The eff The effect of calcium hy ect of calcium hydroxide intr xide intracanal medicament on r acanal medicament on root dentine microhardness: An in vitro study

Abstract

Objective: To evaluate root dentine microhardness after using calcium hydroxide (Ca (OH)₂) intracanal medicament.

Materials and methods: Forty single-rooted teeth were sectioned at the cementoenamel junction level, and the root canals were  prepared till an apical size of #30. The prepared teeth were divided into two groups (n ¼ 20): the no medicament (control) group and the  Ca (OH)₂ group. After 7 days, medicaments were removed using a standardized volume of irrigation. All teeth were sectioned in a  buccolingual plane and embedded in acrylic resin horizontally with the dentine surfaces exposed. Using Vickers microhardness tester  with magnification of £ 100 and a load of 25 g for 10 s, a microhardness assessment was performed. Independent t test was used for  intergroup comparison. One-way analysis of variance and post-hoc Tukey's tests were used for comparisons (P ≤ 0.05).

Results:  Microhardness in the control group was significantly greater than in the Ca (OH)₂ group at the coronal (P < 0.001) and middle (P ¼ 0.006)  sections. At the apical third, no significant difference was detected (P ¼ 0.779). In the control group, the coronal section was significantly  greater than at the apical section (P ¼ 0.002), while no significant difference was detected between the middle sections with both coronal  (P ¼ 0.212) and apical (P ¼ 140) sections. In the Ca (OH)₂ group, no significant effects were noted between different sections (P ¼ 0.385).   

Conclusions: The Ca (OH)₂ reduced root dentine microhardness at both coronal and middle sections, but not the apical.