Use whitening toothpastes only once every day or two. Certain brands can be more abrasive than others. Brands with sodium pyrophosphate are very abrasive. Rembrandt is one of the least-abrasive whitening toothpastes. I question the effectiveness of whitening toothpastes.
Some people claim to notice a brightening of tooth color, while others notice no change.
This difference is partly due to variety in diet and tooth structure among people. If you are serious about whitening your teeth, you should discuss various options, including bleaching, with your dentist. The abrasive agents are usually silica or powdered calcium. The silica is derived from sand. Flavorings are usually derived from plants such as spearmint or peppermint.