Vital Pulp Therapies in Clinical Practice: Findings from a Survey with Dentist in Southern Brazil

Studies based on dentists' clinical practice possess vital relevance to understand factors leading the clinicians to choose by a specific technique over another. This study investigated which clinical conduct therapies are adopted by dentists in front of deep caries. Was evaluated how the place of work, post-graduate training and years since complete graduation influenced their decisions. A cross-sectional study was performed using a self-applied questionnaire with dentists (n=276) in Southern Brazil. Information regarding post-graduation training (specialization, master's or PhD), clinical experience (years since completing graduation) and place of work were investigated. The information regarding pulp vital therapies (materials for direct pulp capping; techniques for caries removal in deep cavities and strategies for indirect pulp capping) were collected by specific questions. Data were submitted to descriptive analysis and Exact Fischer Test. Response rate was 68% (187). The majority of dentists selected the calcium hydroxide (CH) as first material for direct (86.3%) and indirect (80.3%) pulp protection. Partial caries removal was reported by 61.9% of dentists. Less experienced clinical dentists choose partial caries removal more frequently (p=0.009), if compared with dentists graduated 10 years and up ago. The use of MTA was more common among professionals working at academic environment. Besides, MTA was not mentioned by professionals working exclusively in the public health service (p=0.003). In conclusion, the time since graduation influenced the clinical conduct related to caries removal. The choice of liner materials was influenced by dentists' workplace.

Resumo Estudos baseados na prática clínica de dentistas possuem relevância vital para o entendimento dos fatores que influenciam os clínicos na escolha de uma técnica específica em detrimento de outra. Este estudo investigou quais condutas clínicas são adotadas por dentistas frente a lesões profundas de cárie. Foi avaliado como o local de trabalho, curso de pós-graduação e tempo desde a graduação influenciaram suas decisões clínicas. Foi conduzido um estudo transversal utilizando questionários auto- aplicados à dentistas no sul do Brasil (n=276). Informações relacionadas a educação continuada (especialização, mestrado ou doutorado), experiência clínica (anos desde a graduação) e local de trabalho foram investigadas. As informações sobre terapias vitais da polpa (materiais para capeamento pulpar direto, técnicas para remoção de carie em cavidades profundas e estratégias para capeamento pulpar indireto) foram coletadas por meio de perguntas específicas. Os dados foram submetidos à análise descritiva e teste exato de Fisher. A taxa de resposta foi de 68% (187). A maioria dos dentistas selecionam o hidróxido de cálcio (HC) como primeiro material para proteção pulpar direta (86,3%) e indireta (80,3%). Remoção parcial de tecido cariado foi relatado por 61,9% dos clínicos. Dentistas com menor experiência clínica optaram pela remoção parcial de tecido cariado com mais frequência (p=0,009), quando comparados a dentistas graduados há mais de 10 anos. O uso do MTA foi mais comum entre os profissionais que trabalham em ambiente acadêmico. Além disso, o MTA não foi mencionado pelos profissionais que trabalham exclusivamente no serviço público de saúde (p=0,003). O tempo desde a graduação influenciou a conduta clínica relacionada à remoção de cárie. A escolha de materiais para proteção pulpar foi influenciada pelo local de trabalho dos dentistas.

Influence of EDTA and dentine in tissue dissolution ability of sodium hypochlorite.

This study verified whether ethylenediaminetetraacetic acid (EDTA) influences the pulp tissue dissolution capability of different concentrations of NaOCl, in the presence of dentine. NaOCl and EDTA solutions were simultaneously mixed in flasks either containing a dentine disc or those not containing a dentine disc. Previously weighed bovine pulp tissues were immersed in the solutions for 5, 15 and 30 min. The weight loss was measured. The dissolution tests were performed in triplicate. Univariate analysis of variance, along with further Tukey's honestly significant difference pairwise comparisons, was used to verify the effect of EDTA, different concentrations of NaOCl, dentine and time of incubation on the tissue dissolution. Higher concentrations of NaOCl increased the tissue dissolution. EDTA reduced the capacity of NaOCl to dissolve pulp tissue, even in presence of dentine. Dentine negatively affects the capacity of NaOCl to dissolve pulp tissue. In conclusion, the presence of EDTA and dentine negatively affects the tissue dissolution ability of NaOCl.

Vital Pulp Therapies in Clinical Practice: Findings from a Survey with Dentist in Southern Brazil.

Studies based on dentists' clinical practice possess vital relevance to understand factors leading the clinicians to choose by a specific technique over another. This study investigated which clinical conduct therapies are adopted by dentists in front of deep caries. Was evaluated how the place of work, post-graduate training and years since complete graduation influenced their decisions. A cross-sectional study was performed using a self-applied questionnaire with dentists (n=276) in Southern Brazil. Information regarding post-graduation training (specialization, master's or PhD), clinical experience (years since completing graduation) and place of work were investigated. The information regarding pulp vital therapies (materials for direct pulp capping; techniques for caries removal in deep cavities and strategies for indirect pulp capping) were collected by specific questions. Data were submitted to descriptive analysis and Exact Fischer Test. Response rate was 68% (187). The majority of dentists selected the calcium hydroxide (CH) as first material for direct (86.3%) and indirect (80.3%) pulp protection. Partial caries removal was reported by 61.9% of dentists. Less experienced clinical dentists choose partial caries removal more frequently (p=0.009), if compared with dentists graduated 10 years and up ago. The use of MTA was more common among professionals working at academic environment. Besides, MTA was not mentioned by professionals working exclusively in the public health service (p=0.003). In conclusion, the time since graduation influenced the clinical conduct related to caries removal. The choice of liner materials was influenced by dentists' workplace.

Effect of a surfactant on the antimicrobial activity of sodium hypochlorite solutions.

The objective of the present study was to evaluate the antimicrobial activity of sodium hypochlorite (NaOCl) associated with a surfactant. Seventy single-rooted extracted human teeth were inoculated with Enterococcus faecalis, and incubated for 21 days (37 °C). The groups were distributed according to the irrigation solution used during root canal preparation: 5%, 2.5% and 1% NaOCl; 5%, 2.5% and 1% Hypoclean®, a solution containing a surfactant (cetrimide) associated with NaOCl. Three microbiological samples were collected from each tooth: S1 - before instrumentation; S2 - immediately after instrumentation; and S3 - after a seven-day period. Data were submitted to ANOVA and Tukey test with 5% significance level. The results showed that immediately after root canal preparation (S2), E. faecalis was eliminated in all the experimental groups. However, after 7 days (S3), only the groups in which Hypoclean was used, remained contamination-free, including Hypoclean associated with 1% NaOCl, while the root canals irrigated with 1% NaOCl only, presented the highest percentage of bacterial growth. In conclusion, the addition of surfactant increased the antimicrobial activity of 1% NaOCl to levels similar to 5% NaOCl.

Effect of a Surfactant on the Antimicrobial Activity of Sodium Hypochlorite Solutions

The objective of the present study was to evaluate the antimicrobial activity of sodium hypochlorite (NaOCl) associated with a surfactant. Seventy single-rooted extracted human teeth were inoculated with Enterococcus faecalis, and incubated for 21 days (37 °C). The groups were distributed according to the irrigation solution used during root canal preparation: 5%, 2.5% and 1% NaOCl; 5%, 2.5% and 1% Hypoclean(r), a solution containing a surfactant (cetrimide) associated with NaOCl. Three microbiological samples were collected from each tooth: S1 - before instrumentation; S2 - immediately after instrumentation; and S3 - after a seven-day period. Data were submitted to ANOVA and Tukey test with 5% significance level. The results showed that immediately after root canal preparation (S2), E. faecalis was eliminated in all the experimental groups. However, after 7 days (S3), only the groups in which Hypoclean was used, remained contamination-free, including Hypoclean associated with 1% NaOCl, while the root canals irrigated with 1% NaOCl only, presented the highest percentage of bacterial growth. In conclusion, the addition of surfactant increased the antimicrobial activity of 1% NaOCl to levels similar to 5% NaOCl.

O objetivo da presente pesquisa foi avaliar a atividade antimicrobiana de hipoclorito de sódio (NaOCl), associado a um tensoativo. Setenta dentes humanos monorradiculares extraídos foram inoculados com Enterococcus faecalis e incubados durante 21 dias (37 °C). Os grupos foram distribuídos de acordo com a solução irrigadora utilizada no preparo do canal: hipoclorito de sódio a 5%, 2,5% e 1%; Hypoclean(r) a 5%, 2,5% e 1% - uma solução contendo um surfactante (cetrimida) associado com NaOCl. Três amostras microbiológicas foram coletadas de cada dente: S1 - antes de instrumentação; S2 - imediatamente após a instrumentação; e S3 - após um período de sete dias. Os dados foram submetidos à análise de variância e teste de Tukey com 5% de nível de significância. Os resultados mostraram que imediatamente após o preparo do canal radicular (S2), o E. faecalis foi eliminado em todos os grupos experimentais. No entanto, após 7 dias (S3), apenas os grupos em que se utilizou Hypoclean permaneceram livres de contaminação, incluindo Hypoclean 1%, enquanto que os canais radiculares irrigados apenas com hipoclorito de sódio 1% apresentaram a mais elevada percentagem de crescimento bacteriano. Em conclusão, a adição de surfactante aumentou a atividade antimicrobiana de 1% de NaOCl a níveis semelhantes aos do NaOCl 5% .

Hypercementosis: a challenge for endodontic therapy

Introduction and objective: The purpose of this study was to describe through literature review, the morphological characteristics of teeth with hypercementosis that are relevant to endodontic practice. Literature review: The pathologic deposition of cement increases proportionally as the patient's age increases. Genetic factors seem to be related to hypercementosis occurrence in young patients. Based on literature, it is possible to notice a lack of scientific studies which guide the endodontist for treating teeth with hypercementosis, since the cement deposition lead to the length increase of the cementum canal, and consequently, to the increase of the distance from CDC junction to apical root end. Conclusion: Thus, it is clinically relevant to correlate the morphology of teeth with hypercementosis with the specific aspects of endodontic therapy, aiming to establish the limits of root canal treatment in cases of hypercementosis.

Endodontic and orthodontic management of traumatically intruded teeth with horizontal root fracture: a case report.

This report describes the case of an 8-year-old boy that was referred to endodontic and orthodontic treatment after suffering an injury that led to intrusion of the maxillary right permanent central incisor, palatal displacement of the upper right lateral incisor, and root fracture of both central incisors. Both injured teeth were immature and had open apices. The intruded tooth was repositioned by endodontic and orthodontic management. Endodontic therapy was performed in both teeth with periodical changes of calcium-hydroxide-based paste as root canal dressing and introduction of MTA as an apical barrier. The postoperative course was uneventful with clinical and radiographic success up to 3 and 1/2 years of follow up. In the present case, orthodontic repositioning combined with endodontic therapy constitued a viable alternative treatment for intrusive luxations in immature permanent teeth.

Avaliação da resistência à fadiga por flexão de instrumentos rotatórios do sistema protaper universal / Evaluation of the fatigue strength of rotatory instruments from the protaper universal system

O objetivo deste estudo foi avaliar a resistência a fratura por fadiga de instrumentos rotatórios de níquel titânio, por meio de um ensaio estático de resistência a flexão. Foram avaliados instrumentos F1, F2 e F3 pertencentes ao Sistema ProTaper Universal (Dentisply/Maillerfer). O estudo utilizou 60 instrumentos, divididos em três grupos com 20 instrumentos de cada diâmetro. Todos os instrumentos foram submetidos a um ensaio estático de flexão usando um dispositivo especialmente desenvolvido para este estudo. O dispositivo era composto por um canal radicular artificial com ângulo de curvatura de 45º e raio de 5mm, fabricado com aço inoxidável temperado. Um motor elétrico X-Smart (Dentisply/Maillefer) com um contra-ângulo redutor de 16:1 foi programado para funcionar em velocidade constante de 300rpm e torque de 2N.cm. Cada instrumento ProTaper Universal foi encaixado no contra-ângulo e então introduzido no canal artificial onde girava livremente até ocorrer a fratura. O tempo ocorrido até a fratura estática dos instrumentos foi cronometrado e registrado; o número de rotações foi calculado a partir dessa medida. Os resultados deste estudo não mostraram diferenças significantes no número de rotações até ocorrer a fratura. Instrumentos submetidos a velocidade constante em ensaio estático de resistência a flexão, dentro de canais radiculares curvos artificiais, apresentaram número de ciclos até a fratura semelhantes, independente do diâmetro.

The aim of this study was to evaluate the fracture strength under cyclic fatigue load of Nickel-Titanium rotatory endodontic instruments by means of a static flexure strength test. The F1, F2 and F3 instruments from the ProTaper Universal System (Dentisply/Maillerfer) were evaluated. The study used 60 samples, divided in three groups with 20 samples of each diameter. All instruments were submitted to the flexure strength test using a device specially developed for this study. The device was composed by a 45º sloped artificial root canal, made with tempered stainless steel, with radius of 5mm. An X-Smart (Dentisply/Maillefer) electric engine that had a contra-angle with rotatory reduction of 16:1 was stated to work with a constant speed of 300rpm and with a torque of 2N.cm. Each ProTaper Universal Instrument was individually attached to the contra-angle and then introduced into the artificial root canal where rotate freely until failure. The time elapsed until static fracture of the instruments was chronometrically measured and registered; then, the number of rotations was calculated from this measurement.The results of this study showed no statistically significant differences in the mean number of cycles until failure. Instruments submitted to constant speed in static flexure strength test, inside artificial curved canals, presented the same number of cycles to fracture, no matter the diameter.

Inhibition of sodium hypochlorite antimicrobial activity in the presence of bovine serum albumin.

INTRODUCTION: This study investigated the inhibition of the antimicrobial activity of sodium hypochlorite (NaOCl) by bovine serum albumin (BSA). The killing of Enterococcus faecalis, Candida albicans, Staphylococcus epidermidis, and Escherichia coli by NaOCl in concentrations from 2% to 0.03% was measured in the presence of BSA in concentrations between 6.7% and 0.1%. METHODS: NaOCl, BSA, and microorganism suspensions were mixed, and, after 30 seconds, 6 minutes, and 30 minutes, samples were taken and NaOCl was inactivated by 5% sodium thiosulphate. The microbes were incubated in tryptic soy broth broth for up to 7 days for the detection of growth. RESULTS: All microorganisms were killed within 30 seconds by 0.03% NaOCl when BSA was not present. High concentrations of BSA significantly reduced the antimicrobial activity of NaOCl against the four species. CONCLUSIONS: The inhibition of sodium hypochlorite by BSA was directly dependent on their quantitative relationships. The result partly explains the poorer performance in vivo of NaOCl as compared to in vitro experiments.

Reliability of assessing dye penetration along root canal fillings using methylene blue.

Methylene blue (MB) remains the most frequently used tracer for dye penetration tests of endodontic fillings, despite its chemical reactions with different materials. This study checked whether dye penetration displayed by MB is comparable to Rhodamine B (RB). One hundred and seventy-two root canals were filled with gutta-percha and six sealers. Samples were covered with nail varnish except for the apical area, and immersed in MB or RB solutions under negative pressure. After 24 h, roots were bisected, photographed and the maximal dye penetration recorded. Dye penetrations displayed by MB and RB were compared (Newman-Keuls test). MB and RB displayed comparable results for groups filled with AH Plus, EndoREZ and Polifil (P > 0.05). For Endofill, Sealer 26 and Sealapex, a significant lower dye penetration was observed when MB was used (P < 0.05). Laboratory tests using MB for measuring dye penetration through filled root canals can result in misleading conclusions.

Endodontic chelators induce nitric oxide expression by murine-cultured macrophages.

INTRODUCTION: Endodontic chelators may extrude to apical tissues during instrumentation activating cellular events on periapical tissues. This study assessed in vitro the expression of nitric oxide (NO) concentrations by murine peritoneal macrophages after contact with MTAD (Dentsply/Tulsa, Tulsa, OK), Tetraclean (Ogna Laboratori Farmaceutici, Muggio, Italy), Smear Clear (Sybron Endo, Orange, CA), and EDTA (Biodinâmica, Ibiporã, PR, Brazil). METHODS: Macrophage cells were obtained from Swiss mice after peritoneal lavage. Chelators were diluted in distilled water obtaining 12 concentrations, and MTT assay identified the concentrations, per group, displaying the highest cell viability (analysis of variance, p < 0.01). Selected concentrations were tested for NO expression using Griess reaction. Culture medium and lipopolysaccharide (LPS) were used as controls. RESULTS: Analysis of variance and Tukey tests showed that all chelators displayed elevated NO concentrations compared with the negative control (p < 0.01). MTAD induced the lowest NO expression, followed by Tetraclean, EDTA, and Smear Clear. No difference was observed between MTAD and Tetraclean (p > 0.01), Tetraclean and EDTA (p > 0.01), and EDTA and Smear Clear (p > 0.01). LPS ranked similar to both EDTA and Smear Clear (p > 0.01). CONCLUSION: The tested endodontic chelators displayed severe proinflammatory effects on murine-cultured macrophages. Citric acid-based solutions induce lower NO release than EDTA-based irrigants.

Obturação com MTA associada à cirurgia parendodôntica no retratamento de reabsorção radicular apical externa: relato de caso / Root canal filling using MTA in association with parendodontic surgery in the retreatment of an external apical root resorption: case report

Introdução e objetivo: O tratamento de reabsorções inflamatórias apicais deve ser direcionado ao combate da infecção endodôntica. Em determinados casos, a resolução clínica por meio de tratamento endodôntico convencional pode tornar-se inexequível em função das dificuldades de efetuar a instrumentação e a obturação adequadas da região apical. Nessas situações, técnicas alternativas de preparo do canal radicular e de obturação podem ser necessárias, além da instituição de tratamento cirúrgico complementar. Relato do caso: Este trabalho apresenta uma alternativa de retratamento de um caso de reabsorção radicular apical externa com o uso do tampão de MTA associado à cirurgia parendodôntica. Após remoção do material obturador, limpeza e desinfecção do canal radicular, foi instituída terapia com hidróxido de cálcio por 45 dias. Depois desse período, o canal foi obturado com MTA, e em uma sessão posterior foram feitas curetagem da lesão periapical e apicectomia. A proservação do caso deu-se 34 meses e demonstrou reparo da lesão periapical e íntimo contato do trabeculado ósseo com o MTA. Conclusão: O uso do MTA como material obturador, complementado pela cirurgia parendodôntica, mostrou-se como uma alternativa para o tratamento de dentes com reabsorção radicular apical externa.

Introduction and objective: The treatment of external apical root resorption should be directed to eliminate the endodontic infection. In some cases, the clinical resolution by conventional endodontic treatment cannot be performed, due to instrumentation and root canal filling complexity. In these cases, alternative instrumentation and obturation techniques may be necessary, additionally to apical surgery. Case report: This case report shows an alternative to external apical root resorption retreatment, using obturation with MTA associated to parendodontic surgery. After the removal of obturation material and the root canal cleaning and shaping, calcium hydroxide therapy was performed during 45 days. After that the canal was filled with MTA, and in a posterior session apical curettage and apicoectomy were performed. After 34 months, the periapical healing could be radiographically noticed, with close contact between trabecular bone and MTA. Conclusion: The use of MTA as a root canal filling material associated with parendodontic surgery seemed to be an adequate alternative to external apical root resorptions.

Dentin enhances the antibacterial effect of mineral trioxide aggregate and bioaggregate.

The antimicrobial effectiveness of bioaggregate (BA) and mineral trioxide aggregate (MTA) against Enterococcus faecalis was evaluated in vitro. Fresh BA and MTA powders, powder from crushed set materials, and pieces of uncrushed set cements were suspended in autoclaved water at concentrations of 10-100 mg/mL for direct exposure testing. The antimicrobial effect of the cements mixed with equal amounts of human dentin powder was also tested. BA and MTA powder were equally effective in bacterial elimination and caused a significant decrease in bacterial viability within 6 minutes. Powder from crushed set cements was either equally or more effective than fresh powders in killing the bacteria. The addition of equal amounts of dentin powder to the suspension of either BA or MTA powder (both fresh and set) resulted in faster elimination of the bacteria (P < 0.05).

Cytotoxicity evaluation of four endodontic sealers.

This study evaluated in vitro the cytotoxicity of four root canal sealers (Topseal, EndoRez, TubliSeal and Kerr Pulp Canal Sealer E.W.T.) and their effects on reactive oxygen/nitrogen intermediate induction by mouse peritoneal macrophages. Thioglycollate-induced cells were obtained from Swiss mice by peritoneal lavage with 5 mL 10 mM phosphate-buffered saline, washed twice and resuspended (10(6) cells/mL) in appropriate medium for each test. Cytotoxicity was determined by the presence of hydrogen peroxide (H2O2) and nitric oxide (NO) by the peroxidase-dependent oxidation of phenol red and Griess reaction, respectively. Sealer suspensions were obtained in two different concentrations from each material: 18 mg/mL and 9 mg/mL, established according to compatibility parameters following MTT assay. Comparing the sealers, H2O2 release at concentrations of 9 mg/mL and 18 mg/mL was similar: Topseal > positive control (medium + cells + 5 mg/mL zimozan solution) > EndoRez > TubliSeal > Kerr Pulp E.W.T. > negative control (medium + cells). NO release at concentration of 9 mg/mL was: positive control (medium + cells + 10 microg/mL LPS solution) > Topseal > Kerr Pulp E.W.T. > TubliSeal = EndoRez > negative control (medium + cells); at concentration of 18 mg/mL was: positive control > Topseal > Kerr Pulp E.W.T > TubliSeal > EndoRez > negative control. Based on the results, it may be concluded that Topseal presented the highest cytotoxicity among the tested sealers, releasing higher concentrations of NO and H2O2 in macrophage culture.

Ca(OH)2 action on TNF-alpha and NO release in macrophage culture stimulated by Pseudomonas aeruginosa LPS / Ação do Ca(OH)2 sobre a produção de TNF-alfa e NO de cultura de macrófagos estimulada por LPS de Pseudomonas aeruginosa

Purpose: Calcium hydroxide [Ca(OH)2] interaction with the immune system to destroy or neutralize bacteria and their by-products is not completely understood. This study evaluated the calcium hydroxide ability to neutralize Pseudomonas aeruginosa lipopolysaccharides (LPS) using two different methods: nitric oxide (NO) stimulation and Tumoral Necrosis Factor-alpha (TNF-alpha) release in mice macrophage culture. Methods: For the NO assay, peritoneal exudate cells (PECs) were placed in contact with 25ìg/mL and 50ìg/mL LPS and LPS/Ca(OH)2 suspensions (50ìg/25mg and 25ìg/25mg). After incubation for 8h, Griess reagent was used, and the NO release was quantified. In the TNF-alpha assay the LPS solution was tested in 25ìg/mL, and the LPS/Ca(OH)2 suspension was tested in 25ìg/25mg concentration. After incubation for 24 hours, cells were fixed and stained with crystal violet. Absorbance values were obtained. Results were expressed in micromols. All tests were performed in triplicate. Results: The presence of Ca(OH)2 in both tested concentrations significantly reduced NO and TNF-alpha release. Conclusion: It can be concluded that bacteria LPS is a strong stimulus for NO and TNF-alpha release, but calcium hydroxide can neutralize it.

Objetivo: A ação do hidróxido de cálcio [Ca(OH)2] com o sistema imune e o mecanismo de neutralização das bactérias e seus subprodutos ainda não foi completamente esclarecida. Neste estudo foi avaliada a capacidade do Ca(OH)2 em neutralizar o lipopolissacarídeo (LPS) de Pseudomonas aeruginosa, utilizando-se duas metodologias: liberação de Óxido Nítrico (NO) e Fator de Necrose Tumoral Alfa (TNF-alfa) em cultura de macrófagos peritoneais de camundongos. Metodologia: No ensaio do NO, as células peritoneais foram expostas a uma solução de LPS (25mg/mL e 50mg/mL); e à suspensão de LPS/Ca(OH)2 em duas concentrações (50mg/ 25mg e 25mg/25mg). Após 8 horas de incubação, foi utilizado reagente de Griess, e a liberação de NO foi quantificada. No ensaio do TNF-alfa, a solução de LPS foi usada na concentração de 25mg/mL e o LPS/Ca(OH)2 a 25mg/25mg. Após 24 horas, as células foram fixadas e coradas com cristal violeta, e os valores de absorbância foram obtidos. Os resultados foram expressos em micromols. Todos os testes foram realizados em triplicata. Resultados: A presença de Ca(OH)2 nas duas concentrações avaliadas reduziu significativamente a liberação de NO e TNF-alfa. Conclusão: Pode-se concluir que o LPS bacteriano representa um forte estímulo para liberação destas citocinas, mas o hidróxido de cálcio foi capaz de neutralizar este efeito.

Efeito antibacteriano in vitro das soluções Tetraclean, MTAD e modificações: teste de contato direto e ação sobre o biofilme / In vitro antibacterial effect of Tetraclean, MTAD and modifications: direct exposure test and effect on the biofilm

O objetivo deste estudo foi avaliar a atividade antibacteriana dassoluções Tetraclean®, MTAD® e modificações desta formulação sobre uma cepa de Enterococcus faecalis pelo teste de contato direto e frente ao biofilme. Na metodologia de contato direto, uma suspensão de E. faecalis foi exposta às soluções irrigadoras, por períodos de 30 s, 1, 3 e 10 min, e um agente neutralizante foi utilizado. As colônias viáveis foram quantificadas após diluições seriadas e cultura em placas de ágar. Para determinação do número inicial de UFC, água esterilizada foi usada como controle. Para o crescimento do biofilme, amostras de biofilme dentário foram suspensas em BHI (Brain Heart Infusion), e incubadas por 14 dias em anaerobiose, tendo como substrato, discos de hidroxiapatita. Após o período de incubação, os biofilmes foram expostos às soluções irrigadoras por períodos de 30 s, 1 e 3 min. Os biofilmes corados com o Live/Dead Baclight stain (Molecular Probes, Europe BV), que diferencia células viáveis (verde) e células não-viáveis (vermelho) foram observados na microscopia confocal. As imagens do biofilme obtidas pelo software EZ-C1 for Nikon foram transferidas para análise quantitativa da proporção de células viáveis sobre o total de células do biofilme para o software Imaris 5.0. No testede contato direto, o Tetraclean® eliminou completamente o E. faecalis em 30 s, enquanto o MTAD® e o MTAD® + CTR 0,01% eliminaram após 10 min, e oMTAD® + CTR 0,1% resultou em culturas negativas após 3 min de contato com a suspensão bacteriana. Quando removido o Tween 80 do MTAD®, e acrescida a CTR 0,01%, obteve-se culturas negativas após 1 minuto. Os resultados obtidospelo método de exposição ao biofilme confirmaram os achados do teste decontato direto. A análise estatística pelo método de Kruskal-Wallis demonstrouque o tempo de exposição aos irrigantes foi significante na redução das bactérias viáveis do biofilme (P<0,001). Houve também diferença significante entre os...

Efeito antibacteriano in vitro das soluções tetraclean, MTAD e modificações: teste de contato direto e ação sobre o biofilme / In vitro antibacterial effect of tetraclean, MTAD and modifications: direct exposure test and effect on the biofilm

O objetivo deste estudo foi avaliar a atividade antibacteriana das soluções Tetraclean®, MTAD® e modificações desta formulação sobre uma cepa de Enterococcus faecalis pelo teste de contato direto e frente ao biofilme. Na metodologia de contato direto, uma suspensão de E. faecalis foi exposta às soluções irrigadoras, por períodos de 30 s, 1, 3 e 10 min, e um agente neutralizante foi utilizado. As colônias viáveis foram quantificadas após diluições seriadas e cultura em placas de ágar. Para determinação do número inicial de UFC, água esterilizada foi usada como controle. Para o crescimento do biofilme, amostras de biofilme dentário foram suspensas em BHI (Brain Heart Infusion), e incubadas por 14 dias em anaerobiose, tendo como substrato, discos de hidroxiapatita. Após o período de incubação, os biofilmes foram expostos às soluções irrigadoras por períodos de 30 s, 1 e 3 min. Os biofilmes corados com o Live/Dead Baclight stain (Molecular Probes, Europe BV), que diferencia células viáveis (verde) e células não-viáveis (vermelho) foram observados na microscopia confocal. As imagens do biofilme obtidas pelo software EZ-C1 for Nikon foram transferidas para análise quantitativa da proporção de células viáveis sobre o total de células do biofilme para o software Imaris 5.0. No teste de contato direto, o Tetraclean® eliminou completamente o E. faecalis em 30 s, enquanto o MTAD® e o MTAD® + CTR 0,01% eliminaram após 10 min, e o MTAD® + CTR 0,1% resultou em culturas negativas após 3 min de contato com a suspensão bacteriana. Quando removido o Tween 80 do MTAD®, e acrescida a CTR 0,01%, obteve-se culturas negativas após 1 minuto. Os resultados obtidos pelo método de exposição ao biofilme confirmaram os achados do teste de contato direto...

The aim of this study was to evaluate the antibacterial effect of MTAD® and Tetraclean®. The tests were performed on Enterococcus faecalis using the direct exposure test and an in vitro biofilm model. Alternative formulations to MTAD® were also included in the experiments: MTAD® + 0.01% cetrimide (CTR); MTAD® + 0.1% CTR; MTAC (the detergent Tween 80 was substituted for cetrimide) with 0.01% CTR and MTAC (0.1% CTR). In the direct exposure test, a bacterial suspension was mixed with the irrigation solutions. After 30 seconds, 1 minute, 3 minutes and 10 minutes, an inactivator agent was used. The number or viable colonies were calculated after serial 10-fold dilutions and culture in agar plates. To calculate the initial number of colonies, sterilized water was used as a control. Dental biofilm samples were suspended in BHI broth and incubated in anaerobic conditions in hidroxiapatite discs. After incubation for 14 days, the biofilms were exposed to the irrigation solutions for 30 seconds, 1 minute and 3 minutes. Live/Dead Baclight stain (Molecular Probes, Europe BV) was used to diferentiate viable cells (Green) and non viable cells (Red). The samples were observed in the Confocal Laser Microscope. The biofilm images in 3D obtained in the EZ-C1 for Nikon software were transfered to quantitative analysis in the Imaris 5.0 software. The software calculated the ratio of green cells. In the direct exposure test, Tetraclean® and MTAC (0.1% CTR) erradicated E. faecalis in 30 s. MTAD® and MTAD® + 0.01% CTR eliminated E. faecalis after 10 min. MTAD® + 0.1% CTR resulted in negative culture after 3 min. Negative cultures were obtained after 1 min when MTAC (0.01% CTR) was used. The findings from the biofilm exposure method confirmed the results from direct exposure test. The Kruskal-Wallis statistical analysis showed a significant difference in time exposure to irrigant (P<0.001)...

Cytotoxicity evaluation of four endodontic sealers

This study evaluated in vitro the cytotoxicity of four root canal sealers (Topseal, EndoRez, TubliSeal and Kerr Pulp Canal Sealer E.W.T.) and their effects on reactive oxygen/nitrogen intermediate induction by mouse peritoneal macrophages. Thioglycollate-induced cells were obtained from Swiss mice by peritoneal lavage with 5 mL 10 mM phosphate-buffered saline, washed twice and resuspended (106 cells/mL) in appropriate medium for each test. Cytotoxicity was determined by the presence of hydrogen peroxide (H2O2) and nitric oxide (NO) by the peroxidase-dependent oxidation of phenol red and Griess reaction, respectively. Sealer suspensions were obtained in two different concentrations from each material: 18 mg/mL and 9 mg/mL, established according to compatibility parameters following MTT assay. Comparing the sealers, H2O2 release at concentrations of 9 mg/mL and 18 mg/mL was similar: Topseal > positive control (medium + cells + 5 mg/mL zimozan solution) > EndoRez > TubliSeal > Kerr Pulp E.W.T. > negative control (medium + cells). NO release at concentration of 9 mg/mL was: positive control (medium + cells + 10 µg/mL LPS solution) > Topseal > Kerr Pulp E.W.T. > TubliSeal = EndoRez > negative control (medium + cells); at concentration of 18 mg/mL was: positive control > Topseal > Kerr Pulp E.W.T > TubliSeal > EndoRez > negative control. Based on the results, it may be concluded that Topseal presented the highest cytotoxicity among the tested sealers, releasing higher concentrations of NO and H2O2 in macrophage culture.

Este estudo avaliou in vitro a citotoxicidade de quatro cimentos obturadores (Topseal, EndoRez, TubliSeal e Kerr Pulp Canal Sealer E.W.T) e seus efeitos na liberação de reativos intermediários do oxigênio e do nitrogênio em cultura de macrófagos peritoniais de ratos.Tioglicolato foi utlizado para se obter células peritoneias de camundongos. A cavidade peritoneal foi irrigada com 5 mL de solução salina 10 mM. As células foram lavadas duas vezes e foi feita uma suspensão (106 células/mL) em meio apropriado para cada um dos testes. A citotoxicidade dos cimentos foi determinada pela presença de peróxido de hidrogênio (H2O2) e óxido nítrico (NO) pela oxidação peroxidase-dependente do vermelho fenol e pela reação de Griess, respectivamente. Suspensões de cimento foram obtidas em duas diferentes concentrações para cada material: 18 mg/mL e 9 mg/mL, estabelecidas previamente pelo teste de viabilidade celular MTT. Comparando os cimentos, a liberação de H2O2 foi similar nas duas concentrações: Topseal > controle positivo (meio + células + Zimozan a 5mg/mL ) > EndoRez > TubliSeal > Kerr Pulp E.W.T. > controle negativo (meio + células). A liberação de NO na concentração de 9 mg/mL foi: de 9 mg/mL foi: controle positivo (meio + células + solução de LPS a 10 »g/mL) > Topseal > Kerr Pulp E.W.T. > TubliSeal = EndoRez > controle negativo (meio + células); e na concentração de 18 mg/mL; e na concentração de 18 mg/mL: controle positivo > Topseal > Kerr Pulp E.W.T > TubliSeal > EndoRez > controle negativo. Baseado nos resultados, pode-se concluir que o Topseal apresentou a maior citotoxicidade dentre os cimentos avaliados, liberando as mais altas concentrações de NO e H2O2 em cultura de macrófagos.

Conservative treatment of patients with periapical lesions associated with extraoral sinus tracts.

This paper describes the clinical courses of three cases with extra-oral sinus tract formation, from diagnosis and treatment to short-term follow-up and evaluation. All teeth involved had periradicular radiolucent areas noted on radiographic examination and extra-oral sinus tracts appearing on the chin with exudation and unpleasant aesthetic appearance. The adopted treatment protocol included treating the sinus tract surface simultaneously with the root canal therapy. After root canal shaping using 5.25% sodium hypochlorite solution, calcium hydroxide-based pastes associated with different vehicles were inserted into the root canal for 4 months, and were changed monthly. All the sinus tracts healed in 7 to 10 days. The apical lesions were completely repaired in a maximum period of 24 months. The treatment adopted provided a complete healing of the periapical lesions in a short follow-up period. Surgical repair of the cutaneous sinus tract was therefore unnecessary.

In vitro antimicrobial activity of different gutta-percha points and calcium hydroxide pastes.

The aim of this study was to evaluate the antimicrobial activity of different trademarks and compositions of gutta-percha points and calcium hydroxide pastes used in endodontic therapy. The evaluated material consisted of gutta-percha points containing calcium hydroxide (Roeko), gutta-percha points containing chlorhexidine (Roeko), two conventional gutta-percha points (Endo Points and Roeko) and two calcium hydroxide pastes (Calen and Calen/PMCC). Antimicrobial tests included five species of microorganisms: Escherichia coli (ATCC10538), Staphylococcus epidermidis (ATCC12228), Staphylococcus aureus (ATCC6538), Pseudomonas aeruginosa (ATCC27853), and Micrococcus luteus (ATCC9341). The Agar diffusion method was employed. The plates were kept at room temperature for 2 h for prediffusion and then incubated at 37 degrees C for 24 h. The triphenyltetrazolium chloride gel was added for optimization and the zones of inhibition were measured. Statistical evaluation was carried out using analysis of variance and Tukey Test. The obtained results showed that all microbial species used in the study were inhibited by the gutta-percha points containing chlorhexidine and by the calcium hydroxide pastes (Calen and Calen/PMCC), with similar results (p > 0.05). No antimicrobial activity was observed for the other groups. It was concluded that the gutta-percha points containing chlorhexidine presented antimicrobial activity, whereas the gutta-percha points containing calcium hydroxide did not.