You wouldn’t wash only one side of a dirty dish, and then put it back in the cupboard to use again tomorrow, would you? When you brush your teeth, you’re only washing half of the surfaces of your teeth, front and back. You’re neglecting the two sides your toothbrush doesn’t touch. This leaves the sides of your teeth and the area near the gum line dirty, like only washing one side of a dish! Flossing or use of interdental brushes between your teeth is the way to get into these “nooks and crannies,” which need to be kept clean just as much as the rest of your teeth for good gum health.
Interdental brushes are your first choice if these fit in between your teeth. They come in various sizes and you need to ensure a snug fit so go for the largest size that fits. You’ll often need a variety of sizes. If the interdental brushes don’t fit then floss is your next best option.