The dissolution of calcium and silicon ions from mineral trioxide aggregate (MTA) and two modified versions of MTA in culture medium

Abstract

The hypothesis of this study was that [Ca2+] and [Si4+] ions might dissolve from Mineral Trioxide Aggregate (MTA) which enhances hard tissue formation. The purpose of this experiment was to determine the dissolution of [Ca2+] and [Si4+] ions from MTA into culture medium and to determine if this dissolution could be altered by adding 1) 6% Silicon and 4.5% Calcium and 2) 30% Silicon to MTA to yield 2 modified versions, mMTA1 and mMTA2 respectively. Discs (15.6 mm diameter X 2 mm) of MTA, mMTA1, and mMTA2 were prepared and placed into 24 well plates to which 1.5ml of culture medium was added and incubated at 37C, 5% CO2 and 100% humidity. The culture medium was changed, collected, and pH readings were taken every 3-4 days for 15, 30, 60 and 90 day intervals. The [Ca2+] and [Si4+] in the culture medium were analyzed using inductively coupled plasma. The pH readings of the culture medium were not significantly different among the control, MTA, mMTA1 and mMTA2. Using ANOVA and Tukey HSD statistics mMTA1 leached more [Si4+] than MTA and mMTA2 with statistical significance (p[less than]0.05) at all time intervals. MTA and mMTA1 leached more calcium than mMTA2 (p[less than]0.05) at 90 days but no differences were seen among MTA, mMTA1 and mMTA2 at other time intervals. In conclusion, [Ca2+] and [Si4+] dissolves from MTA into culture medium. This dissolution of [Ca2+] and [Si4+] can be modified with the addition of Silicon. Funding by Boston University Departments of Endodontics and Biomaterials.