ABSTRACT Objective: To compare the agreement of images in white light (WL), fluorescence (FL), and digital radiographs (DR), on the diagnosis and treatment decisions for occlusal caries lesions against a micro-CT gold standard. Material and Methods: Ten extracted third molars, with enamel and/or dentin caries (ICDAS 2-4), were included. Occlusal surface images were acquired with an intraoral camera (SoproLife®) in WL and FL modes. DR was obtained using an intraoral X-ray and a semi-direct digital system. A total of 780 images were needed, organized in a template, to be later examined by twenty-six dentists invited to compose the study. The Generalized Estimation Equations model was used to compare the proportions of the correct answers between the three methods and the gold standard. When significant, Bonferroni post-hoc test was used to identify differences (α=5%). Results: Most of the examiners were specialists (76.9%) with 14.5 years of experience. All diagnostic methods were similar and showed low agreement (DR 12.7%, WL 16.5%, and FL 16.5%) compared with gold standard caries diagnostic scores. Regarding treatment decisions, mean agreement for all diagnostic methods was higher (43.2%; p<0.001), and among all methods, WL (48.1%) and FL (51.2%) modes performed better than DR (30.4%, p<0.001). Conclusion: SoproLife® images could help clinicians to propose rational, minimally invasive treatments for occlusal caries lesions.

Abstract Objective: To evaluate the efficacy of silver diamine fluoride (SDF) in arresting dentin caries lesions when applied under different concentrations and times. Material and Methods: Forty-two bovine blocks were selected and fixed in 24-well plates. Each well received a mixed bacterial inoculum added to the culture medium with 5% sucrose. The plates were incubated in microaerophilia (7 days) for caries formation, confirmed by micro-CT (M1). SDF was applied over the carious lesions for different times and concentrations (n=6): SDF 30% - immediate removal, 1 minute and 3 minutes; SDF 38%, - immediate removal, 1 minute and 3 minutes. The group without treatment was the control. Then, the samples were again scanned by micro-CT (M2) and submitted to a second cariogenic challenge for 21 days. Then, a final scan was performed (M3). Results: Mean pH at the culture medium and lesion depth were compared using Kruskal-Wallis and Wilcoxon tests. 38% SDF showed the lowest metabolic activity of the biofilm. All 38% groups and 30% 1 and 3 minutes did not show an increase in mean lesion depth comparing M3 with M1. However, only 30% 3 minutes and 38% 1 and 3 minutes showed a significant reduction of lesion depth. Conclusion: The minimum application time of 30% SDF to arrest dentin caries lesion was 1 minute, while 38% SDF arrested with application and immediate removal.

RESUMO - O aperfeiçoamento de técnicas de propagação in vitro, com auxílio da escolha adequada da fonte de luz artificial e das formulações do meio de cultivo, são importantes, pois viabilizam a produção em massa de indivíduos com grande variabilidade genética. Assim, a presente pesquisa teve por objetivos estudar fontes de luz a partir de lâmpadas fluorescentes e diodos emissores de luz (LEDs) e formulações de meio de cultivo na germinação e no desenvolvimento inicial da espécie de orquídea Brassavola perrinii. O experimento foi instalado em delineamento inteiramente casualizado em esquema fatorial 5 × 4, sendo cinco fontes de luz: lâmpada fluorescente (100%); LED branco (100%); LED azul (100%); LED vermelho (100%) e LED azul (50%) + vermelho (50%), e quatro formulações de meio de cultivo, sendo MS, ½ MS, VW e K, com quatro repetições e média de 125 sementes por parcela. Aos 90 dias após a semeadura foram avaliadas a porcentagem de germinação, protocormos clorofilados e o desenvolvimento dos protocormos através das classes: P1, P2, P3 e P4 para cálculo do índice de desenvolvimento protocormos. Os dados foram submetidos à análise de variância e as médias foram comparadas pelo teste de Tukey p < 0,05. Para Brassavola perrinii, concluiu-se que o percentual de germinação não foi influenciado pelos espectros de luz, mas foi maior nas formulações ½ MS e VW. O maior índice de desenvolvimento dos protocormos de B. perrinii foi observado quando submetidos ao espectro de luz da fonte de iluminação com lâmpadas fluorescentes em meio de cultivo VW.

ABSTRACT - The improvement of in vitro propagation techniques using appropriate artificial light sources and culture medium formulations is important to allow the mass production of individuals with high genetic variability. Thus, this research aimed to study the effect of light sources from fluorescent lamps and light-emitting diodes (LEDs) and culture medium formulations on the germination and initial development of the orchid species Brassavola perrinii. The experiment was set up in a completely randomized design in a 5 × 4 factorial scheme, consisting of five light sources – fluorescent lamp (100%), white LED (100%), blue LED (100%), red LED (100%), and blue LED (50%) + red LED (50%) – and four culture medium formulations – MS, ½ MS, VW, and K –, with four replications and a mean of 125 seeds per plot. The percentage of germination, chlorophyll protocorms, and protocorm development through the classes P1, P2, P3, and P4 to calculate the protocorm development index were evaluated at 90 days after sowing. The data were subjected to analysis of variance and the means were compared by the Tukey test (p < 0.05). The percentage of germination for B. perrinii was not influenced by light spectra but was higher in the ½ MS and VW formulations. The highest protocorm development index of B. perrinii was observed when the species was submitted to the light spectrum of the lighting source with fluorescent lamps in the VW culture medium.

RESUMO Os sistemas de saneamento básico não são suficientes para atender as necessidades sanitárias nas áreas rurais do Brasil. Assim, um sistema anaeróbio descentralizado foi desenvolvido pela Embrapa para viabilizar o tratamento de esgoto doméstico. O efluente de esgoto tratado (EET) pode ser aplicado para substituir totalmente o N oriundo do fertilizante mineral requerido pelas plantas de milho, espécie vegetal típica cultivada por pequenos produtores brasileiros para alimentação animal. Assim, o objetivo deste estudo foi investigar as respostas da cultura do milho ao uso de EET como fertilizante. Um experimento de campo foi realizado em solo franco argilo arenoso em São Carlos, estado de São Paulo, Brasil, na safra de verão 2018-2019 utilizando uma cultivar de milho híbrido com dupla aptidão (produção de grãos e silagem). Foram avaliados quatro tratamentos sobre a aplicação de diferentes fontes de nutrientes, dispostos em blocos casualizados com três repetições: 1- NPK: uréia, superfosfato simples e cloreto de potássio como fontes de nutrientes; 2- EfPK: EET como fonte de N + PK de fertilizantes minerais; 3- Ef: apenas EET; 4- PK: apenas fertilizantes minerais. O EET foi aplicado na cultura por irrigação por sulcos curtos e fechados. O EET pode ser utilizado principalmente como fonte de nitrogênio e outros nutrientes para a nutrição da cultura do milho com base no conhecimento das concentrações de nutrientes do efluente. A aplicação fracionada de EET por fertirrigação pode levar a parâmetros de produtividade do milho próximos aos da aplicação de NPK utilizando apenas fertilizantes minerais como fonte de nutrientes. O reaproveitamento desse efluente é viável para a produção de milho em pequena escala, típica da agricultura familiar brasileira.

ABSTRACT The basic sanitation systems are not enough to meet the sanitary requirements in the rural areas of Brazil. Hence, a decentralized anaerobic system was developed by Embrapa to enable the treatment of domestic sewage. The treated sewage effluent (TSE) should be applied to completely replace the N from mineral fertilizer required by corn plants, a typical crop cultivated by Brazilian smallholder farmings for animal feed. Hence, the purpose of this study was to investigate the corn crop responses to the use of TSE as fertilizer. A field experiment was carried out in a sandy clay loam soil at São Carlos, state of São Paulo, Brazil, over 2018-2019 summer growing season of a hybrid corn cultivar with dual aptitude (grain and silage production). Four treatments about application of different nutrient sources were evaluated in a randomized block design with three replications: 1- NPK: urea, simple superphosphate and potassium chloride as nutrient sources; 2- EfPK: TSE as N source + PK from mineral fertilizers; 3- Ef: TSE only; 4- PK: mineral fertilizers only. TSE was applied to crop by short and closed-end furrow irrigation. TSE can be used as a source of nitrogen mainly and other nutrients for corn crop nutrition based on the knowledge of effluent nutrient concentrations. TSE split application through fertirrigation can lead to corn yield parameters close to those from NPK application using only mineral fertilizers as nutrient sources. The reuse of this wastewater is feasible for small-scale corn production which is typical of Brazilian smallholder farming.

RESUMO Este estudo teve como objetivo avaliar o efeito in vitro de uma única aplicação de soluções experimentais de nanocompósitos na prevenção de cárie dentária em braquetes ortodônticos. Os espécimes foram expostos a nanocompósitos de sílica mesoporosa (MS) contendo fluoreto por associação com tetrafluoreto de titânio (TiF4) ou fluoreto de sódio (NaF). Os nanocompósitos também podem conter cálcio e os grupos foram descritos como MSCaTiF4, MSTiF4, MSCaNaF, MSNaF e controles (TiF4 e NaF). Os espécimes foram submetidos à formação de um biofilme multiespécie para gerar um desafio cariogênico. Após 24h, o pH e a concentração de flúor solúvel total do meio de cultura foram avaliados. A perda mineral foi avaliada pela porcentagem de perda mineral superficial (% SML), variação do volume mineral (ΔZ) do esmalte interno e microscopia de luz polarizada (PL). A rugosidade superficial linear (Ra) e volumétrica (Sa) e a microscopia eletrônica de varredura (MEV) foram utilizadas para avaliar a topografia do esmalte. As análises estatísticas foram realizadas considerando p <0,05. MSNaF apresentou o maior valor de pH do meio de cultura após o desafio cariogênico, semelhante ao MSTiF4. Todas as soluções de nanocompósitos liberaram menos flúor do que seus controles NaF e TiF4 (p <0,05). Todas as soluções de nanocompósitos apresentaram% SML menor em comparação com seus respectivos grupos de controle (p <0,05). Ra, Sa e ΔZ menores foram observados para os grupos experimentais em comparação ao TiF4 (p <0,05). Os resultados foram confirmados por análises PL e SEM. As soluções experimentais de nanocompósitos contribuíram para a menor desmineralização do esmalte ao redor dos braquetes ortodônticos.

Abstract This study aimed to evaluate the in vitro effect of a single application of experimental nanocomposite solutions on the prevention of dental caries around orthodontic brackets. The specimens were exposed to mesoporous silica (MS) nanocomposites containing fluoride by association with titanium tetrafluoride (TiF4) or sodium fluoride (NaF). Nanocomposites also could contain calcium and groups were described as MSCaTiF4, MSTiF4, MSCaNaF, MSNaF, and controls (TiF4, and NaF). Specimens were subjected to the formation of a multispecies biofilm to generate a cariogenic challenge. After 24h, both pH and total soluble fluoride concentration of the culture medium were assessed. Mineral loss was evaluated by percentage of surface mineral loss (%SML), mineral volume variation (ΔZ) of inner enamel and polarized light microscopy (PL). Linear (Ra) and volumetric (Sa) surface roughness and scanning electronic microscopy (SEM) were used to assess enamel topography. Statistical analyses were conducted considering p<0.05. MSNaF had the highest value of culture medium pH after cariogenic challenge, similarly to MSTiF4. All nanocomposite solutions released less fluoride than their controls NaF and TiF4 (p<0.05). All nanocomposite solutions presented lower %SML compared to their respective control groups (p<0.05). Lower Ra, Sa and ΔZ were observed for experimental groups compared to TiF4 (p<0.05). The results were confirmed by PL and SEM analysis. The experimental nanocomposite solutions contributed for lower enamel demineralization around orthodontic brackets.

Abstract This study aimed to evaluate the endodontic instrumentation outcomes with asymmetrical files compared to reciprocating and hand files (HFs) in 3D-printed prototypes of upper primary incisors using micro-computed tomography (micro-CT). For this purpose, 50 prototypes were randomly divided (n = 10) according to the instrumentation technique as follows: HFs, a reciprocating file (WaveOne® Gold [WOG]), and three asymmetrical movement files: XP-Endo® Shaper (XPS), XP-Endo® Finisher (XPF), and XP Clean (XPC). The specimens were scanned and, after registration of the baseline and instrumented volumes, changes in the root canal volume (RCV), debris accumulation, removed root material volume (RRMV), non-instrumented areas, and the presence of cracks/perforations were quantified. Data were analyzed by analysis of variance and Student’s t-test, while the effect size was calculated for statistically significant outcomes. All groups showed an increase in RCV after instrumentation (p < 0.05), but this was higher with HFs (p < 0.05). Accumulated debris was higher for WOG and XPS (p < 0.05), but WOG exhibited more in the medium and apical third areas. HFs showed the highest RRMV (p < 0.05), especially at the apical third. The non-instrumented areas were lower for HFs and XPC than for the other systems (p < 0.05). Cracks were present in a few WOG (n = 2) and HF specimens (n = 3) and in this group, one of the cracked specimens and two others showed perforations. The asymmetric systems resulted in conservative dentin removal and fewer cracks/perforations as compared to HFs and a reciprocation file in prototyped primary upper incisors. XPC showed the best compromise between RRMV and non-instrumented areas with a low accumulation of debris.

Resumo O objetivo deste estudo foi avaliar a eficiência da solução crioprotetora (PVS2) combinada com floroglucinol para a criopreservação de sementes de duas espécies de orquídeas, Encyclia cordigera e Epidendrum ciliare. Sementes de Encyclia cordigera apresentaram viabilidade inicial de 91,03% e germinação de 91,99%. O tratamento das sementes com PVS2 a 0 °C com 1% de floroglucinol por 60 min promoveu a recuperação de 93,79% da viabilidade e 91,01% da germinação após a recuperação do nitrogênio líquido, resultando consequentemente no desenvolvimento mais rápido dos protocormos. Para Epidendrum ciliare, a viabilidade inicial das sementes foi de 85,65% e germinação de 85,90%. E quando suas sementes foram tratadas com solução PVS2 a 0 °C com 1% floroglucinol por 180 min atingiram viabilidade de 39,23% e germinação de 37,88%. Apesar de observada menor porcentagem de germinação para o referido tratamento, 78,90% dos protocormos atingiram estágio de desenvolvimento P3, quando avaliados 45 dias após a semeadura, não apresentando diferença significativa comparada ao controle 1, e apresentando protocormos com desenvolvimento normal. Esses resultados indicam que a utilização da solução crioprotetora de PVS2 combinado ao floroglucinol 1% foi eficiente na recuperação de sementes criopreservadas de Encyclia cordigera e Epidendrum ciliare. O presente estudo também indica que a resposta à criopreservação após o armazenamento a frio é específica da espécie e requer ajustes no tempo de exposição ao PVS2 a 0 °C antes da imersão em nitrogênio líquido.

Abstract The objective of this study was to evaluate the efficiency of cryoprotective solution (PVS2) combined with phloroglucinol for the cryopreservation of seeds of two orchid species, Encyclia cordigera and Epidendrum ciliare. Seeds of Encyclia cordigera had 91.03% initial viability and 91.99% germination. The treatment of the seeds with PVS2 at 0 °C with 1% phloroglucinol for 60 min returned 93.79% viability and 91.01% germination after recovery from LN, consequently resulting in faster development of protocorms. For Epidendrum ciliare, seed viability was 85.65% and germination was 85.90%. Seed exposure to the PVS2 at 0 °C with 1% phloroglucinol for 180 min showed viability of 39.23% and germination of 37.88%. Despite lower germination, 78.90% of the protocorms reached stage P3 of development, when evaluated 45 days after sowing, not significantly different from the control 1, and showed normal development. These results indicate that PVS2 cryoprotective solution is efficient when combined with phloroglucinol for the cryopreservation and successful recovery of seeds of Encyclia cordigera and Epidendrum ciliare. The present study also indicates that response to cryopreservation and success of recovery after cold storage is species-specific and requires adjustments in exposure time to PVS2 at 0 °C prior to immersion in LN.

Resumo Objetivo: Avaliar e reconstruir imagens tridimensionais da vascularização ao longo da trompa de Falópio (TF) e sua relação com o ovário e fímbria do ovário, além de quantificar os vasos sanguíneos ao longo da TF de acordo com seus segmentos anatômicos usando microtomografia confocal (micro-TC). Materiais e Métodos: Nove espécimes (seis com TFs e três com TFs e ovários) foram fixados em solução de formol a 10% por mais de 24 h à temperatura ambiente. A coloração com iodo foi realizada usando solução de Lugol a 10% durante 24 h. Todos os espécimes foram avaliados usando micro-TC. Uma análise morfométrica foi realizada nas imagens reconstruídas para quantificar a distribuição vascular ao longo da TF. Resultados: A densidade dos vasos sanguíneos nas fímbrias foi significativamente aumentada em comparação ao segmento ístmico da TF (p < 0,05). A fímbria ovariana foi claramente identificada, demonstrando importante relação entre esses vasos e as fímbrias da TF. Conclusão: Acreditamos que as fímbrias apresentam vascularização aumentada e desproporcional em comparação com os demais segmentos da TF e que a fímbria ovariana desempenha importante papel nessa diferença.

Abstract Objective: To evaluate and reconstruct three-dimensional images of vascularization along the fallopian tube (FT), as well as to determine its relationship with the ovary and ovarian fimbria, and to quantify the blood vessels along the FT according to its anatomical segments, using confocal microtomography (micro-CT). Materials and Methods: Nine specimens (six FTs and three FTs with ovaries) were fixed in a solution of 10% formalin for > 24 h at room temperature. Iodine staining was performed by soaking the specimens in 10% Lugol’s solution for 24 h. All specimens were evaluated using micro-CT. A morphometric analysis was performed on the reconstructed images to quantify the vascular distribution along the FT. Results: In the FTs evaluated, the density of blood vessels was significantly greater in the fimbrial segments than in the isthmic segments (p < 0.05). The ovarian fimbria was clearly identified, demonstrating the important relationship between these vessels and the FT fimbriae. Conclusion: We believe that the vascularization in the fimbriae is greater than and disproportional that in the other segments of FT, and that the ovarian fimbria plays an important role in the development of that difference.

Abstract Objective: To compare the immediate microleakage of carious fissures sealed with a caries infiltrant covered by a flowable composite or solely with a flowable composite. Material and Methods: Extracted carious molars (n=20) were selected and paired among the experimental groups according to caries progression scores. Experimental groups (n=10) were divided according to the following sealing techniques: 1) caries infiltrant (Icon) + flowable composite (Z350 flow); 2) flowable composite (Z350 flow). Specimens were immersed in 3% methylene blue and evaluated in a stereomicroscope. Microleakage scores were attributed independently by two calibrated evaluators and the mode value was considered as the mean for the specimen. Binomial tests were used to test differences between two independent sample proportions at 5% significance level. Results: In the flowable composite group, a higher prevalence of dye penetration along the full depth of the fissure was observed, compared with caries infiltrant + flowable composite (p<0.05). For specimens showing dye penetration up to half of the fissure, in caries infiltrant + flowable composite group, all specimens showed dye penetration into the sealant, but not over the infiltrant. Conclusion: Using caries infiltrant as sealing material under a flowable composite cover is effective to improve the immediate sealing ability in carious fissures compared to sealing with flowable composite.

Resumo Para avaliar o volume de fissuras dentinárias levando em consideração a idade da dentina e o tipo de sistema de limas utilizadas para procedimentos endodônticos, 40 dentes unirradiculares, incisivos inferiores, apresentando similar volume radicular, recentemente extraídos foram divididos em dois grupos de acordo com a idade do paciente: Grupo Jovem (18 a 30 anos) e Grupo Idoso (60 anos ou mais). Cada espécime foi scaneada por microtomografia computadorizada (micro-CT) em três estágios: (i) antes de qualquer tratamento, (ii) após tratamento endodôntico com limas Reciproc (REC) e (iii) após subsequente retratamento endodôntico. Cada grupo foi subdividido em dois subgrupos, de acordo com a técnica de retratamento utilizada: retratamento com REC ou com lima ProTaper Universal Retreatment (PUR). As imagens foram analisadas quanto às diferenças no volume das fissuras dentinárias nos terços médio e apical dos dentes de acordo com a idade da dentina. Em ambos os estágios (antes e depois da instrumentação), as imagens de micro-CT da dentina radicular idosa apresentaram maior volume de trincas do que as jovens, sem significância estatística (p>0.01). O uso das limas REC mostram não ter diferença estatística significante na geração de fissuras, em qualquer tipo de dentina, quando comparadas às limas PUR (p>0.01). Quando retratada com PUR, a dentina radicular idosa apresentou um volume de trincas significativamente maior (p<0.01) quando comparado com a dentina radicular idosa inicialmente.

Abstract In order to evaluate the volume of dentinal cracks taking into account the age of the dentin and the type of file system used for endodontic procedures, forty freshly extracted single-rooted lower incisive teeth presenting similar root volume, were divided into two groups according to the age of the patient: Group Young (18 - 30 years old) and Group Old (60 years old or more). Each specimen was scanned by microcomputed tomography (micro-CT) in three stages: (i) before any treatment, (ii) after endodontic treatment with Reciproc files (REC), and (iii) after subsequent endodontic retreatment. Each group was subdivided into two subgroups, according to the retreatment technique used: retreatment with REC or with ProTaper Universal Retreatment (PUR) files. For each subgroup, the images were analyzed for differences in the volume of dentinal cracks in the middle and apical thirds of the teeth , according to the dentin age. In both stages (before and after instrumentation), the micro-CT images of the old root dentin presented with higher volume of cracks than those of the young root dentin, statistical significance notwithstanding (p>0.01). The use of REC files appeared to have no statistically significant differences in the generation of cracks in any type of root dentin when compared with PUR files (p>0.01). When retreated with PUR, the old root dentin presented with a significantly higher volume of cracks (p<0.01) when compared with the old root dentin initially.

Abstract The aim of this study was to check the in vitro accuracy of ICDAS criteria on digital images compared to visual examination for the diagnosis of occlusal caries against a micro-CT gold standard. ICDAS was scored in 40 extracted permanent molars by means of visual inspection and stereomicroscopic images. Visual examinations were performed in duplicate and at a one-week interval by three different calibrated examiners. The analysis of digital images by ICDAS criteria was also performed in duplicate, 1 month after visual examinations. The detection methods were compared by means of sensitivity, specificity, area under the curve, predictive positive and negative values, and accuracy for two different thresholds (1- sound vs. carious teeth; 2- tooth requiring operative vs. non-operative treatment). Sensitivity and accuracy values for threshold 1 in the visual ICDAS and image-based ICDAS methods were high for sensitivity (0.93 and 0.97) and for accuracy (0.83 and 0.85), but low for specificity (0.55 for both methods). Specificity values for threshold 2 were 0.77 and 0.82, while sensitivity was 0.33 and 0.28 for each method. Spearman’s rank correlation coefficient was 0.53 and 0.43 (p<0.05) for visual and image-based ICDAS compared to the gold standard scores. Both visual and image-based ICDAS scores were similar to each other in terms of diagnostic accuracy when compared to the micro-CT gold standard. Low specificity for the presence of caries and sensitivity for the detection of caries requiring operative treatment were found.

Resumo O objetivo deste estudo foi avaliar a relação de causa-efeito entre o preparo do canal radicular com o sistema ProTaper Universal (PTU) e a formação de defeitos dentinários usando a análise por micro-tomografia computadorizada (micro-CT). Quarenta raízes mesiais de molares inferiores com a configuração tipo II de Vertucci foram escaneadas com resolução isotrópica de 14.16 μm. A amostra foi distribuída em um grupo experimental (n = 30) e um grupo controle (n = 10), e os canais mesiais foram preparados com o sistema PTU até a lima F2. As amostras do grupo experimental foram escaneadas e as imagens de secção transversal das raízes mesiais, antes e após o preparo, foram analisadas para identificar a presença de defeitos dentinários. No grupo controle, os dentes foram seccionados perpendicularmente em relação ao longo eixo da raiz em fatias de 1 mm de espessura (n = 80) e examinados ao microscópio óptico. Uma vez detectado um defeito dentinário, a fatia foi escaneada através da micro-CT. No grupo experimental, defeitos dentinários foram observados em 4.828 secções transversais (24,04%). Em todas as imagens de secção transversal, os defeitos dentinários após os procedimentos experimentais já estavam presentes na secção pré-operatória correspondente. No grupo controle, 13 das 80 fatias (16,25%) apresentaram pelo menos um defeito dentinário visualizado através do microscópio, o qual foi identificado em um escaneamento posterior. A micro-CT mostrou confiabilidade com a microscopia óptica para detecção e visualização dos defeitos dentinários, permitindo acompanhar o tecido dentinário antes e depois do preparo do canal. O preparo do canal radicular com o sistema PTU não induziu a formação de novos defeitos dentinários.

Abstract This study aimed to evaluate the cause-effect relationship between canal preparation with ProTaper Universal (PTU) system and dentinal defects formation using micro-computed tomography (micro-CT) analysis. Forty mesial canals of mandibular molars with a type II Vertucci's canal configuration were scanned at an isotropic resolution of 14.16 µm. The sample was assigned to an experimental (n = 30) and a control (n = 10) groups, and the mesial canals were prepared with PTU system up to F2 instrument. The specimens from the experimental group were scanned and the cross-section images of the mesial roots, before and after preparation, were screened to identify the presence of dentinal defects. In the control group, the specimens were sectioned perpendicularly to the long axis of the root into 1-mm-thick slices (n = 80) and examined under optical microscope. Once a dentinal defect was detected, the slice was scanned through micro-CT. In the experimental group, dentinal micro-cracks were observed in 4,828 slices (24.04%). In all cross-section images, dentinal defects identified in the postoperative images were already present in the corresponding preoperative image. In the control group, 13 out of 80 slices (16.25%) had at least one dentinal defect visualized under stereomicroscopy, which was identified after a further micro-CT scanning. Micro-CT showed reliability as similar as optical microscopy in detecting dentinal defects, adding the possibility of tracking the dentinal tissue, before and after canal preparation, and providing a clear visualization of micro-cracks. Root canal preparation with PTU system did not induce the formation of new dentinal defects.

Resumo O objetivo deste estudo foi comparar a porcentagem de área não-instrumentada de canais radiculares preparados com diferentes ampliações utilizando sistemas reciprocantes de lima única (Reciproc e WaveOne) e um sistema rotatório convencional de múltiplas limas (BioRaCe) usando a análise da micro tomografia computadorizada. Trinta raízes mesiais de molares inferiores com curvatura moderada (10º a 20º) apresentando a configuração classe II de Vertucci e semelhança de volume do canal foram selecionadas e escaneadas em uma resolução isotrópica de 14,16 µm. A amostra foi dividida em 3 grupos (n=10) de acordo com o sistema utilizado para a preparação do canal radicular: grupo Reciproc, grupo WaveOne e grupo BioRaCe. Segundo e terceiro escaneamentos foram realizados após os canais serem preparados com instrumentos tamanhos 25 e 40, respectivamente. As imagens registradas de voxels da área de superfície dos canais, antes e após o preparo, foram examinadas desde o nível da furca até o ápice para quantificar a superfície não instrumentada. Os dados foram comparados estatisticamente através de GLM para medidas repetidas com um nível de significância de 5%. Os sistemas de instrumentação não influenciaram o percentual de superfícies não tocadas dos canais radiculares (p=0,690), enquanto que uma redução significativa no percentual de voxels estáticos foi observada após o alargamento do canal radicular (p=0,010) em todos os grupos (p=0,507). Nenhum dos sistemas foi capaz de preparar toda a área de superfície do canal mesial dos molares inferiores. O aumento do tamanho final apical resultou num efeito positivo significativo sobre a capacidade de modelar dos sistemas testados.

The aim of this study was to compare the percentage of non-instrumented area of root canals prepared with different enlargements using single-file reciprocating systems (Reciproc and WaveOne) and a conventional multi-file rotary (BioRaCe) system by micro-computed tomographic analysis. Thirty mesial roots of mandibular molars with moderate curvature (10° to 20°) presenting a type II Vertucci canal configuration and similar internal volume were chosen and scanned at an isotropic resolution of 14.16 µm. The sample was assigned to 3 groups (n=10) according to the system used for root canal preparation: Reciproc, WaveOne, and BioRaCe groups. Second and third scans were taken after the canals were prepared with instruments sizes 25 and 40, respectively. The recorded images of the surface area voxels of the canals, before and after preparation were examined from the furcation level to the apex to quantify the non-instrumented surface. Statistical data were compared using GLM for repeated-measures with a significance level set at 5%. Instrumentation systems did not influence the percentage of untouched root canal surfaces (p=0.690) whilst a significant reduction in the percentage of static voxels was observed after the enlargement of the root canal (p=0.010) in all groups (p=0.507). None of the systems was able to prepare the entire surface area of the mesial root canal of mandibular molars. The increased final apical size resulted in a significant positive effect on the shaping ability of the tested systems.

The main factor considered in breeding programs for fish is growth, which can be assessed in terms of a gain in either weight or body measurements. This study was undertaken to evaluate the morphometric traits of GIFT strain tilapia (Oreochromis sp.) selected for weight gain. The data set used contained information on 6,650 animals. The genetic values of 8,590 animals in a relationship matrix of five generations were predicted. The following morphometric measurements were evaluated: standard length; body depth and body width. Body area and volume were also calculated. Bi-character analyses involving morphometric traits were used to estimate (co)variance components. Heritability, larval and fingerling common environmental effects were estimated for each trait, together with the genetic and phenotypic correlations between traits. Bayesian procedures were utilised by Gibbs chains, and the convergence of the chains was tested using the Heidelberger and Welch method. Genetic trends were estimated by segmented regression of the fish breeding values of the generations considered in this study. Estimates of heritability (0.28 a 0.31) had moderate to high magnitudes for all traits. Genetic correlations between traits were all above 0.8, and the genetic gains were satisfactory from the third generation onwards. From the estimates of the genetic parameters and genetic gain the morphometric traits evaluated have good potential for selection.