Conclusions
Cell differentiation potential in the developing swine apex is progressively restricted to the newly formed dental pulp, whereas phenotypic expression of apical papilla cells remains undetermined unless the new microenvironment triggers cell differentiation towards the odontoblastic lineage.
Methods
Three 7-month-old miniature swine were used in this study. A total of 12 teeth, including two immature permanent incisors and two premolar teeth of each case, were extracted and processed for histological and immunohistochemical analysis. Different populations of mesenchymal cells located at the root apex were morphologically evaluated in hematoxylin-eosin serial sections. Additionally, the distribution patterns of tenascin-C and syndecan-1 were assessed immunohistochemically.
Results
Syndecan-1 was strongly expressed in the dental pulp, particularly along the odontoblasts of the root and the newly deposited predentin layer. Tenascin-C was intensely expressed in the dental pulp. The apical papilla and dental follicle showed no expression of either molecule. Conclusions: Cell differentiation potential in the developing swine apex is progressively restricted to the newly formed dental pulp, whereas phenotypic expression of apical papilla cells remains undetermined unless the new microenvironment triggers cell differentiation towards the odontoblastic lineage.