Allograft bone has been widely used for reconstruction of different portions of the skeleton. The fragment of bone harvested must be kept under low temperatures. The cryopreservation also contributes to decrease the antigenic potential of the tissue. Although this technique is considered safe, there is little information about the morphological modifications that the medullary and cortical portions of bone suffer after freezing. Hence, the aim of this study was to investigate the morphology of bone tissue after freezing under different temperatures and periods. Twelve rabbits were used to analyze the effects of two temperatures, -20 degrees C and -70 degrees C, during four periods of time: 30, 60, 90, 120 days. Tissues were analyzed by HE, picro-sirius stains and also by Feulgen's reaction, through qualitative and morphometric ways, considering the area occupied by cells and nuclei, medullary and cortical portions, as well as by collagen expression at cortical. The differences among the treatments were analyzed by Tukey s test, at 5% significance level. Bone freezing increased cellular and nuclear areas at cancellous bone and diminished nuclear area at the cortical bone. Cortical bone collagen suffered denaturation proportionally to temperature decrease and to freezing duration. These alterations compromised the morphology of tissues after 90 or 120 days of freezing at the temperature of -70 degrees C. Cells necrosed during freezing, contributing to reduce bone antigenicity.

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Onlay grafts heal due to osteogenesis which occurs at the lateral region and between the cortex and host mandible. Allogeneic grafts and PRP tend to improve bone formation.

Este estudo tem como objetivo identificar as possíveis mudanças emocionais em adultos causadas pela perda dentária. Foram aplicados questionários em 100 pacientes edêntulos totais ou parciais, sendo ou não usuários de prótese. Os resultados mostraram que a população em estudo apresentou alterações emocionais e físicas após a perda dos dentes. 63% dos entrevistados tiveram a auto-estima afetada e em 70% observou-se dificuldade em aceitar a ausência dos dentes. Concluiu-se que a perda dentária repercute no bem-estar emocional do paciente, além de debilitar a aparência e algumas atividades cotidianas.

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