Fish Zones in Endodontics
Fish described the zones of periapical lesion. He described the reaction of peri-radicular tissue to Bacterial and noxious products and antigenic agents from the root canal.
FOUR FISH ZONES IN ENDODONTICS
1. Zone of Infection (Polymorphonuclear Cells PMNs)
- Characterized by Polymorphonuclear Leucocytes.
- Present in the center of the Lesion
- Micro-organism present only in this area.
2. Zone of Contamination (Round Cell Infiltration)
- Characterized by Round Cell Infiltration
- Cellular Destruction around the Central Zone.
- This Destruction not from bacteria but due to Bacterial Toxins discharge from Central Zone.
- Bone cells died and Empty Lacunae.
- Leukocytes prevalent.
3. Zone of Irritation (Macrophages and Osteoclasts)
- Found away from the Central lesion because toxins get more diluted.
- Degradation of Collagen Fibers by Phagocytes.
- Histologic picture simulates body attempt to repair.
4. Zone of Stimulation (Fibroblasts and Osteoblasts)
- Found at Periphery because toxins are mild enough to act as stimulus.
- Fibroblasts and Osteoblasts secret collagen fibers.