Do you prefer an electric toothbrush? You’re not alone. A 2017 study found that nearly one-third of people use them, and often, dentists recommend electric toothbrushes to those with gum recession, unique mouth shapes, and a habit of brushing too hard. Regardless of your brush preference, bristles wear at the same rate – which means you should be changing out those electric toothbrush heads every three months. Need help staying on top of it? Here’s a handy guide.