38 resultados para Wilcoxon signed ranks test


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Purpose: This study evaluated the effect of different surface conditioning protocols on the repair strength of resin composite to the zirconia core / veneering ceramic complex, simulating the clinical chipping phenomenon.Materials and Methods: Forty disk-shaped zirconia core (Lava Zirconia, 3M ESPE) (diameter: 3 mm) specimens were veneered circumferentially with a feldspathic veneering ceramic (VM7, Vita Zahnfabrik) (thickness: 2 mm) using a split metal mold. They were then embedded in autopolymerizing acrylic with the bonding surfaces exposed. Specimens were randomly assigned to one of the following surface conditioning protocols (n = 10 per group): group 1, veneer: 4% hydrofluoric acid (HF) (Porcelain Etch) + core: aluminum trioxide (50-mu m Al2O3) + core + veneer: silane (ESPE-Sil); group 2: core: Al2O3 (50 mu m) + veneer: HF + core + veneer: silane; group 3: veneer: HF + core: 30 mu m aluminum trioxide particles coated with silica (30 mu m SiO2) + core + veneer: silane; group 4: core: 30 mu m SiO2 + veneer: HF + core + veneer: silane. Core and veneer ceramic were conditioned individually but no attempt was made to avoid cross contamination of conditioning, simulating the clinical intraoral repair situation. Adhesive resin (VisioBond) was applied to both the core and the veneer ceramic, and resin composite (Quadrant Posterior) was bonded onto both substrates using polyethylene molds and photopolymerized. After thermocycling (6000 cycles, 5 degrees C-55 degrees C), the specimens were subjected to shear bond testing using a universal testing machine (1 mm/min). Failure modes were identified using an optical microscope, and scanning electron microscope images were obtained. Bond strength data (MPa) were analyzed statistically using the non-parametric Kruskal-Wallis test followed by the Wilcoxon rank-sum test and the Bonferroni Holm correction (alpha = 0.05).Results: Group 3 demonstrated significantly higher values (MPa) (8.6 +/- 2.7) than those of the other groups (3.2 +/- 3.1, 3.2 +/- 3, and 3.1 +/- 3.5 for groups 1, 2, and 4, respectively) (p < 0.001). All groups showed exclusively adhesive failure between the repair resin and the core zirconia. The incidence of cohesive failure in the ceramic was highest in group 3 (8 out of 10) compared to the other groups (0/10, 2/10, and 2/10, in groups 1, 2, and 4, respectively). SEM images showed that air abrasion on the zirconia core only also impinged on the veneering ceramic where the etching pattern was affected.Conclusion: Etching the veneer ceramic with HF gel and silica coating of the zirconia core followed by silanization of both substrates could be advised for the repair of the zirconia core / veneering ceramic complex.

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Introduction: Some losses resulting from aging can be minimized with the practice of resistive exercises. Objective: To analyze the effects of resistive exercises on flexibility, mobility, muscle strength and balance in the elderly. Method: Twenty elderly individuals were divided between an activity group (AG, n=10; 66.1±6.35 years) and a control group (CG, n=10; 65.4±7.54 years). Mobility, flexibility, muscle strength and balance were evaluated. The AG participated in the training for 13 weeks (one-hour sessions, twice a week). The Wilcoxon non-parametric test (intra-group analysis) was used to analyze the data. A significance level of 5% (p<0.05) was adopted. Results: After training, the AG presented better mobility, lower limb muscle strength, and balance, but no difference in flexibility. Conclusion: The present study allows us to conclude that resistive exercises were able to improve mobility, lower limb muscle strength and balance in elderly individuals.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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OBJECTIVE: The aim of this study was to assess the time spent for direct (DBB - direct bracket bonding) and indirect (IBB - indirect bracket bonding) bracket bonding techniques. The time length of laboratorial (IBB) and clinical steps (DBB and IBB) as well as the prevalence of loose bracket after a 24-week follow-up were evaluated. METHODS: Seventeen patients (7 men and 10 women) with a mean age of 21 years, requiring orthodontic treatment were selected for this study. A total of 304 brackets were used (151 DBB and 153 IBB). The same bracket type and bonding material were used in both groups. Data were submitted to statistical analysis by Wilcoxon non-parametric test at 5% level of significance. RESULTS: Considering the total time length, the IBB technique was more time-consuming than the DBB (p < 0.001). However, considering only the clinical phase, the IBB took less time than the DBB (p < 0.001). There was no significant difference (p = 0.910) for the time spent during laboratorial positioning of the brackets and clinical session for IBB in comparison to the clinical procedure for DBB. Additionally, no difference was found as for the prevalence of loose bracket between both groups. CONCLUSION: the IBB can be suggested as a valid clinical procedure since the clinical session was faster and the total time spent for laboratorial positioning of the brackets and clinical procedure was similar to that of DBB. In addition, both approaches resulted in similar frequency of loose bracket.

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The use of conventional anthelmintic has been a growing concern among consumers who have become more and stricter toward drug residues in products of animal origin. Thus, this research aimed to evaluate the anthelmintic effect of alcoholic extract of propolis, at 30% of concentration, in naturally infected calves. Twelve calves weighting 60 kg and aging 90 days old were used. The treatments were performed by direct oral administration of 10 mL of EAP. The calves received the extract at every 8 h intervals, for five consecutive days. The results were evaluated comprising the detection of light and heavy eggs counted per gram of feces (EPG), immediately before and after treatment, calculating the percentage of reduction. For the statistical analysis, the results were evaluated by Wilcoxon unilateral test of signed points at 5% probability. Trichostrongylus sp. and Strongyloides sp. were found. After treatment, 83% of animals showed an average decrease of 48.48% per counting of EPG. Therefore, propolis may represent an important adjunctive therapy to control helminthiasis in cattle. It was particularly important in ecological organic and biological-dynamic systems of production, whose use of chemicals is prohibitive and limiting factor for certification.