Ultrastructural and histochemical examination of alveolar bone at the pressure areas of rat molars submitted to continuous orthodontic force
Nenhuma Miniatura disponível
Data
2003-10-01
Autores
Bonafe-Oliveira, L.
Faltin, R. M.
Arana-Chavez, V. E.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Blackwell Munksgaard
Resumo
It is usually believed that repair in alveolar bone during orthodontic movement occurs after decreasing of force. However, we have recently observed signs of repair in previously resorbed cementum from human teeth exposed to continuous forces. In order to test the hypothesis that bone resorption and deposition occur concomitantly at the pressure areas, a continuous 15 cN force was applied in a buccal direction to upper first molars from eight 2.5-month-old male Wistar rats for 3 d (n=4) and 7 d (n=4). As a control, two additional rats did not have their molars moved. Maxillae were fixed in 2% glutaraldehyde + 2.5% formaldehyde, under microwave irradiation, decalcified in ethylenediaminetetraacetic acid, and processed for transmission electron microscopy. Specimens from one rat from each group were processed for tartrate-resistant acid phosphatase (TRAP) histochemistry. At both the times studied, the alveolar bone surface at the pressure areas showed numerous TRAP-positive osteoclasts, which were apposed to resorption lacunae. In addition, osteoblasts with numerous synthesis organelles were present in the neighboring areas overlying an organic matrix. Thus, this study provides evidence that the application of continuous forces produces concomitant bone resorption and formation at the pressure areas in rat molars.
Descrição
Palavras-chave
orthodontic movement, resorption, repair, osteoclast, alveolar bone
Como citar
European Journal of Oral Sciences. Copenhagen: Blackwell Munksgaard, v. 111, n. 5, p. 410-416, 2003.