Baking soda can gently polish absent stains over the surface on the teeth. Many people worry that baking soda is just too severe and will grind absent enamel, but study from 2017 found it to be a safe way to eliminate stains. Nexcare is my preferred model, but honorable mention https://tablelamp80235.eedblog.com/18357052/the-single-best-strategy-to-use-for-teeth-whitening