Zone of HOHL refers to:

1. Cell-free zone (Zone of weil) Width approx. 40 µm Not always present Absent in young pulp (Active secretion of primary dentine) and older pulp (tertiary dentine) CONTENTS Capillaries Unmyelinated nerve fibers Cytoplasmic process of fibroblasts 2. Cell Rich Zone (Zone of HOHL) Most numerous cells are fibroblasts Fibroblasts secrete Type I and Type III collagen Also contains undifferentiated mesenchymal stem cells. Vascular supply is extensive and more than cell free zone and odontoblast zone.