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Philips Sonicare DiamondClean Smart Review

Medically Reviewed By: Dr. Gemma Wheeler

(GDC Number: 259369)

Philips Sonicare DiamondClean Smart Review [UK]

Superb in so many ways, just a bit pricey

5 Star Rating

One of the best brushes on the market today. It offers a superb clean and a great box contents. It has more features than you need, but if you desire the best technically, then this is one of them.


  • Premium design
  • Real-time tracking via Bluetooth can be valuable to the most committed users
  • USB charging travel case
  • Reminds you when to replace your brush head


  • Bluetooth connectivity isn’t essential and adds to cost
  • No smartphone stand
  • Expensive

Preview Product Rating Price
Philips Sonicare DiamondClean Smart Philips Sonicare DiamondClean Smart No ratings yet £399.99 £209.99

Cheaper alternatives are available

Make no mistake, the DiamondClean Smart is a seriously great toothbrush. But, unless you have money to burn, Oral-B’s iO6 is a similar alternative.

Naturally, there are pros and con’s. The cleaning action is different and there is no charging travel case, but the cost saving is quite significant for not the biggest compromises.

Alternatively, the 4300 ProtectiveClean from Sonicare doesn’t feature all of the smart tech and is a fraction of the price.

Preview Product Rating Price
Oral-B iO Series 6 - Grey Oral-B iO Series 6 - Grey No ratings yet £299.99 £129.99

Design, usability, clean & general use

First things first, let me talk about the design of the brush, how it looks, how it feels.

Smart and stylish this brush most certainly is.  It is clearly part of the DiamondClean range with the aesthetics that are present here, there is a continuity.

Now, depending on the model you opt for depends on the colour, but it is available in cashmere grey (silver), black or lunar blue.

My personal preference is the black, due to the consistent design but more on that shortly.

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There is a smooth premium finish to the brush handle.  It is hard to explain what it actually feels like.  It is not like a glossy hard plastic. Of course, it is a solid construction but it feels more premium than most other brushes.

On the front of the brush handle, on towards the top is the Philips Sonicare logo in a muted gold colour.

Below this (about two thirds of the way up the handle) is the main power button.

It is of a concave design and the thumb sits comfortably into it.  There is a large power icon on it.

It is not as resistive as some power buttons nor does it give the same level of feedback.  You can of course tell when you have turned the brush on or off.

Below this button are 3 lights, that increase in size left to right.  It looks a little like a phone signal might on your smartphone screen.  Each light represents the intensity setting of the brush.  1 light, the brush is set to low intensity, 2 lights, medium intensity and all 3 well you are rocking on full power brushing intensity.

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Another concave button sits below this light feature. This is the mode/intensity button.  You press this to change between the 5 cleaning modes or change those 3 levels of brushing intensity.

Getting towards the bottom of the handle now, the names of the available cleaning modes are built into the handle.  Each one lights up when selected.  They do not all light up at the same time.

The light that shines out from these cleaning modes and intensity icons is a white light.

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Below this is the brush head replacement reminder and the battery icon.

The brush head icon will illuminate and pulse when it is time to change the brush head for a new one (normally at 3 months).  It is a good visual reminder.  This works in conjunction with the smart chip built into the brush head to know when to remind you.

At the base of the brush is the LED light ring or the pressure sensor indicator.  I will explain this in a bit more detail later in the review.  But when activated it lights up a nice purple colour.

The base of the brush is flat with no recess for a charging pin.

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The remainder of the rounded square handle is smooth to the touch with no additional icons, grips or features to speak of.

Right at the top of the brush handle, just under where the brush head connects is a ring.  On the black and cashmere grey models it’s a dark grey/black colour but on the lunar blue model it is gold.  It contrasts the brush handle slightly.

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I will talk more about the brush heads later, but they are black in colour too rather than the more typical white plastic.  These complement the brush handle well.  There is not the harsher contrast of black and white.

In hand the brush feels weighty, solid and robust, you can feel some of the price is built into the handle.

Of course there is a lot of clever technology built into that handle that we can’t see.

I know it is not particularly pretty, but a few extra grips on this handle would be nice.

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It’s a balance between design and practicality, but when wet this brush is most likely going to be a little more slippery than an Oral-B model that has more rubber grips and naturally resists the slip from the hand better.  Those with limited grip or movement in fingers and wrist might find the DiamondClean Smart a little more tricky to handle.

Now the whole reason for investing in an electric toothbrush is to clean your teeth.  And Sonicare does a good job of this too.

Studies have suggested that Oral-B’s oscillating, rotating and pulsating heads offer better overall cleaning performance.  But there is also plenty of supporting evidence to show how Sonicare does an equally good job.

Sonicare brush heads tend to be a bit larger, so may when compared to Oral-B’s rounded heads feel like they cannot reach as deep into the mouth and into tighter gaps.

It is clinical debate over which is better ultimately, but at the end of the day, there are many benefits to an electric toothbrush.

My personal preference is for the Oral-B style, they feel a bit more aggressive on the teeth and gums, which I like. Sonicare is a softer experience in my mind.

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You get 4 styles of brush head included with the DiamondClean Smart.

These are:

  • 1 x Philips HX9044/06 Sonicare C3 Premium Plaque Control Toothbrush Head
  • 1 x Philips HX9054/06 Sonicare G3 Premium Gum Care Toothbrush Head
  • 1 x Philips HX9064/06 Sonicare W3 Premium White Toothbrush Head
  • 1 x Philips Sonicare T1 TongueCare+  Toothbrush Head

If opting for the newer HX9901/14 variant, just 1 x W3 Premium White brush head is supplied.

There is something special about these brush heads though.

Yes, they have been scientifically engineered with the bristles to be the right length and angle, the black coloured plastic compliments the brush handle superbly well, but equally as clever is the fact that these brush heads are smart.

Or, to be more technically correct, they are Brushsync enabled.

There are 2 parts to this technology (mode pairing and replacement reminder) that are only functional thanks to little RFID chips are built into each brush head.

When connected to the DiamondClean Smart brush handle (or other Brushsync enabled handle) the brush will automatically be set to the most appropriate cleaning mode for that brush head.

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Those cleaning modes are:

  • Clean
    • Clean lasts for 2 minutes and designed to be used with intensity level 3. It gives a thorough and complete clean.  It is recommended that you use the Premium Plaque Defense brush head with this mode.  This is the mode most will use on a daily basis.
  • White+
    • White+ lasts for 2 minutes and 40 seconds and is designed to be used with intensity level 3.  The best brush head to use is the Premium White brush head.
  • Gum Health
    • Gum Health lasts for 3 minutes and 20 seconds and is designed to be used with intensity level 3.  The best brush head to use is the Premium Gum Care brush head.
  • DeepClean+
    • The amount of time DeepClean+ runs for depends on whether or not the handle is connected to the app. In connected mode, DeepClean+ runs for 2 minutes and provides BrushPacer feedback every 20 seconds. In non-connected mode, DeepClean+ runs for three minutes and provides BrushPacer feedback every 30 seconds.
  • Tongue Care
    • Tongue Care lasts for just 20 seconds and is to be used with intensity level 1 and the Tongue Care+ brush head.

The exception here is the DiamondClean Smart 9100, model number HX9901/14, introduced in March 2019 that has just 4 cleaning modes.  It does not have the tongue care mode.

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You may wish to consult the instruction book that comes with the brush for a step by step guide on how to make best use of each of these modes.

So, fit the Tongue Care brush head and the brush will know to operate the Tongue Care mode.

Replace with the Plaque Control brush head and the brush will change to the Clean mode.

You can manually change what mode is used with each brush head and what intensity setting you want, but the brush is clever enough to know and preset some settings for you.

To change the cleaning mode used, whilst the brush is off, press the mode/intensity button the correct number of times until the desired mode is selected.

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When the brush is powered on that button can be used to change the intensity of the brush.  The cleaning mode can be changed only when the brush is powered off.

The brush will remember the last cleaning mode used if the brush automatically powers off at the end of the cleaning cycle. So if clean was the last mode used and the brush turned itself off, it will launch into this when powered on, if the brush head has not been changed.

Now, these super smart brush heads are very cool.  It is a neat touch and something we have thought brushes available today should be able to do.

They go one stage further and work in conjunction with the brush to light up a brush head reminder icon (when appropriate) to give you a visual clue it is time to replace the brush head.  Very clever.  It knows how long each head has been used for because of the chip.

All too often people use brush heads for longer than they are designed to be used for, potentially doing damage to the teeth and gums.  This brush head replacement reminder helps avoid this issue.  You will need this smart brush head to ensure this feature works.

You can tell if it is a smart brush head by the icon towards the bottom of the brush head, it looks like a WiFi logo.

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There is a problem though.  This innovation comes at a cost.  £54 for a pack of 4 brush heads!  That is £13.50 each.  This is a whole new pricing category!  However, given the price of the brush itself, it is about right!

You can use standard Sonicare brush heads (cheaper, but still expensive) on the DiamondClean Smart, but the brush will not automatically change cleaning modes, it will also not tell you when it is time to change brush head.

Most of the other brush heads are finished in white plastics, which do not fit quite so well with the colour scheme, but the benefit is a cost saving.

Smart brush heads like these will also not offer any smart functionality on any other brush other than the DiamondClean Smart, unless that brush has BrushSync technology.

If you want to consider your options, check out our ultimate guide to Sonicare brush heads.

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All Sonicare brush heads (with exception of tongue clean) have reminder bristles that are the blue in colour, which over a typical 3 month period will fade from a relatively strong blue to white colour.  If they turn white, replace the head.  This is another visual clue if the flashing light on the handle doesn’t do it for you.

Inside of the handle is the battery, the motor and all the electronic gadgetry that makes this brush as smart as it is.

There is a whole section in this review dedicated to the battery life, but to touch on it for a moment, inside the handle is a Lithium-Ion battery that lasts up to 3 weeks.

Sonicare has always been good when it comes to battery performance and really set the standard.

One way in which they conserve power is by having the brush automatically turn off at the end of each cleaning cycle.  Whilst this is power conserving, to me, this is also a fantastic feature in that it clearly tells you when the clean is over.

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This functionality ties in with the built-in timer that is in the brush.  At 20 second intervals, you get a notification via a beep, a pause in the motor and brush head motion that it is time to change area and focus on cleaning the next section of the mouth.

You get 6 x 20 second intervals per 2 minute clean, so you focus on the following areas:

  • Upper right back teeth
  • Upper front teeth
  • Upper left back teeth
  • Lower left back teeth
  • Lower front teeth
  • Lower right back teeth

These timings are all based on professional recommendations and most modes last for 2 minutes.

As important as the brush, is the way in which you clean your teeth.  Sonicare goes to quite some detail in the manual about how to clean your teeth, but we too have a page dedicated to showing you how to do it properly.

Sealed inside are all the electronics, which means that this brush is water resistant.  You can rinse it under the tap and it will survive a life a bathroom.  Sonicare does not advise use in the shower and you should not submerge the brush in water.

Part of the ethos behind this brush, particularly the smartphone app is about education – encouraging and advising to clean better.  It is not a lecture on what’s right and wrong, but tips and diagrams to show you how to be better and improve over time.

One feature that helps with this is the pressure sensor.  Built into the brush, when the sensor detects when too much pressure is applied to the teeth it reduces the speed of the brush motor and the light ring on the bottom of the brush handle lights up to emit a purple light.  It will remain purple until such time as the pressure is released.

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The bristles need only skim the teeth.  Too much pressure can be damaging.

If you use the smartphone app it will show on screen too.

As pretty as the light is, you do not want it to come on.

Some might argue the purple light is a bit of a feminine colour, there is no option to change it.

I like the principle of how it is implemented, it looks smart without detracting from the design.  However, unless in a dark room the light is actually not that obvious.  You may see it if brushing in front of a mirror, but I think Oral-B’s neck placement is more obvious, not to mention brighter.

It would be nice if there were some of the customisation options like there is with the Oral-B Genius X LED Smart Ring.

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Part of the reason multiple cleaning modes exist is that we are all different.  We have different needs and preferences.  Some might have particularly sensitive teeth and gums whilst others have particular goals, to whiten the teeth for example.

The DiamondClean Smart gives you the option to choose between 3 different intensity levels: low, medium and high. Based on the brush head you attach, the intensity will be selected automatically.  If you wish to change to a different intensity, you can do so by pressing the mode/intensity button while brushing.

Easy-start is an option that gently increases the power over the first 14 brushings to help you get used to the brushing with the Philips Sonicare DiamondClean Smart.

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The Easystart feature works in all modes other than TongueCare+ mode.

The brush comes with the mode deactivated, but it can be turned on. Refer to our FAQ’s for details on this process.

There is then of course one of the main reasons for opting for the ‘Smart’ DiamondClean, the app.

Available for iOS or Android, the Sonicare app can be downloaded and installed onto your smartphone.  It uses Bluetooth to connect to the brush and synchronise data.

This is the ‘Smart’ element really coming into play.

To get the best value and functionality from the brush, you need to use the app at the same time as you brush your teeth.

This will allow you to see in real-time how well, or not, you are brushing.

Via an on-screen graphic of the teeth in your mouth, the app guides you around the sections of the mouth you need to brush.

The theory is that you clean the teeth evenly when you follow this.

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The teeth turn from a dull colour to a bright white as you brush. The longer you brush the whiter they get. Areas that get insufficient brushing time remain dull.

Although it is best to follow the graphic on screen, you can clean the teeth in any order you see fit and the app will acknowledge the position of the brush and change the colour of the teeth on-screen accordingly. Whilst its not always 100% accurate it is fairly good most of the time.

At the end of the brushing session, areas of the mouth you missed or did not give enough attention to are coloured yellow.

Essentially, the colour changing teeth allow you to really easily see how well you are doing and make improvements straight away, because you are being shown where to pay more attention.

If you don’t use the app when you brush, you won’t get the same level of real-time feedback. However, it will sync data when the 2 are next connected. It stores up to 28 brushing sessions of data.

The app has recently been updated and presents a summarised view of your brushing data for the last 7 days. This is a positive because there is less opportunity to become overwhelmed by all the data.

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You can dig further down into the app for a bit more historic data if you want it, but you don’t get as much historic data (months & years) as you once did.

The main progress screen shows the average time per session and per day. It also shows the pressure levels used.

Green icons are good. Orange icons highlight areas you need to work on.

This information is helpful for sure, particularly for new electric toothbrush users.

Within the app, it gives you details about the brush heads you have been using. It will log each one and show how many brushing sessions you have left.

You can within your profile set details about yourself. You can also get more information about your particular brush handle, as well as update the software that your brush handle is using.

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Sonicare I think have done an ok job with the app. Initial setup and configuration are straightforward and I had no issues pairing the app with the brush. That said there is room for improvement. I think bringing back more data logging would be useful.

In an ideal world, we would like to see the ability for more people to share a brush handle between users (changing the brush head of course) to get more value from it.  Whilst possible, sadly the Bluetooth connectivity option becomes redundant.  This brush can pair with multiple phones but is only capable of logging one set of data.  There is no way to differentiate between users.  The handles see’s any brushing session as that of the main user.  Thus sharing the DiamondClean Smart handle will defeat the very point of the brush.

I am sure in time there will be a solution to this, but presently there is not.

If you have any question over the value of the app, the DiamondClean Smart is not really for you.

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One of the biggest oversights with the Smart is that in the box there is no smartphone holder.

I am not suggesting a bit bulky suction cup affair as per the Oral-B Genius 9000, but some neat cradle that a phone could sit on whilst you are brushing, to hold the phone up at an angle that you can view the screen and keep a hand free.  It would cost just a few pounds to include and finish the package.

Sadly instead you will either need to hold the phone in hand to see what’s going on in the app and track your performance or fashion your own stand.

As for other in box extras, aside from the handle and the brush heads, you get a travel case, charging glass and a bottle of Antibacterial tongue spray.  If you go for the premium DiamondClean Smart, the HX9954/53 you get the brush head stand.

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If the name of the product was not obvious enough, the spray is designed to be used in conjunction with the tongue cleaning mode and brush head to keep your mouth and specifically tongue clean, killing off residual bacteria that is often the cause of bad breath.

The charging glass is the same as the second generation DiamondClean’s charging glass.  On the current 3rd generation, the glass has been replaced for a plastic stand.

Think of a glass tumbler you might have a drink of spirits like a Brandy or Whiskey from.  Put the Sonicare logo on the front of it and sit it on a plate that has a power connector attached to it and you get the idea.

Lent in the glass, the brush does not stand upright.

The power connector is a 100-240v 2 pin connector designed for bathrooms in the UK.  If you want to connect to a 3 pin mains socket you will need to invest in an adapter.  The good news here is that it supports international voltages if travelling.

However, the smartest or coolest way to charge is in my opinion through the travel case.

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Without doubt, the best travel case I have experienced to date for a toothbrush, the hard case is finished in a soft touch leather.

Robust, it will certainly take some knocks and can hold the handle and up to 2 brush heads.

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A magnetic closure keeps the lid shut, not fiddly clasps or buttons, but easy enough to open too. It looks and feels every part as premium as the brush.

A charging cable (which is 60cm in length) is actually built into the case and tucks away underneath it.  On the standard DiamondClean it is a detachable cable, that could easily be lost.

On the underside of the case, you remove a large panel to reveal the cable neatly nestled within the case.  With one end firmly wired into the case, at the other end is a standard USB Type A connection that can be connected to a USB port on a computer, on a wall charger, to a battery bank and more, to charge the brush where you like whilst in the case. I love this, despite the fact you need not charge the brush all that often with a 3 week battery life.

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The cover that hides the cable has been cleverly designed and can actually be refitted whilst allowing the cable to be fed out through the back.

Given the price, including a USB power adapter for a mains connection would have been a nice touch.

Be aware, that this case is not supplied with the newest DiamondClean variant, the 9100.

Last and by no means least is the brush head storage compartment.  Included only with the HX9954/53, our model did not come with this.  However, I wish to speak about it as it is another nice touch.

It holds up to 4 brush heads upright inside a stylish clear plastic container.  It protects them from dust and debris and makes access to them easy.

Extremely disappointing is the fact this is not included across the range or that another type of storage compartment is not included.  It is a shortcoming of the product.

Finally for this section, for added peace of mind the DiamondClean Smart comes with a 2 year warranty.

Summary of design, usability, clean & general use

  • Slim and stylish brush handle with a solid build
  • Minimalist design, potentially could do with more grip points
  • Cleans the teeth very well
  • 5 cleaning modes, shown on brush handle via white light
  • 3 power intensity settings
  • 4 brush heads included
  • Smart brush heads that automatically change the cleaning mode – Expensive
  • Alternative brush heads available
  • Brush head reminder
  • Built-in 20 second pacer and 2 minute timer tells you when to change quadrant and finish brushing
  • Automatically powers off at the end of the cleaning cycle
  • Good battery life – 3 weeks
  • Easy-start function
  • Pressure sensor with LED although light is set to purple and not that bright
  • Bluetooth connectivity with logging and live tracking of clean
  • Smart charging glass supporting 100-240v
  • Great travel case
  • Lacks a smartphone stand or holder
  • Brush head storage should be included with all models
  • 2 year warranty as standard

Battery life

Sonicare always do a top job when it comes to battery life, they have for a long time set the standard.

I would like to say that this DiamondClean Smart is no exception, but the box states a 2 week battery life.

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There is a reason why.

Most brands and here at Electric Teeth quote battery life based on the performance of the default ‘clean’ mode.

In my hands on testing, I managed some 50 cleaning sessions on the standard ‘Clean’ mode with the intensity set to high.  That’s 100 minutes of usage time or 25 days (over 3 weeks), thus living up to the standards previously set by Sonicare.

However, the Gum Health cleaning mode lasts just under twice as long as the standard clean mode, thus reducing the battery life to just 2 weeks.

Whilst Sonicare are actually quoting the worst battery life you might get from the brush, I think they are underselling themselves a bit here.

Unless you decide to always use the longest cleaning sessions you will get anywhere between 14-25 days usage out of this brush.

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The DiamondClean has a Lithium-Ion battery, the same sort that you have in your smartphone.  This type of battery lasts and performs better than older battery technology like Nickel Metal Hydride (NiMh).

The automatic power off facility helps to conserve power, by turning the brush off at the end of each clean.

When the battery power is getting low, approximately 10% or less, the battery indicator lights up an amber/yellow colour rather than white.

When the battery is completely flat the brush will beep 6 times and will not power on.

Unless you are a frequent traveller, you will likely leave your brush at home.  It is quite safe to leave it on the charger at all times, but with such a long battery life you do not need to, you could pack it away.

The DiamondClean Smart has 2 ways in which it can be charged. Via the charging glass or the travel case.

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Charging glass may sound strange but that is what it is.  Like a small tumbler, you might have a stiff drink from, the Sonicare branded glass sits on a plate, which in turn connects to the mains power supply.

The brush sits in the glass at an angle, not upright like most others and uses the wonder that is inductive charging to replenish the internal battery.

The charging indicator on the brush handle flashes white until the DiamondClean Smart toothbrush is fully charged.

It takes at least 24 hours to fully charge your Philips Sonicare. You do not have to fully charge your handle before first use, as the handle is precharged for first use. However, it is recommended to fully charge it after first use.

This charging time is longer than most other brushes, but then the battery life is quite a bit longer.  Given that you don’t always need to access it, no big deal in my mind.

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The travel case is innovative, it is an accessory that is included with the DiamondClean, but with the Smart model we have here, an improvement has been made that rather than a detachable USB cable as before, this is now built-in.

At the other end of the cable is a full sized USB Type A connector.

When not in use this tucks away under the case.

With the brush handle in the case, you can now charge it but connecting the charging travel case to a laptop, a wall-mounted USB socket or a suitable wall adapter.

There is no battery in the travel case itself.

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The charging glass comes with a 100-240v power adapter.  As a 2 pin configuration, this is to be connected to the power supply found in a bathroom here in the UK.  Some homes (mine included) are not equipped with such.  It is possible to connect to a 3 pin socket by using an adapter.

Summary of battery life

  • Up to 100 minutes of usage time or 25 days usage based on 2 cleans a day
  • A charging glass included in the box
  • A travel case capable of charging the brush included too
  • Battery icon flashes amber/yellow when 10% or less
  • Brush beeps 6 times when no power left
  • Takes up to 24 hours to charge fully
  • The battery status light flashes until fully charged
  • Works on 100-240 volts

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.

Almost all electric toothbrushes start out with a Recommended Retail Price (RRP) that is far above what they actually sell for.

Oral-B are well known for being available at 50% or less below RRP from day one that it goes on sale.

Sonicare does tend to discount, but not to quite the same degree, with Philips often being seen as the more premium brand with higher ticket prices.  That said, the DiamondClean has an RRP of £299 and can be purchased today for £135.

I commend Sonicare for not discounting as Oral-B do, there is value in retaining a premium price; after all many of their brushes are finished better, but the feature for pound value can be harder to justify.

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The DiamondClean Smart sets a new bar in my opinion when it comes to electric toothbrush pricing.

Subject to model the RRP is some £360-380 that is incredible.

The model I am reviewing here is the slightly cheaper model, the one that does not include the brush head stand.

I managed to secure a launch offer that ‘saved’ £100 on the price, but even at £260 that is £100 more than I have paid for any other brush.  Even if you like the finer things in life you can tell that this is expensive.

Whether the price will increase or drop I do not know, but even at £260, the brush alone without replacement brush heads costs £0.24p per day to own.  The average electric brush is just 7-8p.  This is 3 times more expensive.

Please note, as of March 2019 a new variant has been launched, the 9100 retails for £250 but forgoes some of the extra box contents of the original DiamondClean Smart models.

So, to the brush heads then, well are you ready….a pack of 4 of admittedly ‘smart’ brush heads, £54!  That is £13.50 per brush head.

One of the most popular electric toothbrushes we recommend and users love is around the same cost of just 2 of these Sonicare brush heads.

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The way we usually calculate the cost of a brush here at Electric Teeth is over 3 years.  Many brushes will last longer, but it gives a baseline against which to compare by.

Whilst there are 4 brush heads in the box, we take the view of assuming you will like one style, the standard style.  This therefore means you will need to buy a further 11 brush heads over a 3 year period.

Therefore, 11 brush heads at £13.50 per time add on the £260 cost and you have a grand total of £408.50.  That is a cool £0.37p per day to own.

Had or if the brush was only available at the RRP, then the total bill will be £508.50 of £0.46 per day.

A much more sensible and reasonable price I would suggest would be around £150, even then that is £298.50 or £0.27p per day.

These prices exclude the cost of water, toothpaste and electric to charge it, but you get a rough idea.

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As much as I love what this brush has to offer, and understand the need to pay for quality and innovation, this is one bitter pill to swallow, even if you are more comfortable financially.  I believe the DiamondClean Smart will be more about justifying a want than a need.

Oral-B’s iO6 is much cheaper with lots of tech. Or the 4300 ProtectiveClean is not packed with so many features but still cleans the teeth well for around one quarter of the price.

I would say you could extend the value of this brush by sharing with others, which you can. BUT there is a massive caveat in that the tracking only works for one user.  Given that so much of this brush is geared around the smart tracking facilities it defeats the point.

It is not for me to tell you how to spend your money.  If you like the Sonicare DiamondClean Smart and can justify the price, go for it.  For your own sake, shop around or consider if this is really the brush for you.

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

  • Recommended retail price of £360-380 (subject to model)
  • Launch offer made it available for a slightly more attractive £260
  • Brush heads typically available for £54 per pack of 4 or £13.50 each
  • Works out at around 37p per day over 3 years (based on the discounted £260 price)
  • Great brush, but consider the alternatives this is a big price to pay

Reliability & long term use

Sonicare is a brand that I have trust in when it comes to reliability.

There is a certain something about their products that you can only really feel and understand when in the hand.

Materials feel more premium, the edges slightly more refined and features slightly more polished.

It is all very well having lots of bells and whistles but if everyday usability, practicality and performance doesn’t match up then things are not great.

The DiamondClean Smart does not leave me questioning my respect for Sonicare.

Solid in hand, it looks and feels the part.

Philips Sonicare DiamondClean Smart Review 3

Here at Electric Teeth, we test the electric toothbrushes in a way that you would use it at home.

Whilst the odd knock or tumble may occur we are not putting the brush through extensive durability or stress tests.

We have tested every toothbrush we write about because that is the only way we can be so honest and direct about the points we make.

To date, I have not experienced any issues with the brush and see few weaknesses.  The biggest weakness is likely the user, you or I actually making full use of what is on offer here.

Should the worst happen and the brush fail, then it is backed by a 2 year warranty.  If you want to know how the Sonicare warranty works and what it covers, read more about it here.

Do be aware that the Sonicare DiamondClean Smart is water resistant so it can get wet and be wiped down with water but it is not waterproof so where possible avoid prolonged exposure to water to avoid doing damage.  Philips explicitly state in the user manual that it should not be used in the shower or bath.  Perhaps more caution than anything, but best not test it!


I cannot deny that this is one super impressive electric toothbrush.  I am inclined to say this is one of, if not the best I have ever used.

It looks great, it has all the neat features and functions that make day to deal cleaning and usability great.

Battery life is right up there, the clean is good, the build quality is superb and I am certainly happy when using it.

I very much doubt that your 80 year old grandparents are going to be rushing out to buy this brush.

The target market is most certainly those who like technology, want the best and have a generous disposable income.

Whilst most suitable for many individuals, sadly for young and old the eye watering price is what holds this brush back.

For a quarter of the price you can have a capable equivalent, for half the price you can excellent alternatives, notably the Oral-B iO Series 6.

The DiamondClean Smart has to be something you REALLY want or can REALLY afford to justify this.

£150 is a price that would sit considerably more comfortably with me, but I guess you have to pay for innovation and nigh on perfection?!

Size Guide

  • Height (without head) – 19cm
  • Height (with head) – 25.5cm
  • Width – 2.7cm
  • Thickness – 3cm
  • Weight (without head) – 137g
  • Weight (with head) – 142g

All are approximates


Are there different versions of the DiamondClean Smart?

There are multiple different versions of the DiamondClean Smart, they are:

  • HX9901/14 – DiamondClean Smart 9100 in Black (4 brushing modes, no brush head holder, no travel case and only 1 brush head) – RRP £250 (
  • HX9917/88 – DiamondClean Smart in White (4 brushing modes, no brush head holder, and 2 brush heads) – RRP £399.99 – Added to range in 2021 – includes newer A3 Premium All-in-One brush head
  • HX9917/89 – DiamondClean Smart in Black (4 brushing modes, no brush head holder, and 2 brush heads) – RRP £399.99 – Added to range in 2021 – includes newer A3 Premium All-in-One brush head
  • HX9924/44 – DiamondClean Smart in Cashmere Grey (no brush head holder) – RRP £360
  • HX9924/14 – DiamondClean Smart in Black (no brush head holder) – RRP £360
  • HX9954/53 – DiamondClean Smart – Premium in Lunar Blue (1 x brush head holder included) – RRP £380

You should also be aware that there is also the DiamondClean series without the ‘Smart’ features.  It is a very capable brush from a cleaning perspective but does not enjoy the connectivity opt

How to change Sonicare DiamondClean Smart toothbrush cleaning mode?

The Philips Sonicare DiamondClean Smart is equipped with a second mode selector button.

First, make sure the toothbrush is turned off

Press the modes button to change modes

Find your preferred mode and put the toothbrush in your mouth

Turn on your Philips Sonicare DiamondClean Smart to start brushing in the selected mode

Your Philips Sonicare DiamondClean Smart will store your preferences for the next brushing session.

How to disable the Philips Sonicare DiamondClean Smart brush head reminders?

Place the handle in the charger

Press and hold the mode selector button

Press the power button three times whilst holding the mode selector button

Release all buttons

The reminder should now be disabled

What is brush head mode pairing?

A microchip in your brush head tells your DiamondClean Smart which one you’re using. So if you click on a gum-care brush head, for example, your toothbrush knows to select the optimal mode and intensity for that brush head. All you need to do is to press the power button.

Do I always need to brush with the Philips Sonicare app?

The brush can store up to about 28 brushing sessions of data.

To avoid losing any data, download the Philips Sonicare app and sync your handle by connecting your toothbrush to the app. You will see that your data will be automatically uploaded to your progress report and the activity-tracking feature.

Can I activate or deactivate the pressure sensor?

Place the handle, with a brush head attached, in the plugged-in charger.

The pressure sensor is enabled by holding the mode/intensity button and by pressing the power button twice while on a charger. The handle will beep twice to confirm it is enabled.

The pressure sensor is disabled by holding the mode/intensity button and by pressing the power button twice while on a charger. The handle will beep once to confirm it is disabled.

How do I activate or deactivate the Easy-Start mode?

Place the handle in the plugged-in charger.

Easy-start is enabled by holding the mode/intensity button and by pressing the power button once while on the charger. The handle will beep twice to confirm it is enabled.

Easy-start is disabled by holding the mode/intensity button and by pressing the power button once while on the charger. The handle will beep once to confirm it is disabled.

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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13 thoughts on “Philips Sonicare DiamondClean Smart Review”

  1. Hi,
    Thank you for your excellent work, I bought the 9100 version (4 modes, without travel case) at a very good price on the philips site (-25% on a price already lowered).

    Do you think this version is compatible with the travel case CP0557 available separately:


    it seems to be the same as the one supplied with the other versions of diamonclean smart, and what worries me is that in the manual, it says that the travel case supplied with certain models is only compatible with the handle hx993S, B, W, P, L but I have the hx992S version ??

    Thank you !!

    • Hi Gerrado.

      Thanks for the question.

      I am pretty confident this is the case you need and it will work with your 9100 model. The handle shape and size is the same as other DiamondClean Smart handles.

      The only thing to be aware of is that although this is the correct case, the USB cable does not come supplied. You will need a USB to microUSB cable to connect to the case and allow the brush to charge whilst inside.

      • Ok it’s ordered (I have a lot of USB cable, no problem).

        Thank you again for all your precious advice, this is my first electric toothbrush and it is day and night !

        I hesitated with a panasonic model recommended by a friend, Doltz EW-DP53, why not test more models from this manufacturer ?

        • Gerado.

          It is an excellent toothbrush you have there.

          Panasonic don’t make that many dental products in the west. We mainly focus on UK/USA products. I had not seen this model you mention, it seems to be sold mainly in Japan, so probably won’t be going hands-on any time soon, but in the future maybe.

  2. Don’t buy Philips Sonicare toothbrushes!!
    Whilst they do clean teeth better than rotary brushes they do not last. We have had lots of problems with the holder switching itself on and off in the early hours of the morning. Philips reluctantly replaced the faulty handset within the warranty period, but the replacement is now acting in the same faulty way. There are lots of public reviews online showing that this is a common fault. Are you are happy to pay £2/300 for a brush which will last two years at best?

    We have returned to the much more reliable Braun Oral B

  3. Where do we put the additional brush heads if there’s no case for more than 2 ? Its ridiculous that the Blue ver case isn’t a standard like it happens with Oral-B.

      • This is nice but doesnt protect from dust. I recently found a sonic toothbrush by nevadent at Lidl for 26 € only and my father really likes it. I think you should review it.It has everything sonicare box has except it has a base like oral b for charging instead of glass. the only downside is that is has half pulses than sonicare Judging by the overall price it should be really cheap to include the case so i dont see why philips didnt do it

  4. Is there a Sonicare electric toothbrush that has all the teeth cleaning settings exactly as the DiamondCleanSmart, so including the tongue care, the three intensity settings and the pressure sensor without all the smart app etc? I just want all the cleaning features but not the app tech.

    • Hi Katie. No, not that I know of.

      You don’t have to use the Bluetooth/App even-though it is available, the brush will work without connecting it to a smartphone.

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