result was analyzed from the inhibition halos measurement (mm). Results: the chlorhexidine 0.12% had the biggest inhibition halo (21,08 ± 1,02) followed by the Orgânico Natural® dentifrice (11,33 ± 4,35) and the Colgate Total 12® dentifrice (3,93 ± 4,67) P<0,05. Conclusion: the inhibition of the S. mutans strain realized in these in vitro assay by the Orgânico Natural® dentifrice demonstrate the antimicrobial potential of the same as a possible aid in the control of the cariogenic dental biofilm. (AU)

In vitro antimicrobial effect of bioadhesive oral membrane with chlorhexidine gel

Abstract This study aimed to evaluate in vitro the antimicrobial effect of a bioadhesive chitosan-based oral membrane with chlorhexidine for local treatment of infections in the oral tissues. Five oral membranes of different compositions were tested: 5% chitosan (G1); 5% chitosan ± 0.2% chlorhexidine (G2), 5% chitosan ± 0.6% chlorhexidine (G3), 5% chitosan ± 1.0% chlorhexidine (G4), and 5% chitosan ± 2.0% chlorhexidine (G5). Also, five gel types were tested according to the following compositions: 5% chitosan gel (G6), 0.2% chlorhexidine gel (G7), 2.0% chlorhexidine gel (G8), 5% chitosan gel ± 0.2% chlorhexidine gel (G9), and 5% chitosan gel ± 2.0% chlorhexidine gel (G10). The antimicrobial action of the samples was tested against Candida albicans and Streptococcus mutans through antibiogram by measuring the inhibition halos. Data were statistically analyzed by Kruskal-Wallis and one-way ANOVA followed by Tukey test (p<0.05). The 2.0% chlorhexidine membrane (G5) and the disks containing 2.0% chlorhexidine gel (G8) showed the greatest inhibition halos for both microorganisms, with statistically significant difference when compared to others tested groups (p=0.008) only for Candida albicans inhibitions results. All the other formulations of membranes and gels showed inhibition halos, but without statistically significant difference. The bioadhesive chitosan-based oral membrane with 2% chlorhexidine and 2% chlorhexidine gel were the most effective in inhibiting the tested microorganisms.

Resumo O objetivo deste estudo foi avaliar in vitro o efeito antimicrobiano de uma bandagem oral bioadesiva de quitosana com clorexidina para o tratamento de infecções dos tecidos orais. Cinco bandagens de diferentes composições foram testadas: Quitosana 5% (G1); Quitosana 5% ± clorexidina a 0,2% (G2), Quitosana 5% ± clorexidina a 0,6% (G3), Quitosana 5% ± clorexidina a 1,0% (G4) e Quitosana 5% ± clorexidina a 2,0% (G5). Foram testados também 5 tipos de géis nas seguintes composições: Gel de Quitosana 5% (G6), Gel de clorexidina a 0,2% (G7), Gel de clorexidina a 2,0% (G8), Gel de Quitosana 5% ± clorexidina a 0,2% (G9) e Gel de Quitosana 5% ± clorexidina a 2,0% (G10). A ação antimicrobiana das amostras foi testada contra Candida albicans e Streptococcus mutans por meio do antibiograma, medindo o halo de inibição. Os dados foram analisados pelo teste de Kruskal-Wallis e ANOVA a um critério seguido pelo teste de Tukey (p<0,05). A membrana com 2,0% de clorexidina (G5) e os discos contendo gel com 2,0% de clorexidina (G8) apresentaram os maiores halos de inibição para os dois microrganismos, com diferença estatisticamente significativa em relação aos demais grupos testados (p=0,008) apenas nos resultados de inibição de C. albicans. Todas as outras formulações de membranas e géis apresentaram halo de inibição, mas sem diferença estatisticamente significativa. A bandagem oral bioadesiva de quitosana com gel de 2% de clorexidina foi a mais efetiva em inibir os microrganismos testados.

Removal and killing of multispecies endodontic biofilms by N-acetylcysteine

ABSTRACT Removal of bacterial biofilm from the root canal system is essential for the management of endodontic disease. Here we evaluated the antibacterial effect of N-acetylcysteine (NAC), a potent antioxidant and mucolytic agent, against mature multispecies endodontic biofilms consisting of Actinomyces naeslundii, Lactobacillus salivarius, Streptococcus mutans and Enterococcus faecalis on sterile human dentin blocks. The biofilms were exposed to NAC (25, 50 and 100 mg/mL), saturated calcium hydroxide or 2% chlorhexidine solution for 7 days, then examined by scanning electron microscopy. The biofilm viability was measured by viable cell counts and ATP-bioluminescence assay. NAC showed greater efficacy in biofilm cell removal and killing than the other root canal medicaments. Furthermore, 100 mg/mL NAC disrupted the mature multispecies endodontic biofilms completely. These results demonstrate the potential use of NAC in root canal treatment.

Eficácia do diacetato de clorexidina incorporado a um reembasador macio no tratamento da estomatite protética: um ensaio clínico randomizado / Efficacy of chlorhexidine diacetate incorporated into a soft liner rebase in the treatment of denture stomatitis: a randomized clinical trial

O objetivo deste estudo piloto foi comparar a eficácia de um reembasador acrílico macio com ou sem diacetato de clorexidina a 1% no tratamento de pacientes com estomatite protética. As hipóteses testadas foram: (I) o eritema seria melhorado (IIa): a contagem de unidades formadoras de colônias seria reduzida, (IIb): a predominância de um tipo morfológico de Candida seria correlacionada com características clínicas e, (IIc) se uma concentração inibitória mínima do antimicrobiano, poderia ser capaz de atuar sobre o crescimento do fungo. Dezesseis pacientes desdentados totais, portadores de prótese e com estomatite protética foram distribuídos aleatoriamente para os grupos controle (reembasamento com Trusoft) e grupo teste (reembasamento com Trusoft contendo 1% de clorexidina) sendo acompanhados por exames clínicos e laboratoriais por 14 dias. Os parâmetros analisados nas duas consultas de acompanhamento foram: avaliação clínica (exame e fotos) e avaliações microbiológicas (esfregaços e culturas de palato e prótese total). Este estudo foi um ensaio clínico randomizado, duplo-cego,controlado.Os resultados obtidos demonstraram que a superfície do eritema foi significativamente reduzida, mas não diferiu significativamente entre os dois grupos (P> 0,05), assim como a redução da contagem de Candida durante o tratamento entre os grupos (P> 0,05). O tipo de Candida não pôde ser correlacionado ao estágio clínico alcançado. Os resultados dos testes de concentração inibitória mínima, revelaram que uma concentração de 0,05 µg/ml de clorexidina já é capaz de inibir o crescimento de 85% das cepas de testadas.A hipótese principal foi confirmada, o que pode ser interpretado como uma remissão clínica acelerada em ambas as terapias propostas. Embora as hipóteses secundárias não tenham sido confirmadas, a persistência de Candida pode ser apenas a colonização, e a plasticidade morfológica de Candida parece ser fortemente influenciada pela virulência fúngica. Sendo assim, os resultados da análise de concentração inibitória mínima sugerem que uma concentração subinibitória de clorexidina possa estar atuando na virulência da Candida spp. No entanto, não foram encontrados resultados para confirmar a eficácia clínica do diacetato de clorexidina a 1% incorporado ao reembasador macio testado no tratamento da estomatite protética.

The aim of this pilot study was to compare the efficacy of rebase using soft acrylic liner with or without 1% chlorhexidine diacetate in denture stomatitis patients. It was hypothesised that: (I) erythema would be improved (IIa): colony forming unit count would be reduced, (IIb): the predominance of a morphological type of Candida would be correlated with clinical features and, (IIc) a minimum inhibitory concentration of the antimicrobial, could be able to act on the growth of the fungus.Sixteen patients who wearing removable dentures and diagnosed with denture stomatitis were randomly assigned to the control groups (rebase with resilient liner) and test group (rebase with resilient liner containing 1% of chlorhexidine), followed by clinical and laboratory tests for 14 days. The analyzed parameters at two follow-up were: clinical evaluation (examination and photos) and microbiological evaluations (smears and cultures of palates and dentures). This study was a randomized, double-blind, controlled clinical trial. The results obtained showed that the erythema surface was significantly reduced, but did not differ significantly between the two groups (P> 0.05), as did the reduction of colony forming unit during treatment between the groups (P> 0.05) . The Candida type could not be correlated to the achieved clinical stage. The minimum inhibitory concentration test results showed that a concentration of 0,05 µg/ml chlorhexidine is already able to inhibit the growth of 85% of the tested strains. The primary hypothesis was confirmed, which can be interpreted as an accelerated clinical remission in both proposed therapies. Although secondary hypotheses have not been confirmed, Candida's persistence may be just colonization, and the morphological plasticity of Candida seems to be strongly influenced by fungal virulence. Thus, the results of the minimum inhibitory concentration analysis suggest that a subinhibitory concentration of chlorhexidine may be acting on the virulence of Candida spp. However, no results were found to confirm the clinical efficacy of 1% chlorhexidine diacetate incorporated into the soft liner in denture stomatitis.

Chlorhexidine and proanthocyanidin enhance the long-term bond strength of resin-based endodontic sealer

Abstract The aim of this study was to evaluate the effects of proanthocyanidin (PA) and chlorhexidine (CHX) on the bond strength (BS), failure pattern, and resin-dentin interface morphology of the endodontic sealers EndoREZ and AH Plus after 24 h and 6 months of water storage. A total of 120 prepared bovine roots were divided into six groups: AH Plus, CHX+AH Plus, PA+AH Plus, EndoREZ, CHX+EndoREZ, and PA+EndoREZ. Dentin was treated for 1 or 5 min with 2% CHX or 15% PA, respectively. Roots were filled and stored in water for 24 h or 6 months (n = 10). Root slices were subjected to push-out test and scanning electron microscopy (SEM). Data were compared using two-way ANOVA and student's t-test (α = 5%). BS decreased over time for AH Plus and untreated EndoREZ (p < 0.05). At 24 h, AH Plus had higher BS than EndoREZ (p < 0.001), with no differences among treatments for both sealers (p > 0.05). At 6 months, EndoREZ had higher BS values for CHX and PA than control (p < 0.05). AH Plus had higher BS than EndoREZ (p < 0.001), while with CHX or PA, similar BS was observed in both sealers (p > 0.05). Cohesive and mixed failures were observed in all groups. SEM revealed sealer tags in the root dentin. In conclusion, BS decreased with time and AH Plus had higher BS than EndoREZ in untreated dentin; however, CHX or PA enhanced long-term BS of EndoREZ. Overall, dentin treatment affected failure pattern and resin-dentin interface morphology, particularly for EndoREZ.

Analysis of the antimicrobial and anti-caries effects of TiF4 varnish under microcosm biofilm formed on enamel

Abstract Titanium tetrafluoride (TiF4) is known for interacting with enamel reducing demineralization. However, no information is available about its potential antimicrobial effect. Objectives This study evaluated the antimicrobial and anti-caries potential of TiF4 varnish compared to NaF varnish, chlorhexidine gel (positive control), placebo varnish and untreated (negative controls) using a dental microcosm biofilm model. Material and Methods A microcosm biofilm was produced on bovine enamel previously treated with the varnishes, using inoculum from human saliva mixed with McBain saliva, under 0.2% sucrose exposure, for 14 days. All experiments were performed in biological triplicate (n=4/group in each experiment). Factors evaluated were: bacterial viability (% dead and live bacteria); CFU counting (log10 CFU/mL); and enamel demineralization (transverse microradiography - TMR). Data were analysed using ANOVA/Tukey's test or Kruskal-Wallis/Dunn's test (p<0.05). Results Only chlorhexidine significantly increased the number of dead bacteria (68.8±13.1% dead bacteria) compared to untreated control (48.9±16.1% dead bacteria). No treatment reduced the CFU counting (total microorganism and total streptococci) compared to the negative controls. Only TiF4 was able to reduce enamel demineralization (ΔZ 1110.7±803.2 vol% μm) compared to both negative controls (untreated: ΔZ 4455.3±1176.4 vol% μm). Conclusions TiF4 varnish has no relevant antimicrobial effect. Nevertheless, TiF4 varnish was effective in reducing enamel demineralization under this model.

Avaliação da atividade antimicrobiana, análise elementar e da lixiviação da resina acrílica autopolimerizável modificada pela incorporação de clorexidina / Evaluation of the antimicrobial, elemental analysis and release of the self-cured acrylic resin modified by the incorporation of chlorhexidine

O objetivo principal do presente estudo, considerando a importância do controle do biofilme, foi avaliar in situ a ação antimicrobiana e análise elementar da incorporação de diacetato de clorexidina(CHX) em resinas acrílicas a base de PMMA. Além disso, avaliar ex vivo o mecanismo de lixiviação da clorexidina por até 14 dias. Primeiramente, foram recrutados 32 indivíduos para utilização de dispositivos acrílicos intraorais palatinos por 24 horas contendo 6 corpos de prova(CPs), sendo subdivididos em 2 grupos: com clorexidina (1%) e sem CHX. A avaliação da atividade antimicrobiana foi realizada por meio de contagem de colônias de microorganismos totais e Estreptococos do grupo mutans. Então, os grupos foram avaliados estatisticamente pelo teste de wilcoxon. A análise estatística aplicada foi o teste de Wilcoxon. No segundo teste, foi feita a análise elementar dos CPs(n=10) por meio das médias das intensidade dos elementos, antes e após o uso do dispositivo, por meio da fluorescência de raio X. Ao final, foi avaliado ex vivo a liberação de clorexidina cumulativa, em meio fechado contendo saliva dos indivíduos(n=5) por até 14 dias, através da ressonância magnética nuclear (RMN). As análises estatísticas da RMN, foram avaliadas pelo programa AMIX e metaboloanalyst. Os resultados mostraram, que para atividade antimicrobiana não houve diferença estatística (p>0,05) entre os grupos. Foi detectado a presença da molécula de clorexidina, antes e após a inserção dos CPs com CHX na cavidade bucal. Já para liberação de clorexidina, foi detectada a droga ao longo de 14 dias em meio fechado para a grupo teste, com liberação maior nas primeiras 24 horas. Conclui-se que, foi comprovada a presença do fármaco na resina acrílica após 24 horas em meio bucal, e seu mecanismo de lixiviação no meio fechado por até 14 dias. Porém, não foram encontrados resultados que confirmem a presença de um potencial antimicrobiano do fármaco, nas concentrações utilizadas nos corpos de prova in situ em 24 horas.

The main objective of the present study, considering the importance of biofilm control, was to evaluate in situ the antimicrobial action and elemental composition of the incorporation of chlorhexidine diacetate (CHX) in acrylic resins based on PMMA. In addition, ex vivo evaluation of the chlorhexidine release mechanism to 14 days. Firstly, 32 individuals were recruited for 24-hour palatal intraoral acrylic devices containing 6 test specimens (SPs), divided into 2 groups: with chlorhexidine (1%) and without CHX. The evaluation of the antimicrobial activity was performed by colonies count of total microorganisms and streptococci mutans group. Then, the groups were statistically evaluated by the wilcoxon test. The statistical analysis applied was the Wilcoxon test. In the second test, elemental analysis of the SPs (n = 10) was done by means of the means intensity of the elements, before and after the use of the device, by X-ray fluorescence. At the end, the release was evaluated ex vivo of cumulative chlorhexidine in a becker containing saliva of the individuals (n = 5) for 14 days, through nuclear magnetic resonance (NMR). The NMR analyzes were evaluated by AMIX and metaboloanalyst. The results showed that for antimicrobial activity there was no statistical difference (p> 0.05) between the groups. The presence of the chlorhexidine molecule was detected before and after the insertion of SPs with CHX in the oral cavity. As for chlorhexidine release, the drug was detected over 14 days in a closed medium for the test group, with a greater release in the first 24 hours. It was concluded that the presence of the drug in the acrylic resin after 24 hours in oral cavity was verified, and its release mechanism in the closed local for 14 days. However, no results were found to confirm the presence of an antimicrobial potential of the drug at the concentrations used in the in situ test specimens in 24 hours

Do different strains of E. faecalis have the same behavior towards intracanal medications in in vitro research?

Abstract: The aim of this study was to evaluate the antimicrobial action of different endodontic pastes against Enterococcus faecalis ATCC 29212, isolated from the urinary tract, and compare the action with E. faecalis ATCC 4083, isolated from the root canal. For this purpose, dentin blocks were infected for 21 days with both bacteria at different time-intervals to ensure there would be no cross contamination. After this period, blocks were immersed in the test medications for 7 days, according to the following groups: CH/S, CH/P, CH/CMCP, CH/CHX, CH/DAP and TAP. Images of the samples were captured with a confocal microscope and the percentage of live cells was computed by means of the Bioimage program. The ATCC 29212 strain was shown to be more resistant to CH/SS, Calen, CH/DAP, and TAP than the ATCC 4083 strain. The antimicrobial action of the medications against each strain were divergent concerning the order of susceptibility. The authors concluded that the strains behaved in a different manner: in general, those extracted from the urinary tract were more resistant to the tested medications. Therefore, when E. faecalis must be used for in vitro research in endodontics, we suggest the use of ATCC 4083 strain to obtain results that are closer to the clinical reality.