(checked 2026-10-10)This current 'iO9 Limited' Amazon listing has only 570 ratings (5% 1-star, 1% 2-star).
CNN's favorite smart brush, with seven modes, a color screen and app coaching. It costs about $300, uses pricier iO-only heads, and testers disagree on how accurate its tracking is. Its battery is shorter than many cheaper brushes.
Top complaints
- Very expensive
CNN Underscored calls the roughly $330 list price a tough sell even on discount. Electric Teeth puts the US suggested price at $299.99. Amazon's summary says value for money is mixed, with some owners finding it overpriced.
- iO-only heads and a mold-prone gap
Electric Teeth puts iO heads at about $8, roughly twice the price of standard Oral-B heads, and says mold can build up in the gap around the magnetic head mount. Wirecutter notes some customer reviewers clean that junction daily.
Source: Electric Teeth, Wirecutter - Tracking accuracy disputed
Electric Teeth found position tracking inconsistent, sometimes logging the wrong zone, and worse for left-handed users. CNN Underscored, by contrast, found the app accurate every time it tested it. Amazon's summary calls tracking mixed.
- About 12 days per charge
Electric Teeth usually got about 12 days against a 14-day claim, though the charger refills it in about 3 hours. Amazon's summary says some owners report it doesn't hold a charge.
What owners love
- Useful real-time feedback
CNN Underscored says the feedback after each session made it easy to improve and that the app caught deliberate mistakes every time.
Source: CNN Underscored - Seven modes, softer iO motor
CNN lists seven modes, including sensitive and super sensitive. Electric Teeth says the iO motor is much softer than older Oral-B models and still cleans as well.
Source: CNN Underscored, Electric Teeth - Holds up over years
CNN's tester has used it for years and says it still functions like new.
Source: CNN Underscored
- You won't use the app
- You're on a budget
- You're left-handed and want reliable position tracking
- People who want app coaching and data
- Building better brushing habits
- Oral-B users who want the quieter iO motor
Scores (tap for why)
What experts say
- CNN Underscored: Best smart electric toothbrush, with accurate coaching and seven modes; the main drawback is the steep price.
- Electric Teeth: 5/5 (reviewed 2026-10-05), but pricey: iO-only heads, non-essential Bluetooth that adds cost, inconsistent tracking, about 12 days of battery, and 72 dB.
- Wirecutter (NYT): Says iO brushes run $50-380 and calls the iO Series 6 the best value in the line; it finds smart brushes generally disappointing because their apps tend to be buggy.