5 research outputs found
Knoop Hardness and Effectiveness of Dual-Cured Luting Systems and Flowable Resin to Bond Leucite-Reinforced Ceramic to Enamel
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Purpose: The aim of this study was to evaluate the Knoop microhardness and microshear bond strength (MSBS) of dual-cured luting systems and flowable resin bonded to leucite-reinforced ceramics and enamel. Materials and Methods: Eighty bovine incisors were randomly divided into four groups per test (microhardness and microshear; n = 10) according to the bonding procedure: Excite DSC/Variolink, Clearfil SE Bond/Panavia F, Adper Scotchbond Multi-Purpose Plus/RelyX ARC, and Adper Single Bond 2/Filtek Z350 Flow. For the KHN measurement, the cement was applied on the enamel surface and light-cured through a ceramic disk (5 mm diameter x 1.2 mm thick). Five indentations were performed in each specimen and measured at HMV-2. For the microshear test, two cylinders of a leucite-reinforced ceramic (1 mm diameter x 2 mm height) were bonded to the enamel substrate in accordance with the bonding procedures previously established. One cylinder was tested 24 hours after cementation, and the other was subjected to thermocycling (2000 cycles) and then submitted to an MSBS test. The data from the hardness and bond strength tests were subjected to one-and two-way repeated-measures analysis of variance (ANOVA), respectively, and to Tukey's test (alpha = 0.05). Results: Scotchbond/RelyX ARC presented higher values of bond strength, while SingleBond/Z350 Flow showed lower values. The thermocycling promoted a reduction in the bond strength values for all groups. Panavia F presented higher values of KHN, and the flowable resin presented the lowest. RelyX ARC and Variolink presented intermediate values on hardness evaluation. Conclusions: For ceramic cementation, dual-cured resin luting systems promoted more reliable bonding and microhardness values than the flowable resin.2215458Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2009/08420-3, 2009-08992-7]CNPq [133077/2009-8
Evaluation of the Effectiveness of a Voice Training Program for Teachers
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Objectives. To investigate the effects of a voice education program to teachers on vocal function exercise and voice hygiene and compare a pre- and post-vocal exercise for the teacher's voice quality. Methods. A random sample of 102 subjects was divided into two groups: experimental group (29 women and seven men) with vocal hygiene and training exercises and control group (52 women and 14 men) with vocal hygiene. Two sessions were held about voice hygiene for the control group and five sessions for the experimental group, one being with reference to the vocal hygiene habit and four vocal exercise sessions. Acoustic analysis of the vowel [i] was made pre- and post-vocal exercise and for the situations of initial and final evaluation of the educational program. Student t test (paired) and Proc MIXED (repeated measures) were used for analyses with level of significance (alpha = 0.05). Results. The training exercises, posture and relaxation cervical, decreased the mean of fundamental frequency (f(0)) for men (P = 0.04), and for the phonation, intensity, and frequency exercises, there was a significant increase for f(0) in woman (P = 0.02) and glottal to noise excitation ratio (P = 0.04). There was no statistically significant difference intergroup evaluations after 3 months. The control group presented increased mean voice intensity in the final evaluation (P = 0.01). Conclusions. Voice training exercises showed a positive and immediate impact on the teacher's quality of voice, but it was not sustained longitudinally, suggesting that actions for this purpose should be continued at schools.275603610Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2009/01507-6
Nongenotoxic effects and a reduction of the DXR-induced genotoxic effects of Helianthus annuus Linne (sunflower) seeds revealed by micronucleus assays in mouse bone marrow
Background: This research evaluated the genotoxicity of oil and tincture of H. annuus L. seeds using the micronucleus assay in bone marrow of mice. The interaction between these preparations and the genotoxic effects of doxorubicin (DXR) was also analysed (antigenotoxicity test). Methods: Experimental groups were evaluated at 24-48 h post treatment with N-Nitroso-N-ethylurea (positive control - NEU), DXR (chemotherapeutic), NaCl (negative control), a sunflower tincture (THALS) and two sources of sunflower oils (POHALS and FOHALS). Antigenotoxic assays were carried out using the sunflower tincture and oils separately and in combination with NUE or DXR. Results: For THALS, analysis of the MNPCEs showed no significant differences between treatment doses (250-2,000 mg.Kg(-1)) and NaCl. A significant reduction in MNPCE was observed when THALS (2,000 mg.Kg(-1)) was administered in combination with DXR (5 mg.Kg(-1)). For POHALS or FOHALS, analysis of the MNPCEs also showed no significant differences between treatment doses (250-2,000 mg.Kg(-1)) and NaCl. However, the combination DXR + POHALS (2,000 mg.Kg(-1)) or DXR + FOHALS (2,000 mg.Kg(-1)) not contributed to the MNPCEs reduction. Conclusions: This research suggests absence of genotoxicity of THALS, dose-, time- and sex-independent, and its combination with DXR can reduce the genotoxic effects of DXR. POHALS and FOHALS also showed absence of genotoxicity, but their association with DXR showed no antigenotoxic effects.14Rede Mineira de Ensaios Toxicologicos e Farmacologicos de Produtos Terapeuticos (REDE MINEIRA TOXIFAR)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG
