A premium electric toothbrush built with frequent travellers in mind, the Philips Sonicare 9900 Prestige requires a little configuration in the mobile companion app, but once it's tailored to your exact preferences you can just hit the power button and brush. The app can also provide real-time guidance as you work your way around your mouth, with location tracking to follow your movements, but it takes careful angling of the brush to assure your virtual hygienist that you haven't missed a spot. It's a pleasure to use though, and its rechargeable travel case and no-mess design make it particularly practical for taking on the road.
Real-time brushing feedback
All-purpose brush heads
Sleek, easy to clean design
Can't change settings without app
Hit-and-miss location tracking
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The Philips Sonicare 9900 Prestige is an absolutely top-end electric toothbrush, and it shows. It's smart and sleek, and even comes with an executive-looking leather-effect travel case that keeps it charged when you're away from home. It's slim and light in the hand, designed to stay as clean as possible, and its compact all-purpose brush head avoids the need to switch between different designs for sensitive and intense brushing.
The downside of that minimalist design is the lack of controls on the handle, which means you'll have to delve into the Sonicare app to make adjustments to the settings. That's not a problem if you know exactly what type of brushing experience you like, and are happy to invest a little time getting it just so, but if you're in a hurry you can't pick a mode on the fly as you can with the Philips Sonicare DiamondClean 9000.
This is a seriously smart toothbrush though, with real-time feedback that warns you if you're scrubbing too hard and, most impressively, a feature that automatically lowers the intensity if you're applying too much pressure. The app will also supply you with advice based on your brushing habits.
That 'AI' technology is the real draw here, adapting to your brushing as you go, but you're also paying for the premium design. If there's such a thing as an 'executive toothbrush', this is it.
Price and release date
The Philips Sonicare 9900 Prestige was released in April 2021, priced at $399.99 / £299.99 (about AU$550). It was one of the most expensive premium electric toothbrushes around at launch, but has already begun to drop in price at third-party retailers like Amazon.
The Philips Sonicare 9900 Prestige is a very sleek, minimalist electric toothbrush, and is available in two colors: champagne and midnight. Unlike many higher-end electric brushes, it has no display and only a single power button. Power level is indicated by three small LEDs below the button, and another LED at the bottom of the handle indicates that it’s powered on.
The Sonicare 9900 Prestige comes with a leather-effect case, which resembles a compact umbrella and will keep your brush safe and charged while you’re travelling (with space for two brush heads). It’s powered up via a USB-C connector, and comes with its own charging cable. There’s just one drawback: unlike the Sonicare 9000 DiamondClean, which has a hidden compartment on the base of its case, there’s nowhere to store the cable for the Sonicare 9900 Prestige’s case when you’re on the move.
When you’re at home, the brush is juiced up via a rather stylish charger base, which plugs into a standard shaver socket. The translucent plastic upper can be lifted off for easy cleaning, and there are no awkward recesses where hard water deposits could accumulate.
The Sonicare 9900 Prestige uses all-in-one brush heads, so there’s no need to mix and match for different purposes. If you need something specific (particularly gentle brushing, for example), you can configure the brush through the mobile app rather than switching the head when you want a different clean. It’s a welcome touch, particularly since premium electric toothbrush heads from any brand are so expensive.
There’s no gap between the brush handle and head (as there is with the Sonicare 9000 DiamondClean), which helps keep the whole device clean.
To get the most out of the Philips Sonicare 9900 Prestige, you’ll want to spend a little time getting your brush set up with the smartphone app before you begin your first clean. The setup process is simple, and although you’ll need to create an account and place your brush on a flat surface briefly for it to be configured, the whole process takes only a minute or so.
Once that’s done, you can set about customizing your brushing experience. As we’ve mentioned, there are no controls other than a power button on the brush itself, so it’s necessary to make all your preferred adjustments within the app, where you can fine-tune the options to create your ideal brushing mode.
That said, the app gives you an impressive degree of control, letting you adjust the brush’s mode (clean, white+, gum health, deep clean, or sensitive) and intensity separately. The brush’s default setting is ‘gentle’, but having tried all brushing intensities, we found ourselves favoring the ‘medium’ option in ‘clean’ mode, which left our teeth feeling smooth and allowed the brush to glide nicely.
The brush can also take action to stop you getting too aggressive with your brushing. If you scrub too hard, it can light up and vibrate to alert you (with a warning in the app as well), and if you apply too much pressure for too long then the handle will pause, then lower the intensity automatically so you don’t damage your gums. In our tests, this appeared much less sensitive than the pressure sensor of the Oral-B iO Series 9 (another premium electric toothbrush). There’s also no light to show if you’re not applying enough pressure, though this is less of a concern.
The Sonicare 9900 Prestige is remarkably quiet, and the sound fades gently in and out as you turn it on and off. We're not sure whether this is an intentional design feature, but it certainly adds to the 'premium' feeling.
The brush feels smooth and comfortable in the hand thanks to its slender handle. You’re advised to hold it gently, like a flute, but despite using a light touch, we found that the brush location wasn’t quite as accurate as that of the Oral-B iO Series 9. It seemed necessary to angle the Sonicare 9900 Prestige quite steeply for it to register that we were brushing some lingual surfaces.
Will the Sonicare 9900 Prestige suit you? It’s mostly a question of how much you enjoy tinkering. A display or a touch control on the handle would make the Sonicare 9900 Prestige more practical for anyone who wants to swap modes regularly (for an occasional gentle brush or deep clean, for example). However, if you know what you like and want a consistent experience, there’s no need to spend time picking a setting every morning and night – after configuring it once, you can simply power it on and begin brushing.
Much like Oral-B’s smart toothbrush app, the Sonicare app presents you with a simple map of your mouth, divided into areas that change color on-screen as you clean each one. The app times you, and shows when it’s time to move around to the next part.
The app shows whether you’re brushing the outer or inner side, which is a nice feature that helps ensure you don’t miss a spot, but your time is split equally between these two, which allows no time for biting and chewing surfaces until the very end, when you’re urged to make finishing touches. It’s a little frustrating.
We did, however, appreciate the ability to change the starting point for our daily brushing sessions (in our case, the bottom right), which allows you to tailor the experience to suit your brushing style. We also liked the real-time warnings on our phone when we were using too much of a scrubbing action; these appeared more quickly than haptic feedback from the brush, so we were able to slow down our brushing straight away.
This is a seriously premium toothbrush, and the app provides a more grown-up experience than those of some rival brands. The Sonicare app will congratulate you on a job well done, you can track your brushing sessions in a calendar to make sure you’re maintaining good habits, and there's an abundance of practical brushing tips, but you won’t be showered with smiley faces, badges and rewards. If you’re looking for something that will keep kids engaged and interested, the Oral-B app will serve them better.
First reviewed July 2021
Buy it if
You're a frequent traveller
The USB-C chargeable case means you can take the Sonicare 9900 Prestige on the road for weeks, and it's designed to stay as clean as possible on your journeys.
You want to perfect your brushing
The real-time feedback will help you develop better technique that'll serve you well long-term, even on days when you don't want to open the app.
Let's be honest, style one of this brush's key selling points. Its sleek design is timeless, and will look the part in any bathroom.
Don't buy it if
You want to encourage kids to brush
The Oral-B app is advanced and very well designed, but it's practical rather than entertaining won't offer awards and achievements for a job well done.
You want to change modes on the fly
If you want to quickly pick a different mode each morning, the lack of controls on the brush handle means you'll need to open the app to make those adjustments. It's not a major time-sink, but could be an inconvenience depending on your habits.
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Cat is the editor of TechRadar's sister site Advnture. She’s a UK Athletics qualified run leader, and in her spare time enjoys nothing more than lacing up her shoes and hitting the roads and trails (the muddier, the better)