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RESUMO: Falhas ósseas são comumente encontradas na medicina veterinária em diferentes enfermidades, principalmente por traumas em grandes animais. Frequentemente faz-se necessário auxiliar este reparo tecidual para melhor correção desta falha. Os biomateriais foram desenvolvidos para cumprir esta função. A fim de avaliar o comportamento celular perante estes substitutos ósseos, a realização de testes in vivo é fundamental. A partir da observação da unidade morfofuncional do tecido é possível avaliar a quantidade e a qualidade do tecido neoformado. Atualmente, em estudos ortopédicos, os ovinos são considerados animais de escolha como modelo experimental. Falhas ósseas foram realizadas experimentalmente em ovinos, onde foram implantados biomateriais à base de quitosana, hidroxiapatita e colágeno. Após 60 dias foi realizada biopsia no local do reparo tecidual e por meio da histomorfometria da matriz orgânica, da análise descritiva da microscopia de luz e da microscopia eletrônica de transmissão, o tecido neoformado foi avaliado e comparado. Na histomorfometria, não houve diferença significativa quanto à quantidade de tecido neorformado do grupo controle e do grupo com biomaterial, porém quando comparado ao osso pré-existente, retirado no momento da confecção da falha, a área de matriz óssea foi menor. Na descrição da microscopia de luz e em maiores detalhes na análise ultra estrutural, observou-se o biomaterial em contato íntimo com o tecido neoformado, sugerindo boa biocompatibilidade. Foi possível observar o padrão da reparação tecidual, onde o membro controle e o membro com biomaterial não diferiram quanto à arquitetura tecidual, porém nas amostras com o implante do biomaterial foi identificada a presença do mesmo. Todas estas informações sugerem que o biomaterial não prejudicou a regeneração óssea, apresentou boa biocompatibilidade e denota potencial para auxiliar na rotina ortopédica de grandes animais. ABSTRACT: Bone defects are commonly found in veterinary medicine through different disease such as trauma, especially in large animals. Frequently it is necessary to assist this tissue repair for better regeneration. Biomaterials in general are designed to this function. In order to understand the bone cells in the presence of bone substitutes, tests in vivo are essential for these studies. The quantity and quality of new tissue formation can be assessed by observation of tissue morphofunctional unit. Currently, in orthopedic studies sheep are considerated animals of choice for experimental development. Bone defects were performed experimentally in sheep and were implanted chitosan, hydroxyapatite and collagen biomaterials. After 60 days, biopsy was performed at the site of tissue repair and the new tissue formation was described, evaluated and compared by organic matrix bone histomorphometry and electronic transmission microscopy. After hystomorfometry analysis there was no difference between control group and biomaterial group, but when compare with pre-existent tissue, the values are smaller. In descriptive analysis was observed intimate contact with biomaterial and new tissue formation suggesting biocompatibility. It observed the pattern of tissue repair in control group and biomaterial group did not differ in the architecture tissue. However, in the biomaterial group was identified presence of the biomaterial in the specimen. All these data suggest that the biomaterial did not impair bone regeneration, had good biocompatibility and potential to assistant in orthopedic routine of large animals.

The objective of this study is to report a clinical case of maxillary sinus with lyophilized, xenogeneic graft, in which, despite a large perforation of the sinus membrane, the surgery was not aborted and the results of histological examinations indicate bone neoformation in the surgical area. Results. This case showed that the biomaterials evaluated in this study and the procedure used to place them proved to be biocompatible and presented high osteogenic potential, leading to a successful surgery and osseointegration implant. Conclusion. Positioning Schneider’s membrane and filling it with the graft biomaterial helped to achieve the desired osteoconduction and proliferation of bone cells even though the patient had a large perforation of the sinus membrane.

Trabalho completo: acesso restrito, p. 210–214 Submitted by Bruna Lessa (lessbruna@gmail.com) on 2012-05-17T19:27:32Z No. of bitstreams: 1 (23)1-s2.0-S0003996910000245-main.pdf: 425223 bytes, checksum: 89ebcc3ea765e8513cb27c15d295d5b9 (MD5) Made available in DSpace on 2012-05-17T19:27:32Z (GMT). No. of bitstreams: 1 (23)1-s2.0-S0003996910000245-main.pdf: 425223 bytes, checksum: 89ebcc3ea765e8513cb27c15d295d5b9 (MD5) Previous issue date: 2010-03 Objective: Although the general mechanisms of dentinogenesis are understood, several aspects regarding tertiary dentine formation still deserve investigation, especially regarding the presence and distribution of some noncollagenous matrix proteins. As dentine matrix protein 1 (DMP 1) is present in primary dentine, it is possible that this protein may also be present in the dentine matrix secreted after injury, but there are no immunocytochemical studies attempting its detection in tertiary dentine. The aim of this study was to examine the ultrastructural immunolocalization of DMP 1 in the tertiary dentine after extrusion of the rat incisor. Study design: Upper incisors were extruded 3 mm and then repositioned into their sockets. After several periods, the incisors were fixed and processed for transmission electron microscopy and for immunocytochemistry for DMP 1. Results: Extrusion yielded both types of tertiary dentine, which varied in aspect and related cells. DMP 1 was found in the mineralized matrix of all types of dentine, presenting high affinity for collagen, but rare colloidal gold particles over predentine. DMP 1 was evident in the supranuclear region and inside the nucleus of some odontoblast-like cells. Conclusion: The observed association between DMP 1 and collagen seem to be essential for reactionary and reparative dentine formation.