Procedures adopted by orthodontists for space closure and anchorage control

OBJECTIVE: The aim of this study was to identify the procedures adopted by Brazilian orthodontists in the following situations: extraction space closure, anchorage control in case of necessary anchorage for group A and frequency of skeletal anchorage use, especially in the upper jaw. METHOD: A questionnaire was sent to the e-mail address of all dentists registered in the Brazilian Federal Council of Dentistry. RESULTS: The results showed that most Brazilian orthodontists usually perform extraction space closure by means of sliding mechanics. The use of palatal bar, inclusion of second molars in the archwire and space closure performed in two phases are the most used techniques for anchorage control in the upper jaw. The skeletal anchorage is referenced by 36.5% of specialists as a routine practice for the upper jaw anchorage. CONCLUSIONS: There is a wide variety of procedures adopted by Brazilian orthodontists for orthodontic space closure and anchorage control.

Relax and cut: limitantes duais para o problema do caixeiro viajante

Pós-graduação em Matemática - IBILCE

Procedures to Evaluate the Efficiency of Protective Clothing Worn by Operators Applying Pesticide

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

Quantification of Biological Tissue and Construction of Patient Equivalent Phantom (Skull and Chest) for Infants (1-5 years old)

Our main purpose in this study was to quantify biological tissue in computed tomography (CT) examinations with the aim of developing a skull and a chest patient equivalent phantom (PEP), both specific to infants, aged between 1 and 5 years old. This type of phantom is widely used in the development of optimization procedures for radiographic techniques, especially in computed radiography (CR) systems. In order to classify and quantify the biological tissue, we used a computational algorithm developed in Matlab (R). The algorithm performed a histogram of each CT slice followed by a Gaussian fitting of each tissue type. The algorithm determined the mean thickness for the biological tissues (bone, soft, fat, and lung) and also converted them into the corresponding thicknesses of the simulator material (aluminum, PMMA, and air). We retrospectively analyzed 148 CT examinations of infant patients, 56 for skull exams and 92 were for chest. The results provided sufficient data to construct a phantom to simulate the infant chest and skull in the posterior anterior or anterior posterior (PA/AP) view. Both patient equivalent phantoms developed in this study can be used to assess physical variables such as noise power spectrum (NPS) and signal to noise ratio (SNR) or perform dosimetric control specific to pediatric protocols.

Can Heat Treatment Procedures of Pre-hydrolyzed Silane Replace Hydrofluoric Acid in the Adhesion of Resin Cement to Feldspathic Ceramic?

Purpose: To evaluate the influence of heat treatment (HT) procedures of a pre-hydrolyzed silane on bond strength of resin cement to a feldspathic ceramic.Materials and Methods: Ceramic and composite blocks (N = 30) were divided into six groups (n = 5) and subjected to the following conditioning procedures: G1: 9.6% hydrofluoric acid (HF) for 20 s + silane (RelyX Ceramic Primer, 3M ESPE) + resin cement (Panavia F2.0, Kuraray) (control); G2: HF (20 s) + silane + heat treatment in furnace (HTF) (100 degrees C, 2 min) + resin cement; G3: silane + HTF + resin cement; G4-HF (20 s) + silane + heat treatment with hot air (HTA) (50 +/- 5 degrees C for 1 min) + resin cement; G5: silane + HTA + resin cement; G6: silane + resin cement. The microtensile bond strength (MTBS) test was performed using a universal testing machine (1 mm/min). After debonding, the substrate and adherent surfaces were analyzed using a stereomicroscope and SEM to categorize the failure types. The data were statistically evaluated using one-way ANOVA and Tukey's test (5%).Results: The control group (G1) showed no pre-test failures and presented significantly higher mean MTBS (16.01 +/- 1.12 MPa) than did other groups (2.63 +/- 1.05 to 12.55 +/- 1.52 MPa) (p = 0.0001). In the groups where HF was not used, HTF (G3: 12.55 +/- 1.52 MPa) showed significantly higher MTBS than did HTA (G5: 2.63 +/- 1.05 MPa) (p < 0.05). All failure types were mixed, ie, adhesive between the resin cement and ceramic accompanied by cohesive failure in the cement.Conclusion: Heat treatment procedures for the pre-hydrolyzed silane either in a furnace or with the application of hot air cannot replace the use of HF gel for the adhesion of resin cement to feldspathic ceramic. Yet when mean bond strengths and incidence of pre-test failures are considered, furnace heat treatment delivered the second best results after the control group, being considerably better than hot air application.

Quantification of Endotoxins in Infected Root Canals and Acute Apical Abscess Exudates: Monitoring the Effectiveness of Root Canal Procedures in the Reduction of Endotoxins

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparison of the performance of natural latex membranes prepared with different procedures and PTFE membrane in guided bone regeneration (GBR) in rabbits

This work assessed the performance of membranes made of natural latex extracted from Hevea brasiliensis prepared with three different methods: polymerized immediately after collection without the use of ammonia (L1); polymerized after preservation in ammonia solution (L2); and polymerized after storage in ammonia, followed by Soxhlet technique for the extraction of substances (L3). Polytetrafluoroethylene (PTFE) membrane was used as control. Two 10-mm diameter bone defects were surgically made in the calvaria of thirty adult male New Zealand rabbits. Defects (total n = 60) were treated with guided bone regeneration (GBR) using L1, L2, L3 or PTFE membranes (n = 15 for each membrane). Ten animals were euthanized after 7, 20 and 60 days postoperatively so that five samples (n = 5) of each treatment were collected at each time, and bone regeneration was assessed microscopically. The microscopic analysis revealed defects filled with blood clot and new bone formation at the margins of the defect in all 7-day samples, while 20-day defects were mainly filled with fibrous connective tissue. After 60 days defects covered with L1 membranes showed a significantly larger bone formation area in comparison to the other groups (P < 0.05, ANOVA, Tukey). Additionally, bone tissue hypersensitization for L1 and PTFE membranes was also investigated in six additional rabbits. The animals were subjected to the same surgical procedure for the confection of one 10-mm diameter bone defect that was treated with L1 (n = 3) or PTFE (n = 3). Fifty-three days later, a second surgery was performed to make a second defect, which was treated with the same type of membrane used in the first surgery. Seven days later, the animals were euthanized and samples analyzed. No differences among L1 and PTFE samples collected from sensitized and non-sensitized animals were found (P > 0.05, Kruskal-Wallis). Therefore, the results demonstrated that latex membranes presented performance comparable to PTFE membranes, and that L1 membranes induced higher bone formation. L1 and PTFE membranes produced no hypersensitization in the bone tissue.

Effects of aging procedures on the topographic surface, structural stability, and mechanical strength of a ZrO2-based dental ceramic

Objective. To determine the effects of different aging methods on the degradation and flexural strength of yttria-stabilized tetragonal zirconia (Y-TZP)Methods. Sixty disc-shaped specimens (0, 12 mm; thickness, 1.6 mm) of zirconia (Vita InCeram 2000 YZ Cubes, VITA Zahnfabrik) were prepared (ISO 6872) and randomly divided into five groups, according to the aging procedures (n=10): (C) control; (M) mechanical cycling (15,000,000 cycles/3.8 Hz/200N); (T) thermal cycling (6,000 cycles/5-55 degrees C/30 s); (TM) thermomechanical cycling (1,200,000 cycles/3.8 Hz/200N with temperature range from 5 C to 55 C for 60s each); (AUT) 12h in autoclave at 134 degrees C/2 bars; and (STO) storage in distilled water (37 degrees C/400 days). After the aging procedures, the monoclinic phase percentages were evaluated by X-ray diffraction (XRD), and topographic surface analysis was performed by 3D profilometry. The specimens were then subjected to biaxial flexure testing (1 mm/min, load 100 kgf, in water). The biaxial flexural strength data (MPa) were analyzed by 1-way ANOVA and Tukey's test (alpha = 0.05). The data for monoclinic phase percentage and profilometry (Ra) were analyzed by Kruskal-Wallis and Dunn's tests.Results. ANOVA revealed that flexural strength was affected by the aging procedures (p = 0.002). The M (781.6 MPa) and TM (771.3 MPa) groups presented lower values of flexural strength than did C (955 MPa), AUT (955.8 MPa), T (960.8 MPa) and STO (910.4 MPa). The monoclinic phase percentage was significantly higher only for STO (12.22%) and AUT (29.97%) when compared with that of the control group (Kruskal-Wallis test, p = 0.004). In addition, the surface roughnesses were similar among the groups (p = 0.165).Signcance. Water storage for 400 days and autoclave aging procedures induced higher phase transformation from tetragonal to monoclinic; however, they did not affect the flexural strength of Y-TZP ceramic, which decreased only after mechanical and thermomechanical cycling. (C) 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Analysis of the procedures used to evaluate suicide crime scenes in Brazil: A statistical approach to interpret reports

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

Binding of antioxidant flavone isovitexin to human serum albumin investigated by experimental and computational assays

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Balanced anesthesia with sevoflurane does not alter redox status in patients undergoing surgical procedures

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

An improved interolog mapping-based computational prediction of protein protein interactions with increased network coverage

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cogeneration design problem Computational complexity analysis and solution through an expert system

Purpose - The purpose of this paper is twofold: to analyze the computational complexity of the cogeneration design problem; to present an expert system to solve the proposed problem, comparing such an approach with the traditional searching methods available.Design/methodology/approach - The complexity of the cogeneration problem is analyzed through the transformation of the well-known knapsack problem. Both problems are formulated as decision problems and it is proven that the cogeneration problem is np-complete. Thus, several searching approaches, such as population heuristics and dynamic programming, could be used to solve the problem. Alternatively, a knowledge-based approach is proposed by presenting an expert system and its knowledge representation scheme.Findings - The expert system is executed considering two case-studies. First, a cogeneration plant should meet power, steam, chilled water and hot water demands. The expert system presented two different solutions based on high complexity thermodynamic cycles. In the second case-study the plant should meet just power and steam demands. The system presents three different solutions, and one of them was never considered before by our consultant expert.Originality/value - The expert system approach is not a "blind" method, i.e. it generates solutions based on actual engineering knowledge instead of the searching strategies from traditional methods. It means that the system is able to explain its choices, making available the design rationale for each solution. This is the main advantage of the expert system approach over the traditional search methods. On the other hand, the expert system quite likely does not provide an actual optimal solution. All it can provide is one or more acceptable solutions.

Uso do método de Monte Carlo para simulação e detecção do espectro de raios-X gerado com feixes de elétrons em alvo de Molibdênio, utilizando o Geant4

The huge demand for procedures involving ionizing radiation promotes the need for safe methods of experimentation considering the danger of their biological e ects with consequent risk to humans. Brazilian's legislation prohibits experiments involving this type of radiation in humans through Decree 453 of Ministry of Health with determines that such procedures comply with the principles of justi cation, optimization and dose limitation. In this line, concurrently with the advancement of available computer processing power, computing simulations have become relevant in those situations where experimental procedures are too cost or impractical. The Monte Carlo method, created along the Manhattan Project duringWorldWar II, is a powerful strategy to simulations in computational physics. In medical physics, this technique has been extensively used with applications in diagnostics and cancer treatment. The objective of this work is to simulate the production and detection of X-rays for the energy range of diagnostic radiology, for molybdenum target, using the Geant4 toolkit. X-ray tubes with this kind of target material are used in diagnostic radiology, speci cally in mammography, one of the most used techniques for screening of breast cancer in women. During the simulations, we used di erent models for bremsstrahlung available in physical models for low energy, in situations already covered by the literature in earlier versions of Geant4. Our results show that although the physical situations seems qualitatively adequate, quantitative comparisons to available analytical data shows aws in the code of Geant4 Low Energy source

Método para reconhecimento de íris baseado na sua região interna

Recognition of individuals through the characteristics of the iris has in recent years become a well accepted technique due to both the high reliability of this procedure and the its non invasiveness. The methods used in such procedures seek information all over the iris, which depending on the algorithm used may result in high computational costs. Considering that most characteristics of the iris are in its inner region the goal of this work is to develop an algorithm for the recognition of individuals using only this region. To bring the outcome of our approach to the level of the best techniques described in the literature this technique has to be further elaborated, even so the results show a promising technique.