"There are so many toothpastes to choose from. How do I know which one to use?" First, when purchasing a toothpaste for you or your child, select one that contains fluoride. Fluoride-containing toothpastes have been shown to prevent cavities. However, one word of caution:Use only a very small amount for children under age 6 (the size of their fingernail). This is because young children swallow toothpaste, and swallowing too much fluoride can lead to tooth discoloration in p