Pointless gadget or a real help: How useful are smart toothbrushes?

Smart toothbrushes are suited to people who are older or limited in their mobility, but they're often best off in the hands of someone who enjoys using apps and technology. — Dirk Kropp/proDente e.V./Kierzkowski/dpa

Smart toothbrushes say they help improve your dental hygiene and motivate you to brush more often. Can they keep these promises?

At least twice a day for two minutes, preferably with an interdental brush or dental floss and a toothpaste with fluoride — proper oral hygiene can be exhausting. Reaching all the parts of your teeth that need to be cleaned isn't easy.