The Next-Generation DiamondClean 9900 joins a growing list of devices with built-in displays that have functioned just fine for decades without. The toothbrush’s touchscreen can be used to select from eight different cleaning modes and three intensity levels, including gentle options for sensitive teeth or gums. The screen also displays a “12-segment mouth map” representing sections of teeth in your mouth that changes color to indicate when the motion-detecting toothbrush thinks…


