Oral-B iO Series 5 vs iO Series 3

If your dentist has ever told you to pay more attention to your lower left molars, the iO Series 5 has an answer for that. It uses Bluetooth and the Oral-B app to track coverage across six zones (upper left, upper right, upper front, lower left, lower right, lower front) and shows you which areas got skimped after each session. Over time that produces an actual evidence base for your technique. The three-zone pressure sensor adds a "too soft" LED state that the iO 3 doesn't have, which nudges you to maintain enough contact for effective cleaning, not just avoid pressing too hard. Five modes — Daily Clean, Intense Clean, Sensitive, Super-Sensitive, and Whitening — let the brush adapt to varying conditions, and the box ships with 3 heads so you can try different styles immediately.

The iO Series 3 is a genuinely different product, not a lesser one. No app. No Bluetooth. No zone map. What it has is the same magnetic drive motor, the same IPX7 rating, the same 2-minute timer with 30-second quadrant alerts, and the same iO head ecosystem. Its three modes (Daily Clean, Sensitive, and Whitening) cover what most people actually use. The two-zone pressure sensor catches the one thing that damages gum tissue: pressing too hard. That's the scenario most worth guarding against. Any iO head you buy for the iO 3 today fits the iO 5, iO 7, or iO 9 if you upgrade the handle later.

Both brushes run up to 2 weeks per charge and charge inductively. The iO 5 gets to full charge in roughly 12 hours; the iO 3 takes about 16. Neither difference affects daily use — you're plugging in once a fortnight either way.

The practical split comes down to whether coaching changes your behavior. If you brush twice a day without much dental history or angst, rarely switch modes from the default, and aren't interested in a post-brush session summary, you'd be paying for infrastructure you won't touch. The iO 3 gives you the core iO performance without it. If you're managing gum recession, working through orthodontic treatment, or genuinely want to close a gap your dentist keeps flagging, the iO 5's 6-zone tracking turns that feedback into something measurable between appointments.

Pick the iO Series 5 if you'll use the coaching system and want Intense Clean or Super-Sensitive in your rotation. Pick the iO Series 3 if you want the iO motor and timer in a simpler package that doesn't ask you to open an app. Both are strong daily drivers. The decision is really about whether the data layer earns its keep in your routine.