Abstract
Abstract : Purpose : This study was designed to understand the effect of iodine potassium iodide (IKI) on the surface texture and mechanical strength of set white mineral trioxide aggregate (WMTA).
Materials and Methods : WMTA powder (ProRoot MTA) was mixed with distilled water (DW) at the ratio of 1 : 3. It was cured in the molds for 3 or 24 hours at 37°C and 100% humidity to form WMTA discs and cylinders. The set discs and cylinders were immersed in DW (D-WMTA) or 2% IKI (I-WMTA) for 24 hours. The surface texture of WMTA discs without immersion (Cont-WMTA), D-WMTA and I-WMTA was analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDX). The compressive strength of the WMTA cylinders and the amount of calcium ion release from the WMTA discs were also investigated.
Results and Discussion : IKI induced discoloration of the WMTA discs and cylinders from yellowish-white to brown and the formation of white precipitate on the bottom of the tubes. The main crystal structure of I-WMTA was the same as that of Cont-WMTA and D-WMTA. The particle morphology and elemental distribution on the surface of I-WMTA were almost the same as those of Cont-WMTA and D-WMTA. I-WMTA significantly increased the amount of calcium ions released into the medium and decreased the compressive strength compared with D-WMTA.
Conclusion : IKI induces no change in the surface texture of set WMTA, but causes its discoloration, decrease of mechanical strength and disruption. IKI-treated WMTA may induce esthetic problems and increase the risk of micro leakage.
