condensation pressure effect on microleakage of mineral trioxide aggregate

objective: the aim of this study is to measure the effect of different condensation pressure on the microleakage of mineral trioxide aggregate (mta).  methods: this study was an invitro study. a total of 55 single rooted straight-canal human extracted sound teeth free of cracks or calcification were selected. teeth were sectioned from cej region at 3 mm above the root apex. remaining specimens were mounted on a putty base material. samples were then divided into 3 test groups of 15 each and 2 groups of 5 each as positive and negative controls. after filing and debridement of the canals to #50, white proroot mta paste was prepared according to the manufacturer’s instruction were being inserted into the canals in each group under condensation pressure of 0.44, 3.22 and 8.88 mpa respectively. each root was then connected to the pipe of liquid filtration device following a 48 hour setting time passed in order to measure the microleakage. mean micro-leakage measures of different groups were calculated and compared using one-way analysis of variance (anova) test. results: mean microleakage for condensation pressure of 0.44, 3.22 and 8.88 mpa were 1.70×10-4, 1.17×10-4   and 0.48×10-4   µl/min. one-way anova test showed that mean microleakage rate has a significantly different rate when groups are compared (p<0.05).the lowest micro-leakage level was observed in condensation pressure of 8.88 mpa. conclusion: conditions of the study showed that as condensation pressure increases the rate of microleakage lowers. statistically, the differences between three groups were highly significant (p<0.05) key words: condensation, filtration, leakage, mta, pressure.