Immunohistochemistry of bone sialoprotein and osteopontin during reparative dentinogenesis in vivo.

ABSTRACT

OBJECTIVE: To investigate the stage-specific and tissue expression of bone sialoprotein (BSP) and osteopontin (OPN) during reparative dentinogenesis in vivo. METHODS: Direct pulp-capping with Ca(OH)2 developed a model used for the investigation of reparative dentinogenesis in the exposed dental pulp. In this model, standardized class V cavities were prepared close to the gingival margin on the buccal surface of each tooth. Animals were sacrificed 3, 7, and 10 days post-operation. Immunohistochemical staining determined the tissue-specific expression of BSP and OPN during the process. RESULTS: Odontoblast-like cells and reparative dentin reacted positively with BSP and OPN. The expression of BSP reached a peak at day 7, then gradually decreased, while the expression of OPN showed no significant difference between day 7 and day 10. CONCLUSION: BSP and OPN may play different roles in reparative dentinogenesis. BSP may serve as a nucleator of hydroxyapatite crystal formation.