Abstract This study evaluated a method to determine the spatial geometry of root canal preparation (RCP) using navigation dynamics and a specific algorithm from a new CBCT software (e-Vol DX). CBCT scans of 168 root canals of mandibular molars were acquired before and after RCP, using nickel-titanium (NiTi) instruments (ProTaper Next, BioRace, Reciproc Blue, and WaveOne Gold). The spatial geometry of the root canals and the operative risk of disproportional wear of dentinal walls after RCP were evaluated using a new CBCT software. A 3-point scoring system was used after the measuring of cementum/dentin thickness before and after RCP in all root thirds. The root thirds were distributed into three parts of similar sizes, and the scores were categorized at three levels: 1. mild risk (1/3), 2. moderate risk (2/3), 3. severe risk (3/3). These levels were proposed according to the risk of creating disproportionate shapes, thin walls, or perforations. The data were analyzed statistically by Fischer’s exact test (α = 5%). There were no significant differences in operative risk among the NiTi engine-driven systems, for the distal or mesial walls of all the root canal thirds (p>0.05). The spatial geometry method to assess operative risk allows clinical planning for a predictable enlargement of the root canal in all root thirds. Based on using a map-reading strategy on root canals in CBCT scans, NiTi engine-driven instruments did not present an increased operative risk during RCPs.

Resumo Este estudo avaliou um método para determinar a geometria espacial do preparo do canal radicular (PCR) usando uma dinâmica de navegação e um algoritmo específico do software e-Vol DX. Imagens de tomografia computadorizada de feixe cônico (TCFC) de 168 molares inferiores foram adquiridas antes e depois do PCR, usando instrumentos de níquel-titânio (NiTi) (ProTaper Next, BioRace, Reciproc Blue e WaveOne Gold). A geometria espacial dos canais radiculares e o risco operatório de desgaste desproporcional das paredes dentinárias após o preparo foram avaliados usando o software de TCFC e-Vol DX. Um sistema de Score de 3 pontos foi usado após a mensuração da espessura cemento/dentina antes e depois do PCR, em toda extensão dos canais radiculares. Os terços radiculares foram distribuídos em três partes de tamanhos semelhantes, e os Scores foram categorizados em três níveis: 1. risco leve (1/3), 2. risco moderado (2/3), 3. risco severo (3/3). Esses níveis foram propostos de acordo com o risco de criar formas desproporcionais, paredes finas ou perfurações radiculares. Os dados foram analisados estatisticamente pelo teste exato de Fischer ((=5%). Não houve diferenças significativas no risco operatório entre os sistemas de NiTi acionados a motor, para as paredes distal ou mesial em todos os terços do canal radicular (p>0,05). O método de geometria espacial para avaliar o risco operatório permite o planejamento clínico para um alargamento previsível do canal radicular em todos os terços radiculares. Com base no uso de uma estratégia de navegação dinâmica de canais radiculares de molares inferiores analisados em imagens de TCFC, os instrumentos de NiTi acionados estudados não apresentaram um aumento do risco operatório durante o preparo dos canais radiculares.

Resumo Este estudo avaliou o efeito da terapia fotodinâmica (PDT) em canais radiculares infectados com E. faecalis. Vinte e um dentes humanos extraídos foram selecionados, e 18 foram infectados por E. faecalis por 60 dias. As estratégias antimicrobianas testadas foram: G1. Preparo do canal radicular (PCR) com instrumentos rotatórios de NiTi, NaOCl 2,5% e irrigação final com EDTA 17%, seguido de PDT com fotossensibilizador azul de metileno e laser diodo de baixa potência; G2. PCR usando limas de aço inoxidável e os mesmos protocolos de irrigação e PDT do G1; G3. Protocolo de PCR similar que G1 sem PDT; G4. Somente irrigação com NaOCl 2,5%; G5. Protocolo similar ao G1, sem PCR; G6. Controle negativo; G7. Controle positivo. Amostras para exames microbiológicos foram coletadas inicialmente (S1), após PCR (S2) e após PDT (S3). Na sequência, as raízes foram seccionadas e preparadas para análise em microscopia eletrônica de varredura (MEV). O crescimento bacteriano foi analisado de acordo com a turbidez do meio de cultura seguida pela densidade óptica espectrofotométrica (nm). O efeito da PDT na estrutura dentinária foi avaliado em aumentos de 1.600X e 5.000X, e descrito qualitativamente. O teste de Wilcoxon foi utilizado para as comparações dos mesmos espécimes e o teste de Mann-Whitney para as comparações entre os grupos ((=5%). Bactérias foram encontradas em todos os grupos experimentais, e em todas as coletas microbiológicas (S1, S2 e S3). A densidade óptica dos meios de cultura foi menor em S2 do que em S1 de G1, 2, 3 e 4 (p>0,05). Após a PDT (S3) em G1 e 2, houve redução adicional na densidade óptica do meio de cultura de 90,0% e 92,0%, respectivamente (p>0,05). No Grupo 5, a análise dos meios de cultura em S2 revelou um aumento de 3,2% na densidade óptica em comparação com S1(p>0,05). Nas imagens de MEV do G1, 2 e 5 foram evidenciadas dentina com áreas de fusão e recristalização. O PDT utilizado após preparo do canal radicular com sistema rotatório ou manual, associado ao NaOCl 2,5%, não foi capaz de eliminar completamente o E. faecalis em biofilme maduro presente no canal radicular.

Abstract This study evaluated the effect of photodynamic therapy (PDT) on infected root canals. Twenty-one human teeth were selected, and 18 were infected by E. faecalis for 60 days. The antimicrobial strategies tested were: G1. Root canal preparation (RCP) using Niquel-Titanium (NiTi) rotary instruments, 2.5% NaOCl, and final irrigation with 17% EDTA, followed by PDT with methylene blue photosensitizer and laser diode low power; G2. RCP using stainless steel files and the same irrigation and PDT protocols as G1; G3. Same RCP protocol as G1 without PDT; G4. Only irrigation with 2.5% NaOCl; G5. Same PDT protocol as G1 without RCP; G6. Negative control; G7. Positive control. Samples for microbiological tests were collected initially (S1), after RCP (S2), and after PDT (S3). Subsequently, the roots were sectioned and prepared for Scanning Electron Microscopy (SEM) analysis. Bacterial growth was analyzed according to the turbidity of the culture medium, followed by spectrophotometric optical density (nm). The effect of PDT on the dentinal structure was evaluated at magnifications 1,600X and 5,000X and described qualitatively. The Wilcoxon test was used for the comparisons from the same specimens, and the Mann-Whitney test was used to compare groups ((=5%). Bacteria were found in all experimental groups’ microbiological samples (S1, S2 and S3). The optical density of culture media was lower in S2 than in S1 of G1, 2, 3, and 4 (p> 0.05). After PDT (S3) in G1 and 2, there was an additional reduction in optical density of the culture medium, respectively (p>0.05). In Group 5, the analysis of culture media at S2 revealed an increase in optical density compared to S1(p>0.05). In SEM images of G1, 2, and 5, dentin with melting and recrystallization areas were evidenced. After preparation of the root canal with the rotary system or manually associated with 2.5% NaOCl, PDT was not able to completely eliminate E. faecalis present in the root canal.

Resumo Este estudo descreve um método para identificar canais radiculares acessórios usando o software e-Vol DX em imagens de TCFC. Os canais radiculares acessórios constituem abrigos estratégicos aos micro-organismos presentes nas infecções endodônticas. A identificação destes pequenos canais em exames radiográficos periapicais apresenta limitações, além de apresentar baixa acessibilidade natural a ação dos instrumentos endodônticos e dos agentes antimicrobianos. Os canais acessórios apresentam diâmetros suficientes para ficarem visíveis em imagens de tomografia computadorizada de feixe cônico (TCFC) de alta resolução espacial. Porém, podem passar despercebidos ou até confundidos quando não ocorrer treinamento específico para este tipo de diagnóstico. A metodologia consiste em estabelecer finos slices (0,1 mm ou menor) obtidos a partir de cortes coronal, sagital e axial. O método consiste nos seguintes passos: ao encontrar uma linha hipodensa de um canal radicular principal em um corte tomográfico (axial, sagital ou coronal) deve-se ajustar as linhas de navegação da reconstrução multiplanar (MPR) para que fiquem paralelas ao canal principal e perpendiculares a esta linha hipodensa (correção de paralaxe). A seguir, depois de criterioso ajuste da imagem em busca do canal acessório, aparece invariavelmente como uma linha em um dos cortes tomográficos da MPR, outra linha em outro corte e um ponto no terceiro corte. Os três cortes da MPR apresentam imagens com a sequência linha-linha-ponto. Desta maneira, pode-se identificar um canal acessório e visualizá-lo em reconstrução volumétrica em filtro específico. Esta metodologia é fácil de ser aplicada e pode beneficiar o diagnóstico quando se deseja identificar canais radiculares acessórios e distingui-lo de linha de fratura radicular.

Abstract This study describes a methodology to identify accessory root canals using the e-Vol DX software in CBCT scans. Accessory root canals are strategic shelters for microorganisms present in root canal infections. The identification of these small canals in periapical radiographic exams has limitations, besides being markedly limited accessibility to the action of endodontic instruments and to the antimicrobial agents. A significant number of accessory canals have sufficient diameters to be visible on cone-beam computed tomography (CBCT) images of high spatial resolution. Therefore, it may go unnoticed or even confused when there is no specific training for this type of diagnosis. The methodology consists in establishing thin slices (0.1mm or smaller) obtained from coronal, sagittal and axial slices. The method consists of the following steps: during navigation along the long axis of a root canal when finding a possible hypodense line of main root canal in a tomographic section (axial, sagittal or coronal), the navigation software lines of the multiplanar reconstruction (MPR) must be adjusted so that they are parallel and perpendicular to the hypodense line (parallax correction). Then, after judiciously adjusted, the accessory canal image will invariably appear as a line on one of the MPR tomographic slices, another line on another slice, and a dot on the third slice. The three sections of the MPR present images with the “line-line-dot” sequence. In this way, it is possible to identify an accessory root canal and also visualize it in volumetric reconstruction in a specific filter. The application of this method is easy to employed and may benefit the diagnosis when you want to visualize accessory root canals and distinguish it from root fracture line.

Abstract The site of the sinus tract depends on the rate of resistance against abscess exudate drainage, bone morphology, and distance from the root apex to the outer cortical bone. Objective To assess apical bone thickness in buccal and palatal/lingual aspects of maxillary and mandibular teeth, using a high-resolution cone-beam computed tomography (CBCT) system. Methodology In total, 422 CBCT examinations were included in the study, resulting in a sample of 1400 teeth. The scans were acquired by PreXion 3D, with a high-resolution protocol. The bone thickness was taken as the distance between the center of the apical foramen and the buccal and lingual/palatal cortical bone. The quantitative variables were expressed as mean values±standard deviation. The independent samples were analyzed using the t-test or the Mann-Whitney test (p<0.05). Results The lowest mean value of bone thickness was observed in the buccal cortical bone of the upper canines (1.49 mm±0.86) and in the upper central incisors (1.59 mm±0.67). In premolar teeth, the lowest values were found in the buccal cortical bone of upper first premolars (1.13 mm±0.68). In the posterior teeth, the lowest values were found in the buccal cortical bone of upper first molars (1.98 mm±1.33). In the lower second molar region, the buccal cortical bone (8.36 mm±1.84) was thicker than the lingual cortical bone (2.95 mm±1.16) (p<0.05). Conclusions The lowest mean values of bone thickness are in the buccal cortical bone of the maxillary teeth. In the mandible, bone thickness is thinner in the buccal bone around the anterior and premolar teeth, and in the lingual aspect of mandibular molars. All these anatomic characteristics could make the occurrence of the sinus tract more susceptible in these specific regions of the maxillary and mandibular alveolar bone.

Abstract: The purpose of this manuscript was to re-discuss apical periodontitis, apical biofilm, and its possible relationship with dendritic cells (DC). DCs are potent regulators of the immune system and their function is divided into three categories that involve the presentation of antigens: the presentation of antigens and activation of T cells; a not well established category suggested that DCs induce and maintain immunological tolerance; and the maintenance of the immune memory in conjunction with B cells. DCs in periapical inflammatory lesions are composed of at least two subpopulations that can be distinguished on the basis of ultrastructure and phenotype. These populations might differ in lineage, state of maturation, differentiation, activation, and/or function. The authors hereby analyzed the root apexes of teeth under SEM, after performing apicoectomy due to the failure of conventional endodontic treatment. Microbial biofilm with multispecies and areas of resorption with the presence of Howship lacunae, and images suggestive of denditric cells could be observed. The presence of DCs in periapical lesion could be an indication of the severity of the lesion, with a constant presence of antigen in the periradicular region.

O sucesso do tratamento endodôntico deve sempre ser o principal objetivo em todas as situações clínicas, evitando-se dentro do possível a perda do dente. O entendimento dos fatores de riscos associados aos fracassos alerta para a importância terapêutica. A lógica é reverter o quadro de doença presente, o que demanda intervenção para neutralizar a agressão e romper biofilme bacteriano presente no complexo anatômico. Quando as defesas imunológicas do hospedeiro são favoráveis, o sucesso é mais previsível. A óptica do sucesso para o profissional, para o paciente e para o dente é distinta. A vida útil do dente tratado endodonticamente (DTE) depende da qualidade do processo de sanificação (estratégias antimicrobianas, alargamento e selamento), cujo referencial apresenta como base o diagnóstico, o planejamento e a excelência da técnica operatória (endodôntica e reabilitadora). A presença de dor contínua, esporádica, e/ou desconforto, associada ao aspecto de uma imagem radiolúcida em DTE pode ser sugestivo de fracasso. As características de sucesso do tratamento (ausência de dor, regressão de periodontite apical (PA), espaço do canal radicular e coronário completamente obturado, e dente em função) devem ser avaliadas ao longo do tempo. Nos casos de dúvida, entre sucesso ou fracasso, a correta localização ou detecção da PA pode ser feita por tomografia computadorizada de feixe cônico (TCFC). A possibilidade de uma navegação pela imagem da TCFC pode caracterizar a realidade de uma estrutura multidimensional, auxiliando com informação precisa sobre a presença, ausência ou regressão da PA. A vida útil do DTE implica no entendimento de resultados biológicos e mecânicos como um evento multifatorial ao longo da vida do indivíduo.

Knowing the outcome of root canal treatment (RCT) is determinant to substantiate the clinical decision making process, especially when RCT is weighed against the extraction of natural teeth or replacement by prosthetic elements. The ideal scenario in all clinical situations should combine healing/prevention of disease (apical periodontitis) and the functional retention of the tooth. Understanding the risk factors associated with endodontic failure is a key factor to increase the chances of success. The logical action is to reverse the existing disease, which requires intervention to neutralize the bacterial invasion and disrupt the bacterial biofilm within the complex anatomy. Success is more predictable when the immune host defenses are favorable. However, success has different meanings to the dentist, to the patient and to the tooth itself. The life of an endodontically treated tooth depends on the accuracy of the diagnosis and planning, excellence of disinfection, instrumentation and filling procedures (antimicrobial strategies, root canal shaping and coronal and apical seal) and finally the rehabilitation management. The interpretation of constant or intermittent pain and/or discomfort associated with apical periodontitis (AP) in endodontically treated tooth may be suggestive of endodontic failure. The success features of RCT, namely absence of pain, regression of AP, tight seal of canal and coronal spaces, and recovery of tooth function, must be reevaluated over time. In case of doubt between success and failure, cone beam computed tomography (CBCT) could be indicated for detection and precise localization of AP. The possibility of map reading on CBCT images characterizes the real multidimensional structure, providing accurate information on the presence, absence or regression of AP. The survival of an endodontically treated tooth implies understanding the biological and mechanical outcomes as multifactorial events over the individual's life span. The objective of this review of literature is to discuss relevant factors associated with patient's health, tooth and dentist that could account for a successful RCT.

Um estudo retrospectivo foi realizado para identificar fatores clínicos e de diagnóstico associado com a dor de origem odontogênica. Foram selecionados 1765 pacientes que buscaram tratamento para dor odontogênica no Serviço de Urgência da Faculdade de Odontologia da Universidade Federal de Goiás. Os critérios de inclusão foram dor de origem pulpar ou periapical antes do tratamento dentário (mínimo de 6 meses depois da última consulta odontológica), e os critérios de exclusão foram dentes com anomalias de desenvolvimento e falta de informações ou registros incompletos. Avaliações clínicas e radiográficas foram realizadas para se obter as características clínicas de dor, incluindo origem, duração, frequência e localização da dor, testes de palpação, percussão e vitalidade pulpar, aspectos radiográficos, diagnóstico endodôntico e características dos dentes. Os testes qui-quadrado e regressão logística múltipla foram utilizados para verificar a associação entre a dor de origem pulpar e periapical e variáveis independentes. O diagnóstico endodôntico de dor de origem pulpar mais frequente foi pulpite sintomática (28,3%) seguido por pulpalgia hiper-reativa (14,4%), e o mais frequente de dor de origem periapical foi periodontite apical sintomática infecciosa (26,4%). Análise de regressão revelou que câmaras pulpares fechadas e cáries estavam altamente associadas à dor pulpar e, inversamente, câmara pulpar aberta estava associada à dor periapical (p<0,001). O diagnóstico endodôntico e fatores locais associados com dor de origem pulpar e periapical sugerem que os fatores clínicos importantes das dores pulpares foram câmaras pulpares fechadas e cáries, e de dor periapical foi câmara pulpar aberta.

A retrospective survey was designed to identify diagnostic subgroups and clinical factors associated with odontogenic pain and discomfort in dental urgency patients. A consecutive sample of 1,765 patients seeking treatment for dental pain at the Urgency Service of the Dental School of the Federal University of Goiás, Brazil, was selected. Inclusion criteria were pulpal or periapical pain that occurred before dental treatment (minimum 6 months after the last dental appointment), and the exclusion criteria were teeth with odontogenic developmental anomalies and missing information or incomplete records. Clinical and radiographic examinations were performed to assess clinical presentation of pain complaints including origin, duration, frequency and location of pain, palpation, percussion and vitality tests, radiographic features, endodontic diagnosis and characteristics of teeth. Chi-square test and multiple logistic regression were used to analyze association between pulpal and periapical pain and independent variables. The most frequent endodontic diagnosis of pulpal pain were symptomatic pulpitis (28.3%) and hyperreactive pulpalgia (14.4%), and the most frequent periapical pain was symptomatic apical periodontitis of infectious origin (26.4%). Regression analysis revealed that closed pulp chamber and caries were highly associated with pulpal pain and, conversely, open pulp chamber was associated with periapical pain (p<0.001). Endodontic diagnosis and local factors associated with pulpal and periapical pain suggest that the important clinical factor of pulpal pain was closed pulp chamber and caries, and of periapical pain was open pulp chamber.

OBJECTIVE: The aim of this study was to detect the prevalence of selected bacterial species in intraoral sites of patients with chronic periodontitis (CP) using multiplex polymerase chain reaction (PCR). METHODOLOGY: Samples were collected from the tongue dorsum, buccal mucosa, supragingival and subgingival plaque and saliva of 30 patients with untreated CP. Multiplex PCR was used to determine prevalence rates, which were then compared using a chi-square test. Significance level was set at p<0.05. Mean and standard deviation values were used to evaluate variations in prevalence according to site. RESULTS: The prevalence of S. mutans was 70% in saliva; 60% in samples collected from the tongue dorsum; 50% in samples collected from the buccal mucosa; 56.5% in the supragingival plaque; and 53.5% in the subgingival plaque. The prevalence of E. faecalis ranged from 3.5% to 13.5% in all intraoral microenvironment. The highest prevalence of P. gingivalis was found in subgingival plaque (53.5%), and of P. intermedia in supragingival plaque (33.5%), subgingival plaque (30%) and tongue dorsum (33.5%). The prevalence of bacteria did not vary significantly among the intraoral sites. CONCLUSIONS: All studied bacteria were identified in intraoral sites. S. mutans, P. gingivalis and P. intermedia had high prevalence rates, but the prevalence of E. faecalis was low. Multiplex PCR proved to be an adequate method for epidemiological studies.

The purpose of this work was to develop a model system to study antimicrobial strategies in endodontic biofilms. Enterococcus faecalis suspension was colonized in 10 human root canals. Five milliliters of Brain Heart Infusion (BHI) were mixed with 5 mL of the bacterial inoculums (E. faecalis) and inoculated with sufficient volume to fill the root canal during 60 days. This procedure was repeated every 72 h, always using 24-h pure culture prepared and adjusted to No. 1 MacFarland turbidity standard. Biofilm formation was analyzed by scanning electron microscopy (SEM). E. faecalis consistently adhered to collagen structure, colonized dentin surface, progressed towards the dentinal tubules and formed a biofilm. The proposed biofilm model seems to be viable for studies on antimicrobial strategies, and allows for a satisfactory colonization time of selected bacterial species with virulence and adherence properties.

The purpose of this paper is to discuss critically the antibacterial efficacy of intracanal medicaments on bacterial biofilm. Longitudinal studies were evaluated by a systematic review of English-language articles retrieved from electronic biomedical journal databases (MEDLINE, EMBASE, CENTRAL) and handsearching records, using different matches of keywords for root canal biofilm, between 1966 and August 1st, 2007. The selected articles were identified from titles, abstracts and full-text articles by two independent reviewers, considering the tabulated inclusion and exclusion criteria. Disagreements were resolved by consensus. The search retrieved 91 related articles, of which 8.8% referred to in vivo studies demonstrating the lack of efficacy of endodontic therapy on bacterial biofilm. Intracanal medicaments were found to have a limited action against bacterial biofilm.

O objetivo do estudo transversal foi avaliar a prevalência de dentes tratados endodonticamente em uma população de Brasileiros adultos. Um total de 1.401 radiografias panorâmicas, oriundas do banco de imagens do Centro de Radiologia e Imagens Orofacial de Cuiabá (CRIOF, Cuiabá, MT, Brasil), entre agosto de 2002 e setembro de 2007 foi analisado. Três examinadores avaliaram todas as imagens, considerando-se a presença de tratamento endodôntico, indiferente à qualidade do tratamento (presença ou ausência de retentor intra-radicular ou periodontite apical). Os dados foram estatisticamente avaliados empregando-se razão de chances (odds ratio), regressão logística e teste Qui-quadrado. A partir de 29.467 dentes avaliados, 6.313 (21,4%) eram endodonticamente tratados. Os pré-molares e molares superiores foram os dentes com maior prevalência de tratamento, enquanto os incisivos inferiores representaram o grupo de menor prevalência. Indivíduos do gênero feminino (61,9%), e com idade entre 46 a 60 anos apresentaram maior prevalência de tratamento endodôntico. O presente estudo encontrou elevada prevalência de dentes tratados endodonticamente em adultos Brasileiros comparada com outros estudos epidemiológicos.

This cross-sectional study examined the prevalence of endodontically treated teeth in 1,401 Brazilian adults. Panoramic radiographs were selected at the Radiological Center of Orofacial Images (CRIOF, Cuiabá, MT, Brazil) between August 2002 and September 2007. Three independent endodontists discussed interpretation criteria and classified specimens according to the following data: presence of root canal treatment, which was defined as partially or completely filled canal space, regardless of whether filling ended at the radiographic apex or not; presence of intracanal post; and associated apical periodontitis. Odds ratio, logistic regression and a chi-square test were used for statistical analyses. Significance level was set at p<0.05. Of 29,467 teeth evaluated, 6,313 (21.4%) were treated endodontically. Endodontic treatment was most frequent in maxillary premolars and molars, whereas mandibular incisors showed the lowest prevalence. Most endodontically treated teeth were found in people aged 46 to 60 years (47.6%, p<0.001) and the prevalence increased with age in this age range. Females (61.9%, p<0.001) showed a higher prevalence of teeth with root fillings than males. The present study found a higher prevalence of endodontically treated teeth in a Brazilian adult population compared to the prevalence reported in epidemiological studies conducted in other countries.

Objetivo deste estudo foi verificar a influência do Iodofórmio no potencial antimicrobiano do hidróxido de cálcio. S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans foram os indicadores biológicos. As substâncias testadas foram: hidróxido de cálcio + solução salina; hidróxido de cálcio + iodofórmio + solução salina; iodofórmio + solução salina. Para o teste de difusão em ágar, 18 placas de Petri contendo 20 ml de ágar BHI foram inoculadas com as suspensões microbianas. Cinqüenta e quatro cavidades foram feitas e preenchidas com as substâncias testadas. Os diâmetros da inibição microbiana foram então mensurados. No teste de exposição direta, 162 pontas de papel absorvente número 50 esterilizadas foram imersas nas suspensões experimentais por 5 minutos, e cobertas pelas pastas testadas. Em intervalos de 24, 48 e 72 horas, as pontas de papel foram imersas em 10 ml de Letheen Broth, seguido de incubação a 37°°C por 48 horas. O crescimento microbiano foi avaliado pela turvação do meio de cultura. Um inóculo de 0.1 ml obtido do Letheen Broth foi transferido para 7 ml de BHI, e incubado a 37°°C por 48h. o crescimento bacteriano foi novamente avaliado pela turvação do meio de cultura. As pastas contendo hidróxido de cálcio e solução salina, hidróxido de cálcio-iodofórmio e solução salina mostraram significativa atividade antimicrobiana nos métodos experimentais estudados. A pasta contendo iodofórmio e solução salina foi inefetiva pelo teste de difusão em agar e, também, por exposição direta, para o B. subtilis e a mistura.

The purpose of this research was to verify the influence of Iodoform on antimicrobial potential of calcium hydroxide. S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans were the biological indicators. The substances tested were: calcium hydroxide + saline; calcium hydroxide + Iodoform + saline; Iodoform + saline. For the agar diffusion test, 18 Petri plates with 20 ml of BHI agar were inoculated with the microbial suspensions. Fifty-four cavities were made and filled with the substances tested. The diameters of microbial inhibition were then measured. In direct exposure test, 162 #50 sterile absorbent paper points were immersed in the experimental suspensions for 5 min, and covered with the pastes. At intervals of 24, 48 and 72 hours, the paper points were immersed in 10 ml of Letheen Broth, followed by incubation at 37°°C for 48h. Microbial growth was evaluated by turbidity of the culture medium. A 0.1 ml inoculum obtained from the Letheen Broth was transferred to 7 ml of BHI, and incubated at 37°°C for 48h. Bacterial growth was again evaluated by turbidity of the culture medium. The calcium hydroxide associated with the saline or the iodoform plus saline showed antimicrobial effectiveness in both experimental methods. The iodoform paste presented antimicrobial ineffectiveness for the agar diffusion test on all biological microorganisms and for the direct exposure test on B. subtilis and on the mixture.

O objetivo do presente estudo foi comparar o efeito antimicrobiano de diferentes pastas obturadoras do canal radicular usadas na Odontopediatria, por dois métodos experimentais. Os materiais testados foram: pasta Guedes Pinto, pasta de óxido de zinco e eugenol, pasta de hidróxido de cálcio, pasta CTZ e Vitapex®, sobre cinco microrganismos (S. aureus, E. faecalis, P. aeruginosa, B. subtilis e C. albicans) obtidos do American Type Culture Collection. As cepas foram inoculadas no Brain Heart Infusion (BHI) e incubadas a 37ºC por 24 h. Para o teste de contato direto, 72 pontas de papel foram contaminadas com suspensões padrão dos microrganismos e expostas às pastas obturadoras por 1, 24, 48 e 72 h. As pontas foram imersas em Letheen Broth (LB), seguido de incubação a 37ºC por 48 h. Um inóculo de 0,1 mL obtido do LB foi transferido para 7 mL de BHI, sobre condições idênticas de incubação e o crescimento microbiano foi avaliado. As pastas mostraram ação entre 1 e 24 h, dependendo da pasta testada. Para o teste de difusão em ágar, 30 placas de Petri com 20 mL de agar BHI foi inoculada com 0,1 mL da suspensão microbiana, utilizando-se de swab esterilizado, semeado de modo confluente no meio. Três cavidades foram feitas em cada placa de ágar (total = 90) e completamente preenchidas com uma das pastas obturadoras. As placas foram pré-incubadas por 1 h em temperatura ambiente e então incubadas a 37ºC por 48 h. As zonas de inibição em torno das cavidades foram mensuradas. O efeito antimicrobiano completo obtido pelas pastas analisadas, por meio do teste por contato direto, foi observado após 24 h em todos os microrganismos. No teste por difusão em ágar, todos os materiais induziram a formação de zonas de inibição, exceto o Vitapex® (variando de 6,0 - 39,0 mm).

The objective of this study was to compare, by two experimental methods, the antimicrobial efficacy of different root canal fillingpastes used in pediatric dentistry. The tested materials were: Guedes-Pinto paste (GPP), zinc oxide-eugenol paste (OZEP), calcium hydroxide paste (CHP), chloramphenicol + tetracycline + zinc oxide and eugenol paste (CTZP) and Vitapex®. Fiven microbial strains (S. aureus, E. faecalis, P. aeruginosa, B. subtilis and C. albicans) obtained from the American Type Culture Collection were inoculated in Brain Heart Infusion (BHI) and incubated at 37ºC for 24 h. For the direct exposure test (DET), 72 paper points were contaminated with the standard microbial suspensions and exposed to the root canal filling pastes for 1, 24, 48 and 72 h. The points were immersed in Letheen Broth (LB), followed by incubation at 37ºC for 48 h. An inoculum of 0.1 mL obtained from LB was then transferred to 7 mL of BHI, under identical incubations conditions and the microbial growth was evaluated. The pastes showed activity between 1 and 24 h, depending on the material. For the agar diffusion test (ADT), 30 Petri plates with 20 mL of BHI agar were inoculated with 0.1 mL of the microbial suspension, using sterile swabs that were spread on the medium. Three cavities were made in each agar plate (total = 90) and completely filled with one of the filling root canal pastes. The plates were pre-incubated for 1 h at room temperature and then incubated at 37ºC for 24 to 48 h. The inhibition zone around each well was recorded in mm. The complete antimicrobial effect in the direct exposure test was observed after 24 h on all microbial indicators. All root canal filling materials induced the formation of inhibition zones, except for Vitapex® (range, 6.0-39.0 mm).

Estudou-se a tensão superficial do hidróxido de cálcio associado a diferentes substâncias (água destilada deionizada, paramonoclorofenol canforado, digluconato de clorexidina 2%, Otosporin, sulfato éter lauril sódio 3%, furacin, PMC furacin) usando tensiômetro. O modelo experimental consistiu na aplicação de uma força para separar um anel de platina imerso na superfície das substâncias, exercido por um tensiômetro. Considerando a metodologia aplicada, pode-se concluir: a água destilada isolada ou associada com o hidróxido de cálcio apresenta alta tensão superficial (70,00 e 68,40 dinas/cm); hidróxido de cálcio associado ao detergente aniônico mostrou baixa tensão superficial (31,60 dinas/cm); paramonoclorofenol canforado mais hidróxido de cálcio apresentou baixa tensão superficial (37,50 dinas/cm); clorexidina 2% associada com hidróxido de cálcio mostrou um alto valor de tensão superficial (58,00 dinas/cm); Otosporin mais hidróxido de cálcio mostrou baixa tensão superficial (35,40 dinas/cm); paramonoclorofenol furacin misturado com hidróxido de cálcio apresentou tensão superficial igual a 45,50 dinas/cm; hipoclorito de sódio apresentou alta tensão superficial (75,00 dinas/cm).

The purpose of this study was to evaluate the surface tension of calcium hydroxide (CH) associated with different substances (deionized distilled water, camphorated paramonochlorophenol, 2% chlorhexidine digluconate, Otosporin, 3% sodium lauryl ether sulphate; Furacin, PMC Furacin) using tensiometer. The action of the substances studied on the dentinal structure enhances the property of surface tension. This method consists in the application of force to separate a platinum ring immersed in the substances. Thus, torsion was applied to the screw until the platinum ring separated during substances testing. Considering the methodology applied, the following can be concluded: distilled water alone or associated with CH presented a high surface tension (70.00 and 68.40 dynes/cm); calcium hydroxide in association with anionic detergent showed low surface tension (31.60 dynes/cm); camphorated paramonochlorophenol plus CH presented low surface tension (37.50 dynes/cm); 2% chlorhexidine associated with calcium hydroxide showed high surface tension values (58.00 dynes/cm); Otosporin plus calcium hydroxide showed low surface tension (35.40 dynes/cm); paramonochlorophenol Furacin mixed with calcium hydroxide presented surface tension equal to 45.50 dynes/cm; sodium hypochlorite presented high surface tension (75.00 dynes/cm). Antimicrobial agents more indicated in endodontics, i.e. CH, chlorhexidine and hypochlorite, presented the highest surface tension.

O objetivo deste estudo foi analisar o tempo necessário para que o hidróxido de cálcio elimine microrganismos em canais infectados. Um total de 168 dentes humanos anteriores foram preparados e esterilizados. Cento e sessenta e dois dentes foram inoculados com suspensões de S. aureus, E. faecalis, P. aeruginosa, B. subtilis e C. albicans. Três dentes foram usados como controle negativo e três como controle positivo. Os canais radiculares foram irrigados com solução fisiológica e preenchidos com pasta de hidróxido de cálcio. Em intervalos de 1 minuto, 7, 15, 21, 27, 30, 45, 60 e 90 dias, a pasta foi removida, amostras foram coletadas e imersas em Letheen Broth. O crescimento microbiano foi analisado por dois métodos, turvação do meio de cultura e subcultura em caldo Brain Heart Infusion (BHI). Após alterações do Letheen Broth, um inóculo de 0,1 mL do meio foi transferido para 7 mL de BHI, e subseqüentemente incubado a 37°C for 48h. O crescimento microbiano foi analisado pela turvação do meio de cultura e em alguns casos pela coloração de Gram. Todos os ensaios foram feitos em triplicata, obedecendo a técnica asséptica. Os resultados indicaram que o efeito antimicrobiano, em culturas de S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans e uma cultura mixta em canais infectados, ocorreu em 60 dias.

The objective of this study was to analyze the time necessary for calcium hydroxide to eliminate microorganisms in infected canals. A total of 168 human anterior teeth were prepared and sterilized. One hundred sixty two teeth were inoculated with suspensions of S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans. Three teeth were used as negative control and three as positive control. Root canals were irrigated with saline and filled with calcium hydroxide paste (CHP). At intervals of 1 minute, and at 7, 15, 21, 27, 30, 45, 60, and 90 days, CHP was removed, samples were collected and immersed in Letheen Broth (LB). Microbial growth was analyzed by two methods, turbidity of the culture medium and subculture on a Brain heart Infusion. After looking for medium change, an inoculum of 0.1 mL obtained from LB was transferred to 7 mL of Brain Heart Infusion (BHI), and subsequently incubated at 37°C for 48 hours. Microbial growth was checked by turbidity of the culture medium and in some cases by Gram stain. All assays were carried out in triplicate under aseptic technique. The results indicated that the antimicrobial effect on the cultures of S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans and one mixed culture in infected canals by CHP occurred in 60 days.