Oral-B iO Series 4 review

We reviewed this toothbrush over several weeks, using it twice daily. It was also taken away on trips to test its portability. All this meant lots of charge cycles as well as plenty of use with the app.

All the settings were tried and evaluated throughout,and it was assessed for cleaning power.

Setup is very simple indeed as this is one of the more basic models in the range. This means you can take the brush and head out of the box, slot them together, tap the button and start brushing right away. Then simply plug in the charger and pop the brush on when you need to get back up to full charge.

Go a little deeper into setup and you’ll access more features. For example, you can use Bluetooth to connect to the Oral-B app on your smartphone or tablet. This unlocks more features, including the ability to personalise how the brush works to make day-to-day brushing even more suited to you – while also offering smart feedback on your brushing.

The charger uses a two-pin head, meaning it can be used right away in a bathroom mirror or wall socket. However, if you want to plug into a standard UK three-pin socket you will need an adapter as that’s not included in the package.

In the box you will get the toothbrush, one standard head, one sensitive head, plus a charging dock. There are also options available with the travel charging case and extra brush heads.

All the brushes in the Oral-B iO series look fantastic, with an aesthetic that appears premium, and a minimalism that continues into the brush’s ease of use. They are slightly larger than standard Oral-B Pro brushes, both in the handle body and the heads. So those with crowded mouths may notice the slight difference in head size. 

For anyone with dexterity issues, this larger body size can be helpful, making holding the brush much easier.

The matte finish is also a welcome design touch that makes for a comfortable grip even when wet. Plus, the minimal nature of the design, with no dirt-collecting rubber, means it’s far easier to keep clean and wash when needed.

The iO series heads are different to Oral-B’s standard models but arguably attach with more ease and are easier to keep clean.

The base of the brush is flat enough to allow it to stand up, while the rounded handle section has enough of a flat back edge for it to lie down without rolling. 

The brush heads on this series are about 10% larger than the Pro range and feature bristles of varying angles and lengths. It all adds up to a very comprehensive cleaning tool. A light in the brush and a notification on the app let the user know when they need to change their brushing style, which helps ensure the best clean. 

What’s lacking is any kind of notification about which mode you’re using. While some models feature a display and others have images that light up, there’s nothing on the iO Series 4.

You have to use the app to set these up, picking the order of the modes you cycle through using the button on the brush, and default one you want when you turn it on each time.

Or you can simply scroll through to the one you want each time. While the Daily Clean is fine for most needs, if you want to set the Sensitive mode as default then you’ll need the app.

The magnetic motor in the iO Series 4 brush is very powerful yet keeps noise to a minimum and, crucially, results in a noticeably cleaner finish. This is an oscillating toothbrush, as are all Oral-B models, yet this feels more subtle and intricate in its delivery of the oscillating movement than the Pro models, thanks to the super-sensitive magnetic motor system.

The end result is a noticeable smoothness on your teeth when you run your tongue over them after a brush. You will also notice a shine that may not have been achievable with a standard-model brush. 

If you’re not accustomed to using electric toothbrushes, they can leave your mouth feeling a little delicate, so we recommend using the sensitive mode for the first week or so. 

There are four modes: Daily Clean, Sensitive, Super Sensitive, and Whiten. This means you don’t get the gum care and tongue-cleaning modes of the top-end models, but in all honesty most people don’t use those anyway. 

While this can be a powerful brush to get used to initially, its head – in combination with the modes – is adaptive, which makes this model fine for use on crowns, fillings and any other sensitive areas that require care when brushing.

All this means there’s enough power to offer a noticeable clean for stains from coffee, tea and red wine, but also enough responsiveness for use on gums and teeth that might be liable to sensitivity.

Additionally, the LED ring can guide you as to the correct amount of pressure to apply when brushing so getting the balance right should be easy. More on that below.

The iO Series 4 uses a smart LED ring that lights up in varying colours as a way to offer feedback on your brushing. The standard colour is green, for when the pressure is just right, and turns red when pressure is too hard. Many brushes offer this; however, this model stands out as the sensor also detects when brushing is too light, changing its colour to white, so you can adapt.

Helpfully, even when you push too hard, the brush helps to avoid damage to teeth and gums by slowing the motor speed. Then, when you’ve returned to the right pressure, the motor speeds back up to give the best possible clean while protecting your gums.

Dentists look for three basic features in a good electric toothbrush: a timer, a pressure sensor and pacer. This model features all of these. The timer gives you a two-minute overall brush time, as recommended as a minimum. The pacer alerts you when to change between each of the four mouth quadrants, stopping the motor vibrating for a short burst so you know to change.

There’s also an option to get even more detailed feedback by using the app. This gives you an onscreen timer, pressure alerts and notifications of the active brush mode being used. All this data is then logged so you can see your progress over time.

It’s worth noting that if you want more feedback, such as monitoring of the sections you’re brushing, then you’ll need to go for a more expensive model such as the iO Series 10 or iO Series 9. These also feature screens on the brush for direct feedback during and after brushing.

For use at night, this is much quieter than other Oral-B models and comes in at 64dB, making it about 10dB less than non-iO models. It has a deeper hum than high-pitched sonic toothbrushes, making this more comfortable on the ear for some people – and it certainly works better if you want to reduce the chances of waking anyone else when brushing.

The head is easy to remove, which is helpful, as it can pay to give this a rinse through every now and then to ensure there is no buildup inside. Do this and you’ll note a lack of the stain ring that many models can leave on your surfaces, even when you do clean them regularly.

The Oral-B iO Series 4 battery life is very good, lasting for close to three weeks on a charge when used twice daily for two minutes at a time.

During testing, we were able to get a good 20 days on a charge in some instances, which is more than the 18 days that Oral-B says it can provide. That said, there were a few times when it came up shorter, too – so it might be that varying modes, using Bluetooth and changing the pressure levels all play a part in battery performance.

Charging is simple, as the brush locks into the charging dock to hold in place. This is where the premium models stand out, though, as they offer magnetic docks and a full charge in just three hours.

This iO Series 4 model requires a full 16 hours to get a full charge – an annoying length of time that requires you to pop it back on charge between brushing sessions. However, the LED alert is helpful, showing when it has reached full charge.

While this model represents one of the best-value picks in the iO Series, it’s still a pricey electric toothbrush. That said, the price has dropped to under £100 on some websites, making it very appealing. Wait until sale season and you’ll likely get it for even less.

The basic model doesn’t come with a travel case and only has one standard head and one sensitive head. It might be worth looking for the travel case option as this can be as little as £10 more and gives you that storage option in the longer term.

Since the iO heads are about double the cost of those in the Pro model range, at £8 each, it’s worth factoring this into your initial costs. Typically, these need replacing around every three months.

You get a two-year warranty as standard, but register your brush online when you buy and that’s extended to an impressive three years. Spread this cost over those three years, including heads, and it really does become an affordable option for a brush that offers some of the best cleaning results available right now.

The main alternatives to Oral-B come from Philips, which offers the sonic style electric toothbrush. These have larger heads but a give a gentler clean. But if you prefer an oscillating brush, then there are plenty of options from Oral-B at varying price points.

If you’re set on a sonic toothbrush, there are a few options, but the best of the best is the Philips Sonicare Prestige 9900, which has numerous smart features and can be found for around the £300 mark.

Alternatively, go for the top-end Oral-B iO Series 10, for its smart dock. It offers LED feedback on your brushing pressure and can help you with sectors of the mouth as you brush.

It also has a clock display, which can be used to show other useful data. Or save money by opting for the iO Series 8, which still has most of the best features.

The Oral-B iO Series 4 electric toothbrush provides a very impressive clean that will leave dentists and hygienists alike happy with the results.

That comes from the quieter and more efficient magnetic motor, which is synonymous with the iO Series. Then there’s its good looks, with a minimalist design and easy-cleaning build quality.

Thanks to a timer, pacer and LED pressure notifications, you should find the perfect brushing technique for the cleanest teeth with the best possible gum protection. There’s also an app to pair with for more detail and longer-term analysis.

The Oral-B iO Series 4 lacks an on-brush mode notification, which can make finding the right mode tricky. It also doesn’t feature the zonal tracking smarts of the more expensive models. Plus, it won’t offer you fast charging. But if all those are unnecessary extras to you then this could be a great way to get the iO-series clean without the steep price.