You connect a smart electric toothbrush with app, also known as a smart toothbrush, to a smartphone app via Bluetooth. The useful thing about an electric toothbrush with Bluetooth is that it gives you feedback on your brushing behavior via an app. The accuracy of the feedback depends on the model. For example, some toothbrushes give feedback on how frequently you brush and if you apply the right amount of pressure. Other models additionally indicate how you brush each individual tooth and if you make the right brushing motions. Useful, because you can improve your brushing routine and prevent cavities.