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Effect of Different Chemicals on the Micro-Hardness of Mineral Trioxide Aggregate - An In vitro Study
Hannah Rosaline1, Mathan Rajan Rajendran2, Kuzhanchinathan Manigandan2
1Department of Conservative Dentistry and Endodontics, Tagore Dental College and Hospital, Chennai, Tamil Nadu, India.
Aim:
Mineral trioxide aggregate (MTA) is a dental biomaterial that is used for various endodontic treatments. However, the major limitation of MTA is its hardness and retrievability. The aim of this study is to evaluate the influence of various chemicals on micro-hardness of MTA.
Materials And Methods:
200 hollow cylindrical stainless-steel molds of specified dimensions (5 mm height and 5 mm internal diameter) were made. MTA was mixed homogeneously and condensed into the molds. After the setting, MTA was exposed to three experimental groups, Group 1: back-set, Group 2: carbonic acid, and Group 3: citric acid at 1, 3, and 5 minute exposure at the end of Day 1 and 21. Then the samples were evaluated exposed to Vickers micro-hardness testing. The data were evaluated statistically using analysis of variance (ANOVA) and post-hoc with P = 0.05 were used to perform multiple comparison tests.
Results:
On day 1, the reduction in micro-hardness was greater in back-set when compared with carbonic acid and citric acid. At the end of Day 21, the highest mean surface micro-hardness reduction was seen with back-set at 5 min, 3 min, and 1 min intervals, respectively. However, there was no significant difference noted between the citric and carbonic acids at 1 and 3 minutes.
Conclusion:
It can be concluded that back-set was found to be the most effective in reducing the micro-hardness of MTA when compared to citric and carbonic acid.
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