الفهرس 
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Abstract
This study was conducted to assess the dissolving ability of carbonic acid, acetic acid, and ethylenediaminetetraacetic acid on set white mineral trioxide aggregate through measuring the surface microhardness using microvickers hardness testing machine at four intervals via the study time named zero initial, day one, day 21, and day 30 periods respectively of adding the chemical. Saline solution was used as control.
Twenty cylindrical stainless steel ring molds filled with set freshly prepared white proroot mineral trioxide aggregate and condensed to four millimeter height then compacted using a specially made device were used in this study. Stero optical macroscope was used to examine any cracks, defects or gaps between the set paste and mold; later on it was used for visual assessment.
Each specimen was left to completely set for 24 hours and tested for surface hardness before add of any chemical and named zero initial for all specimens. Then they were divided in to four groups according to the added chemical: acetic acid group, ethylenediaminetetraacetic acid group, carbonic acid group, and saline group respectively. Each group was left in incubator till the time of measuring the surface hardness.
Results were collected and statistically analyzed. It was found that all the three chemicals have reduced the surface hardness of the set white mineral trioxide aggregate. Of them, carbonic acid has the fastest and strongest action, even from day one. On day 21 there was not statistically significant difference between ethylenediaminetetraacetic acid and carbonic acid groups. On day 30 there was not statistically significant difference between acetic acid and carbonic acid groups