Almost half of all Americans are affected by periodontal disease, according the American Dental Association. As a result, the war on plaque is heating up. The latest weapons? Electric toothbrushes with new methods of blasting bacteria off your pearly whites. A few even connect to your smartphone to monitor the quality of your brushing, ensure you’re not pressing too hard (a common problem), and coach you toward whiter teeth and better gum health. Do you really need the help of an app? Not necessarily, if you brush thoroughly. At the least, all five of these new models have a two-minute timer to make sure you brush long enough, plus alerts to divide your mouth into sections so you can be confident you’ve hit every part of your smile. We tested them all to find which cleans best.