AIM: To characterize the hard tissue formed in human teeth experimentally pulp 
capped either with calcium hydroxide or with Emdogain Gel (Biora AB, Malmö, 
Sweden) - a derivative of enamel matrix (EMD), using two markers for dentine; 
dentine sialoprotein (DSP) and type 1 collagen (Col I).
METHODOLOGY: Affinity-purified rabbit anti-Col I and anti-DSP polyclonal 
antibodies were used to stain histological sections from nine pairs of 
contra-lateral premolars that had been experimentally pulp amputated and 
randomly capped with EMDgel or calcium hydroxide. Twelve weeks after the teeth 
had been pulp capped, they were extracted, fixed, demineralized and serially 
sectioned prior to immunohistochemical staining.
RESULTS: In the calcium hydroxide treated teeth DSP was seen in the new hard 
tissue which formed a bridge. DSP was also seen in the newly formed hard tissue 
in the EMDgel-treated teeth. Proliferated pulp tissue partly filled the space 
initially occupied by EMDgel and DSP-stained hard tissue was observed alongside 
exposed dentine surfaces as well as in isolated masses within the proliferated 
pulp tissue, although the new hard tissue did not cover the pulp exposure. DSP 
staining was also seen in the cells lining the hard tissue in both groups. Col I 
staining was seen in the newly formed hard tissue in both groups.
CONCLUSIONS: The new hard tissue formed after pulp capping with EMDgel or 
calcium hydroxide contained DSP and Col I, considered to be markers for dentine. 
Thus, the newly formed hard tissue can be characterized as dentine rather than 
unspecific hard tissue.