Physicochemical properties and antimicrobial activity of calcium hydroxide pastes in association with other compounds

Aim: This study aimed to evaluate the pH, Ca2+ release, solubility, and antimicrobial activity of calcium hydroxide (Ca(OH)2) pastes in association with different substances. Methods: Sixty acrylic teeth (n=10) were filled with pastes that associated Ca(OH)2 with the following substances: benzalkonium chloride 5% (G1) and 50% (G2) both in propylene glycol, arnica glycolic extract (G3), green tea glycolic extract (G4), Calen/PMCC™ (G5), and Calen™ (G6). In the group G1 to G4 were used 1g of Ca(OH)2 powder with 0,8g of vehicle. pH and Ca2+ release was measured after 7, 15, and 30 days. For solubility, micro-CT was used immediately and at the periods of 7, 15, and 30 days. For the antimicrobial analysis, a biofilm of E. faecalis was induced in vitro on bovine dentin discs. Live/dead viability dye and confocal scanning microscopy were used. Results: The highest pH values occurred on the first 7 days, and the G6, G1, G3, and G5 presented the highest pH values at this period (P <0.05). Ca2+ release was higher in all groups at 7 days, with the highest values observed in G1, G5, and G6. The volume of all pastes showed no significant difference in the intragroup analysis at 7 and 15 days (P <0.05). G1 and G2 showed the highest antimicrobial action (P <0.05). For the biovolume, there was difference between the G6 and the other groups (P >0.05) with G1 presenting the lowest values. Conclusion: Benzalkonium chloride 5% increases the antimicrobial action of the Ca(OH2), without impairs physicochemical properties

Profile of host cell responses to exposure to stressed bacteria in planktonic; dislodged, and intact biofilm mode.

The host defense response to microbial challenge emerging from the root canal system leads to apical periodontitis. The aim of this study was to evaluate the expression of inflammatory cytokines and Nitric Oxide (NO) by macrophages after interaction with Enterococcus faecalis in the: plankton and dislodged biofilm mode; intact biofilm mode stimulated by calcium hydroxide (CH), CH and chlorhexidine (CHX) or Triple Antibiotic Paste (TAP). For this purpose, culture of macrophages from monocytes in human peripheral blood (N=8) were exposed to the different modes of bacteria for 24 hours. Subsequently, the cytokines, such as, Tumor Necrotic Factor- alfa (TNF-α), interleukin (IL)-1ß, IL-6, IL-10; and NO were quantified by Luminex xMAP and Greiss reaction, respectively. In addition to the potential therapeutic effects of the intracanal medication, their antimicrobial activity against Enterococcus faecalis biofilm were also tested in vitro by confocal microscopy. The experiments` data were analyzed by the Kruskal-Wallis test with the Dunn post hoc test (α < 0.05). Bacteria in dislodged biofilm mode were shown to be more aggressive to the immune system than bacteria in plankton mode and negative control, inducing greater expression of NO and TNF-α. Relative to bacteria in intact biofilm mode, the weakest antimicrobial activity occurred in Group CH. In Groups CH/CHX and TAP the percentage of dead bacteria was significantly increased to the same extent. Interestingly, the biofilm itself did not induce the release of pro-inflammatory cytokines - except for NO - while the biofilm treated with TAP and CH based pastes enhanced the levels of IL-6 and TNF-α; and IL-1 ß, respectively. In contrast, the levels of a potent anti-inflammatory (IL-10) were increased in Group TAP.

Profile of host cell responses to exposure to stressed bacteria in planktonic; dislodged, and intact biofilm mode

Abstract The host defense response to microbial challenge emerging from the root canal system leads to apical periodontitis. The aim of this study was to evaluate the expression of inflammatory cytokines and Nitric Oxide (NO) by macrophages after interaction with Enterococcus faecalis in the: plankton and dislodged biofilm mode; intact biofilm mode stimulated by calcium hydroxide (CH), CH and chlorhexidine (CHX) or Triple Antibiotic Paste (TAP). For this purpose, culture of macrophages from monocytes in human peripheral blood (N=8) were exposed to the different modes of bacteria for 24 hours. Subsequently, the cytokines, such as, Tumor Necrotic Factor- alfa (TNF-α), interleukin (IL)-1β, IL-6, IL-10; and NO were quantified by Luminex xMAP and Greiss reaction, respectively. In addition to the potential therapeutic effects of the intracanal medication, their antimicrobial activity against Enterococcus faecalis biofilm were also tested in vitro by confocal microscopy. The experiments` data were analyzed by the Kruskal-Wallis test with the Dunn post hoc test (α < 0.05). Bacteria in dislodged biofilm mode were shown to be more aggressive to the immune system than bacteria in plankton mode and negative control, inducing greater expression of NO and TNF-α. Relative to bacteria in intact biofilm mode, the weakest antimicrobial activity occurred in Group CH. In Groups CH/CHX and TAP the percentage of dead bacteria was significantly increased to the same extent. Interestingly, the biofilm itself did not induce the release of pro-inflammatory cytokines - except for NO - while the biofilm treated with TAP and CH based pastes enhanced the levels of IL-6 and TNF-α; and IL-1 β, respectively. In contrast, the levels of a potent anti-inflammatory (IL-10) were increased in Group TAP.

Resumo A resposta de defesa do hospedeiro ao desafio microbiano que emerge do sistema de canais radiculares leva à periodontite apical. Os objetivos deste estudo foram avaliar a expressão de citocinas pró e anti-inflamatórias e Óxido Nítrico (NO) por macrófagos após interação com Enterococcus faecalis no modo: planctônio e de biofilme desalojado; biofilme intacto estimulado por hidróxido de cálcio (CH), CH e clorexidina ou Pasta Tri Antibiótica (TAP). Para isto, a cultura de macrófagos originados de monócitos do sangue periférico de humanos (N=8) foi exposta aos diferentes tipos de bactéria por 24 horas. Então, a quantificação da produção de of Fator de Necrose Tumoral- alfa (TNF-α), interleucina (IL)-1β, IL-6, IL-10 e NO por macrófagos se deu por meio do Luminex xMAP e reação de Greiss, respectivamente. Além dos potenciais efeitos terapêuticos desses compostos, sua atividade antimicrobiana contra E. faecalis também foi testada através microscopia confocal. Os dados dos experimentos foram analisados através do teste de Kruskal-Wallis com Dunn`s post hoc (α < 0.05). Bactéria em modo de biofilme desalojado se mostrou mais agressivo ao sistema imune que as bactérias planctônicas e controle negativo induzindo a maior excreção de NO e TNF-α. Em relação ao biofilme intacto, a atividade antimicrobiana mais fraca ocorreu no grupo de CH. Os grupos CHX e TAP aumentaram significativamente a porcentagem de bactérias mortas na mesma extensão. Interessantemente, o biofilme por ele mesmo não induziu a liberação de citocinas pro-inflamatórias - exceto por NO - enquanto que o biofilme tratado com TAP ou pastas a base de CH aumentaram os níveis de IL-6; e TNF-α e IL-1 β respectivamente. Em contraste, os níveis da potente citocina anti-inflamatória (IL-10) foram aumentados pelo grupo TAP.

Influence of EDTA and its Association with Benzalkonium Chloride on Enterococcus faecalis Adhesion to Dentin / Influencia del EDTA y su Asociación con Cloruro de Benzalconio en la Adhesión de Enterococcus faecalis a la Dentina

ABSTRACT: The aim of this in vitro study was to investigate the influence of ethylenediaminetetraacetic acid (EDTA) associated with the benzalkonium chloride (BAK) on the adhesion and formation of Enterococcus faecalis biofilms attached to coated dentin. Discs standard bovine dentin blocks were treated with the coating materials evaluated: Saline solution (control), 17 % EDTA, 17 % EDTA associated with 1 % BAK for 5 minutes and subsequently washed with saline solution. Afterwards, biofilms of E. faecalis (ATCC 29212) were grown on the surface of coated dentin blocks for time intervals of 1 hour and 7 days (n = 20) and were subsequently washed with phosphate-buffered saline (PBS). Bacterial viability and total biovolume were analyzed by confocal laser scanning microscopy (CLSM) using the Live/Dead technique. Nonparametric Kruskal-Wallis followed by Dunn tests were used to determine statistical differences (a = 5 %). The 17 % EDTA + 1 % BAK group showed significantly lower biovolume and bacterial viability values at the end of 1 hour (p < 0.05). After 7 days of contamination, the 17 % EDTA and 17 % EDTA + 1 % BAK groups showed similar results that differed statistically from those of the control group (p < 0.05). The saline solution group showed higher values. The use of BAK associated with EDTA on dentin blocks surfaces before exposure to contamination was able to interfere in the adhesion of E. faecalis to dentin. Also, dentin treatment by BAK associated with a chelating agent influences the secondary biofilm formation, which could have important effects on the long-term success of root canal treatment.

RESUMEN: El objetivo del estudio consistió en investigar in vitro, la influencia del ácido etilendiamino-tetraacético (EDTA) con cloruro de benzalconio (BAK) en la adhesión y formación de biopelículas de Enterococcus faecalis a la dentina. Discos de dentina bovina fueron tratadas con solución salina (control), 17 % de EDTA, 17% de EDTA asociado con 1 % de BAK durante 5 minutos y lavadas con solución salina. Las biopelículas de E. faecalis (ATCC 29212) se cultivaron sobre los discos de dentina durante intervalos de tiempo de 1 hora y 7 días (n = 20), lavados con solución salina tamponada con fosfato (PBS). La viabilidad bacteriana y el biovolumen total se analizaron mediante microscopía de barrido por láser (CLSM) utilizando la técnica Live / Dead. Se realizó prueba no paramétrica de Kruskal-Wallis, seguida por Dunn con una diferencia estadística (a = 5 %). El grupo de 17 % EDTA + 1 % BAK mostró valores significativamente menores de biovolumen y viabilidad bacteriana al final de 1 hora (p < 0,05). Después de 7 días de contaminación, los grupos de 17 % EDTA y 17 % EDTA + 1 % BAK mostraron resultados similares que diferían estadísticamente del grupo control (p < 0,05). La solución salina mostró valores más altos. La asociación de BAK con EDTA antes de la contaminación interfirió en la adhesión de E. faecalis. Además, el tratamiento de la dentina por BAK asociado con EDTA influye en la formación de biopelículas secundarias, lo que podría tener efectos importantes sobre el éxito a largo plazo del tratamiento del conducto radicular.

Antimicrobial Activity and Physicochemical Properties of Antibiotic Pastes Used In Regenerative Endodontics.

The purpose of this study was to evaluate the pH, solubility and antimicrobial action of Calcium Hydroxide Paste (CH), Double Antibiotic Paste (metronidazole+ciprofloxacin-DAP), calcium hydroxide added to DAP (CH/DAP) and Triple Antibiotic Paste (metronidazole + ciprofloxacin+minocycline-TAP). pH (n=10) were measured by pHmeter. Root canals of acrylic teeth (n=10) were filled with the above-mentioned intracanal-dressings, immersed in ultrapure water, and solubility was measured by the difference between the initial and final volume (7,15 and 30 days) by using micro-computed tomography. Enterococcus faecalis biofilm was induced on bovine dentin disc surfaces (n=20), and treated with the pastes for 7 days. Percentage bacterial viability was verified by confocal microscope, with LIVE/DEAD dye. CH and CH/DAP presented the highest pH values. Regarding solubility, after 7 days, antibiotic groups presented significant volume loss. CH and CH/DAP showed no statistical difference compared with the Control in antimicrobial action against E. faecalis biofilm. However, TAP and DAP presented a significant percentage reduction in bacterial population. Due to high solubility of the pastes, renewing antibiotic dressings every 7 days, or using the medications for this period in regeneration protocols is recommended. DAP is indicated for killing E. faecalis in biofilm because it has antimicrobial action similar to TAP. Adding Calcium Hydroxide to DAP significantly decreased its antimicrobial action. In spite of its the low solubility and high pH values, the CH paste showed a low level of antimicrobial action against E. faecalis in biofilm.

Antimicrobial activity of intracanal medications against both Enterococcus faecalis and Candida albicans biofilm.

Enterococcus faecalis and Candida albicans have been associated with cases of secondary and persistent root canal infections, been resistant to calcium hydroxide. So, the evaluation of the susceptibility of these microorganisms biofilms to new drugs is an important practice for establishing the best drug and consequently success of treatment. For this, in vitro biofilm formation of E. faecalis and C. albicans was induced separately on blocks obtained from bovine teeth. After the period of specimen incubation for biofilm maturation, the samples were immersed in the pastes: 1 - calcium hydroxide (CH), 2 - chlorhexidine (C), 3 - ciprofloxacin (CP), 4 - metronidazole (MT), 5 - ketoconazole (KE), 6 - double antibiotic (DB), 7 - triple antibiotic (TA), 8 - ciprofloxacin + ketoconazole (CPKE); 9 - ciprofloxacin + metronidazole + ketoconazole (CPMTKE), 10 - metronidazole + ketoconazole (MTKE), and 11 - control (CO) for 7 days. Next, the specimens were live/dead stained for analysis by confocal microscopy. By means of the Bioimage program, the biovolume and percentage of live cells were measured. The data were statistically compared (p = .05). For the C. albicans biofilm, the best antimicrobial action was found for MTKE, CPKE, and MT groups. Whereas for E. faecalis biofilm, the lowest percentage of live bacteria was found in TA, DB, and CP groups; however, KE, CPKE, CPMTKE, and MTKE groups shown to be effective. The authors concluded calcium hydroxide paste and chlorhexidine was not effective for both biofilms. The MTKE and CPKE pastes presented effectiveness for both biofilms. TA and DB pastes were effective just in the E. faecalis biofilms.

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

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.

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.

Comparative Effectiveness of New Mechanical Irrigant Agitating Devices for Debris Removal from the Canal and Isthmus of Mesial Roots of Mandibular Molars.

INTRODUCTION: The aim of this study was to compare the effectiveness of Easy Clean (Easy Dental Equipment, Belo Horizonte, MG, Brazil) in continuous and reciprocating motion, passive ultrasonic irrigation (PUI), Endoactivator systems (Dentsply Maillefer, Ballaigues, Switzerland), and conventional irrigation for debris removal from root canals and isthmus. METHODS: Fifty mesial roots of mandibular molars were embedded in epoxy resin using a metal muffle; afterward, the blocks containing the roots were sectioned at 2, 4, and 6 mm from the apex. After instrumentation, the roots were divided into 5 groups (n = 10) for application of the final irrigation protocol using Easy Clean in continuous rotation, Easy Clean in reciprocating motion, PUI, Endoactivator, and conventional irrigation. Scanning electron microscopic images were taken after instrumentation and after the first, second, and third activation of irrigating solution to evaluate the area of remaining debris with image J software (National Institutes of Health, Bethesda, MD). RESULTS: The protocol of 3 irrigating solution activations for 20 seconds provided better cleaning of the canal and isthmus. On conclusion of all procedures, analysis of the canals showed a statistical difference only at 2 mm; the Easy Clean in continuous rotation was more efficient than conventional irrigation (P < .05). On conclusion of all steps, the largest difference was observed in the isthmus in which the Easy Clean in continuous rotation was more effective than conventional irrigation at the 3 levels analyzed and the Endoactivator at 4 mm (P < .05). The PUI promoted greater cleaning than conventional irrigation at 6 mm (P < .05). There was no statistical difference between Easy Clean in continuous rotation, Easy Clean in reciprocating motion, and PUI (P > .05). CONCLUSIONS: Irrigating solution activation methods provided better cleaning of the canal and isthmus, especially the Easy Clean used in continuous rotation. The protocol of 3 irrigating solution activations for 20 seconds favored better cleaning.

Uso do endoactivator no tratamento endodôntico / Use of the endoactivator in endodontic treatment

Introdução: a irrigação é uma das etapas essenciais no preparo biomecânico e, buscando aumentar a eficiência desta, novos métodos vem sendo empregados no intuito de melhorar a ação e o alcance das soluções irrigadoras. Objetivo: analisar a eficácia do sistema EndoActivator em várias etapas do tratamento endodôntico. Resultados e discussão: apesar de diferenças de metodologias na literatura, o EndoActivator apresentou bons resultados em comparação com a irrigação convencional quando empregado em diferentes fases do tratamento endodôntico. Conclusão: o sistema EndoActivator é seguro e eficaz durante o preparo biomecânico, porém, assim como outros dispositivos de agitação mecânica da solução irrigante, não é capaz de promover completa limpeza dos canais radiculares.

Introduction: the irrigation is an essential part of biomechanical preparation and seeking increase the efficiency of this, new methods have been used in order to expand the effect of irrigating solutions, and promote the reach for areas with difficult access. Objective: the objective of this literature review was to analyze the effectiveness of the EndoActivator system in several stages of endodontic treatment. Results and Discussion: despite differences in methodologies in the literature, the EndoActivator presented good results in comparison to conventional irrigation when used in different phases of endodontic treatment. Conclusion: the EndoActivator system is safe and effective during biomechanical preparation, but, like other mechanical agitation devices of the irrigating solution, it is not able to promote complete cleaning to root canals.

Antimicrobial Activity and Physicochemical Properties of Calcium Hydroxide Pastes Used as Intracanal Medication.

INTRODUCTION: The aim of the present study was to evaluate the pH, calcium release, solubility, and antimicrobial action against biofilms of calcium hydroxide + saline solution, Calen (SS White Artigos Dentários Ltd, Rio de Janeiro, Brazil) (CH/P), Calen camphorated paramonochlorophenol (CMCP) (CH/CMPC), and calcium hydroxide + chlorhexidine (CH/CHX) pastes. METHODS: The pH of the pastes was determined with a calibrated pH meter placed in direct contact with each paste. The root canals of acrylic teeth (N = 10) were filled with the previously mentioned intracanal dressings and immersed in ultrapure water to measure hydroxyl (pH meter) and calcium ion release (atomic absorption spectrophotometer) at time intervals of 3, 7, 15, and 30 days. To assess solubility, the root canals of acrylic teeth (N = 10) were filled with the previously mentioned pastes and scanned by micro-computed tomographic imaging before (initial) and after 7, 15, and 30 days of immersion in ultrapure water. The solubility of each specimen was the difference between the initial and final volume scanning. For antimicrobial analysis, monospecies and dual-species biofilms were in vitro induced on dentin blocks (N = 20). Afterward, they were treated with the pastes for 7 days. Live/dead dye and a confocal microscope were used to measure the percentage of living cells. Data were statistically compared (P < .05). RESULTS: The highest OH- ion release values were found in 3 and 30 days. Ca2+ releases were greater in CH/CMCP. CH/P and CH/CMCP showed a higher percentage of volume loss values. CH/CHX presented the greatest antimicrobial action. CONCLUSIONS: CH/P and CH/CMPC showed higher solubility values in the period analyzed. Seven days of contact may be insufficient for calcium hydroxide + saline solution, CH/P, and CH/CMCP pastes to kill bacterial cells in the biofilms studied. Chlorhexidine added to CH favored greater effectiveness against the previously mentioned bacterial biofilms.

Influência das diferentes etapas de processamento nas propriedades físico- químicas de dois cimentos à base de silicato de cálcio / Infuence of different processing phases on the physicochemical properties of two calcium silicate-based cements

Objetivo: o objetivo do presente estudo foi avaliar se a etapa de processamento em que o cimento é obtido in uencia nas suas propriedades físico-químicas. Foram avaliados a composição química, o tempo de presa, solubilidade, pH e liberação de íons cálcio do cimento Portland (Grupo 1), que passa por todas as etapas do processamento; e do cimento que foi obtido na etapa de calcinação (Grupo 2). Métodos: para avaliação da composição química, foi utilizado um microscópio eletrônico de varredura na função EDS. Os testes de tempo de presa e solubilidade foram realizados de acordo com as normas #57 da ADA. Para determinação do pH e liberação de íons cálcio, foram utilizados um peagômetro e um espectrofotômetro de absorção atômica, respectivamente. Resultados: a composição química de ambos os cimentos apresentou maior quantidade de íons cálcio e silício; porém, o cimento Portland apresentou traços de enxofre. Com relação ao tempo de presa, o Grupo 2 apresentou média de tempo de presa estatisticamente menor do que o Grupo 1 (p < 0,05). Com relação à solubilidade, ambos os cimentos apresentaram valores dentro do que é recomendado pela ADA, que é de no máximo 3%; porém, houve diferença significativa, sendo o Grupo 2 mais solúvel (p < 0,05). Na análise do pH e liberação de íons cálcio, observou-se que ambos os cimentos promoveram alcalinização e liberação de íons cálcio, independentemente do tempo analisado. Conclusão: com base nos resultados obtidos, conclui-se que a etapa do processamento em que é obtido o cimento influencia em suas propriedades físico-químicas.

Ação antimicrobiana e propriedades físico-químicas de diferentes pastas empregadas como medicação intracanal / Antimicrobial activity and physicochemical properties of different pastes used as intracanal medication

A medicação intracanal nas necropulpectomias tem como função principal corroborar com a ação antisséptica sobre micro-organismos que sobreviveram ao preparo biomecânico do sistema de canais radiculares. A associação de fármacos e outras substâncias à pasta de hidróxido de cálcio vem sendo sugerida, com intuito de aumentar a efetividade antisséptica da pasta. Pastas antibióticas também vêm sendo utilizadas pelo seu amplo espectro de ação. O objetivo deste estudo foi avaliar pH, liberação de íons cálcio, solubilidade e ação antimicrobiana sobre dentina infectada por biofilmes orais, das pastas: Hidróxido de Cálcio + Solução Salina (G1), Calen (G2), Calen PMCC (G3), Hidróxido de Cálcio + Clorexidina (G4), Hidróxido de Cálcio + Diantibiótica (G5) e Triantibiótica (G6). Materiais e Métodos: Todos os experimentos foram divididos em 6 grupos de acordo com as medicações em questão. Medição de pH e liberação de cálcio: dentes de acrílico tiveram seus canais preenchidos com as medicações intracanal (N=10) e suas coroas seladas. Estes dentes foram imersos em água deionizada e, após os períodos de 3, 24, 72 e 168 horas, foram trocados de frasco. Na água em que estavam imersos foi aferido o pH por meio de um peagâmetro e o cálcio liberado através de espectrofotômetro de absorção atômica. Teste de solubilidade: A solubilidade foi avaliada pela medição volumétrica das pastas inseridas em cavidades padronizadas em 60 dentes de acrílico (N=10), antes e depois de submersas em água deionizada, usando imagens do Micro-CT. Ação antimicrobiana: Sobre blocos de dentes bovinos foi induzida a formação de biofilme in vitro de Enterococcus faecalis e Enterococcus faecalis + Pseudomonas Aeruginosa. Após a indução, as amostras foram tratadas com as pastas por 7 dias. A porcentagem de células vivas foi mensurada através do corante Live/Dead pelo microscópio confocal (N=20) Resultados: G1, G2, G3 e G4 se comportaram de maneira semelhante nos testes de pH, cálcio e solubilidade. G5 e G6 obtiveram os maiores valores de solubilidade. Na ação antimicrobiana, G4 e G6 obtiveram os melhores resultados em ambos biofilmes. Conclusões: O veículo parece não interferir no pH, liberação de cálcio e solubilidade das pastas de hidróxido de cálcio analisadas. Nenhuma das pastas matou 100% das bactérias no biofilme. Mesmo em pH alto, 7 dias foi insuficiente para efetiva ação antimicrobiana das pastas G2 e G3 em biofilme. A associação do hidróxido de cálcio à pasta diantibiótica não é favorável em relação à sua ação antimicrobiana. A pasta Triantibiótica foi a mais efetiva contra biofilmes, porém obteve a maior solubilidade.(AU)

Introduction: The main function of intracanal dressing, in the treatment of teeth with pulpal necrosis, is the antimicrobial action against microorganisms which survived to the biomechanical preparation of root canal system. The combination of Calcium Hydroxide paste with other drugs has been suggested in order to increase the antiseptic capacity of the medication. The aim of this study was to evaluate the pH, calcium release, solubility and antimicrobial action on biofilms of the pastes: Calcium Hydroxide + Saline Solution (G1), Calen (G2), Calen CMCP (G3), Calcium Hydroxide + Chlorhexidine (G4), Double Antibiotic Paste (G5) and Triple Antibiotic Paste (G6). Material and methods: Measurement of pH and calcium release: acrylic teeth had their canal filled with the pastes in study (N=10) and the crown access sealed. Next, they were immersed in deionized water and after 3, 7, 15 and 30 days, removed from the flasks and put in a new flask. The pH and calcium ion of the water were measured by a pH meter and by an atomic absorption spectrophotometry, respectively. Solubility test: To evaluate the solubility, 60 acrylic teeth with standardized foramens (N=10) were filled with pastes and scanned at initial, 7, 15 and 30 days periods, before and after immersion in ultrapure water. The solubility of each specimen was the difference between the initial and final volume scanning. Antimicrobial activity: Biofilm in vitro of mono-specie (Enterecoccus faecalis) and dual-specie (Enterococcus faecalis + Pseudomonas Aeruginosa), were induced on blocks of bovine teeth. (N=20). Next, the samples were treated by the pastes for 7 days. The percentage of living cells were measured by using Live/Dead dye and confocal microscope. The data were statistically compared. Results: G1, G2, G3 and G4 did not present statistical difference to pH, calcium release and solubility values. G5 e G6 had the higher values of solubility. G4 e G6 presented the better action against biofilms. Conclusion:.The vehicle of paste seems not to interfere with pH, calcium release and solubility of calcium hydroxide pastes. None of the pastes killed 100% of the bacteria into the biofilm. Even with a high pH, 7 days may be an insufficient time for CH/P and CH/CMCP pastes to kill bacterial cells into the biofilm. Calcium hydroxide in addition to DAP, not favored its antimicrobial action. The TAP paste presented the bigger solubility and antimicrobial action.(AU)

Seladores coronários temporários usados em endodontia: revisão de literatura / Temporary Coronary Sealers used in Endodontics: Literature Review

Entende-se que o selamento coronário é tão importante para o sucesso da terapia endodôntica quanto o próprio tratamento em si, podendo ser considerado parte integral deste. Objetivo: realizar uma revisão de literatura sobre os principais seladores coronários temporários e suas propriedades, para elucidar aos endodontistas e clínicos gerais, qual as melhores opções. Resultados e Discussão: a melhor capacidade de vedamento foi atribuída a materiais fotoativados, cimento de ionômero de vidro e coltosol. Porém, a variação de metodologias encontrados na literatura é grande, tornando difícil suas comparações. Conclusões: existe a necessidade de padronização destes testes, e verificação de sua legitimidade para que possamos ter conclusões concretas sobre o assunto em questão...

It is known that the coronal sealing ability is so important to the endodontic therapy`s success, as the treatment itself, could being considered an integral part of it. Objective: a literature review of the main temporary filling materials and their properties, for the avoidance of the incorrect use of these, by endodontics and general practitioners. Results and Discussion: photoactive material, Ionomer Cement Glass and Coltosol were found to exhibit the best coronal seal. However, variation of regimens used in literature was large, making comparison of reports difficult. Conclusion: it is necessary the standardization of these tests and checking of its legitimacy, so we will have concrete conclusions on the subject in question...