Abstract
The purpose of this study was to evaluate the effectivenes of various agents on hard tissue formation (dentin bridge and hard tissue deposited on the root canal wall i. e., reparative dentin) and to evaluate the pH changes of these materials. Rat molars were used. The groups were as follows: no agent (control), calcium hydroxide, Life®c, a lcium carbonate, magnesium hydroxide, aluminium hydroxide, calcium phosphate cement, calcium phosphate cement containing 10% fluoride,0.1% tetraethylammonium hydroxide sol. applied for 15 min., alkaline sol. for 15 min., alkaline sol. for 15 min.4 times every 12 hours and acidic sol. for 15 min. After 28 days, histopathological changes of the pulp and evidence of hard tissue formation were examined. All pulpotomy agents were applied to the dorsal subcutaneous tissue of rats and the pH values were measured.
The results were as follows:
1) Hard tissue formation in descending order was: calcium hydroxide > Life®> alkaline sol. applied 4 times > tetraethylammonium hydroxide sol. > calcium phosphate cement containing fluoride >others (p<0.0001).
2) The sterility of the agents, high alkalinity, and presence of Ca2+ and OH- were external factors influencing hard tissue formation (p<0.001).
These findings suggest that the factors influencing hard tissue formation are multiple. Calcium hydroxide having sterility, high alkalinity, and presence of Ca2+ and OH- was shown in this study as being an ideal agent for hard tissue formation.
