During odontogenesis, amelogenins from the preameloblasts are translocated to 
differentiating odontoblasts in the dental papilla, suggesting that amelogenins 
may be associated with odontoblast changes during development. In the present 
study, we have explored the effects of enamel matrix derivative (EMD) on the 
healing of a pulpal wound. Coronal pulp tissue of permanent maxillary premolars 
of miniature swine were exposed through buccal class V cavities. The exposed 
pulp was capped with EMD. The contralateral teeth served as controls and were 
capped with a calcium hydroxide paste (Dycal). The cavities were sealed with 
glass-ionomer cement. After 2 and 4 weeks, the histology of the teeth was 
analyzed. In the EMD-treated teeth, large amounts of newly formed dentin-like 
hard tissue with associated formative cells outlined the pulpal wound separating 
the cavity area from the remaining pulp tissue. Inflammatory cells were present 
in the wound area but not subjacent to the newly formed hard tissue. 
Morphometric analysis showed that the amount of hard tissue formed in 
EMD-treated teeth was more than twice that of the calcium-hydroxide-treated 
control teeth (p < 0.001), suggesting that EMD is capable of promoting 
reparative processes in the wounded pulp more strongly than is calcium 
hydroxide.