Authors : Seyed Mohsen Hasheminia , Sadegh Norozynasab and Mahboobe Feizianfard
Abstract: The aim of this study, was to evaluate the effect of a calcium hydroxide-glycerin mix, calcium hydroxide-saline mix and calcium hydroxide-distilled water mix on the microhardness of root dentine after 7 and 14 days of treatment. In this in vitro study, 15 freshly extracted maxillary canine and central incisor teeth were used. The crowns of the teeth were removed and the canals were prepared. The teeth were sectioned transversally to produce a total of 30 dentine discs from the middle-third of the root. The specimens were then divided into 3 groups of 10 discs each. Dentine samples were proximate with calcium hydroxide-glycerin mix, calcium hydroxide-saline mix or calcium hydroxide-distilled water mix for 7 and 14 days. Dentine microhardness was measured with a Vicker’s indenter with a load of 200 g for 15 second before and after treatment. Data were statistically analyzed using repeated measure analysis, paired t-test and LSD. Statistical analysis showed that all 3 combinations decreased dentine microhardness. After 7 days, the reduction in dentin microhardness following the use of a calcium hydroxide glycerin combination was significantly greater than that of a calcium hydroxide-saline and calcium hydroxide-distilled water combination. After 14 days, the reduction in dentine microhardness following the use of calcium hydroxide-distilled water combination was considerably greater than that of the other 2 groups. According to the results of this study, the use of calcium hydroxide combinations as an intra canal dressing softens dentine. At 7 days period, calcium hydroxide-glycerin combination decreased the microhardness of dentine more than two others, but at 14 days period calcium hydroxide-distilled water combination was most reductive.
Seyed Mohsen Hasheminia , Sadegh Norozynasab and Mahboobe Feizianfard , 2009. The Effect of Three Different Calcium Hydroxide Combinations on Root Dentine Microhardness. Research Journal of Biological Sciences, 4: 121-125.