[Histological investigation of neural plexus on developing permanent teeth. Study on puppies].

On permanent premolars of 9 puppies (three groups of 45 days, 3 and 4 months old) the neural plexus was studied, using the Alcian blue/PAS and Bielschowsky staining techniques. Nerve fibres were observed on the 45 days group, directed to the odontoblastic layer, as well as fine nerve bundles, parallel to the vessels. On the 3-months group nerve fibres were seen in the dental papilla and the dental sac. Furthermore a significant increase in number size of the nerve fibres was noticed on the 4-months group, comparing with those of the 3-months group.