You need to use an interdental brush to feel refreshed.

Even if I brush my teeth diligently, it is difficult to get them completely clean between the teeth.

In such cases, use an interdental brush.

I was startled when I first used it because blood came out, but the swelling between my gums seems to be going away, and it feels really refreshing.

If you use it for a day or two, it doesn't cause bleeding and is great for finishing your brushing. It comes in two shapes, straight and right, but the right shape is more comfortable for molars.