Fig. 1. Surface of demineralized dentin matrix (DDM) powder26. A. The surface of the DDM is stained gray due to the dentinal tubules, while the mineralized core is stained violet (H&E). B. Scanning electron micrography of DDM. The dentinal tubules are enlarged (dentinal tubule pores), and there is loosened surface collagen26. C. Scanning electron micrography of DDM. The dense interfibrillar spaces are loosened (interfibrillar space pores)26.