Durante o preparo químico-cirúrgico são utilizados instrumentos e substâncias químicas, que constituem um binômio indivisível e necessário para alcançar a modelagem e a sanificação dos canais radiculares. Assim, propõe-se com este trabalho avaliar in vivo, por meio de método molecular de PCR quantitativo, baseado em DNA (qPCR), a eficiência do preparo químico-cirúrgico empregando como agente de irrigação o Hipoclorito de Sódio (NaOCL) a 2,5% ou o Gel de Endo PTC associado ao Hipoclorito de Sódio a 1,0% na redução bacteriana de canais radiculares de dentes portadores de periodontite apical primária. Foram selecionados 30 pacientes portadores de infecção endodôntica primária, totalizando 30 dentes, com rarefação óssea periapical visível na radiografia, sem tratamento endodôntico prévio. Os pacientes foram divididos de forma randomizada em dois grupos distintos, de acordo com a substância química auxiliar utilizada durante a instrumentação, NaOCL 1% + Endo-PTC leve ou NaOCL 2,5%. Em todos os casos empregou-se instrumentos Reciproc R40 ou R50 e as coletas foram realizadas antes (S1) e após o prepare químico-cirúrgico (S2). A análise de aderência foi realizada por meio do teste de Kolmogorov-Smirnov, as análises intragrupo foram realizadas com teste de Wilcoxon para amostras relacionadas e as comparações entre os dois grupos foram realizadas com o teste de Mann-Whitney, para a análise quantitativa de bactérias. Em ambos os grupos, houve diminuição significativa no número de bactérias entre S1 e S2 (p<0,05). No grupo NaOCL 1% + Endo-PTC leve, houve redução de 3,7x105(S1) para 5,7x104 (S2). No grupo NaOCl 2,5%, redução de 1,3x105 (S1) para 1,1x104(S2). Na comparação entre grupos, o NaOCL a 2,5% (91,62%) promoveu maior redução bacteriana do que o grupo NaOCL 1% + Endo-PTC (84,60%) (p<0,05). / During the chemomechanical preparation, instruments and chemical substances are used, which constitute an indivisible and necessary binomial to achieve modeling and sanification. Knowing the auxiliary chemical substances, understanding their mechanisms of action, being able to use them efficiently, is fundamental, so that the chemical-surgical preparation is well performed by the clinician. Thus, the purpose of this study is to evaluate in vivo, the efficiency of the chemomechanical preparation using as the irrigant agent 2,5% sodium hypochlorite and Endo-PTC gel, associated to 1% sodium hypochlorite, to assess the bacterial reduction of root canals of teeth with primary apical periodontitis, using a molecular quantitative method DNA-based - polymerase chain reaction (qPCR). Were selected 30 patients with primary infection totaling 30 teeth, with visible periapical bone rarefaction on the radiography, without previous endodontic treatment. Patients were randomly divided into two distinct groups according to the auxiliary chemical substances used during the instrumentation, 1% sodium hypochlorite associated with Endo-PTC gel or 2,5% sodium hypochlorite. In all cases, reciproc instruments R40 or R50 were used and the samples were taken before (S1) and after chemical surgical preparation (S2). The adherence analysis was performed using the Kolmogorov-Smirnov test, intragroup analysis were performed with Wilcoxon test for related samples and comparisions between the two groups were performed with the Mann-Whitney test for the quantitative analysis of bacteria. In the both groups, there was a significant decrease in the number of bacteria between S1 and S2 (p<0,05), the inicial sample (S1) of the group Endo-PTC, the median 3,7x105, reduced to 5,7x104. In the other group of NaOCl, the median in S1 was 1,3x105 that reduced to 1,1x104 . In the comparision between groups, the 2,5% NaOCl promoted a greater microbial reduction of 91,62%, than the Endo-PTC associated with 1% NaOCl (p<0,05) 84,60%.

O presente estudo teve por objetivo avaliar in vivo a eficácia do preparo de canais radiculares na redução bacteriana em dentes portadores de periodontite apical primária, com auxílio do sistema EndoVac de irrigação e aspiração. Foram coletadas amostras dos canais radiculares de 20 pacientes, antes (S1) e após (S2) o preparo com instrumentos rotatórios Protaper, variando somente a técnica utilizada para irrigação e aspiração: Grupo A (irrigação convencional n=10) e Grupo B (irrigação com auxílio do sistema EndoVac n=10). Após a extração do DNA presente nas amostras, este foi quantificado através da reação de PCR em tempo real, pelo método SYBR Green, identificando o número de cópias do gene 16SrRNA. Em todas as amostras, com exceção de uma pós-preparo com EndoVac, foram identificadas cópias do gene alvo. A média para todos os casos foi de 1,6 X 108 e 8,8 X 105 cópias do 16SrRNA, antes e após o preparo, respectivamente. Para os grupos isoladamente, os mesmos valores foram: 2,0 X 108 e 5,5 X 105 (convencional), e 1,1 X 108 e 1,2 X 106 (EndoVac). O percentual médio de redução foi de 97,52% (97,02% para convencional e 98,04% para o EndoVac). O teste de Mann-Whitney permitiu concluir que ambas as técnicas reduziram significativamente os microrganismos presentes antes do preparo (p<0,0001), sem haver diferença entre as mesmas (p=0,9705). Nenhuma das técnicas foi efetiva na eliminação completa de bactérias sob a metodologia utilizada. A eficácia antibacteriana do sistema EndoVac, sob esta metodologia, foi semelhante a obtida com a irrigação e aspiração convencional. / The present study aimed to analyze in vivo the effectiveness of root canal preparation on bacterial reduction in patientss teeth with primary apical periodontitis. Samples were collected from 20 patients before (S1) and after (S2) preparation with ProTaper rotary files, varying only the technique used for irrigation and aspiration: Group A (conventional irrigation - n = 10) and Group B (with the aid of EndoVac system - n = 10). After extraction, the DNA present in the samples was quantified by real-time PCR with the SYBR Green method, identifying the number of 16SrRNA gene copies. In all samples, except for a post-preparation case with EndoVac, copies of the target gene were identified. Average for all cases was 1,6 X 108 and 8,8 X 105 copies of the 16SrRNA, before and after preparation, respectively. For the groups separately, the same values were 2,0 X 108 and 5,5 X 105 (conventional) and 1,1 X 108 and 1,2 X 106 (EndoVac). The mean percentage of reduction was 97.52% (97.02% for the conventional and 98.04% for the EndoVac). The Mann-Whitney test concluded that both techniques significantly reduced the microrganisms after preparation (p<0,0001), with no differences between them (p=0,9705). None of the techniques were effective in the complete elimination of bacteria under this methodology. The antibacterial efficacy of the EndoVac system under this methodology was similar to that obtained with conventional irrigation and aspiration.

Made available in DSpace on 2016-12-23T14:37:37Z (GMT). No. of bitstreams: 1 Fabiola Lacerda de Souza Barros.pdf: 6472406 bytes, checksum: d8013423c68ed8608b3a5668f18e35ac (MD5) Previous issue date: 2008-07-10 / Foram realizados experimentos in vivo e in vitro objetivando a propagação assexuada do mamoeiro (Carica papaya L.). O experimento in vivo foi realizado com a cultivar Golden , do grupo Solo , em lavoura comercial com dois anos e meio de idade em final de produção, onde se estudou o efeito da poda em diferentes alturas do tronco (inteira sem o ápice, 0,5, 1,0, 1,5, 2,0 m) a partir do solo, para se identificar qual destas proporcionaria maior rendimento de brotações laterais aptas à estaquia. Uma contagem de brotações aos 25 dias após a poda a diferentes alturas foi realizada no experimento in vivo. As brotações contabilizadas foram podadas e, posteriormente, feita outra contagem de novas brotações aos 50 dias. Com a poda a 2,0 metros de altura, obteve-se maior número de brotações aos 25 e aos 50 dias, no período do verão, mostrando viabilidade no reaproveitamento de lavouras em final de produção na propagação assexuada. Meios de enraizamento foram testados nos experimentos in vitro. No primeiro experimento foram estudadas as concentrações do meio MS a 100%, 50% da força e MS modificado associados aos níveis do regulador de crescimento AIB (0; 0,1; 0,2; 0,4 e 0,8 mg L-1). No primeiro experimento o enraizamento foi insatisfatório devido à contaminação bacteriana, aliada a uma possível fitotoxidez do antibiótico utilizado (cefotaxima 100 mg L-1), ou ainda, ao acúmulo de citocinina remanescente da fase de multiplicação, prejudicando as reações morfogênicas e o enraizamento. No segundo experimento, utilizou-se meio de enraizamento contendo ou não carvão ativo, na concentração 1gL-1, associado aos níveis do regulador de crescimento ANA (0; 0,25; 0,5; 1,0; 2,0 mgL-1). Também não se obteve sucesso no enraizamento, provavelmente pela quantidade ou associação dos antibióticos utilizados (rifampicina 300 mg L-1 +cloranfenicol 100 mg L-1) ao meio de cultura, mesmo tendo controlado acontaminação bacteriana. O carvão ativo a 1 g L-1 acrescentado ao meio, apesar de não auxiliar o enraizamento, mostra significância de forma isolada, sendo benéfico ao desenvolvimento da parte aérea e impedindo o calejamento na base dos ramos, mostrando eficiência na adsorção de substâncias tóxicas do meio de cultivo, em relação ao tratamento que não recebeu o carvão ativo / The experiments were carried out in vivo and in vitro having of the objective the assexual reproduction of the papaya tree (Carica papaya L.). The experiment in vivo was accomplished with to cultivate Golden, of the group Sole, in commercial farming with two and a half years of age in production end, where it was studied the effect of the pruning in different heights of the trunk (it completes without the apex, 0,5, 1,0, 1,5, 2,0 m) starting from the ground, and to identify which of these it would provide larger income of capable production of lateral shoots to the cutting. With the pruning to 2,0 meters of height was obtained larger shoots number, in two consecutive pruning, in other words, to the 25 and 50 days, in the period of the summer, showing viability in the recycling of farmings in production end in the assexual reproduction. In the experiments in vitro were tested rooting medium. In the first experiment were studied the concentrations of the MS medium of 100%, 50% of the force and MS modified associates at the levels of the growth regulator AIB (0; 0,1; 0,2; 0,4 and 0,8 mg L-1). The rooting was unsatisfactory due to the bacterial contamination, allied to a possible phytotoxity of the used antibiotic (cephotaxin 100 mg L-1), or still, to the kitocinin accumulation remaining of the multiplication phase harming the morphogenics reactions and the rooting. In the second experiment was used rooting medium containing (1 g L-1) or not active coal, associate at the levels of the growth regulator ANA (0; 0,25; 0,5; 1,0 and 2,0 mg L-1). It was not also obtained success in the rooting probably for the amount or association of the antibiotics used (Rifampicin 300 mg L-1 + cloranphenicol 100 mg L-1) in the culture medium, even having controlled the bacterial contamination. The active coal to 1 g L-1 increased to the medium, in spite of not aiding the rooting show significance in an isolated way, being beneficial to the development of the aerial part and impeding the calluse in the base of the shoots, showing efficiency in the adsorption of poisonous substances of the culture medium, in relation to the treatment that didnt receive the active coal

La capacité d’une plante à réguler sa croissance racinaire est une composante importante de l’acclimatation aux stress environnementaux. A l’échelle cellulaire, cette régulation est effectuée via le contrôle de la division et de l’élongation des cellules mais les rôles respectifs de chaque processus et leurs interactions sont peu connus. Notamment, l’activité de production de cellules du méristème apical racinaire (RAM) est trop souvent négligée. Dans cette thèse, l’analyse spatiale de la croissance le long de l’apex racinaire et l’analyse temporelle des trajectoires de croissance des cellules ont été couplées pour comprendre les liens existants entre division et élongation cellulaire. Pour cela, j’ai développé un système de phénotypage de la croissance à haute résolution spatio-temporelle qui a été appliqué à l’étude de racines d’un peuplier euraméricain (Populus deltoides × Populus nigra) en réponse à différents stress (stress osmotique, impédance mécanique). Une forte variabilité du taux de croissance racinaire entre individus ainsi que des variations individuelles cycliques de la croissance ont été observées malgré des conditions environnementales contrôlées. L’utilisation de cette variabilité couplée à la quantification de l’activité du RAM a mis en évidence l’importance du taux de production de cellules pour soutenir la croissance racinaire. Ces travaux analysent une nouvelle échelle de variations spatiales et temporelles de la croissance peu prise en compte jusqu’à présent. Hautement applicable à d’autres questions scientifiques, l’analyse du devenir des cellules une fois sortie du RAM est également discutée pour des conditions de croissance non stables / Regulation of root growth is a crucial capacity of plants for acclimatization to environmental stresses. At cell scale, this regulation is controlled through cell division and cell elongation but respective importance of these processes and interactions between them are still poorly known. Notably, the cell production activity of the root apical meristem (RAM) is often excluded. During this thesis, spatial analyses of growth along the root apex were coupled with temporal analyses of cell trajectories in order to decipher the links between cell division and cell elongation. This required the setup of a system for phenotyping root growth at a high spatiotemporal resolution which was applied to study the growth of roots from an euramerican poplar (Populus deltoides × Populus nigra) in response to different environmental stresses (osmotic stress or mechanical impedance). An important variability of root growth rate between individuals as well as individual cyclic variations of growth along time were observed despite tightly controlled environmental conditions. Use of this variability coupled with quantification of the RAM activity led us to a better understanding of the importance of the cell production rate for sustaining root growth. This work analyses a new spatiotemporal scale of growth variability poorly considered. Widely applicable to others scientific questioning, temporal analyses of cell fate once produced in the RAM is also discussed for non-steady growth conditions

En se développant, les plantes produisent des organes le long des tiges suivant des organisations stéréotypées, appelées phyllotaxies. Ces structures se forment dans les méristèmes, qui abritent une niche de cellules souches : les organes y sont produits successivement et leur positionnement dépendrait d'interactions dynamiques avec les organes pré-existants. Ces interactions seraient notamment dues à des champs inhibiteurs générés par le transport polaire de l'hormone végétale auxine. Afin de rechercher si d'autres facteurs que l'auxine contrôlent la phyllotaxie chez Arabidopsis thaliana, nous nous sommes intéressés au rôle possible des cytokinines, une autre hormone végétale. Nous avons développé des nouvelles méthodes statistiques pour analyser la structure de la phyllotaxie. Cette approche nous a permis d'identifier des anomalies de phyllotaxie chez des plantes mutantes pour le gène AHP6 (ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER protein 6), un inhibiteur de la signalisation des cytokinines. Notre analyse suggérait des possibles perturbations du plastochrone, la période de temps séparant l'initiation de deux organes, ce que nous avons alors confirmé par imagerie confocale en temps réel. Nos données montrent que AHP6 contrôle la régularité du plastochrone, et suggèrent que les perturbations de phyllotaxies sont dues à l'initiation simultanée de deux à trois organes dans le méristème. De plus, AHP6 est exprimé dans les organes et sa protéine établit des champs qui inhibent la signalisation des cytokinines au delà des organes. Pour mieux comprendre les rôles possibles de ces champs, nous avons généré un modèle numérique théorique de la phyllotaxie. Notre étude suggère que le plastochrone pourrait être déstabilisé par du bruit affectant le seuil d'activation nécessaire aux cellules méristématiques pour se différencier en organe. Des champs inhibiteurs pourraient filtrer les effets de ce bruit en influant sur la cinétique d'émergence des organes. Les propriétés observées des champs de AHP6 sont en accord avec ce modèle et nos données expérimentales suggèrent en effet que AHP6 et les cytokinines peuvent moduler la signalisation auxine lors de l'émergence des organes. Nous proposons comme modèle que le transport et la signalisation de l'auxine positionnent de manière robuste les organes mais génèrent un plastochrone irrégulier en présence de bruit. Des champs inhibiteurs de cytokinines stabiliseraient le plastochrone, assurant un couplage plus robuste entre le temps et l'espace lors de l'établissement de la phyllotaxie. / During development, plant aerial organs are produced along the stems following stereotyped patterns. This so-called phyllotaxis is initiated at the shoot meristem, which contains the stem cell niche: organs are produced iteratively and their precise position is thought to depend on dynamic interactions with preexisting organs. These interactions would notably result from inhibitory fields generated by the polar transport of the plant hormone auxin. To investigate whether other factors than auxin regulate phyllotaxis, we studied the potential role of cytokinin signaling. We developed a new pipeline of methods based on statistics to analyze phyllotactic patterns. This approach allowed us to identify phyllotactic perturbations in mutants of the AHP6 (ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER protein 6), an inhibitor of cytokinin signaling that suggested perturbations in the plastochron, the time between two organ initiations. This was further confirmed using confocal live-imaging. We demonstrated that AHP6 controls the regularity of the plastochron, and our results suggest that the defective phyllotaxis in ahp6 is caused by concomitant initiations of two or three organs in the meristem. Interestingly, AHP6 is expressed in organs and the protein can move beyond these domains, generating cytokinin signaling inhibitory fields. To explore further the putative role of these secondary fields, we generated a mathematical model of phyllotaxis. This suggested that plastochron instabilities could be caused by noise affecting the threshold at which meristematic cells are recruited into organs. Inhibitory fields generated by AHP6 could filter out the effect of noise by modifying the kinetics of early organ emergence. Consistently, the properties of AHP6 fields fit the model predictions and our experimental data show that AHP6 and cytokinin modulate auxin signaling during organ emergence. We thus propose a model in which auxin transport and signaling robustly control organ positioning but generates plastochron instablities in noisy backgrounds. In this scenario cytokinin inhibitory fields would stabilize the rhythmicity of organ initiation, ensuring a robust coupling of space and time during pattern formation.

La reabsorción radicular es el proceso de eliminación de cemento y / o dentina a través de la actividad fisiológica o patológica. La reabsorción radicular patológica puede ocurrir en asociación con varias afecciones como el trauma, reimplantación, terapia de ortodoncia, erupción tardía e irregular de dientes o tumores y quistes en expansión. La reabsorción radicular localizada en un diente asociado a una lesión apical crónica de origen inflamatorio pos-trauma, podría ocasionar un ápice abierto. Es importante establecer un correcto diagnóstico, plan de tratamiento y controles para estos casos. El tratamiento indicado para un diente con ápice abierto, lesión apical crónica de origen inflamatorio pos-trauma, es realizar un tope apical para evitar la extrusión de las soluciones de irrigantes y los materiales de relleno hacia la zona periapical. En la actualidad el uso de los cementos biocerámicos es recomendado para realizar topes apicales mostrando excelentes resultados en biocompatibilidad y micro-dureza; existiendo diferentes cementos biocerámicos para conseguir tal propósito. El objetivo de este reporte de caso es presentar el manejo clínico de una reabsorción con ápice abierto realizando un tope apical con el cemento biocerámico NeoMta ™ Plus ®. / Root resorption is the process of separating cement and / or dentin through physiological or pathological activity. Pathological root resorption can result in association with various conditions such as trauma, reimplantation, orthodontic therapy, late and irregular eruption of teeth, or expanding tumors and cysts. Localized root resorption in a tooth associated with a chronic apical lesion of inflammatory origin after trauma, could cause an open apex. It is important to establish a correct diagnosis, treatment plan and controls for these cases. The treatment indicated for a tooth with an open apex, chronic apical lesion of inflammatory origin after trauma, an apical stop is made to avoid the extrusion of irrigant solutions and filling materials into the periapical area. Currently, the use of bioceramic cements is recommended to make apical stops showing excellent results in biocompatibility and micro-hardness; there are different bioceramic cements to achieve this purpose. The objective of this case report is to present the clinical management of an open apex resorption by executing an apical stop with the NeoMta ™ Plus ® bioceramic cement. / Trabajo académico

Introduction: Takotsubo cardiomyopathy is an apical ballooning syndrome, which can be triggeredby stress. Only few case reports describe the onset of Takotsubo as a complication of neurosurgery procedures. Clinical presentation: A case of a 53 year-old female with a spinal neurinoma and surgery-associated Takotsubo cardiomyopathy is demonstrated. The patient developed typical signs of a myocardial infarction with circulation depression and ST elevation, but normal cardiac enzymes at the end of surgery. Cardiac catheterization and levocardiography confirmed the absence of any critical coronary disease but the presence of a typical apical ballooning and midventricular hypokinesis. The patient recovered completely under supportive conservative and cardiological therapy, showing regular left ventricular pumpfunction. Conclusion: Interventions in neurosurgery and perioperative care should be kept as stress free as possible. Due to the possibility of neurogenic mechanisms related to cardiomyopathy, Takotsubo cardiomyopathy as an entity of stress-induced complications should be taken into consideration.

Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Elimination of bacteria and active infection within an infected root canal system is one of the primary objectives of nonsurgical root canal treatment. One of the measures of successful root canal treatment is subsequent bone healing of periapical lesions caused by previous infection. A previous study by Yumoto et al. showed that electromagnetic wave stimulation can increase proliferation of osteoblastic cells with no cytotoxicity, and it can also up-regulate growth factors such as vascular endothelial growth factor and platelet-derived growth factor.18 They also showed increased proliferation of an immortalized osteoblastic MC3T3-E1 cell line 3 days following electromagnetic stimulation (EMS).18 Previously, Pauly et al. found increased alkaline phosphatase (ALP) activity with 10 mA EMS application to primary murine calvaria-derived osteoblastic cells with 5 pulses at 1 second per pulse, but no significant differences were found for MTS proliferation nor mineral deposition compared to a negative control group.82 Optimization of the different variables including post-treatment incubation time, current delivery, and number of pulses per treatment may be necessary to improve osteogenic activity. The use of mesenchymal stem cells from murine bone marrow may also offer a physiologically relevant model for osteoblastic regeneration of periapical lesions. Objectives: The goal of this study was to investigate and optimize the effects of electromagnetic wave stimulation (EMS) on murine bone marrow mesenchymal stem cells (MSCs) by evaluating the proliferation and differentiation of the cells after exposure to different EMS treatment regimens. Materials and Methods: 5 x104 stromal osteoblasts (SOBs) were cultured in 24-well plates in α-MEM containing 10% fetal bovine serum. Cells were then subjected to pulsed EMS treatments of 1 mA, 10 mA, and 50 mA. EMS was generated using an electromagnetic apical treatment (EMAT) device created by J. Morita MFG Corp. Proliferation was assessed via MTS assay 1 days after treatment. For osteogenic differentiation, ascorbic acid and β-glycerol phosphate were added to the culture media, and SOBs were cultured for 14 days. Afterwards, alkaline phosphatase (ALP) activity and Alizarin-red S mineral deposition were quantified as measures of osteoblast activity. Cells grown in osteogenic media without EMS treatment served as the negative control. Results: Although MSC proliferation was unaffected by different EMS treatment regimens, 50 mA EMS resulted in a decrease in ALP activity and mineral deposition by osteoblasts. Conclusions: Our findings suggest bone healing by EMS may involve a different cellular mechanism, that is not reproduced in vitro in our studies. Utilizing different amperage and EMS regimens may improve osteogenic differentiation.

Les études épidémiologiques ont démontré un risque accru d’autisme chez les enfants nés d’une mère hospitalisée pour infection au cours de la grossesse. L’imitation d’une infection virale dans le but de déclencher une Activation Immunitaire Maternelle (MIA) a été réalisé avec succès dans des modèles animaux. Ceci a démontré qu’une MIA conduit à des altérations physiologiques et comportementales sur le long terme. Notre but consistait à étudier la présence de séquelles néonatales chez des souris nées de mère MIA. Nous avons observé que la MIA altère l’activité et la morphologie des neurones dès la naissance, et que ces modifications restaient présentes dans les animaux âgés de deux semaines. La MIA subie au cours de la grossesse altère donc les neurones dès la naissance. / Epidemiological studies have shown an increased risk for autism in children born from mothers hospitalized for infection during pregnancy. Mimicking a maternal infection during pregnancy to trigger a Maternal Immune Activation (MIA) has been successfully achieved in animal models, showing that it leads to long term physiological and behavioural alterations. Our goal was to investigate neonatal sequels in MIA mice offspring. We found that already at birth MIA alters neuronal activity and morphology, and these changes were still present in two-week-old animals. Consequently, MIA during pregnancy alters neurons already at birth.

O objetivo deste estudo foi avaliar a morfologia da superfície externa de ápices radiculares de dentes decíduos de humanos com necrose pulpar, com e sem lesão periapical visível radiograficamente, e de dentes com vitalidade pulpar, por meio da microscopia eletrônica de varredura (MEV). Dezenove dentes foram extraídos sendo cinco dentes com vitalidade pulpar (Grupo I), seis com necrose pulpar sem lesão periapical (Grupo II) e oito com necrose pulpar e lesão periapical (Grupo III). Os dentes (incisivos e molares) foram lavados com solução salina e imersos em solução de tripsina 0,03g/mL por 20 minutos. Decorrido esse período, os dentes foram lavados com solução tampão de cacodilato de sódio 0,1M e armazenados em solução de Karnovsky modificada. Após 5 dias, os ápices radiculares foram seccionados, desidratados em série crescente de etanol, submetidos à secagem pelo método do ponto crítico com dióxido de carbono, fixados em \"stubs\" e metalizados com ouro puro para análise em MEV. A superfície do ápice radicular foi avaliada com relação à presença de fibras e áreas de reabsorção dentinária e cementária. Na superfície radicular apical dos dentes com vitalidade pulpar e com necrose pulpar sem lesão periapical foi observada a presença de fibras e ausência de reabsorção em todos os casos (100%). Por outro lado, todos os espécimes (100%) com necrose pulpar e presença de lesão periapical apresentaram ausência total de fibras e áreas de reabsorção cementária. Áreas de reabsorção dentinária foram observadas em 2 espécimes. Os resultados obtidos demonstraram a presença de diferenças morfológicas na região apical de dentes decíduos com diferentes graus de patologia pulpar e periapical. A presença de áreas de reabsorção cementária e ausência de fibras nos dentes decíduos com lesão periapical indicam a necessidade da aplicação de medidas terapêuticas específicas. / The objective of this study was to evaluate, by scanning electron microscopy (SEM), the morphology of the outer surface of root apexes of human primary teeth with pulp vitality and teeth with pulp necrosis, with and without radiographically visible periapical lesion. Nineteen teeth were extracted, being five teeth with pulp vitality (Group I), six with pulp necrosis without periapical lesion (Group II) and eight with pulp necrosis and periapical lesion (Group III). The teeth (incisors and molars) were washed in saline and immersed in 0.03 g/mL trypsin solution during 20 minutes. After this period, the teeth were washed in 0.1 M sodium cacodylate buffer solution and stored in modified Karnovsky\'s solution. After 5 days, the root apexes were sectioned, dehydrated in an ascending ethanol series, critical-point dried with CO2, mounted on stubs, and sputter-coated with gold for SEM analysis. The root apex surface was examined with respect to the presence of fibers and areas of dentinal and cemental resorption. In the apical root surface of the teeth with pulp vitality and teeth with pulp necrosis without periapical lesion presence of fibers and absence of resorption were observed in all cases (100%). On the other hand, all specimens (100%) with pulp necrosis and periapical lesion showed total absence of fibers and areas of cemental resorption. The results of this study demonstrated the existence of morphological differences in the apical region of primary teeth with different degrees of pulpal and periapical pathology. The presence of areas of cemental resorption and absence of fibers in the primary teeth with periapical lesion indicate the need for application of specific therapeutic measures.