Can my teeth become stained again after whitening?

Yes, the whitening effect is not permanent, so if you continue to consume pigmented foods, the teeth can gradually darken again. It is common for the color to return little by little over 6 to 12 months. To slow down restaining, it helps to 1) rinse with water right after eating staining foods such as coffee, wine, or curry, 2) quit smoking, 3) get regular scalings to remove surface stains, and 4) do a touch-up whitening every 6 to 12 months. However, if only one tooth becomes noticeably darker, it could be due to a nerve problem or another cause, so please visit us for an evaluation.