The purpose of this study was to examine the changes of the dentin-pulp complex from aged rat by light and scanning electron microscopy. For this study, thirty rats of the 3, 12, 24 months of age were used.
Animals were perfused through the left venticle with 2.5% glutaraldehyde under anesthesia with sodium pentobarbital.
For light microscopy, lower incisor was removed and decalcified in 0.1M EDTA with glutaraldehyde solution for 2 weeks. Each specimen was processed for paraffin embedding, sectioned at 6um, stained with hematoxylin and eosin, and viewed the middle portion of dentino-pulpal junction..
For the scanning electron ,microscopy, the specimen was removed and defatted in 20% KOH solution at 60°C for 24 hours, and dehydrated with aceton. Subsequently, specimen was coated with gold and viewed middl ´portion of dentinopulpal junction with scanning electron microscope (Hitachi S-450).
The results were as follows;
1. In the light microscopic observations, the odontoblast was decreased in number and size with age.
2. In the scanning electron microscopic observations, the calcospherites was became irregular and decreased in number and size with age.
3. In the scanning electron microscopic observations, there was continued deposition of pen-tubular dentin, resulting in a gradual reduction in the diameter of the dentinal tubule with age.
4. In the light and scanning electron microscopic observations, the dentinal tubule was became irregular and decreased in number with age.
5. The age changes within the odontoblast were reflected in dentin.
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