The effect of two different calcium hydroxide combinations on root dentine microhardness

PubMedID: 15548273Aim: To evaluate the effect of a calcium hydroxide and glycerine mix and a calcium hydroxide and water mix on the microhardness of human root dentine. Methodology: Eleven freshly extracted maxillary canine and central incisor teeth were used. The teeth were sectioned transversally to produce a total of 22 dentine discs from the middle-third of the root. The specimens were divided into two groups of 11 discs each. Dentine samples were treated with either a Ca(OH)2-glycerine combination or a Ca(OH)2-distilled water combination for 1, 3 and 7 days. Dentine microhardness was measured with a Knoop indenter with a load of 100 g tor 15 s before and during the experimental period. Each root disc received a series of three indentations around the pulp space, 1 mm from canal wall. Results: Statistical analysis showed that both combinations significantly decreased dentine microhardness after 3 and 7 days (P < 0.01). The reduction in dentine microhardness following the use of a Ca(OH)2-glycerine combination was significantly greater than that after a Ca(OH)2-distilled water combination after 3 and 7 days (P < 0.01). Conclusion: The use of Ca(OH)2 combinations for intracanal dressing softens dentine