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Published: February 7, 2024

Oral-B iO4 review

Author: Jon Love (2 Comments)
Oral-B iO4 review 1

Great brushing results and a worthy option if you want a cheaper iO

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The iO Series 4 has a modern design and a quiet motor. It’s a more affordable iO model, but the smart features are not required and don’t do as much as you might expect.

In the long term, it costs more than other Oral-B brushes because of the expensive iO-specific brush heads.

Oral-B iO Series 4 (iO4)
Oral-B iO Series 4 (iO4)
Oral-B iO4 review 2 Oral-B iO4 review 2 Oral-B iO4 review 2 Oral-B iO4 review 2




Premium looking handle that is easy to keep clean


No cleaning mode labels/icons


Quieter than other Oral-B brushes


Requires iO specific heads which are more expensive


Reminds you when to replace the brush head


Bluetooth connectivity isn’t essential and adds to the cost

The Oral-B iO3 is cheaper, but the Smart 1500 is better value still with comparable cleaning results

If you are prepared to ditch the Bluetooth connectivity but want to retain the premium features the iO Series offer, the iO3 is the brush to buy.

But, you can save even more and still get a comparable clean and features from the Oral-B Smart 1500, our top rated electric toothbrush.

Oral-B iO Series 3 (iO3)
Oral-B iO Series 3 (iO3)
Oral-B iO4 review 2 Oral-B iO4 review 2 Oral-B iO4 review 2 Oral-B iO4 review 2 Oral-B iO4 review 2

Its smart features are a bit underwhelming

As is the case with most iO brush handles, the iO4 has Bluetooth connectivity and can connect to the Oral-B app available for Android and iOS mobile phones.

Yet unlike the iO5, 6, 7, 8, 9 and 10 this does not have real-time tracking. Meaning, you don’t get feedback on what areas of the mouth you have and have not brushed.

When using the app you get an on-screen timer, alerts about the amount of brushing pressure and notification of the active brushing mode.

Data such as brushing time are logged in the app and available for review in the future. You do too have some customization options for the handle.

Whilst you can get insights into some of your oral care habits, it isn’t going to really highlight and educate you as much as you might have expected or hoped.

If you know you don’t brush regularly enough or for long enough, that’s exactly what the app will say.

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Useful dentist-recommended features are built-in

Used correctly, a manual toothbrush is perfectly satisfactory, but electric brushes have a number of benefits that no manual brush is able to match.

Most dental professionals, our in-house team included, only have a couple that they feel are really beneficial: a pressure sensor, timer and pacer. The iO4 has them.

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The best pressure sensor on toothbrushes today

For many years a large number of Oral-B brushes have alerted users if they were brushing too hard. They do this because too much force can lead to additional and unnecessary wear on the teeth and gums.

But, equally, good toothbrushing habits does require a small amount of pressure to be applied. It’s a balance that can take some getting used to. With the iO4, striking this balance is made much easier as the brush tells you when you are doing it right and wrong.

And you will be pleased to know it doesn’t nag you in a way that you will find irritating.

The light ring around the brush head changes color based on the applied pressure.

  • 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.

Don’t fret if it takes some getting used to and you see the red light more often than you like. The motor will slow the bristle movements to further protect the teeth until such time the pressure is relieved.

If using the app, it will show on the screen if you are using the correct pressure or not.

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Brush for longer with the help of the timer and pacer

Statistics would suggest that the vast majority of people fail to brush their teeth for anywhere near enough time to maximize plaque removal.

2 minutes is the recommended minimum time. 

Activated when you begin brushing the timer and pacer encourage you to brush the teeth evenly, not paying attention to just the teeth at the front of the mouth.

At 30 second intervals, the brush motor momentarily pauses. The sound and brushing sensation change. This is your notification to move to the next section of your mouth. Come 2 minutes, the alert is 3 momentary pauses. Hear this and you’ve brushed for the recommended minimum time. By achieving this twice a day you are going to help minimize your dental health issues in the future.

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The iO4 gives a softer and quieter brushing experience

With few exceptions, most electric toothbrushes will do a brilliant job of cleaning the teeth, if used correctly.

Oral-B has decades of experience that have gone into making the iO4’s brushing results as good as they are.

And just because this isn’t the top of the range model, the motor's functionality isn’t limited in any way. Thus you get as good a clean using the 4 Series as you do the 8, 9 or 10.

Less aggressive on the teeth than non-iO models

I often describe Oral-B brushes as providing an intense and almost aggressive clean. It’s the best way I can describe the sensation of the round brush head passing over the teeth and gums. It can be quite satisfying, your teeth instantly feel cleaner, but I know it’s not a sensation everyone likes. Particularly if you are used to the softer experience given by sonic toothbrushes from the likes of Philips Sonicare or Colgate.

Redesigned for the iO Series, the magnetic brush motor produces a cleaning action which is noticeably softer and less intense, but still very satisfying.

I do prefer the sensation you get with the iO4 compared to the likes of the Genius X for example. But, it isn’t worth switching to this brush for the different brushing sensation alone, it’s just a positive perk.

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The brush head is bigger than what you might be used to

Specific heads are required for the iO4. Compared to brush heads you might be familiar with from Oral-B, they are marginally deeper. You're looking at about a 10 percent difference.

For most, this won’t pose any issues, but for those with the most crowded of mouths, you might find it a little more difficult to position the round brush head.

The overall size is still significantly smaller than most sonic toothbrush heads.

It’s not as quiet as many other brushes, but far less noisy than non-iO models

Oral-B brushes are far more noisy than most electric toothbrushes, but the iO Series handles are quieter.

On average, they operate at 10 decibels (dB) less. The iO4 registers a maximum of 64dB. But, on the sensitive mode, it was a couple of dB quieter still. 

The sound is less mechanical than non-iO models. It is now a deeper humming or vibration noise. It isn’t as high pitched as most sonic toothbrushes that operate in the 60-70dB range.

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iO design and features cost more

The iO Series 4 has a retail price of $100. Do not pay this price. It’s common practice for Oral-B brushes to be sold at 20% below retail, thus the average cost is $80.

Each iO4 tends to come with a travel case included, that holds the handle and up to 2 heads. This is a great addition.

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A single Ultimate Clean head is included with the iO4. Alongside the Gentle Care head, it is one of our preferred options from the 4 different styles of iO brush heads available.

iO specific these heads command an average price of around $12 each. This is twice the price of a non-iO brush head you would buy and fit to the Pro 1000, Smart 3000 and Genius X.

Over 3 years, the iO4 will cost in the region of $212.

If you are prepared to forgo the Bluetooth connectivity, you can have the iO3 and save $10+.

Forgo the iO design and the Smart 1500 will cost $120 and still clean the teeth comparably.

Battery life is a bit below average and inconsistent

Expect about 18 days of use on a full charge of the iO4, assuming twice daily brushing, 2 minutes per time.

I actually achieved up to 20 days in my hands-on testing, which is good, but you could hear and feel the motor slowing a bit once past 18 days.

But, like the iO9 and 10, the battery performance is a little inconsistent. At times, I’ve gotten only 14 days from the battery. I can’t explain why.

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I’ve not experienced this with the iO Series 3, which as far as I am aware has the same rechargeable Lithium-Ion battery sealed inside the handle.

Many brands of toothbrushes now last 3-4 weeks on a single charge, so the Series 4 really falls a bit short. Particularly when you consider the size of the handle compared to the likes of SURI, which is much slimmer.

A recess in the base of the brush handle allows the protuberance on the top of the provided charging stand to fit inside. The charger is white in color with a 1.2 meter (4 foot) cable hardwired into it.

The plug on the end of the cable is a 2 pin power adapter. It will recharge the battery in up to 16 hours.

An LED on the brush handle gives feedback on the charge status.

A premium, minimal design that looks good and is easy to clean

A selling point of the iO range is the cleaner and more minimal handle design. It has what many, myself included, believe to be a premium vibe.

Rounded, the smooth brush handle is nicely weighted and feels balanced in the hand in use.

Able to stand upright on a countertop, it doesn’t tend to roll all that much when laid on a flat surface either.

The lack of gloss plastics helps give the premium look and you can purchase the iO4 in black, white and blue color options. 

Black colored handles do normally come with a black brush head, but the charging stand will be white.

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Despite the lack of rubber grips, the brush doesn't feel slippery in hand. And for those with dexterity issues, the larger profile might actually make it easier to grip and handle. 

The 2 function buttons are not too stiff and do provide reassuring feedback to the fingertip.

It is generally pretty easy to keep the handle clean and free from grime. But, do make sure you pay close attention to the brush head. Give it a good rinse after each use.

The design means that grime can get stuck inside the head and this can lead to mould without thorough rinsing. 

It isn’t a problem exclusive to the iO Series, but compared to previous generations, there is a gap between the magnetic attachment and the plastic frame that offers an ideal trap and breeding ground for bacteria.

You’ll be alerted when the brush heads need to be replaced

A yellow light will be lit inside the mode button on the iO4’s handle when it is time to replace the bristles. You will get an in app notification too, if you use it.

You can expect this to happen every 3 months as this is the recommended usage time for a brush head.

Using it for a couple of weeks longer isn’t a major issue, but after 90 days the bristles are worn. This means less effective cleaning and the potential of being more abrasive on the teeth and gums.

When you get the alert it is easy to reset this.

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4 different cleaning modes, but no icons or labels on the handle

The iO4 offers 4 different cleaning modes. 

Your options are:

  • Daily Clean
  • Sensitive
  • Super Sensitive
  • Whitening

Realistically you don’t need so many. Daily Clean is more than enough for most, but sensitive mode is welcomed by those suffering with tender gums. It is too a less intense option for new electric toothbrush users to start out with.

Cleaning performance is comparable between each with limited evidence to really suggest one is better than another. You’re certainly not going to get significantly whiter teeth just by using whitening mode.

Unless you are using the app, or have memorized the order of the modes (as above) there is no indication from the brush handle itself as to which mode you have selected.

Many brushes have labels or icons on the handle that are lit to inform you. You don’t get this on the iO4.

The app does allow you to configure the order of the modes and even disable them if you desire. So you can make sensitive the default mode rather than daily clean.

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Image used for illustration purposes. Box contents may differ.

Industry average 2 year warranty included

Despite a real need to move to more sustainable approaches, it is common practice for electric brushes not to be user serviceable. The iO4 is no exception.

Oral-B is an established player within the oral care sector and their electric toothbrushes are on the whole reliable.

It is not possible to say that the iO4 would never fail, but the odds are very low.

There are fewer failure points than more premium models and the fact the electrical components are sealed inside helps limit the chances of failure.

A 2 year warranty is included, which is pretty standard for a premium brand like Oral-B.

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.

The iO4 comes in a box that is perhaps a little bigger than it needs to be. But, it's not terribly oversized. It’s easily recycled and in many instances, you are not getting lots of unnecessary extras included.

There is potentially more e-waste generated as a result of the Bluetooth connectivity, but it’s not as bad as the handles in the range that have displays built in.

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.

Conclusion: Clever but somewhat limited tech

The iO Series 4 is a good toothbrush, I can’t say it is bad. It does what it needs to do well. 

After each use the teeth feel clean and thanks to the timer, pacer and pressure sensor you are kept on track.

But, the Series 4 is an expensive toothbrush with more features than you need. There are better value brushes within the Oral-B range.

Size guide

  • Toothbrush height with head - 24cm / 9.5 inches
  • Toothbrush height without head - 18.3cm / 7.2 inches
  • Width - 2.8cm / 1.1 inches
  • Depth/thickness - 2.8cm / 1.1 inches
  • Weight with head - 136g / 4.8oz
  • Weight without head - 127g / 4.5oz
  • Package weight - 439g / 15.5oz


  • 64dB

Country of manufacture

  • Germany (handle & brush head)
Author: Jon Love

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Leave a comment

August 29, 2023

Hi, What is the difference between oralB Io4 and iO4N ? Thanks in advance Bernard

Jon Love - Chief tester
August 30, 2023

It is often just another way to describe the same product. It can vary but sometimes the brush head supplied differs. Usually with the 'N' variant you get the ultimate clean brush head. With the iO4S for example, you get softer bristled 'Gentle Care' brush head.

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