Fem and Von Mises analysis of OSSTEM ® dental implant structural components: evaluation of different direction dynamic loads

Abstract PURPOSE: The objective of this investigation is to study prosthodontics and internal components resistance to the masticatory stress and considering different force directions by using Finite Element Method analysis (FEM). The structural materials of the components are usually Titanium alloy grade 4 or 5 and thus, guarantee the integration of the fixture in the bone due to the osteointegration phenomena. Even if the long-term dental implant survival rate is easy to be obtained and confirmed by numerous researches, the related clinical success, due to the alteration of the mechanical and prosthodontics components is still controversial. METHODS: By applying engineering systems of investigations like FEM and Von Mises analyses, it has been investigated how dental implant material was held against the masticatory strength during the dynamic masticatory cycles. A three-dimensional system involved fixture, abutment and the connection screws, which were created and analyzed. The elastic features of the materials used in the study were taken from recent literature data. RESULTS: Data revealed a different response for both types of devices, although implant neck and dental abutment showed better results for all conditions of loading while the abutment screw represented aweak point of the system. CONCLUSION: The data of this virtual model showed all the features of different prosthetic retention systems under the masticatory load. Clinicians should find better prosthetic balance in order to better distribute the stress over the component and to guarantee patients' clinical long-term results

Corrosion polarization behavior and microstructuralanalysis of AA1070 aluminium silicon carbide matrix composites in acid chloride concentrations

The effect of SiC content and NaCl concentration on the corrosion resistance of AA1070 aluminium in 2 M H2SO4 was evaluated with potentiodynamic polarization technique, open circuit potential measurement (OCP) and optical microscopy. Results showed SiC increased the corrosion susceptibility of the alloy at lower NaCl concentrations compared to results obtained at 0% NaCl which showed significant decrease in corrosion rates, with maximum inhibition efficiency of 90.84% at 20% SiC content. The corrosion rates decreased at higher NaCl concentration,with maximum inhibition efficiency of 94.12 and 77.27% at 20% SiC. Alloy samples in 2 M H2SO4/0% NaCl at 0 and 20% SiC visibly decreased in OCP value over wide variation compared to samples with varying NaCl concentration due to loss of passivity. OCP values for alloys at varying NaCl concentration decreased over a very short variation due to repassivation. Statistical data showed silicon carbide to be the only relevant variable responsible for the corrosion rate values with F-values of 8.85 corresponding to a percentage significance of 54.8%. Optical images showed the presence of corrosion pits of smaller dimension, yet deeper on the morphology of the alloy without silicon carbide compared the alloy containing it, whose corrosion pits, seems wider but very shallo

Length Weight Relationship of Whip Fin Silver Biddy Gerres Filamentosus (Cuvier) from Sharavathi Estuary, Central West Coast Of India

The length weight relationship and relative condition factors were studied between Jan. and Dec. 2008. Length weight relationship of Gerres filamentosus did not differ significantly between the sexes and combined equation is given by W= 0.000001663 L3.1675. The highest Kn value in female was in June (1.0950) and lowest in July (1.0950). Similarly the highest Kn value in male was in Dec (1.0587) and lowest in July (0.8994). Both in males and females the Kn value was highest in the size of 101-110 mm which can be attributed to feeding

Facundity of Whipfin Silver Biddy Gerres filamentosus (Cuvier) from Sharavati Estuary, Central West Coast of India

Fecundity of Gerres filamentosus varied from 48,300to 1,16760 in fishes ranging in size from 154 to 240 mm..Fecundity increases at the rate of cube of the total length .The number of ova per gram of body weight varied from 485 to 955, while the number of ova per gram ovary weight ranged from 11761 to  24250. The relationship between weight of ovary and fecundity is linear and number of ova increases at a rate less than that in relation to total length and body weight

Voter Buying: Shaping the Electorate through Clientelism

Studies of clientelism typically assume that political machines distribute rewards to persuade or mobilize the existing electorate. We argue that rewards not only influence actions of the electorate, but can also shape its composition. Across the world, machines employ “voter buying” to import outsiders into their districts. Voter buying demonstrates how clientelism can underpin electoral fraud, and it offers an explanation of why machines deliver rewards when they cannot monitor vote choices. Our analyses suggest that voter buying dramatically influences municipal elections in Brazil. A regression discontinuity design suggests that voter audits—which undermined voter buying—decreased the electorate by 12 percentage points and reduced the likelihood of mayoral reelection by 18 percentage points. Consistent with voter buying, these effects are significantly greater in municipalities with large voter inflows, and where neighboring municipalities had large voter outflows. Findings are robust to an alternative research design using a different data set

Spatial resolved high-energy particle diagnostic system using time-of-flight neutral particle analyzer in Large Helical Device

The time-of-flight-type neutral particle analyzer has an ability of horizontal scanning from 40 to 100° of the pitch angle. The information from the spatially resolved energy spectrum gives not only the ion temperature but also the information of the particle confinement and the electric field in plasmas. We have been studying the energy distributions at various magnetic configurations in the neutral beam injection (NBI) plasma. The spatially resolved energy spectra can be observed during long discharges of the NBI plasma by continuous scanning of the neutral particle analyzer. The shape of spectra is almost similar from 44° to 53°. However, the spectra from 55° are strongly varied. They reflect the injection pitch angle of the beam. The pitch angle scanning experiment during the long discharge of NBI plasma has also been made under the reversal of the magnetic field direction. NBI2 becomes counter injected with the reversal. We can easily observe the difference between co- and counter injections of NBI. During the electron cyclotron heating in the low-density plasma for the formation of the internal thermal barrier, large neutral particle increase or decease can be observed. The degree of the increase/decrease depends on the energy and the density. The reason for the variation of the particle flux is that the orbit of the trapped particle changes due to the electric field formed by the strong electron cyclotron heating

Latissimus dorsi rotational flap combined with a custom-made scapular prosthesis after oncological surgical resection: A report of two patients

BACKGROUND: Sarcomas that arise from the scapula or periscapular soft tissues often require a total scapulectomy. This often implies a large complex tissue defect that needs adequate reconstruction of both bone and soft tissue. Although various methods have been developed, no optimal procedure has emerged. Postoperative complications are common and functional recovery is not always satisfactory. This study aims to present a new surgical technique that combines a custom-made scapular prosthesis with a functional latissimus dorsi flap. CASE PRESENTATION: Two patients diagnosed with malignant tumour of the scapular region were surgically treated after proper multidisciplinary evaluation. The first patient underwent the procedure as a first surgery, the second as revision surgery. The new technique comprises three surgical stages: excisional surgery with soft tissue resection and scapulectomy, bone reconstruction with custom-made prosthesis, and soft tissue reconstruction using a latissimus dorsi rotational flap overturned on the prosthesis. The goal is to set up a new functional unit combining an anatomically shaped implant (manufactured using latest three-dimensional printing technology) and a muscular flap, and to maintain the neurovascular supply. The patients were followed up to evaluate functional outcome and complications. Both patients were alive with no evidence of disease. Functional results were satisfactory and the Musculoskeletal Tumor Society scores were 87% and 63%, respectively. No surgical complications such as implant breakage, joint collapse, wound dehiscence, or infection were observed. CONCLUSIONS: This new technique upgrades the role of the latissimus dorsi flap to a functional tool in combination with an anatomical, three-dimensionally printed, custom-made prosthesis, and provides adequate well-vascularized and healthy tissue to maximize the likelihood of successful limb salvage

THERAPEUTIC PATIENT EDUCATION (TPE) IN STROKE: EFFICACY OF LAY -LOOK AFTER YOURSELF- SELF-MANAGEMENT PROGRAM

Guidelines recommend Therapeutic Patient Education (TPE) in stroke patients, but there are no strong evidences of efficacy (variability in type, timing and setting of existing programs). Aim: to develop and evaluate the efficacy of a standardized TPE program on empowerment of self-management (SM) for stroke inpatient and facilitation of social reintegration after rehabilitation discharge