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Oral-B iO4 Review

Great brushing results aided by clever tech, but there is a price to be paid.

4 star rating

The iO Series 4 has a modern design and a quiet motor. It’s one of the cheapest brushes in the iO range, but its smart features aren’t necessary for the average user and don’t do as much as you might think.

Long term ownership costs are impacted by the more expensive iO specific brush heads.


  • Premium looking handle that is easy to keep clean
  • Quieter than other Oral-B brushes
  • Reminds you when to replace your brush head
  • American Dental Association (ADA) approved


  • No cleaning mode labels/icons
  • Requires iO specific heads which are more expensive
  • Bluetooth connectivity isn’t essential and adds to the cost

Preview Product Rating Price
Oral-B iO Series 4 - White Oral-B iO Series 4 - White 10,018 Reviews $99.94Amazon Prime

Also worth considering

Unless you really want a smart toothbrush, you could save money and go for a brush like the Smart 1500.

If you are interested in the technology of the iO range, consider the iO6 instead — we rate it as the best value iO brush. It’s a bit more expensive, but the extra spend is worth it, for those committed to making use of features, like real-time tracking.

Preview Product Rating Price
Oral-B Smart 1500 - Blue Oral-B Smart 1500 - Blue 3,626 Reviews $79.99Amazon Prime

How the iO4 looks, feels and works

In my opinion, the retail packaging of the iO4 has been improved compared to some other models.

The overall design of the packaging has been made cleaner and more modern, to fit the design ethos of the brush itself. 

What I particularly like is more of the features including the cleaning modes are highlighted. You learn more about the brush prior to purchase than you do with the retail packaging on some other models. In the past, it has just said 4 cleaning modes but didn’t actually specify what they were.

It is great to see that most of the box is also recyclable. 

The travel case probably doesn’t need to come in a plastic sleeve, but I can understand why it does.

Oral-B iO Series 4 White Alabaster

A stylish toothbrush handle that is easy to keep clean

There is no denying that the iO4 is a smart looking toothbrush. It has the same handle shape and size as the other iO models.

The handle has a rounded design, with no harsh edges.

But there is one fairly major difference compared to the 6, 7, 8, 9 and 10 Series. Notably, it lacks the display within the handle.

Instead, you have 2 buttons placed inside an elliptical rubber grip. 

In this particular case, the grip is a muted grey color. It is a classy and subtle contrast to the white handle. It is a little more pronounced on the black and blue variants.

The upper button is the power switch that turns the brush on and off. It has a power icon within it. It has a concave design, so it is easily picked up by the fingertip.

The lower one is the mode button that you use to change between the 4 cleaning modes. It has a solid circle in the middle that lights up as part of the brush head replacement reminder system.

White Oral-B iO Series 4 under a tap

The rubber grip is functional and helps retain a secure hold of the brush in hand.

The iO Series are not as grippy to the touch as models like the Vitality and Genius. But, I can’t say they feel very slippery to the touch. The finish to the plastic is resistive.

The benefit is the handle looks sleek and is a little easier to keep clean compared to those with more extensive rubber/silicone grips. The contours in the grips are known for catching toothpaste residue and being a bit tricky to keep clean.

The iO4 feels good quality and durable

The iO Series has a very minimal design and this remains true on the iO4 despite being the less feature rich model.

On the front of the handle, aside from the aforementioned buttons, there is a Bluetooth icon as well as the Oral-B iO logo printed in the lower third. 

The back and sides of the handle are free from any notable ports or controls.

Although of a plastic construction it feels solid and well built when in the hand.

It stands upright on a countertop, despite having a recess in the base to allow it to sit on the charger.

Laid flat the shape and weight mean it can wobble a little, but it doesn’t have a tendency to roll away.

iO Series 4 white stood upright

It’s water resistant, but not submergible

The iO is water resistant. 

This means it has been designed to resist the water, toothpaste and saliva that it will come into contact with.

This does mean a rinse under the faucet or use in the shower is completely fine. 

However, it isn’t designed to be submerged in water for long periods. If it does fall in a sink full of water it will likely be fine, but avoid it if you can.

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

4 different cleaning modes are available on the iO4. Your choices are:

  • Daily Clean
  • Sensitive
  • Super Sensitive
  • Whitening

To change between each, you press the lower of the 2 buttons on the front of the brush handle.

Unfortunately, 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.

You will eventually learn the difference between the modes, the sound and the cleaning action is a little different, but this is frustrating.

The smartphone app will tell you which mode you are using if you are brushing with this open.

Connect the brush to the app and you can change the order of the modes. So, you can make the Super Sensitive mode the first and default mode if you so wish. 

Or if you wish you can actually disable specific modes altogether.

It is worth noting that you can’t change the mode prior to turning the toothbrush on.

Oral-B iO4 Review 1

Daily Clean is the best mode to use for most people, although the Sensitive modes can be beneficial if you want a less intense cleaning action.

Despite its presence on the handle, the whitening mode doesn’t provide any significant benefit to you.

If you want to learn more about the different brushing modes on Oral-B handles, do check out our guide to Oral-B cleaning modes.

The timer and pacer help you to brush for the right amount of time

The default recommended brushing time is 2 minutes.

You should be brushing your teeth twice a day 2 minutes at a time and cleaning in between the teeth at least once a day too.

The reality is far too few do, with the average brushing time being just 45-70 seconds in total per day.

If you are guilty of this, you are putting your oral health at risk.

Oral-B iO4 Review 2

The iO4 has a built-in timer to encourage brushing for the recommended time, but to also help achieve even brushing.

It is not good to brush for 2 minutes if the entire time is spent brushing just the front teeth.

As the brush is turned on the pacer and timer are activated.

At 30 second intervals the pacer kicks in. You will note a pause in the bristle motion, a change in sound and brushing sensation and a vibration in the handle. This is your cue to move from one section of the mouth to another.

This then repeats every 30 seconds, until the brush gets to 120 seconds (2 minutes).

The idea is that you break the mouth up into 4 sections: 

  • upper right
  • upper left
  • lower right 
  • lower left

You spend 30 seconds cleaning each section. As you do, you try to give equal attention to the front, back and biting surfaces of the teeth. 

If you do, come the 2 minutes of brushing time, you should have achieved an even clean to the teeth and gums.

Of course, you don’t have to follow it, but it is good practice.

At the end of a cleaning cycle, the light ring will run through a series of colors in a rainbow like display as confirmation you have achieved the recommended brushing time.

Unlike some toothbrushes, this does not turn itself off automatically at the end of a cleaning cycle. You must turn it off. 

It will turn itself off if you brush for longer than 5 minutes.

The smart pressure sensor alerts you when you brush with the correct or incorrect amount of pressure

This is probably one of the best pressure sensor implementations in any electric toothbrush on the market today.

Around the neck of the brush handle is a light ring that changes color depending on the pressure applied.

The colors and what they mean are as follows:

  • White  – Low pressure – not enough force is being applied. This is the default setting.
  • Green – The right amount of pressure is being used.
  • Red – High or excessive pressure is being applied and the force should be reduced.

As best as possible you want the light ring to be lit green for the entirety of the brushing session.

Oral-B iO Series 4 Smart Pressure Sensor

It is worth noting that the white light can be customized to an alternative color via the smartphone app.

Too much pressure can damage the teeth and gums. As such when the red light is active, in the daily clean and sensitive modes the number of brush head movements will be reduced until the pressure is relieved.

If using the smartphone application when brushing you will be alerted via the on-screen graphics only when too much force is being applied.

The sound of the brush handle does differ very slightly when excessive force is being used. It does not alter the vibration pattern felt via the handle, like Sonicare brushes do.

The iO’s motor is quieter

When the iO Series was introduced so too was a new motor.

Different from motors used in other models, the brushless magnetic drive system used exclusively in the iO Series results in a slightly different, albeit similar cleaning experience.

The motor used in the iO4 is the same as all other iO models.

But another benefit is that the brush is quieter in operation, with a different pitch to the sound. Some other brushes are really quite loud. 

The iO4 operates at approximately 64 decibels.

To see how this compares to other models, see our post on the quietest electric toothbrushes.

The cleaning results are pleasing

I can’t fault the cleaning experience.

After each use, my teeth felt lovely and clean. It is cliche but I do get that dentist clean feeling.

Just like other Oral-B brushes the iO4’s head has an oscillating and rotating cleaning action. This means the head moves rapidly from side to side in a circular motion.

There is an extra dimension to the cleaning known as micro vibrations that help to ensure the best possible results.

My at home plaque disclosing results confirmed the clean was as good as I thought. This isn’t all that surprising seeing as Oral-B’s cleaning action has been clinically proven.

Compared to the motor in the Smart 3000, Vitality, and Genius X for example, the sensation of the brushing is different.

It is hard to describe exactly, but it is softer and a little less intense. This is a good thing. But, it still moves in such a way that the cleaning is really invigorating.

Removable brush head Oral-B iO Series 4

When it comes to dental advice and information on how to take care of your teeth, the American Dental Association (ADA) is one of the leading bodies.

Therefore you gain extra peace of mind and reassurance in knowing that the iO4 has achieved the ADA’s Seal of Acceptance.

The association awards products this seal when they are proven to be safe and when they have shown efficacy in removing plaque and helping prevent and reduce gingivitis. 

Oral-B has iO-specific brush heads you must use

The iO4 comes supplied with 1 x Ultimate Clean brush head, which provides a very satisfying clean.

It has slightly firmer bristles that are angled at 16 degrees to effectively remove plaque from the teeth and along the gumline.

It is not the only style of head available for the iO4 though.

You can choose between:

  • Ultimate Clean
  • Gentle Care
  • Radiant White
  • Specialized Clean

The ultimate clean and gentle care are our top choices. 

You can choose the one you prefer, you don’t have to stick with the style that comes included in the box.

The Gentle Care may well be met with more approval from your dental professional as it has softer bristles.

You can learn more about the specific differences between each head and why we select each by reading our Oral-B brush heads article.

Despite Oral-B having produced electric toothbrushes for many years, the refills for most Oral-B brushes are not compatible with the iO Series.

Only iO Series heads will fit the iO Series 4.

The heads compatible with the Vitality, Pro, Smart and Genius series do not fit the iO4.

These iO specific heads do unfortunately command a price premium twice that of the regular ones.

Be reminded when it is time to replace your brush head

The lower of the 2 buttons on the iO4’s brush handle has an LED in the middle of it.

It won’t light up all that often, but when it does, a yellow/orange light is emitted and the handle will vibrate.

This is the brush head replacement reminder.

When you see this it is time to replace the brush head you are using with a new one.

It is recommended to replace the head on average every 3 months. This is because the bristles on a head become worn and clean less effectively.

If the bristles are splayed or heavily worn before achieving 3 months of use, replace the head sooner.

Once you have replaced the head, you need to reset the brush head replacement reminder. To do this, press the mode button for 2 seconds. A vibration and illumination confirm the reset.

If you don’t replace the head and no action is taken, an automatic reset happens after several days.

It is possible to customize the brush head replacement settings from the smartphone app.

The app will remind you if you use this.

Oral-B App Brush Head Replacement Reminder

It is worth noting that despite having been using the provided Ultimate Clean head on the handle, it kept changing the configuration to show I was using the CrossAction head. A bug in the software maybe?!

The reminder system is a neat feature that will be beneficial for some.

I can see the reminder annoying some users, albeit the intention behind it is good. 

I am a little concerned that it turns itself off automatically after a few days.  Doesn’t it defeat the point? 

But I suppose this is the happy medium to suit all users.

Connect the iO4 to your smartphone via Bluetooth

Making the iO4 a little different to other brushes is the fact that it has Bluetooth connectivity.

It is what some might call a ‘smart toothbrush’.

As a general rule, we don’t recommend smart brushes. This is because you don’t need them to achieve a good clean. 

Not to mention they use more resources and can be more expensive.

Nonetheless, you have the option to pair the iO4 to an iOS or Android device.

The free app available from the marketplaces allows you to customize your brush and log your brushing habits.

Changes and improvements are being made all of the time, but you can customize the order of the cleaning modes, set specific oral care journeys, change the color of the light ring and track how long you have been using a particular brush head.

Oral-B App On Screen Timer

You can’t track the position of the brush in the mouth

When using the smartphone app at the same time as the brush, on-screen you will be presented with a timer. 

It will count how long you have been brushing for, show the cleaning mode in use and alert you when you are brushing with too much force.

What the iO4 does not do is track the position of the toothbrush in the mouth.

There is no real-time tracking available on this brush like there is on the iO5 through to the iO10.

You do not get on-screen visualizations and feedback of where you have and have not brushed.

There isn’t the personalized coaching that comes with other models.

It will log data such as brushing time, pressure and additional information such as bleeding and tongue cleaning. 

With the iO4 you can get a good overview of your oral care habits, but you’re not going to learn if you are brushing your teeth wrong like you might with AI enabled brushes within the iO Series.

3 colors to pick between

There are 3 different color options for the iO4.

They only difference is the handle and accessory colors.

  • Matte Black
    • 1 x matte black iO4 handle 
    • 1 x black Ultimate Clean brush head
    • 1x black travel case
    • 1 x white charging stand
  • Quite White
    • 1 x quite white iO4 handle 
    • 1 x white Ultimate Clean brush head
    • 1 x white travel case
    • 1 x white charging stand
  • Icy Blue
    • 1 x icy blue iO4 handle 
    • 1 x white Ultimate Clean brush head
    • 1 x white travel case
    • 1 x white charging stand
Oral-B iO4 box contents
Image used for illustration purposes

Accessories and extras

Included in the box is a pretty basic but perfectly functional travel case. It does the job of protecting the handle and preventing accidental activation. 

Holding the case vertically, it is hinged on the left side, opening up like a book.

It is made from lightweight molded plastic and is either black or white in color.

The ends of the case are rounded, as is the top lid. The base is flat, so it sits on a worktop.

Debossed onto the top lid is the Oral-B iO logo with a push style clip on the right side to lock the case close or to open it up.

Inside the case, it holds the brush handle and up to 2 brush heads.

There are a couple of small openings to allow for airflow so that a wet brush head can dry out whilst inside.

Travel case for Oral-B iO4

Summary of design, usability & general use

  • Clean minimal look to the brush handle which is easy to keep clean
  • No display in the handle like some iO models
  • Available in a variety of colors
  • Separate power and cleaning mode buttons
  • 4 different cleaning modes
  • No cleaning mode labels or icons on the brush handle
  • It has a built-in 2 minute timer and 30 second pacer
  • Excellent visible smart pressure sensor helps reduce the chance of doing damage
  • Quiet, brushless magnetic motor
  • Great cleaning results from the small round brush head
  • American Dental Association approved
  • 1 x Ultimate Clean brush head supplied
  • Additional brush head styles are available separately 
  • Brush head replacement reminder system
  • Connects to a free smartphone application for logging brushing sessions
  • Does not track the brush movements in real-time
  • Options to customize the brush handle
  • Travel case included

The battery lasts 18 days on a full charge

Oral-B is not explicit about the battery life for this model, but seeing as other iO models are all claimed to have 2+ weeks I suspect this to be the same.

In my hands-on testing, I achieved up to 40 brushing sessions, each 2 minutes in length.

That is equivalent to 20 days of use or about 6 days longer than the advertised 2 weeks.  But the average was 18.

As a general rule, my minimum expectation is 2 weeks for a rechargeable brush like this which the iO4 easily surpasses. 

But, do be aware that there are competing products that do far outperform in this area.

Oral-B iO4 Review 3

Usage time does appear to vary

As far as I am aware the physical battery is the same in all iO models, but there does seem to be slight differences in the usable life.

During my testing the iO4 has given some very odd battery performance results unlike any other iO brush. It has lasted longer than any other brush.

Perhaps the lack of display has a part to play?!

But, the performance hasn’t always been consistent. I have gotten anything from 14 days on a full charge through to 20.

I don’t know why, there seems to be no pattern to the behavior. 

There were times where I was thinking you should be flat now, but no, still plenty of charge remaining.

18 days was about the average I have gotten from the iO4, but I have achieved at times just 14.

I try to keep my usage as consistent as possible, but I use the brush as you would at home, rather than bench tests in a lab.

A charging stand is included in the box

Supplied in the box is a charging stand. It is not a magnetic charging stand as is advertised with some other iO models.

It is instead the standard white colored countertop charger supplied with almost all Oral-B electric brushes.

The stand has a 2 pin US power adapter hardwired into it.

The cable is about 1.2 meters (4 feet) in length.

On top of the stand is a prong which fits into the recess on the base of the brush handle. 

The brush will only sit one way on the stand.

Once on the charger, it takes up to 16 hours to fully recharge.

Built into the toothbrush is technology to prevent overcharging, so you can leave it on the charger all the time if you prefer. 

The charging stand supports 110-130v. This means should you travel overseas to Europe for example you will require a voltage and plug adapter. Or it might just be easier to source a European charger.

Oral-B iO4 on charging stand

How the battery LED notifications work

The power icon within the power button of the iO4 is backlit to give feedback on the charge status of the battery.

If the battery level is good, above approximately 10% the icon will be lit with a white light.

When the battery is low and ideally in need of a recharge, a red pulsing light will be emitted.

When sat on the charger, the light will slowly pulse with white light. 

Once fully charged the light will go out.

The battery is not user replaceable

Sealed inside the brush handle is a rechargeable Lithium-Ion (Li-Ion) battery.

Sealing it inside helps prevent water ingress and any risk of damage. This approach is commonplace for electric brushes.

Unfortunately, this approach also means the battery is not replaceable.

It is rare for a battery to fail. I would suggest that the typical life of an electric toothbrush is in the region of 5-7 years. But, there is a need to be more sustainable and reduce our impact on the environment. The iO4 doesn’t help with this.

Should the battery fail within the warranty period it will be repaired or replaced, but outside this time you have no option other than responsibly recycling the toothbrush.

Summary of battery life

  • Rechargeable Lithium-Ion battery built-in
  • Expected to last 2+ weeks on a full charge
  • Lasted 18 days in hands-on testing
  • A charging stand is included in the box
  • 2 pin power adapter hardwired into the stand
  • Charging stand supports 110-130v
  • Takes up to 16 hours to recharge the battery
  • The power icon on the power button illuminates to give feedback on the battery level
  • A pulsing red light means the battery could do with being recharged
  • A pulsing white light when on the stand means the battery is being recharged
  • No light when on the stand means the battery is fully charged

Price & where to buy

I have included links to buying options here at the start of the review.

In the section below, I discuss the price more generally and in relation to similar products.

As you might have already gleaned from the information provided so far, this isn’t the cheapest electric toothbrush.  But to be fair it is far from the most expensive either.

The retail price for the iO Series 4 at the time of review is $99.99.

At this price, I don’t think it is a bad value purchase, just not the ‘best value’.

Discounts are available

Quite often you are able to buy electric toothbrushes for less than their suggested selling price.

It isn’t a hard and fast rule, but a typical discount is around 20%.

This brings the cost down to a more reasonable, $80 or thereabouts.

How it compares to other Oral-B prices

The iO4’s retail price is comparable to other iO and Oral-B models.

The iO5 that sits above the iO4 commands a $119.99  retail price and the superior iO6, $149.99.

But these too get discounted by 20 odd percent, meaning that the iO6 at $150 becomes $120 and the iO5,  just under $100.

The iO4 will on most occasions be the cheaper model, but special pricing and promotions can mean that more premium models end up being the same price or just a few dollars dearer.

iO Series 4 with travel case

A quick word on brush head pricing

The iO4 comes with 1 x Ultimate Clean brush head included in the box.

This is one of 4 different styles of brush heads on offer from Oral-B.

It is the Ultimate Clean and Gentle Care that are our top choices.

The iO Series has its own range of brush heads that work with iO models only.

There is a range of Oral-B heads that are not compatible with the iO Series.

These iO specific heads are more expensive. Whilst prices vary quite considerably, you should be expecting to pay $12 per head.

Compare this to about $5 for one of the non iO brush heads Oral-B produces. 

I go into more detail in our post on the best Oral-B brush heads.

How the long term ownership costs work out

At Electric Teeth we like to price a brush over a 3 year period to give a bit of a benchmark by which to compare it to other models.

A toothbrush might be very affordable to buy initially, but expensive replacement brush heads can make the longer term ownership costs very high. Or, it could be the other way around.

Assuming 1 user, you will need to purchase a further 11 brush heads at a cost of $132. 

Add this to the typical selling price of $80 and you have a total cost of $212 over 3 years.

Compare this to the likes of the Smart 1500 which comes out at $120  and you are paying nearly twice the price for the iO Series 4. You certainly are not getting twice the cleaning ability.

Please note that all prices quoted are approximates and will vary based on location, supplier and time of purchase.  These figures were correct at the time of writing and should not be relied upon as hard fact, but used as a guide during your decision process.

Summary of price & where to buy

  • List of buying options included here
  • Recommended retail price of $99.99
  • Generally available with a 20% discount to make it $80
  • Replacement brush heads cost about $12 each
  • Works out at $212 over 3 years
  • Models like the Smart 1500 are about half this

My thoughts on reliability and repairability

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

The handle design is newer, but based on a very similar handle that has been in use for a good few years.

As standard, you get a 2 year warranty which is satisfactory.

Unfortunately, no parts on the brush are designed to be user serviceable. This isn’t uncommon for an electric toothbrush. With a need to move to more sustainable approaches this is disappointing.


Electric toothbrushes don’t fare well in their impact on the environment because of materials needed for their electrical components, heavy weight when shipping, and the need to be disposed of as e-waste.

This doesn’t mean that you shouldn’t use one. You need to balance effective cleaning and disease prevention against the environmental impact.

Electric toothbrushes can reduce the need for dental treatment. And avoid the need for planetary impacts that come from procedures such as fillings.

There is a lack of detailed evidence to confirm that a filling is worse than use of an electric toothbrush. But, with the data available, dentist Gemma Wheeler believes that a single filling is worse than an electric brush with a usable life of 5 years.

There is no perfect solution as yet. We want to see manufacturers doing more to tackle this issue and achieve significant improvements.

Schemes to recycle brush heads only scratch the surface of what needs to be done.

Related to the iO4 specifically:


  • Limited box contents (subject to variant) – not lots of unnecessary extras. This reduces the weight of transportation
  • Recyclable cardboard box and inner tray.
  • No LCD display in the handle like some other iO models


  • The travel case comes wrapped in plastic, which isn’t necessary.
  • The Bluetooth technology isn’t necessary requiring additional components.
  • No user serviceable parts.
    • Removing the battery breaks the brush.


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 a slightly more expensive toothbrush with more features than you need. There are arguably better value brushes within the Oral-B range.

It is one of the more affordable iO models, but if you want more features and particularly like the idea of Bluetooth connectivity, there are other models that will better serve you.

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) – 127g / 4.48 ounces
  • Weight (with head) – 136g / 4.8 ounces

All are approximates


  • 64dB

More Oral-B iO content

In case you hadn’t noticed, the Oral-B iO range now includes several models. 

We explain the differences in our Oral-B iO comparison

We’ve also reviewed each brush individually: 

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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