Caracterização Microestrutural e Tribocorrosiva de Sistemas Metalocerâmicos Odontológicos do Tipo Ni-Cr/Porcelana E Ni-Cr/Ti/Porcelana

The partial fixed prosthodontics restoration is used to rehabilitate form and function of partial or total compromised teeth, having to remain permanently joined to remainder tooth. The most useful material on prosthodontics is the feldspar porcelain, commercialized as aluminosilicate powders. Dental porcelains are presented with limited mechanical properties to rehabilitate extensive spaces. The association with Ni-Cr metallic systems (metal-ceramic system) allows that the metallic substructure compensates the fragile porcelain nature, preserving the thermal insulation and aesthetics desirable, as well as reducing the possibility of cracking during matication efforts. Cohesive flaws by low mechanical strength connect the metallic substructure to the oral environment, characterized by a electrolytic solution (saliva), by aggressive temperature, pH cyclic changes and mechanical requests. This process results on ionic liberation that could promote allergic or inflammatory responses, and/or clinical degradation of ceramometal system. The aim of this study was to evaluate the presence of an intermediate titanium layer on the microscopic fracture behavior of porcelains on ceramometal systems. Plasma deposition of titanium films result in regular passivating oxide layers which act as barriers to protect the metallic substrate against the hazardous effects of corrosive saliva. Tribocorrosion tests were performed to simulate the oral environment and mechanical stress, making it possible the early detection of crack formation and growth on metal-ceramic systems, which estimate the adherence between the compounds of this system. Plain samples consisting of dental feldspar porcelain deposited either onto metallic substrates or titanium films were fired and characterized by scanning electron microscopy. The result showed that the titanium film improved the adherence of the system compared to conventional metal-ceramic interfaces, thus holding crack propagation

A importância do holding na reorganização afetivo-social de crianças que manifestam tendência anti-social

This study aims to understand as the children who show expressive behaviors of antisocial trends at Núcleo de Ação Social da Praia do Meio in Natal-RN city, linked to Secretaria Municipal do Trabalho e Assistência Social-SEMIT, which experience the relation with the social educator in role of caregiver. This matter was investigated within an interpretation and approach qualitative view of the social phenomena, using the Thematic Analysis technique of drawings and stories which express the relation with the caregiver gotten in sessions of playful interactions between child and researcher in order to understand the child experiences with the social educator. The used theoretical referential is by D. W. Winnicott who associates the social trend to a failure of environment in child holding. The subjects expressed the need of a firm and protective environment and they look for this in NASPM educators. Moreover, they show as solitude and vulnerability take part their lives due to the lack of emotional holding on family that favors the involvement with violent groups. But, it is worth pointing out that the children value the Nucleus environment when has offered them a safe holding which can be positive the established linking with it. Such conclusion points out to the possibility, recognized theoretically, that exists from these children to resume the way of healthy development