I know it's complicated but I hope you find this information helpful.
Many people have had success with the toothpaste line for lighter teeth. I want to add that I haven't been able to find a line for darker teeth (i.e. black/brown teeth) but I am not sure if there are any other brands. The most expensive brands of toothpaste for darker teeth are $40+ per bottle, and the cheapest one is about $0.20. I've seen several people purchase this line from Amazon for $11.99 and I have found one brand for my darker teeth at about the same price as the Amazon link. If you're looking for brightening toothpaste for your darker teeth, I am the one to try. I have tried many of these brands and have found that some of them are better than others. If you find yourself having trouble with the toothpaste, the following steps will help you to get your money back. 1. Use a small toothbrush (I like a toothbrush that has two bristles that are on opposite ends). 2. Clean the toothbrush bristles thoroughly (don't use your hands or your fingers). 3. After you have cleaned your toothbrush, hold it in one hand and the toothpaste in the other hand. Do not brush all the way.