Effect of resorbable collagen plug on bone regeneration in rat critical-size defect model

Objective: The purpose of this investigation was to examine the effect of resorbable collagen plug (RCP) on bone regeneration in rat calvarial critical-size defects. Methods: About 5-mm-diameter calvarial defects were created in forty 12-week-old male Sprague-Dawley rats and implanted with or without RCP. Animals were killed at 1, 2, 4, and 8 weeks postoperatively. After being killed, specimens were collected and subjected to microcomputed tomography (mCT) and histological analysis. Results: The mCT showed a significant increase of newly formed bone volume/tissue volume in RCPimplanted defect compared with controls at all designated time points. After 8 weeks, the defects implanted with RCP displayed almost complete closure. Hematoxylin and eosin staining of the decalcified sections confirmed these observations and evidenced active bone regeneration in the RCP group. In addition, Masson's trichrome staining demonstrated that RCP implantation accelerated the process of collagen maturation. Conclusions: The RCP enhances bone regeneration in rat criticalsize cranial defects, which suggest it might be a desired material for bone defect repair.