SEM study of glass ionomer cement surface: to ETCH or not to ETCH?

ABSTRACT

Fifteen specimens of Ketac-Cem GIC were packed in Heliotest teflon split die. They were divided into three equal groups of five teeth each where they were either left untreated [control] or etched using 37% phosphoric acid. The etched samples were either etched after 15 min. or 24 hours from the start of the mix then the GIC surfaces were washed using air water spray for 30" and dried using oil free compressed air. SEM photomicrograph were taken to study the microstructure and the surface roughness of the GIC samples. The micro graphs revealed increased roughness of the samples etched after 24 hours followed by that of the untreated control surface then the 15 min. etched surface of the GIC samples. The GIC surface may be either left unetched to avoid the future deterioration of the surface or to postpone the etching treatment for at least 24 hours to allow the GIC to set undisturbed to avoid the damaging effects of premature etching of the matrix on the GIC surface