Histologic study of pulp capping in rat molars using calcitonin

Calcitonin, a calcium regulating hormone, has been found to affect bone formation and resorption. In this study a calcitonin preparation and a calcium hydroxide preparation for comparison were applied to both exposed and unexposed rat molar pulps. Histologic examinations were conducted after periods of 1 day to 28 days. Calcium hydroxide pulp caps produced varying amounts of secondary dentin and inflammation. Calcitonin applied as an indirect agent had a similar effect. When calcitonin was applied to exposed pulp, a large amount of dense fibrous connective tissue reminiscent of scar tissue was formed. With increased time this connective tissue exhibited signs of progressive, orderly calcification continuing through a large portion of the coronal pulp.