Think cavities are kid’s stuff? Your risk for tooth decay actually goes up over the years. “As we get older we produce less saliva, which helps to wash away food debris and reduce plaque,” says Julia Hallisy, D.D.S., president of the nonprofit Empowered Patient Coalition. Plus our gums recede, meaning more cavities can occur at the gum line, which are harder to fix. Over time teeth are likely to be weakened by fillings, crowns, root canals, or cracks. Here’s how to protect them.