History and Objectives: Morphogenesis is achieved by the effect of different tissue factors including mesenchymal-epithelial interaction, but its chemical basis is unknown. One of the most appropriate models is the mammalian tooth, especially its pulp. The phenomena migration, proliferation and differentiation within dental pulp are affected by the components of extracellular fluid. In this respect, tenascin is one of these components that is involved in the initial stages of development and differentiation of some fetal tissues including teeth and is important in the pathogenesis of tumors.

Materials and Methods: The present study was conducted on 40 ball-c mice. Different development stages of dental pulp were evaluated within the days 12-19, using immunohistochemical methods and monoclonal antibody against tenascin.

Results: The finding showed that at the bud stage, tenascin is found in the ectomesenchymal tissue and basement membrane of enamel organ in a high quantity and there is reduction in its level in cap stage. With developmental progression, the tenascin level increases significantly in early bell stage for pulp and in late bell stage in cortex.

Conclusion: Tenascin can play an important role in morphogenesis during development of pulp. In this respect, epithelial-mesenchymal interaction is very important. Therefore, it is recommended to conduct more studies to determine the role of tenascin in the differentiation oddentoblasts following injury.