Beans are a commonly consumed food and a staple in many regions worldwide. Pinto beans (Phaseolus vulgaris), categorized as legumes, are dried seeds from plants and are high in protein, carbohydrate and fiber, and low in fat. They are also a good source of various minerals and well as thiamin, riboflavin, niacin, vitamin B6, and folate Beans are typically soaked and thermally processed before consumption. Different processing methods can impact the composition of beans. The purpose of this study was to examine the effect of thermal treatments on vitamin concentration in pinto beans. Beans were simmered, canned, dried-flaked, or dried-extruded, and measured for thiamin, riboflavin, folate, and vitamin B6. Beans were then reheated and measured again for vitamin concentration. Vitamin loss was comparable between the most commonly consumed stages of processing: Simmered, canned reheated, dried-flaked reheated and dried-extruded reheated. The only statistically significant differences were that simmering caused the least amount of degradation of thiamin and dried-flaked product had the least amount of vitamin B6 degradation. Though dried-flaked and dried-extruded beans generally decreased in vitamin concentration, these two products were comparable to the simmered and canned reheated products. This suggests that drying is a nutritionally acceptable means of processing pinto beans, resulting in products that are more economical to transport and more convenient to prepare.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-03-24T11:28:12Z No. of bitstreams: 1 2016 - Marcos Fabio de Lima.pdf: 2778933 bytes, checksum: 3359fd462f05a8841046bf8ef8191dac (MD5) / Made available in DSpace on 2017-03-24T11:28:12Z (GMT). No. of bitstreams: 1 2016 - Marcos Fabio de Lima.pdf: 2778933 bytes, checksum: 3359fd462f05a8841046bf8ef8191dac (MD5) Previous issue date: 2016-06-17 / Three experiments were conducted in animal nutrition sectors and Pastures of the Animal Science Institute of the Federal Rural University of Rio de Janeiro; Poultry Research Centre of the Instituto Federal de Educa??o Ciencia e Tecnologia do Rio de Janeiro and Feed Production Unit Bananal - SP Company Reginaves Industria e Comercio de aves. In the first experiment, there was a metabolism assay for the determination of metabolizable energy and energy corrected apparent Metabolizable (EMAn), the traditional method of excreta collection using broilers fed with extruded semi-whole soybean (SSIE) at different temperatures. The treatments consisted of four levels of extrusion temperatures of the SSIE: 60% reference diet + 40% SSIE to 90 ? C; 60% reference diet + 40% SSIE to 100 ? C; 60% reference diet + 40% SSIE to 110 ? C and 60% + 40% reference diet SSIE to 120?C. In the second experiment it was determined the true total and digestible amino acids in 300 chickens from 16 to 21 days old. The treatments were: diet SSIE to 90 ? C; diet SSIE 100 ? C; SSIE diet at 110 and at 120 SSIE diet. The third experiment was conducted to verify the diets SSIE the 110C with four different nutritional matrixes: diet with commercial soybean meal (DFS); diet with nutritional matrix SSIE the 110C and corrected (DSC); diet with nutritional matrix SSIE to 110C determined by the analysis of online NIRS (DSN) and diet SSIE nutritional matrix as Brazilian Tables (DSTB). the growth performance, economic indices and carcass characteristics of broiler chickens submitted to the treatments were analyzed. The values of AME, AME, true digestible amino acid digestibility coefficients were significantly influenced by the extrusion temperature of the semi-integral soybean. The higher EMA (3720.09 kcal / kg) and AMEn (3424.99 kcal / kg) were obtained with the extrusion temperature of the semi-integral soybean approximately 105.6 ? C. The digestible amino acid values and true digestibility coefficients were influenced by the extrusion temperature of the semi-integral soybean. The best extrusion temperatures of the semi-integral soybean estimated for the real amino acid digestibility figures were 112.12?C to lysine, methionine 107.14?C, 106.11?C to cystine, arginine 111.77 112.25 and serine. The standardization of the SSIE extrusion temperature and the proper use of nutritional matrix of this ingredient in feed formulation positively influence the performance and economic index / Foram realizados tr?s experimentos nos setores de Nutri??o Animal e Pastagens do Instituto de Zootecnia da Universidade Federal Rural do Rio de Janeiro; Centro de Pesquisas Av?colas do Instituto Federal de Educa??o Ci?ncia e Tecnologia do Rio de Janeiro e Unidade de Produ??o de Ra??es de Bananal ? SP da Empresa Reginaves Industria e Comercio de Aves Ltda. No primeiro experimento, foi realizado um ensaio de metabolismo para a determina??o dos valores de energia metaboliz?vel e Energia Metaboliz?vel aparente corrigida (EMAn), pelo m?todo tradicional de coleta total de excretas utilizando frangos de corte alimentados com ra??es contendo soja semi-integral extrusada (SSIE) em diferentes temperaturas. Os tratamentos consistiram em quatro n?veis de temperaturas da SSIE : 60% dieta referencia + 40% SSIE a 90?C; 60% dieta referencia + 40% SSIE a 100?C; 60% dieta referencia + 40% SSIE a 110?C e 60% dieta referencia + 40% SSIE a 120?C. No segundo experimento foram determinados os amino?cidos totais e digest?veis verdadeiros em 300 frangos de 16 a 21 dias de idade. Os tratamentos estudados foram: dieta com SSIE a 90?C; dieta com SSIE a 100?C; dieta com SSIE a 110?C e dieta com SSIE a 120?C. O experimento tr?s foi realizado para verificar as dietas contendo SSIE a 110?C com quatro matrizes nutricionais diferentes: dieta com farelo de soja comercial (DFS); dieta com matriz nutricional da SSIE a 110?C e corrigida (DSC); dieta com matriz nutricional da SSIE a 110?C determina pela analise do NIRS online (DSN) e dieta com matriz nutricional da SSIE conforme Tabelas Brasileiras (DSTB). Foram analisados o desempenho zoot?cnico, ?ndices econ?micos e as caracter?sticas da carca?a dos frangos de corte submetidos aos tratamentos. Os valores de EMA, EMAn, amino?cidos digest?veis verdadeiros coeficientes de digestibilidade foram influenciados significativamente pelas temperaturas de extrus?o da soja semi-integral. Os maiores valores de EMA (3720,09 Kcal/ Kg) e de EMAn (3424,99 Kcal/Kg) foram obtidos com a temperatura de extrus?o da soja semi-integral de aproximadamente 105,6?C. Os valores de amino?cidos digest?veis e coeficientes de digestibilidade verdadeiros foram influenciados pelas temperaturas de extrus?o da soja semi-integral. As melhores temperaturas de extrus?o da soja semi-integral estimadas para os valores de digestibilidade de amino?cido verdadeiro foram de 112,12?C para lisina, 107,14?C para metionina, 106,11?C para cistina, 111,77 para arginina e 112,25 para serina. A padroniza??o da temperatura de extrus?o da SSIE e a utiliza??o correta da matriz nutricional deste ingrediente na formula??o de ra??es influenciam positivamente os ?ndices produtivos e econ?micos

The aim of this diploma thesis was to test the production effectiveness of cereals and compound feed and at the same time, find out what influence they have on the water quality when applied in the semi-intensity carp farming. The feeding test was taking place in the period of 112 days in 10 experimental storage ponds. The feed which was tested, was cereals, extruded feed from the Aller Aqua company with 24% share of protein, pelleted feed glycid type feed with the 12,5% share of protein (KP) and pellet feed glycid type compound feed with 12,5% share of protein and reduced share of phosphorus (KPminus). A tested carp population of the same density was left without any additional feeding, to be fed only on the natural nutrition. Every one of these separated carp populations were fed three times a week in the morning and on the same spot of the fish tank. The testing was taking place twice.The measuring of the parametres of the water (temperature, oxygen, pH) took place once a fortnight, taking samples of the water once a month. At the end of the experiment, the level of phosphorus and the observed production parametres were evaluated.The highest production effectiveness was reached in the carps that were fed with cereals (FCR - Food Convertion Ration 2,41 - 0,46, SGR - Specific Growth Rate 0,54 - 0,07 %.d-1). The lowest production effectiveness was achieved with the pelleted feed KPminus (FCR - 3,72 - 0,30, SGR - 0,39 - 0,02 %.d-1). The highest retention of phosphorus (88%) in the fish biomass was reached with cereals. The lowest retention of phosphorus (60%) was reached in the carps fed with the pelleted feed KP. Feeding carps with tested feeds did not have any significant influence on the water quality. From both the economic and the environmental point of view, the best feed for carp pond farming is cereals.

Purpose: This project compares two foundation insulation materials: cellular plastic and cellular glass. Currently, cellular plastic is the most used material for foundation insulation. While cellular glass is not widely utilized. Its disadvantage lies in its higher cost, which makes contractors prefer the cheaper alternative, cellular plastic. Cellular glass exhibits exceptional properties, including its notable attributes of high load-bearing capacity and superior moisture resistance. The aim of this study is to demonstrate how material savings can be achieved by using cellular glass instead of cellular plastic in the load-bearing parts of the foundation. In addition to cost savings, the study also includes the analysis of carbon dioxide emissions during the production of these materials and specific heat losses through the material. Method: To facilitate understanding of the study, two different buildings were visualized: a two-story building and a seven-story building. The choice of different building sizes aimed to investigate how different loads on foundation insulation affect insulation material costs, carbon dioxide emissions, and the heating requirements of the buildings. Revit and AutoCAD were used for modelling and visualization. Flixo and manual calculations were employed for energy calculations, while manual calculations were used for structural calculations. One Click LCA Software was used to determine the carbon dioxide emissions for the different foundation insulation scenarios. Results: The study suggests that for buildings with lighter loads, cellular plastic is a cost-effective choice, while a hybrid insulation approach combining cellular glass and cellular plastic is the best option considering environmental factors. However, for buildings with higher loads, cellular glass outperforms cellular plastic both in terms of economics and the environment. Nonetheless, a combination of cellular glass and cellular plastic remains the most favourable choice among the three scenarios, as energy losses are approximately the same due to the similar thermal conductivity values of these materials. Conclusion: Hybrid insulation proves to be the most advantageous option in terms of both the environment and economics for both types of buildings studied: the two-story residential building and the seven-story residential building. By using cellular glass F for the load-bearing structures and cellular plastic EPS S60 for the ground slab, effective insulation is achieved. The use of cellular glass F results in material savings, such as cellular plastic XPS 700, which has half the load-bearing capacity of cellular glass F. Additionally, reducing the use of extra concrete for load-bearing foundation constructions decreases the load on the foundation insulation material.

L’apport de graines oléagineuses dans la ration de la vache laitière pendant 1 à 3 mois pourrait améliorer la qualité nutritionnelle du lait, mais également pénaliser dans certains cas les performances zootechniques. Peu de données sont disponibles sur les effets de ces stratégies alimentaires sur de plus longues périodes. L’objectif de cette thèse est de quantifier au cours de 2 lactations consécutives, les effets de supplémentations en lin ou en trois différentes formes de colza de rations à base d’herbe conservée en hiver et pâturée en été sur les performances zootechniques de la vache laitière et la composition fine en acides gras du lait. Les effets des suppléments étudiés persistent au sein de chaque période (hiver et été) et sont répétables d’un été à l’autre. Ils sont par ailleurs similaires à ceux observés lors d’études de durée plus courte (1 à 3 mois). Ces stratégies ne permettent pas d’améliorer les performances zootechniques et diminuent parfois le taux protéique du lait, notamment en hiver. Toutefois, elles réduisent les teneurs du lait en acides gras saturés au profit de l’acide oléique et, dans le cas du lin de l’acide α-linolénique. Ces modifications peuvent être considérées comme une amélioration de la qualité nutritionnelle du lait. Cependant, le lin extrudé et le tourteau de colza gras augmentent les acides gras trans et les suppléments diminuent souvent l’acide ruménique du lait au pâturage. La distribution des isomères des acides gras insaturés cis et trans du lait dépend du type de graine et du niveau d’amidon de la ration, mais pas de la forme d’apport du colza, qui influence toutefois l’amplitude des effets observés. Par ailleurs, l’analyse détaillée du profil en acides gras du lait a permis de mieux comprendre le métabolisme des acides linoléiques et linoléniques conjugués, en lien avec la lipogenèse mammaire. / Addition of oilseed supplements to dairy cow diets for 1 to 3 months may improve the milk nutritional quality, but detrimental effects on animal performance may also occur. However, data is scarce on long-term effects of these nutritional strategies. The objective of this thesis was to quantify the effects of extruded linseed and three forms of rapeseed-derived supplements on dairy cow performance and detailed milk fatty acid composition, during 2 consecutive lactations. Basal diet was conserved grass during winter and pasture during summer. Oilseed supplements effects persist within each period (winter and summer) and are repeatable between the 2 summer periods. Long-term effects observed over 2 consecutive lactations are similar to those observed during short-term (1 to 3 months) studies. These oilseed-derived supplements not improve dairy cow performance, but decrease the milk protein content in some instances, especially during winter period. Nevertheless, oilseed supplementations reduce milk saturated fatty acid content and increase milk content in oleic acid and with linseed in α-linolenic acid. Such changes could be considered as an improvement of the milk nutritional quality. However, extruded linseed and fat-rich rapeseed meal increase milk trans fatty acid content, and oilseed supplements often decrease milk rumenic acid at pasture. Isomer distribution of cis and trans unsaturated fatty in milk fat is dependent on the oilseed nature and diet starch content, but not on the rapeseed form. However, rapeseed form modifies the magnitude of observed effects. Furthermore, the detailed analyses of milk fatty acid profile allowed to explore conjugated linoleic and linolenic fatty acids metabolism, and their relationship with mammary lipogenesis.

Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-12-20T16:06:34Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marcel Adriano Jobbins.pdf: 799698 bytes, checksum: 9bb4362171f6c452c9c0332d5169dd9e (MD5) / Made available in DSpace on 2018-12-20T16:06:34Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Marcel Adriano Jobbins.pdf: 799698 bytes, checksum: 9bb4362171f6c452c9c0332d5169dd9e (MD5) Previous issue date: 2018-09-28 / Este estudo foi desenvolvido para determinar os coeficientes de digestibilidade aparente (CDA) de matéria seca (MS), energia bruta (EB), proteína bruta (PB), amido, lipídios, fibra bruta (FB), cinzas (CZ) e de aminoácidos (AA) essenciais e não essenciais de farinha de feijão in natura (FI) e feijão extrusada (FE) para juvenis de tilápia do Nilo utilizando dois marcadores de digestibilidade: óxido crômio (Cr2O3) ou cinza insolúvel em ácido (CIA). Foi elaborada uma dieta referência peletizada (DR) contendo 35,19% de PB e 17,78 MJ/ kg de EB. As dietas testes constituíam-se de 70% da DR e 30% de FI ou FE. Grupos de 15 individuos (150,16 ± 20,32 g) foram distribuídos em seis aquários de digestibilidade de 200 L, em um esquema fatorial 2 x 2, onde foram avaliados dois métodos de processamento (FI ou FE) e dois marcadores (Cr2O3 ou CIA), com duas repetições, compondo o “pool” de fezes de cada dieta testada. Os maiores CDA, referentes a interação (processamento x marcador), foram encontrados para MS, EB, PB, CZ e AA essenciais como: arginina (Arg), histidina (His), isoleucina (Ile), leucina (Leu), lisina (Lys), metionina (Met),fenilalanina (Phe), treonina (Thr) e nos AA não essenciais: ácido aspártico (Asp), cisteína (Cys), ácido glutâmico (Glu), glicina (Gly), serina (Ser) e tirosina (Tyr). O CDA de amido e para os AA essencias triptofano (Trp) e valina (Val) foi maior no FE em comparação ao FI, deferenciando dos lipídios que apresentaram melhores resultados para FI. Para FB e o AA não essencial alanina (Ala), por sua vez, não houve influência dos tratamentos dietéticos e marcadores. Independentemente do processamento a Met, His e Arg foram os AA limitantes para dietas contendo farinhas de feijão. Em conclusão, a FE apresentou -se como sendo boa fonte de energia e nutrientes, porém, os teores de Met e Cys devem ser considerados para as necessidades dietéticas de AA contendo enxofre e o marcador CIA não se mostrou sendo confiável para tilápia do Nilo. / The trial aimed to evaluate the apparent strain digestibility coefficients (ADC) of dry matter (DM), gross energy (GE), crude protein (CP), starch, lipids, crude fiber (CF), ashes (AS) and essential and non-essential amino acids (AA) of in natura bean flour (FI) and extruded bean flour (FE) for juvenile Nile tilapia using two digestibility markers: chromium oxide (Cr2O3) or acid insoluble ash (AIA). It was elaborated a pelleted reference diet (RD) containing 35.19% CP and 17.78 MJ / kg GE, the test diets consisted of 70% RD and 30% of FI or FE. Groups of 15 individuals (150.16 ± 20.32 g) were distributed in six digestibility aquariums of 200 L, in a 2 x 2 factorial scheme, two processing methods (FI or FE) and two markers (Cr2O3 or AIA) were evaluated, with two replicates, composing the faeces pool of each diet tested. The highest ADC referring to the interaction (processing x marker) were found for DM, GE, CP, As and essential AA as: arginine (Arg), histidine (His), isoleucine (Ile), leucine (Leu), lysine (Lys), methionine (Met), phenylalanine (Phe), threonine (Thr) and for non-essential AAs: aspartic acid (Asp), cysteine (Cys), glutamic acid (Glu), glycine (Gly), serine (Ser) and tyrosine (Tyr). The CDA of the starch and the essential AA tryptophan (Trp) and valine (Val) was higher in FE compared to FI, different from lipids, which presented better results for FI. For GE and nonessential amino acid alanine (Ala) there was no influence of dietary treatments and markers. Regardless of the processing, Met, His and Arg were the limiting AAs for diets containing bean flours. In conclusion, FE proved to be a good source of energy and nutrients, however, the low levels of Met and Cys should be considered for the dietary requirements of AA containing sulfur. The AIA marker proved to be unreliable for Nile tilapia.

Aluminum alloys are of great importance in the automotive and truck industries due to the weight savings that they can help to achieve. However, the use of such alloys in applications where they are subjected to alternating stresses requires knowledge about their fatigue behavior. Moreover, extrusion induces a strong texture and microstructural heterogeneity in the material and gives a surface with long grooves parallel to the extrusion direction (ED), so-called die lines. This anisotropy in surface conditions and microstructure may affect the fatigue properties. To investigate how die lines and microstructure affects fatigue in aluminum, the high cycle fatigue properties cycles of three peak-aged AlMgSi alloys were evaluated. Flat profiles of 6060-T6, 6063-T6 and 6082-T6 were tested in uniaxial stress (R = 0.1) in a servo-hydraulic fatigue testing machine with a constant stress amplitude. Two specimen types were tested for 6063 and 6082: one with the ED parallel to the loading direction (longitudinal), and one with the ED perpendicular to it (transverse). It was found that both 6063 and 6082 displayed anisotropy in fatigue lives, with the longitudinal orientation performing better. The anisotropy was far stronger in 6082 than in 6063. Furthermore, 6060 longitudinal displayed higher fatigue strength than 6063 longitudinal at higher stress amplitudes, but lower fatigue strength at lower amplitudes. Metallographic investigations with SEM indicated that grain boundaries of the surface-layer grains were involved in the initiation of the fatigue crack. Intergranular crack propagation and separation was observed on the fracture surfaces, especially in the surface layer. The extruded surfaces also showed evidence of intergranular crack propagation. The exact sites of crack initiation could not be found so it could not be proven conclusively that die lines were sites of crack initiation in transverse specimens, but there were some indications from metallographic and macrofractographic investigations that this was the case. / Aluminiumlegeringar används mycket i bilindustrin på grund av de viktbesparingar som kan åstadkommas. Användandet av sådana legeringar i tillämpningar där det utsätts för cykliska laster kräver dock kunskap om deras utmattningsbeteende. Dessutom skapar extrusionsprocessen en stark textur och heterogenitet i mikrostrukturen och resulterar i en yta med fina fåror parallella med pressriktningen, s.k. die lines. Anisotropin i ytbeskaffningen och mikrostrukturen kan påverka utmattningshållfastheten. För att undersöka hur die lines och mikrostruktur påverkar utmattningen i aluminium testades högcykelutmattningsegenskaperna hos tre toppåldrade AlMgSi legeringar. Platta profiler av 6060-T6, 6063-T6 och 6082-T6 testades i enaxlig dragspänning (R = 0.1) i en servohydraulisk utmattningsmaskin med konstant lastamplitud. Två sorters provstavar testade av 6082 och 6063: en med pressriktningen parallell med lastriktningen (längsriktning) och en med pressriktningen vinkelrät mot lastriktningen (tvärriktning). Både 6063 och 6082 uppvisade olika utmattningsliv beroende på pressriktningens orientering mot lastriktningen, där längsriktningen hade längre utmattningsliv för båda legeringarna. Anisotropin var mycket starkare in 6082 än 6063. Dessutom uppvisade 6060 i längsriktningen högre utmattningsstyrka än 6063 vid höga lastamplituder, men lägre utmattningsstyrka vid lägre lastamplituder. Metallografiska undersökningar med SEM indikerade att korngränser i ytlagret var involverade i sprickinitieringen. Spricktillväxt i och separation av korngränser observerades på brottytorna, speciellt i ytlagret. Den extruderade ytan visade också bevis för interkristallin spricktillväxt. De exakta platserna för sprickinitering kunde inte hittas så det kunde inte entydigt bevisas att sprickinitieringen skedde i die lines i provstavar med pressriktningen vinkelrät mot lastriktningen, men i metallografiska och fraktografiska undersökningar fanns vissa indikationer att så var fallet.

O controle da extrusão apical durante a reintervenção endodôntica é essencial para o sucesso do novo tratamento. Nesse contexto, o presente estudo teve como objetivo comparar a quantidade de material sólido extruído na desobturação de canais radiculares variando-se a técnica de esvaziamento e o limite de obturação. Foram utilizados 40 incisivos inferiores previamente tratados divididos em dois grupos de acordo com o limite de obturação estabelecido. Cada grupo foi subdividido em dois subgrupos levando-se em conta a técnica de desobturação empregada; manual (subgrupos A1 e B1) e mecânico-rotatória com limas de Ni-Ti (Quantec LX) (subgrupos A2 e B2). O material sólido extruído foi coletado por meio do sistema de filtração Millipore, levado à secagem em dessecador de sílica e pesado em balança analítica de precisão. Os resultados obtidos foram submetidos a ANOVA para dois fatores de variação sendo em seguida empregado o Teste de Tukey (&#945; = 5%). A técnica de desobturação mecânico-rotatória produziu menor extrusão (0,66mg) que a manual (1,11mg), havendo diferença estatística significante entre elas (p < 0,05). Os canais preenchidos até o vértice radiográfico apresentaram maior quantidade de extrusão (1,38mg) do que os obturados 1 mm aquém do forame (0,39mg), observando-se diferença estatística significante entre eles (p < 0,05). A menor quantidade extrusão foi observada no subgrupo A2 (0,20mg), em que foi empregada a técnica rotatória de desobturação em canais obturados 1mm aquém do forame apical, sendo constatada diferença estatisticamente significante deste subgrupo com os demais (p < 0,05). A extrusão de material sólido durante a desobturação de canais radiculares é influenciado pela técnica empregada e pelo limite apical de obturação. / The apical extrusion control during the endodontic retreatment is essential for the success of the new treatment. The purpose of this study was to compare the quantity of solid apically extruded material during filling removal according the gutta-percha removal technique and root filling limit. Forty mandibular incisors with a single straight canal were selected. The canals were previously endodontically treated and then divided into two groups according the filling level. Each group was subdivided in two groups considering the retreatment technique: stainless steel hand files (subgroups A1 and B1) versus niquel-titanium rotatory instruments (subgroups A2 and B2). The extruded solid material was collected by Millipore filtration system, dried in silica desiccators and weighed in an eletrobalance. The results were analyzed using ANOVA with two variation factors and Tukey Test (&#945; = 5%). The niquel-titanium rotatory instruments produced less extrusion (0,66mg) than the stainless steel hand files (1,11mg), with significant statistical difference between them (p < 0,05). The canals filled until the radiographic apex showed larger amount of extruded material (1,38mg) than those filled 1 mm beyond the foramen (0,39mg). It was observed significant statistical difference between them (p < 0,05). The smaller extruded debris amount was observed in subgroup A2 (0,20mg), in which one the rotary technique was used to remove the gutta-percha of canals filled 1mm beyond the apical foramen. It was verified significant statistical difference of this subgroup with the other ones (p < 0,05). The extrusion of solid material during the gutta-percha removal is influenced by the technique as well as the apical filling limit.

O controle da extrusão apical durante a reintervenção endodôntica é essencial para o sucesso do novo tratamento. Nesse contexto, o presente estudo teve como objetivo comparar a quantidade de material sólido extruído na desobturação de canais radiculares variando-se a técnica de esvaziamento e o limite de obturação. Foram utilizados 40 incisivos inferiores previamente tratados divididos em dois grupos de acordo com o limite de obturação estabelecido. Cada grupo foi subdividido em dois subgrupos levando-se em conta a técnica de desobturação empregada; manual (subgrupos A1 e B1) e mecânico-rotatória com limas de Ni-Ti (Quantec LX) (subgrupos A2 e B2). O material sólido extruído foi coletado por meio do sistema de filtração Millipore, levado à secagem em dessecador de sílica e pesado em balança analítica de precisão. Os resultados obtidos foram submetidos a ANOVA para dois fatores de variação sendo em seguida empregado o Teste de Tukey (&#945; = 5%). A técnica de desobturação mecânico-rotatória produziu menor extrusão (0,66mg) que a manual (1,11mg), havendo diferença estatística significante entre elas (p < 0,05). Os canais preenchidos até o vértice radiográfico apresentaram maior quantidade de extrusão (1,38mg) do que os obturados 1 mm aquém do forame (0,39mg), observando-se diferença estatística significante entre eles (p < 0,05). A menor quantidade extrusão foi observada no subgrupo A2 (0,20mg), em que foi empregada a técnica rotatória de desobturação em canais obturados 1mm aquém do forame apical, sendo constatada diferença estatisticamente significante deste subgrupo com os demais (p < 0,05). A extrusão de material sólido durante a desobturação de canais radiculares é influenciado pela técnica empregada e pelo limite apical de obturação. / The apical extrusion control during the endodontic retreatment is essential for the success of the new treatment. The purpose of this study was to compare the quantity of solid apically extruded material during filling removal according the gutta-percha removal technique and root filling limit. Forty mandibular incisors with a single straight canal were selected. The canals were previously endodontically treated and then divided into two groups according the filling level. Each group was subdivided in two groups considering the retreatment technique: stainless steel hand files (subgroups A1 and B1) versus niquel-titanium rotatory instruments (subgroups A2 and B2). The extruded solid material was collected by Millipore filtration system, dried in silica desiccators and weighed in an eletrobalance. The results were analyzed using ANOVA with two variation factors and Tukey Test (&#945; = 5%). The niquel-titanium rotatory instruments produced less extrusion (0,66mg) than the stainless steel hand files (1,11mg), with significant statistical difference between them (p < 0,05). The canals filled until the radiographic apex showed larger amount of extruded material (1,38mg) than those filled 1 mm beyond the foramen (0,39mg). It was observed significant statistical difference between them (p < 0,05). The smaller extruded debris amount was observed in subgroup A2 (0,20mg), in which one the rotary technique was used to remove the gutta-percha of canals filled 1mm beyond the apical foramen. It was verified significant statistical difference of this subgroup with the other ones (p < 0,05). The extrusion of solid material during the gutta-percha removal is influenced by the technique as well as the apical filling limit.