Philips Sonicare DiamondClean 9900 Prestige review: A high-tech toothbrush with a useful twist

I've tested plenty of the best electric toothbrushes over the years, but the Philips Sonicare DiamondClean 9900 Prestige takes things further than most. With smart sensors, an interactive display and real-time coverage feedback, there's no denying it's more advanced than your average model.

That said, I was also keen to find out whether all those extra features actually make a difference to the everyday brushing experience, or whether you're simply paying for technology you don't really need. After using it for a few weeks, here's how I got on.

Price and availability

The 9900 Prestige is priced at £599.99 (around $800) and is available from selected retailers and dental practices.

That said, as is often the case with Philips, I've already seen it discounted significantly. For example, Boots is currently listing it at £289.99, so it's worth shopping around before you buy.

It's available in Quartz Black, Silver White and Storm Blue, which is the colour I've been testing.

Design and features

At the core of the 9900 Prestige is the brand's SenseIQ Adaptive Intensity technology, which senses your individual brushing style and automatically adjusts the pressure and motion to provide a more personalised clean. Alongside this, Philips has introduced its Next-Generation Sonicare Technology, which automatically adjusts the motor power to maintain performance and delivers up to 62,000 bristle movements per minute.

You also get a range of cleaning modes and three intensity levels, including Clean for everyday brushing, Deep Clean for a more intensive clean, White for helping remove surface stains, Gum Health for focusing on the gumline and Sensitive for a gentler clean.

The biggest change compared with its predecessors is the addition of an interactive display on the handle, which gives you a visual guide to your brushing. It works alongside Philips' new Smart Coverage Feedback system, so as you brush, the handle's light ring tracks where you've been and uses different colours to guide you around your mouth. Yellow indicates an area that still needs attention, whilst blue shows that an area has been cleaned.

Once you've finished brushing, the display shows a visual coverage map, so you can see exactly which areas you've missed and go back over them. There's also real-time pressure feedback, with the ring glowing green when you're applying the right amount of pressure and alerting you when you're pressing too hard.

The smart features extend to the Sonicare app, which gives you personalised guidance and lets you keep track of your brushing routine. However, the 9900 Prestige's interactive display means you don't have to rely on this to understand how well you've brushed, making the new model feel less dependent on an app than some other smart toothbrushes.

The overall package is completed by a Premium All-in-One brush head, which comes with a replacement reminder that tells you when it's time to swap it for a new one.

You also get the rather premium-looking glass charging setup and a Prestige charging travel case. At home, you simply place the toothbrush in the glass, which sits on the charging base, whilst the travel case doubles as a charger when you're away.

Performance

After using the 9900 Prestige for a few weeks, the feature I noticed most was the feedback built directly into the handle. I'm firmly in the camp of people who don't tend to use Bluetooth toothbrush apps, so I like being able to see which areas I've covered and where I need to spend a little more time without using my phone.

Once the brushing cycle is finished, the handle shows a more detailed visual mouth map, and I particularly like how immediate this feedback is. The app goes further if you want more detailed information, but I like how the handle gives you enough information to make a noticeable difference to the everyday experience.

In the example below, I could see that I'd done a good job brushing the front of my teeth, but hadn't paid quite as much attention to the inside. It meant that the next time I brushed, I already knew where to focus.

The actual brushing experience is very much what I'd expect from a high-end Philips Sonicare electric toothbrush. It feels powerful and thorough, and my teeth felt very clean after each use. After trying the different settings, I found myself coming back to Clean mode at medium intensity most often, which felt like the right balance for me.

That said, I liked having plenty of options to choose from, particularly if I wanted to change things up depending on how my teeth and gums were feeling. The three intensity levels are also easy to adjust, and you can swipe through the modes on the touchscreen before selecting your choice with the secondary button.

For the price, I did expect the toothbrush to come with another brush head, but it's not a deal-breaker.

The glass cup charger is another interesting addition, and I like that it can sit at any angle rather than having to be positioned upright. Unfortunately, I don't actually charge my toothbrush in the bathroom, so it's not something I've found particularly useful in my own routine. That said, I can see the appeal if you do keep your toothbrush there and want it to have a dedicated charging spot, and the fact the cup can be lifted off the base and used for rinsing is a nice touch as well.

I do, however, really like the travel case. It's slim and feels premium, and the fact it charges means you don't have to find another way to power the toothbrush whilst you're away.

Verdict

The Philips Sonicare DiamondClean 9900 Prestige has surprised me with how useful its smart features actually are. The brushing itself is excellent, but it's the feedback built into the handle that really sets it apart. Being able to see where I've brushed, where I've missed and when to move on, all without reaching for my phone, makes a bigger difference than I expected. It isn't cheap, and whilst the glass charger is a clever idea, it didn't really suit my routine. However, after a few weeks of testing, I've become a big fan of having a toothbrush that tells me how I'm brushing – and I'm not sure I want to go back to one that doesn't.

Alternatives to consider

Philips is one of our favourite toothbrush brands at T3, so I'd also recommend the Philips Sonicare 7100 as a cheaper alternative. It still offers four brushing modes, three intensity levels, a visible pressure sensor and app connectivity, but it doesn't have the 9900's interactive display and Smart Coverage Feedback.

The SURI 2.0 is another option if you're after something a little less tech-heavy. It's a slimmer, more minimalist electric toothbrush that still offers sonic cleaning, a pressure sensor and a useful travel case, whilst its replaceable-head approach is designed to reduce waste.