No abstract

RESUMOO manejo inadequado do solo tem promovido a degradação de suas propriedades físicas, químicas e biológicas. O objetivo deste trabalho foi avaliar, após três anos da instalação de sistemas de manejo do solo, os efeitos da rotação com adubo verde, soja ou milho (verão) e feijão "de inverno", sendo utilizadas as seguintes espécies na adubação verde: mucuna-preta, milheto, crotalária e guandu, nas propriedades físicas e químicas de um Latossolo Vermelho distroférrico e na produtividade das culturas. Outro tratamento foi adicionado como alternativa à adubação verde, o pousio. Os sistemas de manejo do solo foram: semeadura direta não consolidada e preparo convencional. O estudo foi realizado em Selvíria-MS, no ano agrícola de 1999/2000. O delineamento experimental foi em blocos casualizados com parcelas subdivididas e quatro repetições. O sistema de semeadura direta, após três anos de instalada a rotação, degradou mais as propriedades físicas do solo na camada superficial. Por outro lado, neste sistema e camada de solo, houve acréscimo no teor de matéria orgânica e no pH, bem como na produtividade do milho, superior à do sistema de preparo convencional. O feijão em rotação à cultura do milho, na semeadura convencional, e em rotação à soja, na semeadura direta, foi a melhor opção quanto à produtividade.Termos de indexação: milho, soja, feijão, adubo verde, restos culturais, pousio.

Objective:The aim of this study was to verify, in vivo and in vitro, the prevalence of root canal bifurcation in mandibular incisors by digital radiography.Material and Methods:Four hundred teeth were analyzed for the in vivo study. Digital radiographs were taken in an orthoradial direction from the mandibular incisor and canine regions. The digital radiographs of the canine region allowed visualizing the incisors in a distoradial direction using 20° deviation. All individuals agreed to participate by signing an informed consent form. The in vitro study was conducted on 200 mandibular incisors positioned on a model, simulating the mandibular dental arch. Digital radiographs were taken from the mandibular incisors in both buccolingual and mesiodistal directions.Results:The digital radiography showed presence of bifurcation in 20% of teeth evaluated in vitro in the mesiodistal direction. In the buccolingual direction, 17.5% of teeth evaluated in vivo and 15% evaluated in vitro presented bifurcation or characteristics indicating bifurcation.Conclusions:Digital radiography associated with X-ray beam distally allowed detection of a larger number of cases of bifurcated root canals or characteristics of bifurcation.

The aim of this study was to evaluate the effectiveness of 2% peracetic acid for the disinfection of gutta-percha cones contaminated in vitro with Escherichia coli, Staphylococcus aureus, Streptococcus mutans, Candida albicans and Bacillus subtilus (in spore form). Two hundred and twenty-five gutta-percha cones were contaminated with standardized suspensions of each microorganism and incubated at 37°C for 24 h. The cones were divided into 10 experimental groups (n = 15), according to the microorganism tested and disinfection testing times. The disinfection procedure consisted of immersing each cone in a plastic tube containing the substance. The specimens remained in contact with the substance for 1 or 2.5 minutes. Afterwards, each cone was transferred to a 10% sodium thiosulphate solution (Na 2 S 2 O 3 ) to neutralize the disinfectant. Microbial biofilms adhering to the cones were dispersed by agitation. Aliquots of 0.1 ml of the suspensions obtained were plated on Sabouraud dextrose agar, or brain and heart infusion agar, and incubated at 37°C for 24 h. The results were expressed in colony forming units (CFU/ml) and the data were submitted to the Wilcoxon Signed Rank Test (level of significance at 0.05). A significant reduction was observed, after 1 minute of exposure, in the test solution for C. albicans (p = 0.0190), S. aureus (p = 0.0001), S. mutans (p = 0.0001), B. subtilis (p = 0.0001), and E. coli (p = 0.0001). After 2.5 minutes of exposure, 100% of the microbial inocula were eliminated. It was concluded that the 2% peracetic acid solution was effective against the biofilms of the tested microorganisms on gutta-percha cones at 1 minute of exposure.

The aim of this study was to evaluate the effects of different light-curing units and resin cement curing types on the bond durability of a feldspathic ceramic bonded to dentin. The crowns of 40 human molars were sectioned, exposing the dentin. Forty ceramic blocks of VITA VM7 were produced according to the manufacturer's recommendations. The ceramic surface was etched with 10% hydrofluoric acid / 60s and silanized. The dentin was treated with 37% phosphoric acid / 15s, and the adhesive was applied. The ceramic blocks were divided and cemented to dentin according to resin cement / RC curing type (dual-and photocured), light-curing unit (halogen light / QTH and LED), and storage conditions (dry and storage / 150 days + 12,000 cycles / thermocycling). All blocks were stored in distilled water (37°C / 24h) and sectioned (n = 10): G1 -QTH + RC Photo, G2 -QTH + RC Dual, G3 -LED + RC Photo, G4 -LED + RC Dual. Groups G5, G6, G7, and G8 were obtained exactly as G1 through G4, respectively, and then stored and thermocycled. Microtensile bond strength tests were performed (EMIC), and data were statistically analyzed by ANOVA and Tukey's test (5%). The bond strength values (MPa) were: G1 -12.95 (6.40) ab ; G2 -12.02 (4.59) ab ; G3 -13.09 (5.62) ab ; G4 -15.96 (6.32) a ; G5 -6.22 (5.90) c ; G6 -9.48 (5.99) bc ; G7 -12.78 (11.30) ab ; and G8 -8.34 (5.98) bc . The same superscript letters indicate no significant differences. Different light-curing units affected the bond strength between ceramic cemented to dentin when the photocured cement was used, and only after aging (LED > QTH). There was no difference between the effects of dual-and photo-cured resin-luting agents on the microtensile bond strength of the cement used in this study.

(1) Bolsista da FAPESP -IC e Pós-graduanda em Agronomia FEIS/UNESP -Av. Brasil Centro, 56 -Ilha Solteira -SP. CEP -15.385-000.

Objective: To evaluate the apical leakage exhibited by different endodontic sealers. Material and Methods:(maxillary molars) and distal roots (mandibular molars) sectioned, standardized and instrumented with Mtwo condensation technique and divided into three groups (n=10), according to the endodontic sealer employed: G1-AH Plus, G2-Fill Canal, G3-MTA Fillapex. All sealer. Gutta-percha points were immersed into sodium hypochlorite for 24 h to achieve disinfection. After the ink for posterior diaphanization and obtainment of the images through stereomicroscopy. By analyzing the images in Adobe Illustrator CS5 software, the level of apical leakage was determined. The data obtained were submitted to Kruskal Wallis and Dunn tests, with level differences were found between G1 and G3. G2 did not the smallest apical leakage mean (12.85), followed by G2 (109.84) and G3 (101.15). Conclusions: Root canal obturation with gutta-percha points and AH plus sealer through lateral condensation technique provided lower apical leakage rates than the other endodontic sealers evaluated. KEYWORDSSealers; Sodium hypochlorite; apical leakage. RESUMOdiculares obturados com guta-percha e três diferentes cimentos obturadores. Material e Métodos: Foram utilizados 35 molares humanos, os quais tiveram suas raízes linguais (molares superiores) e distais (molares inferiores) seccionadas, padronizadas e instrumentadas com o sistema rotatório Mtwo. As raízes foram obturadas através da técnica de condensação lateral ativa e divididas em 3 grupos (n=10), de acordo com o cimento obturador utilizado: G1-AH Plus, G2-Fill Canal, G3-MTA Fillapex. Todos os grupos foram obturados com o conjunto guta-percha e cimento obturador, sendo que a guta-percha utilizada permaneceu 24 h imersa em hipoclorito de sódio, para sua desinfecção. Após a obturação, as raízes foram imersas em corante tinta da Índia, para posterior diafanização e obtenção de imagens através de estereomicroscópio. Através da análise das imagens no programa Adobe Illustrator CS5 foi determinado o aos testes estatísticos de Kruskal Wallis e Dunn, com nível de diferiu estatisticamente dos demais grupos. O G1 apresentou (109.84) e G3 (101.15). Conclusões: A obturação de canais radiculares com cones de guta-percha e cimento AH plus através da técnica de condensação lateral proporciona baixos índices obturadores avaliados.

<p>The fracture of anterior teeth after root canal treatment is a real and multifactorial possibility. This is due to the weakening of the root due to lost of the remaining tooth added to oblique-existing occlusal forces. This fracture in addition to causing a masticatory dysfunction, will also influence the aesthetics of the patient. In prevention, one of the treatments used and widely accepted, is the use of intraradicular. These can be made of metal, carbon fiber, fiberglass and ceramics. The pins of metal and carbon fiber are very efficient but don't favor the aesthetic, as the pins fiberglass and ceramics are very resistant and favor aesthetics. Reinforcing with these biomaterials is beneficial and leads to a favorable prognosis. This study shows a case which the building could have prevented the intracanal fracture of an devitalized upper anterior tooth and makes a brief discussion about the available options for this type of rehabilitation. The use of reinforced glass fiber as reinforcement of the structure of devitalized teeth is indicated for the prevention of dental fractures. Cast ceramic cores are indicated for the insufficient coronary remaining to support the filling material.<strong></strong></p>