Cellular damages in the Allium cepa test system, caused by BTEX mixture prior and after biodegradation process

Petroleum and derivatives have been considered one of the main environmental contaminants. Among petroleum derivatives, the volatile organic compounds benzene, toluene, ethylbenzene and xylene (BTEX) represent a major concern due to their toxicity and easy accumulation in groundwater. Biodegradation methods seem to be suitable tools for the clean-up of BTEX contaminants from groundwater. Genotoxic and mutagenic potential of BTEX prior and after biodegradation process was evaluated through analyses of chromosomal aberrations and MN test in meristematic and F 1 root cells using the Allium cepa test system. Seeds of A. cepa were germinated into five concentrations of BTEX, non-biodegraded and biodegraded, in ultra-pure water (negative control), in MMS 4×10 -4M (positive control) and in culture medium used in the biodegradation (blank biodegradation control). Results showed a significant frequency of both chromosomal and nuclear aberrations. The micronucleus (MN) frequency in meristematic cells was significant for most of tested samples. However, MN was not present in significant levels in the F 1 cells, suggesting that there was no permanent damage for the meristematic cell. The BTEX effects were significantly reduced in the biodegraded samples when compared to the respective non-biodegraded concentrations. Therefore, in this study, the biodegradation process showed to be a reliable and effective alternative to treat BTEX-contaminated waters. Based on our results and available data, the BTEX toxicity could also be related to a synergistic effect of its compounds. © 2011 Elsevier Ltd.

Blood cells attachment after root conditioning and PRP application: An in vitro study

Aim: Root conditioning is aimed at smear layer removal and at dental matrix collagen exposure, which may promote periodontal regeneration. This in vitro study assessed smear layer removal, collagen fiber exposure and the influence of PRP (platelet-rich plasma) application on adhesion of blood cells to the root surface using scanning electron microscopy (SEM). Materials and methods: Scaled root samples (n = 160) were set in five groups and conditioned with: group I - control group (saline solution); group II (EDTA 24%); group III (citric acid 25%); group IV (tetracycline hydrochloride 50 mg/ml); group V (sodium citrate 30%). Eighty samples were assessed using the root surface modification index (RSMI). The other eighty samples were set in two groups. The first group (n = 40) received PRP gel application with a soft brush and the second group (n = 40) received PRP application and then a blood drop. The fibrin clot formation was assessed in the first group and the blood cells adhesion was assessed in the second group using the BEAI (blood elements adhesion index). A previously trained, calibrated, and blind examiner evaluated photomicrographs. Statistical analysis was performed using the Kruskal-Wallis's and Dunn's tests. Results: Group III attained the best results for RSMI and BEAI. Moreover, it was the only group showing fibrin clot formation. Conclusion: Citric acid was the most efficient conditioner for smear layer removal, collagen fiber exposure and blood cell adhesion. Moreover, it was the only group showing fibrin clot formation after PRP application. Clinical significance: This study demonstrated that root conditioning followed by PRP application may favor blood cell adhesion on root surface which may optimize periodontal healing.

Wound healing of dehiscence defects following different root conditioning modalities: An experimental study in dogs

Objective: The purpose of this study was to investigate the periodontal healing pattern of dehiscence-type defects following different chemical root conditioning modalities. Materials and methods: Buccal osseous dehiscence defects were created on six teeth of seven dogs. After dental plaque accumulation, defects were treated with sterile saline solution (control group) or one chemical conditioning modality: citric acid (CA group), ethylenediaminetetraacetic acid (EDTA group), tetracycline (TTC group), citric acid + tetracycline (CA + TTC group), or tetracycline + citric acid (TTC + CA group). After 3 months of healing, clinical parameters were evaluated, and the animals were killed. Histological sections were processed, and a computer-assisted histometric analysis was used to evaluate the formation of new cementum, new bone, and epithelial apical migration. Results: All treatments yielded significant improvements in terms of probing depth decrease and clinical attachment level gain compared to baseline values; however, without significant differences among the groups (p > 0.05; one-way ANOVA). The highest amount of new cementum was noted in the EDTA group (3.72 ± 0.83 mm, 77.6 %), while the lowest amount of new bone was observed in the TTC group (0.7 ± 0.94 mm, 14.3 %). However, no statistically significant differences could be observed among the groups regarding epithelial apical migration, new cementum, and alveolar bone formation (p > 0.05). Conclusion: Chemical root surface conditioning did not promote any significant improvement in periodontal healing pattern of dehiscence-type defects in dogs. Clinical Relevance: Chemical root surface conditioning after surgical debridement did not promote positive or negative effects on periodontal healing pattern of dehiscence-type defects. © 2012 Springer-Verlag Berlin Heidelberg.

Root coverage stability of the subepithelial connective tissue graft and guided tissue regeneration: A 30-month follow-up clinical trial

Objectives: The aim of this study was to compare the long-term clinical effects produced by subepithelial connective tissue graft (SCTG) and guided tissue regeneration combined with demineralized freeze-dried bone allograft (GTR-DFDBA) in the treatment of gingival recessions in a 30-month follow-up clinical trial. Methods: Twenty-four defects were treated in 12 patients who presented canine or pre-molar Miller class I and/or II bilateral gingival recessions. GTR-DFDBA and SCTG treatments were performed in a randomized selection in a split-mouth design. The clinical measurements included root coverage (RC), gingival recession (GR), probing depth (PD), clinical attachment level (CAL) and keratinized tissue width (KTW). These clinical parameters were evaluated at baseline and after 6, 18 and 30 months post-surgery. Results: The changes in RC, GR, PD and CAL did not show significant differences between groups (p > 0.05). Both procedures promoted similar RC (GTR-DFDBA: 87% and SCTG: 95.5%) and similar reduction in GR (GTR-DFDBA: 3.25 mm and SCTG: 3.9 mm), PD (GTR-DFDBA: 1.6 mm and SCTG: 1.2 mm) and CAL (GTR-DFDBA: 4.9 mm and SCTG: 5.0 mm). The increase in KTW was significantly higher (p = 0.02) in the SCTG group (3.5 mm) than in the GTR-DFDBA group (2.4 mm). Conclusions: Both techniques for treatment of gingival recession (SCTG and GTR-DFDBA) lead to favourable and long-term stable results, but SCTG promoted a more favourable increase in keratinized tissue. © 2012 Elsevier Ltd. All rights reserved.

In vitro antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis in root canals

Objective: The aim of this study was to evaluate the antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecali's inoculated in root canals. Material and Methods: Seventy-two human tooth roots were contaminated with C. albicans and E. faecalis for 21 days. The groups were divided according to the auxiliary chemical substance into: G1) 2.5% sodium hypochlorite (NaOCl), G2) 2% chlorhexidine gel (CHX), G3) castor oil, G4) glycolic Aloe vera extract, g5) glycolic ginger extract, and G6) sterile saline (control). The samples of the root canal were collected at different intervals: confirmation collection, at 21 days after contamination; 1st collection, after instrumentation; and 2nd collection, seven days after instrumentation. Microbiological samples were grown in culture medium and incubated at 37°C for 48 hours. Results: The results were submitted to the Kruskal-Wallis and Dunn (5%) statistical tests. NaOCl and CHX completely eliminated the microorganisms of the root canals. Castor oil and ginger significantly reduced the number of CFU of the tested bacteria. Reduction of CFU/mL at the 1st and 2nd collections for groups G1, G2, G3 and G4 was greater in comparison to groups G5 and G6. Conclusion: It was concluded that 2.5% sodium hypochlorite and 2% chlorhexidine gel were more effective in eliminating C. albicans and E. faecalis, followed by the castor oil and glycolic ginger extract. The Aloe vera extract showed no antimicrobial activity.

Biocompatibility and biomineralization assessment of a new root canal sealer and root-end filling material

Objective: This study investigated the short-term subcutaneous tissue reaction and biomineralization ability of two epoxy-based root canal sealers containing calcium hydroxide (MBP and MBPc) and ProRoot MTA. Materials and methods: Polyethylene tubes containing the materials were implanted into the dorsal connective tissue of Wistar rats (n = 52) for 7 or 30 days; empty implanted tubes served as controls. Specimens were stained with hematoxylin-eosin and von Kossa stain or left unstained for observation under polarized light. Qualitative and quantitative evaluations of all tissue reactions were performed. One-way anova and the Kruskal-Wallis test were used for statistical analysis (P < 0.05). Results: No significant differences were observed among the groups. All three materials induced mild-to-moderate tissue reactions at 7 days, which decreased over time. Dystrophic mineralization and birefringent structures were observed only in the ProRoot MTA ® group. Conclusion: Both MBP and MBPc appear to be biocompatible but do not stimulate biomineralization. © 2012 John Wiley & Sons A/S.

The efficacy of the self-adjusting file and ProTaper for removal of calcium hydroxide from root canals

Objective: The goal of this study was to evaluate the efficacy of the Self-Adjusting File (SAF) and ProTaper for removing calcium hydroxide [Ca(OH)2] from root canals. Material And Methods: Thirty-six human mandibular incisors were instrumented with the ProTaper system up to instrument F2 and filled with a Ca(OH)2-based dressing. After 7 days, specimens were distributed in two groups (n=15) according to the method of Ca(OH)2 removal. Group I (SAF) was irrigated with 5 mL of NaOCl and SAF was used for 30 seconds under constant irrigation with 5 mL of NaOCl using the Vatea irrigation device, followed by irrigation with 3 mL of EDTA and 5 mL of NaOCl. Group II (ProTaper) was irrigated with 5 mL of NaOCl, the F2 instrument was used for 30 seconds, followed by irrigation with 5 mL of NaOCl, 3 mL of EDTA, and 5 mL of NaOCl. In 3 teeth Ca(OH)2 was not removed (positive control) and in 3 teeth canals were not filled with Ca(OH)2 (negative control). Teeth were sectioned and prepared for the scanning electron microscopy. The amounts of residual Ca(OH)2 were evaluated in the middle and apical thirds using a 5-score system. Results: None of the techniques completely removed the Ca(OH)2 dressing. No difference was observed between SAF and ProTaper in removing Ca(OH)2 in the middle (P=0.11) and the apical (P=0.23) thirds. Conclusion: The SAF system showed similar efficacy to rotary instrument for removal of Ca(OH)2 from mandibular incisor root canals.

Effect of Zingiber officinale and propolis on microorganisms and endotoxins in root canals

The purpose of this study was to evaluate the effectiveness of glycolic propolis (PRO) and ginger (GIN) extracts, calcium hydroxide (CH), chlorhexidine (CLX) gel and their combinations as ICMs (ICMs) against Candida albicans, Enterococcus faecalis, Escherichia coli and endotoxins in root canals. Material and Methods: After 28 days of contamination with microorganisms, the canals were instrumented and then divided according to the ICM: CH+saline; CLX, CH+CLX, PRO, PRO+CH; GIN; GIN+CH; saline. The antimicrobial activity and quantification of endotoxins by the chromogenic test of Limulus amebocyte lysate were evaluated after contamination and instrumentation at 14 days of ICM application and 7 days after ICM removal. Results and Conclusion: After analysis of results and application ofthe Kruskal-Wallis and Dunn statistical tests at 5% significance level, it was concluded that all ICMs were able to eliminate the microorganisms in the root canals and reduce their amount of endotoxins; however, CH was more effective in neutralizing endotoxins and less effective against C. albicans and E. faecalis, requiring the use of medication combinations to obtain higher success.

Effect of the treatment of root surface-adhered necrotic periodontal ligament with propolis or fluoride in delayed rat tooth replantation

Objectives: The purpose of this study was to evaluate the application of 15 % propolis and 2 % acidulated-phosphate sodium fluoride solutions on the root surface-adhered necrotic cemental periodontal ligament in delayed tooth replantation. Materials and methods: Thirty Wistar rats (Rattus norvegicus, albinus) had their right upper incisor extracted and maintained in dry storage for 60 min. After this period, the dental papilla, enamel organ, and pulp tissue were removed, and the animals were randomly assigned to three groups: group I = immersion in saline for 10 min; group II = immersion in a 2 % acidulated-phosphate sodium fluoride solution for 10 min; and group III = immersion in a 15 % propolis and propylene glycol solution for 10 min. The root canals were filled with a calcium hydroxide paste and the teeth were replanted. Results: Inflammatory resorption, replacement resorption, and ankylosis were observed in all groups without a statistically significant difference (p > 0.05) among them. Conclusions: Under the tested conditions, the application of fluoride or propolis on root surface-adhered necrotic periodontal ligament did not favor the healing process in delayed tooth replantation. © 2013 Springer-Verlag Berlin Heidelberg.

Setting Time Affects In Vitro Biological Properties of Root Canal Sealers

Introduction: Biocompatibility of root canal sealers is important because of the long-term contact of their eluates and/or degradation products with periapical tissues. The literature still lacks studies about the genotoxic effects of these materials and the influence of setting time on biological properties. The cytotoxicity and genotoxicity of an epoxy resin-based sealer (AH Plus), a single methacrylate-based sealer (EndoRez), and a silicone-based sealer (RoekoSeal) were assessed. Methods: Chinese hamster fibroblasts (V79) were cultured and exposed to different dilutions of extracts from the sealers that were left to set for 0, 12, and 24 hours before contact with culture medium. Cell viability was measured by the methyl-thiazol-diphenyltetrazolium assay. Genotoxicity was assessed by the comet assay. Data were statistically analyzed by Kruskal-Wallis and Dunn tests (P < .05). Results: Root canal sealers were statistically more cytotoxic than the untreated control group, except for the silicon-based sealer. Cell viability ranking was the following (from the most to the least cytotoxic): methacrylate-based > epoxy resin-based > silicone-based. The setting time influenced the epoxy resin-based sealer cytotoxicity (decreased at 12 hours) and the general genotoxicity (increased at 24 hours). DNA damage ranking was the following (from the most to the least genotoxic): methacrylate-based > silicone-based = epoxy resin-based. Conclusions: The setting time had influence on the cytotoxicity of the epoxy resin-based sealer and genotoxicity of all tested sealers. The methacrylate-based sealer was the most cytotoxic, and the silicone-based sealer was not cytotoxic. Genotoxicity was observed for all sealers. © 2013 American Association of Endodontists.

Digital soil mapping: evaluation of sampling systems for soil surveys and refinement of soil maps at lower cost using legacy data

In soil surveys, several sampling systems can be used to define the most representative sites for sample collection and description of soil profiles. In recent years, the conditioned Latin hypercube sampling system has gained prominence for soil surveys. In Brazil, most of the soil maps are at small scales and in paper format, which hinders their refinement. The objectives of this work include: (i) to compare two sampling systems by conditioned Latin hypercube to map soil classes and soil properties; (II) to retrieve information from a detailed scale soil map of a pilot watershed for its refinement, comparing two data mining tools, and validation of the new soil map; and (III) to create and validate a soil map of a much larger and similar area from the extrapolation of information extracted from the existing soil map. Two sampling systems were created by conditioned Latin hypercube and by the cost-constrained conditioned Latin hypercube. At each prospection place, soil classification and measurement of the A horizon thickness were performed. Maps were generated and validated for each sampling system, comparing the efficiency of these methods. The conditioned Latin hypercube captured greater variability of soils and properties than the cost-constrained conditioned Latin hypercube, despite the former provided greater difficulty in field work. The conditioned Latin hypercube can capture greater soil variability and the cost-constrained conditioned Latin hypercube presents great potential for use in soil surveys, especially in areas of difficult access. From an existing detailed scale soil map of a pilot watershed, topographical information for each soil class was extracted from a Digital Elevation Model and its derivatives, by two data mining tools. Maps were generated using each tool. The more accurate of these tools was used for extrapolation of soil information for a much larger and similar area and the generated map was validated. It was possible to retrieve the existing soil map information and apply it on a larger area containing similar soil forming factors, at much low financial cost. The KnowledgeMiner tool for data mining, and ArcSIE, used to create the soil map, presented better results and enabled the use of existing soil map to extract soil information and its application in similar larger areas at reduced costs, which is especially important in development countries with limited financial resources for such activities, such as Brazil.

O plantio associado entre banana (Musa acuminata Cultivar Cavendish "Grande Naine") e feijão-de-porco (Canavalia ensiformis (L.) D. C.): uma avaliação agronômica dos efeitos da competição por água, nitrogênio e energia luminosa

Nas regiões de clima tropical, o monocultivo da banana vem causando conseqüências ambientais desastrosas e, muitas vezes, impedindo uma exploração continuada de uma mesma área. A redução do rendimento é devido principalmente as limitações físico-químicas do solo e a rápida degradação do sistema radicular, agravada pela ação de parasitas do solo (nematóides, fungos, etc.). Em virtude destas limitações, várias iniciativas vem sendo buscadas para a minimização das perdas agronômicas e ambientais, destacando-se o melhoramento e a modificação genética, e a associação deste cultivo com espécies leguminosas. Porém uma das grandes dificuldades de avaliarmos os novos sistemas de cultivo alternativos concentra-se na falta de referenciais agronômicos relacionados principalmente com o funcionamento de sistemas de cultivos associados, especialmente relacionados aos fatores e condições que interferem diretamente na definição do rendimento da espécie principal. O presente estudo testou , em campo experimental, o uso de plantas de serviço associada a bananeira e seus efeitos na produção de biomassa durante seu o ciclo vegetativo. Isto porque é durante esta fase que a bananeira constrói sua capacidade de reservas de fotoassimilados e, consequentemente, define o potencial de produção e enchimento dos frutos. Além do monocultivo, definiu-se mais duas parcelas associadas com o feijão-de- porco: 1) o plantio simultâneo das duas espécies e; 2) o plantio de feijão-de-porco e, após 2 meses, a introdução da banana. Além de acompanhamento semanal das parcelas, realizou-se, bimensalmente, coletas destrutivas de dados sobre produção de matéria seca, superfície foliar e análise nutricional das plantas. Após a análise agronômica da fase vegetativa, aplicou-se a modelização dos sistemas de cultivo estudados e comparou-se os possíveis cenários sobre o rendimento final da bananeira, além de outros indicadores sobre os fatores de crescimento das plantas. Após o acompanhamento dos 7 primeiros meses do ciclo vegetativo, concluiu-se que a data de estabelecimento da associação foi determinante para o sucesso do cultivo associado. Podemos destacar que a associação entre a bananeira e o feijão-de-porco não causou limitações na produção de biomassa (4,2 ton/ha), quando comparada com o monocultivo (4,5 ton/ha). A redução do número de capinas também foi um indicador animador deste sistema de cultivo alternativo. Por outro lado, quando a bananeira foi plantada 60 dias após a leguminosa, a mesma representou uma séria limitação na produção de biomassa (2,7 ton/ha). Esta limitação deveu-se ao estado de forte competição devido a agressividade com que o feijão-de-porco recobria toda a parcela e alcançando uma altura (74 cm) superior que a muda de banana (29 cm). Em relação a primeira parte da metodologia aplicada - o diagnóstico agronômico -, a mesma foi eficiente para a avaliação do ciclo vegetativo da associação estudada, ficando a necessidade da continuidade do acompanhamento do ciclo reprodutivo, para a confirmação dos resultados em termos de formação e produção de frutos. Na fase de modelização, chegou-se a uma leitura dos resultados próxima dos resultados obtidos no campo. Em termos de rendimento em frutos, o monocultivo com adubação (400 kg/ha de nitrogênio) e irrigação (133 mm) teve um aumento na ordem de 50% no rendimento final (28 ton/ha) Quando comparada com a parcela nas condições reais do experimento (19,6 ton/ha). Já o rendimento em frutos da associação, apresentou o mesmo resultado com e sem adubação e irrigação (16 ton/ha). No tocante a contrução dos cenários, confirmou-se novamente algumas das vantagens da associação, principalmente na redução da adubação nitrogenada aplicada nos sistemas convencionais de cultivo. Finalmente, podemos imaginar a construção de várias formas de testar e otimizar o uso destes sistemas associados (cenários). Porém, confirma-se que a construção de novos referenciais agronômicos sobre sistemas de cultivo mais complexos (os cultivos associados) torna-se ainda muito necessário para a realização de avaliações mais precisas sobre estas alternativas. E, com estes novos referenciais técnicos, podemos imaginar, a médio e longo prazo, alguns dos benefícios das leguminosas sobre as propriedades físico-químicas do solo cultivado (cobertura viva, adubo verde, redução de adventícias, etc) e sobre a manutenção do rendimento dos cultivos (adubação verde).

Avaliação antifungica, farmacognóstica e toxicológica sazonal de Petiveria alliacea L. (Phytolaccaceae)

O estudo das plantas medicinais desperta grande interesse científico, principalmente devido às mesmas serem consideradas fontes potenciais de moléculas bioativas com estrutura diferenciada e mecanismo de ação inovador. A importância de pesquisas voltadas para a descoberta e produção de novos fitoterápicos deve-se a grande contribuição que estes vêm apresentando diante de diversas patologias. A espécie Petiveria alliacea é uma planta medicinal utilizada amplamente pela população da região amazônica e destaca-se por apresentar diversas alegações de uso e ainda algumas classes de metabólitos com comprovadas ações terapêuticas. O presente trabalho teve o objetivo de avaliar os parâmetros farmacognósticos sazonais da espécie, o potencial antifúngico dos extratos produzidos em diferentes períodos de coleta sobre espécies de Aspergillus e a toxicidade dos mesmos in vitro e in vivo. Na avaliação farmacognóstica sazonal de P. alliacea, utilizando métodos descritos na Farmacopéia Brasileira, os resultados demonstraram parâmetros reprodutíveis para o controle de qualidade da droga vegetal, não havendo diferença na presença dos constituintes químicos do pó e do extrato hidroalcoólico, sendo observada a presença de saponinas, acúcares e alcaloides em toda a planta e nos extratos da raiz apenas sesquiterpenolactonas e depsídeos/depsidonas. Os resultados do método da microdiluição realizadas com extratos das raízes de dois períodos, evidenciaram fraca atividade antifúngica in vitro, porém não foi observado nenhum efeito dos extratos das partes aéreas. A atividade citotóxica, avaliada pelo método colorimétrico MTT, demonstrou que o extrato hidroalcóolico da raiz dos dois períodos não reduz a viabilidade celular em nenhuma das concentrações testadas. Também não foram detectados sinais de toxicidade aguda do extrato na dose de 5000mg/kg em camundongos. Estes dados são considerados relevantes e o estudo em questão evidenciou que P. alliacea é uma espécie medicinal promissora, porém investigações mais detalhadas são necessárias para que sejam confirmadas suas várias alegações de uso e para que a planta seja utilizada no desenvolvimento de um novo agente fitoterápico.

Comparison of the effects of TripleGates and Gates-Glidden burs on cervical dentin thickness and root canal area by using cone beam computed tomography

The search for new instruments to promote an appropriate cervical preparation has led to the development of new rotary instruments such as TripleGates. However, to the best of the authors' knowledge, there is no study evaluating TripleGates effect on the “risk zone” of mandibular molars. Objectives: The aim of this study was to evaluate the effects of a crown-down sequence of Gates-Glidden and TripleGates burs on the remaining cervical dentin thickness and the total amount of dentin removed from the root canals during the instrumentation by using cone beam computed tomography. The number of separated instruments was also evaluated. Material and Methods: Mesial roots of 40 mandibular first molars were divided into 2 equal groups: crown-down sequence of Gates-Glidden (#3, #2, #1) and TripleGates burs. Cervical dentin thickness and canal area were measured before and after instrumentation by using cone beam computed tomography and image analysis software. Student’s t-test was used to determine significant differences at p<0.05. Results: No significant differences (p>0.05) were observed between the instruments, regarding the root canal area and dentin wall thickness. Conclusion: Both tested instruments used for cervical preparation were safe to be used in the mesial root canal of mandibular molars.

Rapidity distributions in exclusive Z plus jet and gamma plus jet events in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)