Abstract : The purpose of this study was to evaluate the effects of a light-activated calcium hydroxide on the new hard tissue formation at the orifice and the pulpal stimulation after pulpotomy.

 Twenty teeth of two adult beagle dogs were used. The coronal pulp was mechanically removed with #3 round bar, after which the orifice was dressed with a calcium hydroxide pastes containing saline, or light-activated calcium hydroxide (Ultrablend). The animals were sacrificed one week, one month and three months after operation, and histopathologically evaluated.

 The result were as follows :

 The formation of new hard tissue in light-activated calcium hydrtxide was less than that in the calcium hydroxide paste. Beside in the three-month cases of light-activated calcium hydroxid, inflamation remained in pulp.