Woman with toothbrush (Stigur Karlsson | Getty Images)

Bleeding gums are never a good sign. “If your gums bleed when you brush, that’s your body’s way of telling you that you have plaque trapped under the gum line,” says New York City dentist Jennifer Jablow, DDS. And that means that it’s time for a trip to the dentist for a professional cleaning—the only way to eradicate plaque that has already crystalized on teeth.

At home, you can help keep plaque (and bleeding) at bay by stepping up your brushing routine. Jablow recommends an electric brush that uses a gentle, side-to-side vibrating motion (such as the Sonicare) rather than one with rotating bristles. “Brushes with rotating bristles are like weed wackers,” warns Jablow. “They can actually cut the tiny fibers that attach the gums to the teeth.”