Dentine sialoprotein and Collagen I expression after experimental pulp capping in humans using Emdogain®Gel

P>Aim To characterize the hard tissue formed in human teeth experimentally pulp capped either with calcium hydroxide or with Emdogain (R) Gel (Biora AB, Malmo, 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.