The distribution of stresses in bone, implants, and prosthesis were analyzed via three-dimensional finite element modeling in different implant configurations for a fixed implant-supported prosthesis ...in an edentulous mandible.
A finite element model was created with data obtained from computed tomographic scans of a human mandible. Anisotropic characteristics for cortical and cancellous bone were incorporated into the model. Six different configurations of intraforaminal implants were tested, with the number of implants varying from three to five and the distal implants inserted either parallel to the other implants or tilted distally by 17 or 34 degrees. A prosthetic structure connecting the implants was designed, with 20-mm posterior cantilevers for the parallel implant configurations, and a load of 200 N was applied to the distal portion of the cantilevers. Stresses were measured at the level of the implant, the prosthetic structure, and the bone. Bone-level stresses were analyzed at the implant-bone interface, at the external cortical bone surface, distal to the terminal implant, and in the cancellous bone along the implant body.
A three-parallel-implant configuration resulted in higher stress in the implant and bone than configurations with four or five parallel implants. Configurations with the distal implants tilted resulted in a more favorable stress distribution at all levels.
In parallel-implant configurations for fixed implant-supported mandibular prostheses, four and five implants resulted in similar stress distribution in the bone, framework, and implants. A distribution of four implants with the distal implants tilted 34 degrees (ie, the "All-on-Four" configuration) resulted in a favorable reduction of stresses in the bone, framework, and implants.
The aim of the work is to analyze stress distribution on 3D Finite Element (FE) models at bone, implant, and framework level of different designs for fixed implant-supported prostheses in completely ...edentulous patients, comparing results on whole and partially resected mandibles.
3D anisotropic FE models of a whole and of a partially resected mandible were created using a TC scan of a cadaver's totally edentulous mandible. Two types of totally implant-supported rehabilitation were simulated, with four implants: parallel fixtures on whole mandible and on resected mandible, All-on-four-configured fixtures on whole mandible and on partially resected mandible. A superstructure comprising only metal components of a prosthetic framework were added, while stress distribution and its maximum values were analyzed at bone, implant, and superstructure level.
The results highlight that:
(1) implant stresses are greater on the whole mandible than on the resected one;
(2) framework and cancellous-bone stresses are comparable in all cases;
(3) on the resected mandible, maximum stress levels at the cortical-bone/implant interface are higher than in whole-mandible rehabilitation. The opposite applies for maximum stresses on external cortical bone, measured radially with respect to the implant from the point of maximum stress at the interface.
On the resected mandible, All-on-four configuration proved biomechanically superior to parallel implants considering radial stresses on implants and cortical bone. Still, maximum stresses increase at the bone/implant interface. A design with four parallel implants minimizes the stress on a resected mandible while, on the whole mandible, the All-on-four rehabilitation proves superior at all levels (bone, implant, and framework).
Purpose: The study evaluated in vitro the retention force and the wear resistance over simulated function of four matrix components of ball attachments for implant‐retained overdentures.
Materials ...and Methods: Four types of matrices for ball attachments were evaluated in a fatigue study simulating 5500 cycles of insertion and removal. The matrices used were (1) a Teflon matrix supported by a metal housing, (2) a titanium matrix, (3) a gold alloy matrix, (4) an O‐ring matrix using the red color ring for medium retention. Dimensional changes of the ball attachments were investigated with a profilometer.
Results: The Teflon matrices showed an increase of 27% in retention at 5500 cycles while the gold alloy matrices showed an increase of 50% in retention in the first 500 cycles and remained relatively stable up to 5500 cycles. On the other hand, titanium matrices and O‐ring matrices exhibited progressive loss of retention ending with 68% and 75% of retention loss, respectively, at 5500 cycles. Dimensional analysis by profilometer revealed significant wear on the ball attachment only for titanium matrixes.
Conclusions: Gold alloy and Teflon matrices showed the highest retention values without retention loss after 3 years of simulated function. Titanium and O‐ring matrices presented a continuous loss of retention with the highest wear on the ball attachments when combined with the titanium matrix.
O objetivo deste trabalho é apresentar as práticas adotadas no Brasil relativas à avaliação contábil da carteira de investimentos de fundos de investimento de venture capital e private equity e ...verificar o seu alinhamento às práticas contábeis internacionais, considerando o contexto da harmonização contábil mundial. Possibilitando um melhor entendimento do assunto, apresenta-se a definição de capital de risco, o contexto evolutivo da indústria de venture capital e private equity, os agentes e os tipos e estágios de investimento, o ambiente regulatório no país e as principais práticas contábeis adotadas no Brasil e em âmbito internacional. Para atingir o objetivo do trabalho a pesquisa trouxe uma abordagem qualitativa de cunho descritiva, embasada na pesquisa bibliográfica e, também, uma pesquisa em informações disponíveis nas demonstrações financeiras arquivadas na Comissão de Valores Mobiliários (CVM). O resultado da análise revela que as práticas contábeis adotadas no Brasil, especificamente relativas à avaliação da carteira de investimentos de fundos de investimento de capital de risco, ainda não estão harmonizadas às práticas contábeis internacionais.
The aim of this paper is to present the practices adopted in Brazil for the accounting valuation of the investment portfolio of investment funds (venture capital and private equity) and check their alignment with international accounting practices, considering the context of global accounting harmonization. Enabling a better understanding of the subject, presents the definition of venture capital, the changing context of industry, venture capital and private equity players and the types and stages of investment, the regulatory environment in the country and the major accounting practices in Brazil and internationally. To achieve the goal of the research work has brought a qualitative approach of descriptive, based on literature research and also research on information available in financial statements filed with the Comissão de Valores Mobiliários (CVM). The test result shows that the accounting practices adopted in Brazil, specifically concerning the assessment of the investment portfolio of investment funds in venture capital and private equity, are still not harmonized with international accounting practices.
Objectives
Patients undergoing hemimandibulectomy suffer from mandibular deviation.
The purpose of this article is to describe a new therapeutic possibility for the prosthetic management of these ...patients using only one device both for physiotherapy and eating.
Methods
A 56-year-old man’s pre-existing mandibular removable partial prosthesis was modified to use as a partial prosthesis as a device to correct mandibular deviation. In fact, two precision attachments patrix were inserted into buccal surface of partial prosthesis base and corresponding matrix were inserted into a transparent acrylic resin guide-flange.
Results
In this way the patient can use only one prosthesis both for physiotherapy and eating simply inserting and removing the guide flange. The transparent resin employ is important for the day by day use.
Conclusion
This technique permits to use only one device both for mechanical correction of mandibular deviation and masticatory function while literature shows that two different devices are usually used in patients with mandibular deviation to satisfy both these functions.
The aim of this study was to evaluate differences in the inflammatory profile of young (<or=40 years) systemically healthy periodontal patients comparing chronic (CP) versus aggressive periodontitis ...(AP) in terms of cytokines, chemokines and C-reactive protein levels.
Systemically healthy subjects affected by severe CP or AP were enrolled in this study. Differential diagnosis was performed according to the criteria suggested by the American Academy of Periodontology. Blood samples for the evaluation of high sensitivity C-reactive protein levels, cytokine levels (IL-1beta, IL-1RA, IL-4, IL-6, IL-10, IL-12, interferon-gamma, interferon-gamma-inducible protein 10, tumour necrosis factor alpha) and chemokine levels (IL-8, vascular endothelial growth factor, monocyte chemoattractant protein 1, macrophage inflammatory protein 1alpha and macrophage inflammatory protein 1beta) were obtained from all patients.
A total of 45 systemically healthy patients with severe periodontitis were consecutively selected, 21 with CP (mean age 36.8+/-3.5; mean clinical attachment level CAL 4.72+/-0.69) and 24 with AP (mean age 35.9+/-3.8; mean CAL 4.68+/-0.75). No statistically significant difference between the two groups was detected for periodontal variables and for all the investigated inflammatory markers.
The inflammatory profile of severe periodontitis in young patients (<or=40 years) may be similar for chronic and aggressive types. Differential diagnosis between CP and AP may not be able to detect a different systemic inflammatory profile in young adults.
Clinical and laboratory procedures to fabricate a transitional prosthesis for patients treated with laryngofissure surgery have been described. Hard resin promoted healing of the surgical area and ...maintained the opening because of its stiffness. The prosthesis, which can be highly polished, was easily removed by the patient for proper hygiene and was fabricated to accurately fit the inside margins of the wound. All these factors were important for a good clinical result.
Mood disorders (major depressive disorder, MDD, and bipolar disorder, BD) are considered leading causes of life-long disability worldwide, where high rates of no response to treatment or relapse and ...delays in receiving a proper diagnosis (~60% of depressed BD patients are initially misdiagnosed as MDD) contribute to a growing personal and socio-economic burden. The immune system may represent a new target to develop novel diagnostic and therapeutic procedures but reliable biomarkers still need to be found.
In our study we predicted the differential diagnosis of mood disorders by considering the plasma levels of 54 cytokines, chemokines and growth factors of 81 BD and 127 MDD depressed patients. Clinical diagnoses were predicted also against 32 healthy controls. Elastic net models, including 5000 non-parametric bootstrapping procedure and inner and outer 10-fold nested cross-validation were performed in order to identify the signatures for the disorders.
Results showed that the immune-inflammatory signature classifies the two disorders with a high accuracy (AUC = 97%), specifically 92% and 86% respectively for MDD and BD. MDD diagnosis was predicted by high levels of markers related to both pro-inflammatory (i.e. IL-1β, IL-6, IL-7, IL-16) and regulatory responses (IL-2, IL-4, and IL-10), whereas BD by high levels of inflammatory markers (CCL3, CCL4, CCL5, CCL11, CCL25, CCL27, CXCL11, IL-9 and TNF-α).
Our findings provide novel tools for early diagnosis of BD, strengthening the impact of biomarkers research into clinical practice, and new insights for the development of innovative therapeutic strategies for depressive disorders.
•The immune-inflammatory signature classifies BD and MDD with a high accuracy.•BD was predicted mainly by pro-inflammatory markers.•MDD was predicted by high levels of both pro-inflammatory and regulatory markers.
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