Brushing Abhaslon of Ormocers Exposed to Acid

and microhardness of Admira and Definite following acid conditioning. Half of the samples were either used as controls or brushed for 10 minutes using an electric teothbrush with srurry. The remaining specimens were st・ored in orthophosphorie acid with a pH of 1.9 for 24 hours and then half were brushed. The surface roughness of Admira and Definite was not significantly at'fected by storage under acidic conditions, However, the specimens of both materials in the control groups and the ones tested after aeidie storage were found to be significantly smoother than the specimens subjected to toothbrushing alone and brushing follewing acid conditioning, For both materials, significantly higher values of microhardness were obtained after