RESUMO
Microfocus computed tomography (micro-CT; R_mCT) is a dynamic noninvasive method for measuring bone regeneration. This study evaluated whether R_mCT was equivalent to histomorphometry in assessing bone augmentation. Two plastic caps of graft material with (experiment) or without hydroxyapatite (HA; control) were placed in the exposed calvaria of rats. Images of bone augmentation within the plastic caps were then taken using R_mCT. Histological sections were cut along the same plane as that used for the micro-CT images. Bone regeneration beyond the skeletal envelope occurred at both the experimental and control sites. Bone volume also increased at both sites. In addition, consistent patterns of bone formation were observed in both R_mCT and histological images. R_mCT analysis enables highly quantitative and qualitative measurement of bone augmentation in living animals.
Assuntos
Regeneração Óssea/fisiologia , Regeneração Tecidual Guiada/métodos , Crânio/cirurgia , Microtomografia por Raio-X , Animais , Materiais Biocompatíveis/uso terapêutico , Substitutos Ósseos/uso terapêutico , Calcificação Fisiológica/fisiologia , Durapatita/uso terapêutico , Processamento de Imagem Assistida por Computador , Masculino , Osteogênese/fisiologia , Ratos , Ratos Wistar , Crânio/diagnóstico por imagem , Crânio/patologia , Fatores de TempoRESUMO
OBJECTIVES: A new microfocus computerized tomography (R-mCT) system that quickly produces clear images of the bones of small animals allows the continuous observation of living experimental animals. This study used the new R-mCT system to examine the dynamics of marrow penetration within a titanium cap in rabbit calvarium. STUDY DESIGN: In a rabbit, the calvarium was exposed, and circular grooves were prepared bilaterally. Within the circular groove, the external cortical surface of the skull was perforated mechanically. The rate of penetration was 28% (experiment) or 14% (control). Images of bone augmentation within the titanium cap were taken using R-mCT. RESULTS: The augmented mineralized tissue increased gradually with repeated resorption and acceleration. The dynamics of bone augmentation did not differ with the penetration rate. CONCLUSIONS: Accurate noninvasive longitudinal monitoring of bone augmentation or response to therapy can now be done in the same living animal by using R-mCT.
