Influence of various implant platform configurations on peri-implant tissue dimensions: an experimental study in dog

AimTo evaluate the influence (i) of various implant platform configurations and (ii) of implant surface characteristics on peri-implant tissue dimensions in a dog model.Material and methodsMandibular premolars and first molars were extracted bilaterally in six Labrador dogs. After 3 months of healing, two implants, one with a turned and a second with a moderately rough surface, were installed on each side of the mandible in the premolar region. on the right side of the mandible, implants with a tapered and enlarged platform were used, while standard cylindrical implants were installed in the left side of the mandible. Abutments with the diameter of the cylindrical implants were used resulting in a mismatch of 0.25 mm at the tapered implant sites. The flaps were sutured to allow a non-submerged healing. After 4 months, the animals were sacrificed and ground sections were obtained for histometric assessment.ResultsAll implants were completely osseointegrated. A minimal buccal bone resorption was observed for both implant configurations and surface topographies. Considering the animals as the statistical unit, no significant differences were found at the buccal aspect in relation to bone levels and soft tissue dimensions. The surface topographies did not influence the outcomes either.ConclusionsThe present study failed to show differences in peri-implant tissue dimensions when a mismatch of 0.25 mm from a tapered platform to an abutment was applied. The surface topographies influence a neither marginal bone resorption or peri-implant soft tissue dimension.To cite this article:Baffone GM, Botticelli D, Pantani F, Cardoso LC, Schweikert MT, Lang NP. Influence of various implant platform configurations on peri-implant tissue dimensions: an experimental study in dog.Clin. Oral Impl. Res. 22, 2011; 438-444.

Biomechanical Evaluation of Platform Switching in Different Implant Protocols: Computed Tomography-Based Three-Dimensional Finite Element Analysis

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

Photoelastic comparison of single tooth implant-abutment-bone of platform switching vs conventional implant designs

Objectives: The maintenance and stability of peri-implantar soft tissue seem to be related to the crestal bone around the implant platform and different implant designs connections might affect this phenomenon. The aim of this study was to evaluate by photoelastic analysis the stress distribution in the cervical and apical site of implant-abutment interface of conventional implant joints (external hex, internal hex and cone morse) and compare to the novel platform switching design. Materials and methods: It was fabricated photoelastic models using five different implant-abutment connection, one set of external hex (Alvim Ti, Neodent, Curitiba, Brazil), one set of internal hex (Full Osseotite, Biomet 3i, Florida, USA), one cone morse set (Alvim CM, Neodent, Curitiba, Brazil), and two sets of internal hex plus platform switching concept (Alvim II Plus, Neodent, Curitiba, Brazil) (Certain Prevail, Biomet 3i, Florida, USA). These models were submitted to two compressive loads, axial from 20 kgf (load I) and another (load II), inclined 45° from 10 kgf. During the qualitative analysis, digital pictures were taken from a polariscope, for each load situation. For the quantitative analyses in both situations of load, the medium, minimum and maximum in MPa values of shear strain were determined in the cervical and apical site. The Kruskal-Wallis test was used to compare the results between the different systems and between cervical and apical site were compared using Mann-Whitney U test. Results: The results from qualitative analysis showed less concentration of strain in the cervical area to the internal hex plus platform switching (Certain Prevail), in both situation of load. The same results were get in the quantitative analysis, showing less stress concentrations around the implant Certain Prevail with internal hex plus the novel design (17.9 MPa to load I and 29.5 MPa to load II), however, without statistical significant difference between the systems. Conclusion: The minor stress concentration strongly suggest the use of platform switching design as a manner to prevent bone loss around the implant-abutment platform. Clinical Significance: From the result of this study its possible to make clinical decision for implant system which provides implant components with platform switching characteristics.

Using multiple abstraction levels to speedup an MPSoC virtual platform simulator

Virtual platforms are of paramount importance for design space exploration and their usage in early software development and verification is crucial. In particular, enabling accurate and fast simulation is specially useful, but such features are usually conflicting and tradeoffs have to be made. In this paper we describe how we integrated TLM communication mechanisms into a state-of-the-art, cycle-accurate, MPSoC simulation platform. More specifically, we show how we adapted ArchC fast functional instruction set simulators to the MPARM platform in order to achieve both fast simulation speed and accuracy. Our implementation led to a much faster hybrid platform, reaching speedups of up to 2.9 and 2.1x on average with negligible impact on power estimation accuracy (average 3.26% and 2.25% of standard deviation). © 2011 IEEE.

Networked control system for the guidance of a four-wheel steering agricultural robotic platform

A current trend in the agricultural area is the development of mobile robots and autonomous vehicles for precision agriculture (PA). One of the major challenges in the design of these robots is the development of the electronic architecture for the control of the devices. In a joint project among research institutions and a private company in Brazil a multifunctional robotic platform for information acquisition in PA is being designed. This platform has as main characteristics four-wheel propulsion and independent steering, adjustable width, span of 1,80m in height, diesel engine, hydraulic system, and a CAN-based networked control system (NCS). This paper presents a NCS solution for the platform guidance by the four-wheel hydraulic steering distributed control. The control strategy, centered on the robot manipulators control theory, is based on the difference between the desired and actual position and considering the angular speed of the wheels. The results demonstrate that the NCS was simple and efficient, providing suitable steering performance for the platform guidance. Even though the simplicity of the NCS solution developed, it also overcame some verified control challenges in the robot guidance system design such as the hydraulic system delay, nonlinearities in the steering actuators, and inertia in the steering system due the friction of different terrains. Copyright © 2012 Eduardo Pacincia Godoy et al.

Towards a strategic CSR: A Brazilian case study

Purpose - Organisations may be considered, at the same time, either part of the problem or part of the solution for the social-environmental crisis that is occurring. To be part of the solution, they must head for a strategic management of corporate social responsibility (CSR). The objective of the present study is to identify and analyse the interfaces between theoretical models of strategic implementation of CSR and the variables and major players involved in this process. Design/methodology/approach - This is a qualitative research using a case study strategy. The company chosen for this case study has been highlighted as one of the best national companies to work for, with significant social responsibility indices. Findings - The case study found some results, such as the importance of aligning with human resource management for strategic implementation of CSR and the integrative characteristic between different workers, that are essential for this process. Originality/value - Only a few international articles discuss CSR in Brazil. The results could be useful for classes focusing on Doing business in Brazil. © Emerald Group Publishing Limited.

Regular and switching platform: Bone stress analysis with varying implant diameter

The aim of this study was to evaluate stress distribution of the peri-implant bone by simulating the biomechanical influence of implants with different diameters of regular or platform switched connections by means of 3-dimensional finite element analysis. Five mathematical models of an implant-supported central incisor were created by varying the diameter (5.5 and 4.5 mm, internal hexagon) and abutment platform (regular and platform switched). For the cortical bone, the highest stress values (rmax and rvm) were observed in situation R1, followed by situations S1, R2, S3, and S2. For the trabecular bone, the highest stress values (rmax) were observed in situation S3, followed by situations R1, S1, R2, and S2. The influence of platform switching was more evident for cortical bone than for trabecular bone and was mainly seen in large platform diameter reduction.

A success in Toxinology translational research in Brazil: Bridging the gap

Basic research is fundamental for discovering potential diagnostic and therapeutic tools, including drugs, vaccines and new diagnostic techniques. On this basis, diagnosis and treatment methods for many diseases have been developed. Presently, discovering new candidate molecules and testing them in animals are relatively easy tasks that require modest resources and responsibility. However, crossing the animal-to-human barrier is still a great challenge that most researchers tend to avoid. Thus, bridging this current gap between clinical and basic research must be encouraged and elucidated in training programmes for health professionals. This project clearly shows the challenges faced by a group of Brazilian researchers who, after discovering a new fibrin sealant through 20 years of painstaking basic work, insisted on having the product applied clinically. The Brazilian government has recently become aware of this challenge and has accordingly defined the product as strategic to the public health of the country. Thus, in addition to financing research and development laboratories, resources were invested in clinical trials and in the development of a virtual platform termed the Virtual System to Support Clinical Research (SAVPC); this platform imparts speed, reliability and visibility to advances in product development, fostering interactions among sponsors, physicians, students and, ultimately, the research subjects themselves. This pioneering project may become a future model for other public institutions in Brazil, principally in overcoming neglected diseases, which unfortunately continue to afflict this tropical country. © 2013 Elsevier Ltd.

Design & prototipagem: conhecimento e uso da prototipagem rápida no design brasileiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da interface e aplicação dos materiais mimétricos ao design de produto e segurança do trabalho

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Design de produtos virtuais e transdisciplinaridade: cibercepção e construção de objetos em Second Life : um estudo acerca do design de relações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do tipo de conexão protética, do platform-switching e do designe do implante no ambiente biomecânico de implantes imediatos com carga imediata

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Economic design of Shewhart control charts for monitoring autocorrelated data with skip sampling strategies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Strategic feed formulation for relation of electrolytes to promote performance and prevent heat stress in broilers

An experiment was conducted to evaluate the impact in relation of dietary electrolytes, based on changes in the balance Na+K-Cl (DEB) and the ratio (K+Cl)/Na (DER) on the performance and survival of broilers subjected to acute heat stress. A total of 1575 male broiler chicks from 1 to 46 d of age were allocated in a 5x3 factorial arrangement in a completely randomized design, totaling of 15 treatments with 3 replicates of 35 birds each. The treatments consisted of 5 diets with electrolyte balances, arising from combinations DEB/DER (150/3, 250/2, 250/3, 250/4 and 350/3), associated with different times of application or not of the acute heat stress on birds at 25 and 36 d old. All diets were cornsoybean meal based and formulated to meet or exceed NRC requirements. Chicks had ad libitum access to feed and water in floor pens with wood shavings as litter. It was possible to verify that a DEB of 250 mEq/kg and a DER very close to the 3:1 providing a more nutritionally adequate diet. There was, however, the impossibility of obtaining a more suitable electrolyte ratio for a very low DEB (150 mEq/kg) or very high (350 mEq/kg) and also, to a very narrow DER (2:1) or very wide (4:1), due to an unfavorable performance and survival rate of birds in these conditions electrolytes adjustments of K, Na and Cl. There was clear indication, with significant difference (P < 0.05), that the DER has the potential to improve the performance of broilers, since simultaneous adjustment made in DEB, even in conditions of acute stress. The results of performance and survival rate of this study also indicate clearly that DER could not replace the DEB, and vice versa, in practical diets for broilers. Therefore, it can be affirmed that the strategic formulation of the correct electrolyte balance for DEB and DER enhances the performance and is able to prevent the effect of heat stress in broiler chickens, leading to better performance and survival.

Implantes Platform Switching: longevidade e preservação óssea: revisão crítica da literatura

The concept of switching platform is the use of an implant by platform wider than the abutment. Recently, researches have shown that this type of dental implant design tends to offer a higher preservation of crestal bone when compared to the traditional pattern of bone loss. The present study aims to perform a critical review on the switching platform concept establishing possible advantages of the technique. A search was performed on Medline/Pubmed about the topic “dental implant” and “platform switching”, and after applying inclusion criteria 40 studies were selected. The literature on longevity present prospective studies that show less bone loss, studies in biomechanics exhibit better or similar stress distribution around the bone crest, however, is not yet defined the role of the biological width. Thus, studies of longevity, and randomized prospective studies are of a great relevance to be performed in order to confirm the benefits of this technique and to establish a protocol indication. It is possible, based on this literature review, to conclude that longitudinal and randomized studies show that the platform switching implants have longevity and less bone loss. Biomechanically, the technique is possible.