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Oral-B iO Review (Series 9)

Oral-B iO Series 9 (iO9) Review

The best of Oral-B: what you need & lots more, but it’s expensive

5 Star Rating

The iO9 is a great toothbrush. It cleans the teeth well and is packed full of tech to help you brush better.

But it’s expensive and only the most committed users will get maximum value from it.


  • Premium design with colour screen
  • Quieter than other Oral-B brushes
  • Rapid recharging
  • Real-time tracking via Bluetooth can be valuable to the most committed users
  • American Dental Association Approved


  • Requires iO specific heads
  • Bluetooth connectivity isn’t essential and adds to the cost
  • Charging travel case requires a separate power adapter

Preview Product Rating Price
Oral-B iO Oral-B iO 5,716 Reviews $379.97Amazon Prime

Consider these and save $

The iO Series 6 is similar but significantly cheaper. You get a regular travel case, rather than a charging one. There are 2 fewer cleaning modes and a black and white display rather than color. Our iO comparison explains the differences in full.

Or, if you like value for money, the Smart 2000 is a better buy, but it doesn’t offer any of the smart features.

Preview Product Rating Price
Oral-B iO Series 6 Oral-B iO Series 6 1,921 Reviews $199.99 $176.05Amazon Prime

The most detailed real-time tracking but it’s not always accurate

Perhaps the most unique and defining feature of the iO Series 9 is its ability to track the position of the toothbrush in your mouth using sensors built into the handle.

The iO9 is Bluetooth-enabled, making it a smart toothbrush. This allows data to be transferred from the brush handle to an Oral-B app on your smartphone, which provides visual insights into how you are brushing.

As a general rule, we don’t recommend smart brushes. You can brush your teeth just as well without one, they use more resources and they are usually more expensive.

Nonetheless, the intention is that the data is presented by the app in such a way that it educates you and encourages you to pay more attention to what you are doing. 

Oral-B iO Review (Series 9) 1
Oral-B smartphone app tracks the real-time position of the toothbrush and gives a coverage score.

The 16 zone tracking is more granular than other iO models

Unlike the vast majority of iO Series brushes that track 6 zones, the iO Series 9 (and the iO10) have 16 zone tracking.

When tracking 16 zones, you are essentially tracking specific tooth surfaces.

Those zones are:

  • Upper rear right (inner, outer & biting) 
  • Upper front (inner & outer)
  • Upper rear left (inner, outer & biting)
  • Lower rear right (inner, outer & biting)
  • Lower front (inner & outer)
  • Lower rear right (inner, outer & biting)
Oral-B iO Review (Series 9) 2

The logic is that with this more granular data, you can make more focused improvements.

For example, where the iO Series 6 might highlight that you don’t brush your lower back teeth well enough (1 of 6 tracked zones), the iO9 is more specific and shows that you don’t brush the inner surface of the back right teeth.

The whole system is very clever and with serious commitment, some will gain a real benefit.

The tracking is sometimes inaccurate, particularly if you are left-handed

No brush with real-time tracking — irrespective of brand — is perfect.

With the iO9, there is a real inconsistency in how well the sensor monitors the brush’s position. I’ve yet to establish any notable pattern to the cause. Left handed users (myself included) seem to fare worse.

Some sessions are better than others. It regularly thinks you are brushing a different zone to the one you are in, or not register it at all. There can also be a noticeable lag/delay in the visuals. 

Marginal improvements have been made, but accuracy should be better. I know many will be frustrated by this.

The app doesn’t force you to brush tooth surfaces in a specific order. I wonder whether it would improve the tracking if it did. It would also be useful for encouraging better techniques and habits.

Oral-B iO Review (Series 9) 3

The app has some useful customization features

Using the Oral-B app you can change the order of the cleaning modes or disable them. You can set specific oral care journeys, change the brushing time and alter the pacing of the timer.

You can see the remaining battery life and how long you have been using a particular brush head.

You don’t have to use the app every time that you brush your teeth — the data is retained by the handle and shared with the app next time you use it.  

When using the app while you brush, you get a very different screen setup. Not only do you see where you are brushing, but you also see which cleaning mode is selected and how long you have been brushing for. It will show you if you are applying too little or too much pressure.

All in all these are useful features, if not essential. 

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You can achieve similar results for less money and without the need for all this tech

You don’t need a smart toothbrush to achieve clean teeth and make positive improvements to your oral care routine. You can do all you need with a manual brush, if not a cheaper electric toothbrush. 

The tech the iO9 offers can certainly help detect areas for improvement, but there is a good chance you already know what these are.

It does make analyzing your brushing more fun and engaging, but it comes at a cost.

If you’re committed to the app enough to gain the insights, it still relies on you making the changes to your technique. 

You have the best opportunity to make required changes if you use the app whilst you brush as you will be shown on the screen what’s not going well.

But once you’ve perfected everything, then what? Will you continue to use the app once you’ve achieved a nigh-on perfect brushing score every time?

Even as someone who tests such products, I don’t regularly use the apps outside my testing.

To help perfect your brushing technique you could occasionally use plaque disclosing tablets, which are far cheaper. 

The colour screen looks impressive but impacts battery life

The Series 9 is one of three iO models that have a colour display. 

I can’t deny it looks impressive and adds a certain appeal to the brush, but it does far less than you might expect. It didn’t need to be colour, black and white like the iO6 or 7 would have been fine. And it seems to impact the battery life negatively too.

The biggest benefit is that it displays an icon and a text label for the cleaning modes. It’s a big step up from the icon only or no icons at all of some other brushes.

It’s not a touchscreen, which is a good thing. Instead, it is controlled via the function buttons above and below.

As you use the brush the screen displays a timer, although it isn’t that easy to see given the way you hold a toothbrush.

Oral-B iO Review (Series 9) 5
A timer is shown on screen during a standard cycle to show elapsed time.

You don’t get any real-time brushing feedback via the screen. It won’t show you if you have missed a zone, for example. Oclean does something similar on its X Pro Elite. I think Oral-B has missed an opportunity here. Instead, after brushing, the iO9 displays an emoji face to communicate whether you brushed poorly, ok or great.

A few seconds later the remaining battery power is shown with an icon and an exact percentage.

A number of settings like the brush language, Bluetooth connectivity and light ring can be accessed via the screen, but more settings and choices are available from the app.

Inconsistent battery life: it doesn’t always reach 2 weeks

With the majority of electric brushes offering a month or more of battery life, the iO9 ranks well below average. Oral-B claims a battery life of 14 days, but I’ve often found it to be worse – approximately 12 days use is most common from my testing. 

Despite having used the iO9 since its launch a few years ago, I can’t categorically say what’s causing it. My suspicion is the colour display. I will often see it activated as a result of vibration or movement nearby. To my knowledge, other iO brushes have the same lithium-ion battery sealed inside, yet achieve up to 17 days.

This isn’t a major issue for the vast majority of users. I wouldn’t say it’s a reason to avoid it, particularly as the Series 9 has a magnetic fast charger capable of topping the battery up in just 3 hours. If you are a frequent traveler it is something to bear in mind.

The magnetic charger is circular in shape and wider and deeper than a standard issue Oral-B stand. It doesn’t have the prong on top for the brush to sit on. Instead, a  slight convex zone in the center aligns with the concave base of the iO9’s handle.

Oral-B iO Review (Series 9) 6
The magnetic charger is able to recharge the battery fully in just 3 hours.

A 2 pin power adapter is hardwired into it. The cord is about 4 feet (1.2 meters) in length. The stand supports 100-240 volts, unlike the 110-130 volts of the standard charger. This is more convenient if you are a regular international traveller.

Feedback on the charge is available via the smartphone app and the screen of the brush. When the power is really low the light ring at the top of the brush handle will flash red. It pulses white when on charge.

Oral-B iO Review (Series 9) 7
An example of the box contents of the iO Series 9.

It’s got the features your dentist recommends

The key features that dentists recommend for an electric toothbrush are a timer, pacer and pressure sensor. The iO9 does have all of these. 

Pressure sensors don’t come smarter than this

The visual pressure sensor on the iO9 is one of the best out there. This is useful if you brush too hard or scrub your teeth. 

The light ring illuminates in different colours to alert you when you are brushing with too much or too little force: 

  • White  – low pressure – not enough force is being applied. 
  • Green – the right amount of pressure is being used.
  • Red – high – excessive pressure is being applied and the force should be reduced.

If using the app it will alert you on screen too.

Oral-B iO Review (Series 9) 8
The light ring is lit red when too much pressure is applied during brushing.

Frustratingly, the alerts are visual only. Blind or partially sighted users will struggle. It would be even better if the handle used a vibration alert, particularly when too much pressure is being applied.

Brush your teeth evenly and for longer

2 minutes is the optimum time to rush. Unsurprisingly the iO encourages you to achieve this. As you brush, the motor pauses at 30 second intervals to prompt you to move to the next part of your mouth. 

If you want to brush for longer you can – unlike some other brushes, the iO9 doesn’t power off automatically after 2 minutes. 

The pacing is deactivated when you use the app and real-time tracking

When you brush in real-time with the app, the pacing is disabled. The logic is that you are paying attention to the timer and visuals on screen, therefore you don’t need the prompts. 

You can see when you have brushed each surface and when you should move to the next one.

Oral-B iO Review (Series 9) 9
Black onyx brush handle comes with matching brush heads.

The motion of the larger brush head is gentler and achieves great cleaning results 

It sounds somewhat cliche, but the iO9 does deliver that dentist clean feeling after every use. 

Oral-B’s oscillating-rotating and micro vibrating cleaning action is backed by clinical data. The iO9 specifically has achieved the American Dental Association’s Seal of Acceptance.

The brush heads have gotten bigger and are iO-specific

With the introduction of the iO Series came a similar, but different range of brush heads.

The long established range of brush heads compatible with the vast majority of Oral-B brushes do not fit iO handles.

You now need an iO-specific head, of which there are 4 styles, when using the iO9.

Oral-B iO Review (Series 9) 10
4 different styles of brush heads are available and fit to the iO Series brush handles.

If you’re used to an Oral-B brush head, you may well notice how they have gotten a little bigger. They are approximately 10% deeper. It’s not a big difference, but it is noticeable. If you have a very cramped mouth you may prefer to avoid the iO range.

The price has also gone up. On average, iO brush heads are twice as expensive as non-iO Oral-B heads. Expect to now pay $12 per replacement head.

Just like any other toothbrush, you need to replace the bristles every 3 months. The app and brush can track the head and alert you (in the app and via the display) when this is required. It’s useful and not as intrusive as you might think.

A gentler brushing experience

With the introduction of the iO Series came an entirely new brush motor. This is significant because it has reduced the harshness of the brushing experience.

I’ve always liked the intense clean that the round brush head gives, but some, understandably, have found it to be too much. 

There is a noticeable difference with the iO Series. It is much softer and ultimately makes for a more enjoyable time using the brush. Importantly it still cleans the teeth just as well.

Oral-B iO Review (Series 9) 11

Quieter, but still quite loud

The rather loud mechanical noise from older Oral-B models has been replaced with a softer and less irritating sound. It’s an improvement, but it still isn’t at the same more enjoyable pitch of most sonic toothbrushes. 

We registered it at up to 72 decibels (dB). That’s only a few dB less than most Oral-B brushes, but it’s noticeable.

Newer iO models (Series 3, 4, 5 and 6) have been improved further producing just 64dB. 

I can’t help but feel Oral-B has missed an opportunity to really make a significant change. The brush didn’t need to be silent, but it could have been reduced further to compete with the quietest electric toothbrushes.

The iO9 and its replacement heads are expensive

You need pretty deep pockets to buy and maintain the iO Series 9. If you can afford and justify it, you are getting a fantastic toothbrush.

The suggested retail price is $399.99. The reality is that it often sells with a 20% discount so costs around $320.

That is still about 4 times more expensive than our top recommended Oral-B toothbrush!

With iO-specific heads now costing about $15 you can expect the Series 9 to cost $440 over 3 years.

As I have made clear, you don’t need to spend this to achieve clean teeth. The Oral-B Smart 2000 costs about a third of the price and cleans the teeth just as well.

But if you want the best, there is no denying that the tech is impressive, even with some irritations.

Oral-B iO Review (Series 9) 12

It’s probably the best looking brush Oral-B has made

Oral-B has failed to keep up with the competition when it comes to design aesthetics and the iO9 addresses this to a large degree.

It looks much more modern, with a clean and minimal appearance. I particularly like the lack of gloss plastics.

Large areas of textured grips found on some handles have been sacrificed here, but the matt finish to the handle creates some resistance to the fingertip.

In the palm, the cylindrical handle feels solid and well balanced. It stands upright on a countertop and doesn’t roll when laid on a flat surface.

It is of practical plastic construction, not metal like SURI.

Of course, the display helps with the appeal too.

Each function button has a slightly concave shape and a different material finish from the rest of the handle, thus it’s obvious to the fingertip where it is positioned. 

Ultimately, the brush, available in 4 colours, white, black, aquamarine and rose quartz is more refined.

Mould can build up inside the head if you’re not careful

This tooth cleaning device needs to be kept clean too, otherwise you could find a nasty surprise in your brush head.

Failure to properly rinse and clean the brush head after each use has resulted in many people finding mould growing inside the brush head.

It’s not a new problem with Oral-B brushes and is linked to the holes in the brush head. With the iO range it has become more obvious as a result of the gap around the magnetic attachment point at the top of the handle. It offers an ideal trap and breeding ground for bacteria.

The iO9 is water-resistant despite its OLED display and can be happily rinsed under a tap and even used in the shower. 

Oral-B iO Review (Series 9) 13
The iO9 is water resistant and fairly easy to keep clean.

A brushing mode for every day of the week

No less than 7 different cleaning modes are available on the iO Series 9.

I’ve yet to find anyone who uses them all or any real justification for having so many. The reality is the cleaning results between each are very similar.

Nonetheless, your choices are:

  • Daily Clean 
  • Sensitive 
  • Whiten 
  • Gum Care
  • Intense 
  • Super Sensitive 
  • Tongue Clean 

My preference is Daily Clean, but the sensitive mode is nice to have for those times your teeth and gums might be feeling a bit tender. It is also a useful mode for those starting out their journey with an electric toothbrush because it’s not as intense. 

Unlike many other models (and that includes other iO models), it is really simple to switch between modes and know which you have selected. You don’t have to remember a specific order or know what each icon means.  The colour screen makes it easy to see and select the mode you want.

The bulky power adapter makes the charging travel case less useful

The iO9 premium travel case is, in my opinion, the worst available today. Those that come with the Sonicare 9900 Prestige, SURI and others are far better.

Oral-B iO Review (Series 9) 14
A premium charging travel case is included with the Series 9.

It is admittedly one of a select few that have the ability to charge the brush whilst in the case. But, it is hampered by the bulky proprietary power adapter.

The competition uses USB connectors and cables. Thus you can likely use the same power adapter for your toothbrush as you can your smartphone (as long as it’s not an iPhone). That is not the case here (excuse the pun).

To be clear, there is no battery in the power2go case. It must be connected to a power outlet to charge the toothbrush.

One redeeming factor is that the 2 pin power adapter does support 100-240v, so you need only a plug adapter when travelling, not a voltage adapter too.

It is a very durable travel case too. Thicker and heavier than most, it holds the handle and 1 brush head.

When connected to power, an LED on the outside gives feedback on the charge status.

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An industry average 2 year warranty

Where more affordable brushes from lesser known brands typically come with a 1 year warranty, the iO9 is supplied with a 2 year guarantee. This is pretty typical for an Oral-B brush and those from other leading brands like Philips Sonicare.

It’s not impossible, but not all that common for a brush to fail during this time. Oral-B has had years to perfect the design and manufacturing to limit such.

A number of iO brushes I have been using for several years remain functional with no issues.

Regretfully the iO9 or any of the iO models have not been designed to be repaired yourself. It is common practice for electric brushes not to be user serviceable. It’s a shame more environmentally considerate approaches are not being factored in by leading brands.

Environmental impact

The environmental impact of electric toothbrushes is on average 11 times greater than a manual brush. This doesn’t mean that you shouldn’t use one. You need to balance effective cleaning and disease prevention against the environmental impact.

With the additional, non-essential technology built into the iO9, plus the extra accessories, bigger box and increased shipping weight the impact is likely much higher than lower spec’d brushes.

While Oral-B has partnered with schemes such as TerraCycle, it does not yet have its own recycling scheme for used brush heads or faulty products.

Its brush heads are made from petroleum-based plastic, which uses up the planet’s finite resources compared to using plant-based plastics.

Come the end of its life the extra electrical components required for the smart technology results in more e-waste. 

Conclusion: fantastic, but you’re paying for non-essential features

The iO9 is a top of the range brush and one I do recommend.

It isn’t for everyone and even if you can afford the premium price, I will reiterate, you don’t need the extra features. More affordable brushes (see the Smart 2000) clean the teeth just as well.

But, if you love your tech and want the best, this is it. For those committed to getting the most from the iO9, it can pick up on your mistakes and encourage you to do better. Used to its full capability, it will help you achieve cleaner and healthier teeth.

Just be aware that the battery life isn’t amazing. The tracking isn’t perfect and you’re stuck buying more expensive brush heads.

Size Guide

  • Height (without head) – 18.3cm / 7.2 inches
  • Height (with head) – 24cm / 9.45 inches
  • Width – 2.8cm / 1.1 inches
  • Thickness – 2.8cm / 1.1 inches
  • Weight (without head) – 131g / 4.6 ounces
  • Weight (with head) – 140g / 4.9 ounces

All are approximates


  • 72dB


How do I turn on or off Bluetooth on the iO9?

Disable Bluetooth by entering the «Settings» menu on the interactive display-> Bluetooth -> disable. Follow the same procedure to enable Bluetooth again.

How do I change the language on the iO9?

Press the lower mode/function button (under the display) multiple times until you see the settings icon. Looks like a cog icon.

Press the power button once to enter the settings menu.

Press the mode button twice to get to Language.

Press the power button once.

Press the mode button multiple times until the language you desire is shown on the display.

Press the power button to confirm the language choice.

About Jon Love

Jon is a leading voice on electric toothbrushes and has been quoted by mainstream media publications for his opinions and expertise. Having handled & tested hundreds of products there really is very little he does not know about them. Passionate about business and helping others, Jon has been involved in various online enterprises since the early 2000s. After spending 12 years in consumer technology, it was in 2014 that he focused his attention on dental health, having experienced first-hand the challenge of choosing a new toothbrush.

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10 thoughts on “Oral-B iO Review (Series 9)”

  1. My 3768 charger has never worked from day one of purchase. I have always just charged it on my partner’s charger but now we are splitting up. I do not feel I should have to purchase a new replacement one since mine has never worked. It is about 2 yrs old.

  2. I have tested the OralB IO 6 and it puts out over 700mG (EMF) while the previous OralB toothbrushes only about 10-15mG.

    Think about that for a minute.

  3. Hi Jon,
    Great Review! I recently acquired an Oral-B IO 9 and have been researching it on the internet as it did not come with a user manual. Your write up has been super helpful. Is there a specific order/technique for the 16 zones to better allow the ai tracking? I would like to increase the accuracy of the tracking while using the app.
    Thank you for such a thorough review.

    • Hi Kevin.

      Thanks for the comment. I am not aware of any particular order/technique to allow the AI track better. Most have their own approach.

      I personally focus on one quadrant of teeth at a time. So for example, upper right, outside surfaces, followed by inside by biting, before moving to the left hand side and repeating, until I have completed all 4 sections.

    • Hi Jason.

      Great question. However, this is one I can’t answer honestly right now. I have not yet tested the new Gentle Care head for the iO. My model came with the Ultimate Clean heads. We have some Gentle Care heads on order and I will be able to answer in a couple of weeks time. They should be comparable, but I will aim to come back to you with more insight when I have them.

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