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: Guided bone augmentation (GBA) in its most challenging form is the creation of new bone through the guidance of bone cells to an area beyond the original outer skeletal envelope. We used a microfocus computerized tomography (R_mCT) system to examine bone augmentation beyond the skeletal envelope in the rat calvarium. STUDY DESIGN: The calvarium was exposed and critical-size 5-mm defects were prepared bilaterally. Two resin caps were placed with or without hydroxyapatite (HA), and images of bone augmentation within the resin cap were obtained using R_mCT. RESULTS: The experimental site showed bone regeneration beyond the skeletal envelope. Bone continuity was observed between the defect edge and HA. In contrast, no new bone formation was observed beyond the skeletal envelope at the control site. The bone volume increased significantly at the experimental site compared with the control site in a time-dependent manner. CONCLUSIONS: The R_mCT system enabled the continuous observation of guided bone augmentation with graft materials in rat calvarium.
