1. Cheng and her husband told university officials they had no idea how the stain had gotten there. 2. Q. Leftover creosote was spilled on a concrete floor, and in summer it gets worse, smelly and the stain gets wet in humid weather. 3. This red stain gets into the pores of the open-pored wood that mahogany is, and never comes out. 4. If these stains get near any restoration work, they will be absorbed through micro-leakages between the restoration and the tooth surface. 5. Tar stains also get absorbed into dental plaque and are difficult to remove. |