2006 Volume 5 Issue 1 Pages 50-56
To evaluate the usefulness of new hydroxyapatite (HAP) as a pulp capping agent, comparisons with a calcium hydroxide agent (calvital®) and formocresol, which are generally used for pulpotomy, were performed. Serial changes in pH in these materials were investigated. Furthermore, after pulpotomy in rat molars using each material, the degree of the formation of dentine-like hard tissue and inflammatory changes in the pulp tissue were micro CT radiographically and patho-histologically examined. It has been reported that calvital® was a strong alkali (≥pH 12) causes a high level of pulp irritation, which were same as our result. The new sintered hydroxyapatite was almost neutral in pH, with a low level of pulp irritation. Furthermore, as a result of micro CT radiographical and histopathological evaluation, dentin-like hard tissue formation underneath the sectioned pulp surface was most marked in the calvital® group, and no dentin-like hard tissue formation underneath the sectioned pulp surface was noted in the HAP group. However, the HAP group developed no necrotic layers, and inflammation improved at an earlier stage.
Our experiments suggested that HAP can be a good pulp capping agent, since pulp irritation was lower with HAP than with calvital® and formocresol.
