An experimental study on the vasoconstriction effect of calcium hydroxide using rat mesentery.

Abstract

Calcium hyroxide has been used for eliminating persistent intracanal exudation. In order to address the mechanism behind this action, we investigated whether calcium hydroxide solutions cause the constriction of microvessels in the mesenteric microcirculation bed of rats. The exteriorised mesentery from anaesthetised rats was spread in a chamber, and arterioles, venules and capillaries were viewed under a digital microscope. Various concentrations of calcium hydroxide solutions were applied for 10 sec, and the diameter of the microvessels was recorded. In arterioles, calcium hydroxide solutions caused rapid and transient constriction. A statistically significant difference versus original diameter was detected 1 min after the application of 4.0 x 10(-3) mol/l and 1.0 x 10(-2) mol/l solutions (p < 0.05, one-way analysis of variance and Tukey-Kramer test). No statistically significant constriction occurred in capillaries and venules. It was concluded that the arteriolar constriction might be an explanation for the exudation-controlling effect of intracanal calcium hyroxide dressings.