Oral-B iO Series 9 full review

Let’s start off with this: I think that the Oral-B iO Series 9 could help to improve dental health. So, if that's a concern and you can afford the investment, it could be worth it.

But there’s a caveat. The iO is a tool that could help to seriously overhaul your brushing technique in the same way that My Fitness Pal or a FitBit can help to improve your diet and fitness, ie only if you’re willing to use it as the makers intended. That means there’s a bit of commitment involved.

The other point is that, although the iO is one of the best brushes I've tested for performance, you're really paying for the extra features, including the OLED screen and app. This is what sets it apart from other brushes on the market. 

But it’s not perfect and you’ll have to balance what use you'll get from those features and whether you can overlook its flaws to decide if it's worth its very serious price tag. With that in mind, let's take a closer look.


The iO is approximately the same size and shape as Oral-B's Genius brushes. Its neck is a little sturdier but the main difference (OLED screen aside) is its brushing head, which has been redesigned. It's larger and its bristles have been split further into separate, compact brushes.

Brush head comparison

It gives much more coverage and feels extremely effective when you brush. It's also been redesigned internally too, and cleans via tiny vibrations as well as oscillating, rather than the straightforward oscillation of earlier Oral-B brushes. It's a big change to the performance and, I think, a noticeable improvement to what was already good technology.

The Series 9 comes in black, white and pink. The light ring can be personalised in one of a number of colours. 

OLED screen

This, of course, is the most obvious point of difference with the iO: the full colour OLED screen. No other electric toothbrush has one. Do you need it? No. Do I like it? I have to say I do. (Has this year left me massively, weirdly over-habituated to responding to screens? Probably.)

The iO greets you with an image of the sun and a hello. You'll be relieved to hear it doesn’t actually speak, although the thought of that makes me fearful of the toothbrush technology lurking around the corner.

iO welcome screen

You can select your brushing method via the screen. There are seven options: daily clean, whitening, sensitive, super sensitive, gum care, tongue clean and intense. There are brushing settings for any individual and in any situation, so you can always find something comfortable and effective.

Brushing settings

Still, I think that the intense setting is needlessly intense (the Philips DiamondClean 9000 is also guilty of this). I grazed my gum trying it out. Over-brushing or brushing too hard can lead to sensitive teeth and receding gums. Electric toothbrushes, with their variable settings and pressure sensors, should be able to help people avoid this bad habit.

Moving on from that ticking off, the screen also gives you access to settings, including turning on and off the Bluetooth and light ring and restoring factory settings.

When you begin to brush, an onscreen timer displays how far you are through your dentist-approved two-minute brushing time. This works in conjunction with the brush vibrations, which pause every thirty seconds to tell you to move on to the next quadrant of your mouth. After two minutes, there's a longer pause. Unlike similar brushes, it doesn't stop altogether at two minutes and will continue to time you.  

The countdown timer makes it very easy to see how long you have left to brush, and that's a feature I haven't seen in any other electric toothbrush.

When you've finished, the remaining battery life will be displayed and you'll get feedback for your brushing in the form of a smiley or sad face. How you feel about that will probably determine how well you'll get on with the iO in general.

iO's sad face

The app

The light ring doubles as the pressure sensor alert. Press too hard and the light ring glows a warning red. This, plus the timer and vibration pauses and feedback smiley means you get a lot of brushing help without actually needing to open the app.

But since this is one of the two best apps for brushing feedback (the other being the Colgate E1), you should give it a go.

Hold your phone in front of you while your brush and you'll get real-time feedback about how long to continue brushing each part of your mouth to achieve total coverage.

I found that the sensor was accurate in determining where I was brushing but in order to complete brushing to the app's satisfaction, I had to continue for longer than the optimum two minutes.

iO app

This raised a couple of issues: first, was trying to get a perfect score via the app's feedback making me brush for too long? And second, brushing for longer drains the battery life noticeably. But more on that later.

The app will also keep track of your brushing history, along with an overall percentage score (calculated from how long you brushed, how much coverage you achieved and whether or not you pressed too hard). It also keeps track of how long you've been using your brush head and can send you an alert to remind you when the three month recommended period of use is up. 

There are also some daft inclusions in the app. Do you really need to gamify your brushing routine by collecting medals? Although 'Captain Gum Guard' sounds kid-friendly, another medal, 'Kissable', sounds less so, so it's not clear who they're aimed at or why they're there, except to fill app space. 

There's also the option to sync data to Apple Health (if you're an iPhone user) and plan "dental care journeys", but these are really just other ways to log and assess your brushing. 

Battery life

The trade-off for the iO's screen is battery life. The OLED screen uses a lot of power, which means that the iO's time between charges is not great compared to other high-quality electric brushes. Oral-B reckons you can use it for two weeks before you need to recharge but in reality, it doesn't last that long. As I tend to brush for a bit longer than the recommended two minutes each time, I found that I used 10% of the battery life each day.

That would obviously give me only ten days between charges, at most. Oral-B suggests that you keep your brush in its charger as there's a failsafe to keep it from overcharging. If you can do that, then battery life won't be an issue. But for many people, that's less than ideal.

Charging is quick, however, at just three hours.  


The iO comes with a magnetic charging base with a two-pin bathroom adapter, a travel case with a second two-pin adapter and a separate case that'll store two spare brush heads.

iO accessories

The accessories are a bit disappointing, especially for a brush at this price point. The magnetic stand is efficient and simply designed but a USB charging option would have been welcome.

The travel case is basic and plasticky and not nearly as plush as the Philips DiamondClean 9000's case, or the very beautiful case for the PomaBrush, both of which have an elegant, inbuilt USB charging solution. 

Price and availability

The iO Series 9 is currently available in the UK from Boots and Amazon. Its RRP is £500 but ignore that, as both sites have settled on a price of £250 if you buy at the right time. This actually compares favourably with the Philips DiamondClean 9000, which is rival Philips' flagship brush and is currently available for £270-£340, depending on the site.

If you're in the US, you can buy the iO Series 9 on Amazon for $299.99

You'll probably be able to find a deal on the iO, either on Prime Day or Black Friday.


Performance-wise, the iO Series 9 is a winner. As far as I'm concerned, it's earned its stars right there.

And if you've been meaning to take your dental care in hand, its feedback, via both handle and app, will help you to remember to brush properly and well.

But if you're happy with the condition of your teeth and the way you brush, you'll probably ditch the app pretty quickly. So, the smart element of this product will be useless to most people. 

But that's okay, because really, the USP of the iO is the screen. It's fun, ridiculous, useful and unnecessary in roughly equal measures. You definitely don't need it. But you might want it.  


If you're looking for more options, and to see how the iO measures up, check out our round-up of the best electric toothbrushes we've tested.

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