Philips Sonicare 9900 Prestige vs DiamondClean Smart

Detailed comparison: what’s the difference between the DiamondClean Smart and 9900 Prestige?

Despite the list above, the differences between these models are not significant.

The differences are very subtle and both brushes are excellent choices.

On paper, the Prestige 9900 looks to be a replacement for the DiamondClean Smart (DCS). But according to Sonicare, this is not the case.  I do think in time the DCS will be phased out though.  There seems little reason to have such similar models on sale.

At Electric Teeth, we are passionate about giving you all the important information you need to know.  This then allows you to make a clear, and informed decision on what to buy.

Something not spoken about enough is how you don’t need a premium toothbrush to clean your teeth well.

Both models have the features I consider essential built-in. They do also have lots of non-essential extras. You are paying for these extras, which many people don’t end up using.

If you want a quality, but affordable Sonicare toothbrush, consider the ProtectiveClean 4300.

That said, if you want to own the best, then these are amongst the most capable options available today.

Let me start by covering the handle design.

At first glance, the 2 brushes look quite similar.  

They have the typical electric toothbrush look. Handle at the bottom, brush head at the top.  A cylindrical design and an easy to use power button.

But, there are a few more differences to be aware of.

The Prestige is smaller than the DCS and a little lighter too.

The Prestige 9900 measurements are: 

• Height (without head) – 17.5cm
• Height (with head) – 24cm
• Width – 2.7cm
• Thickness – 2.8cm
• Weight (without head) – 117g
• Weight (with head) – 123g

The DCS measurements are:

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

The Prestige is available in 2 colour options, champagne and midnight blue.

The DCS 9700 is available in 1 colour option, lunar blue.

There is a 9100 variant that is available in white.

With the 9900, the provided travel cases are colour matched to the handle.  With the DCS, the travel case is black in colour.

The 9900 comes with black coloured brush heads for the midnight blue option. And white for the champagne.  The DCS comes with black coloured brush heads.

Both brushes have a dedicated power button to turn the toothbrush on and off.

However, the button on the Prestige is what is referred to as a seamless design.  There is no physical break around the edge of the button, like there is with the DCS.

This is intentional. It is designed to stop dirt, debris and gunk from residual toothpaste building up.

Sonicare have seen this as a potential issue on models like the DCS. They are addressing it in the design stages of the Prestige.

The result is more of a pressure sensitive button on the Prestige.  It works, but it feels less natural.  You do not get the same level of feedback as you would usually expect from a button.  I would suggest it takes a little more time to get used to the Prestige’s power button than the DCS.

The DCS has a second button on the handle. This if for controlling the cleaning modes and intensity settings the brush offers.

The Prestige has a second button, but the design is different.  It is a pressure sensitive button, like the power button.  It is located above the SenseIQ logo on the handle, right where the brushing intensity icons are.

Unlike the DCS, this button controls the intensity settings only. It does not allow you to control the cleaning modes.

Another subtle difference, are the cleaning mode labels on the DCS.

When the brush is switched on the relevant label is backlit. Despite having multiple cleaning modes, there are no labels on the 9900. You can’t tell which mode is selected.

Both brushes offer 5 cleaning modes.  The modes on offer are very slightly different.

The Prestige offers:

• Clean
• White+
• Deep Clean+
• Gum Health
• Sensitive

The DCS offers:

• Clean
• White+
• Deep Clean+
• Gum Health
• Tongue Clean (not available on DCS 9100)

I prefer the options on the Prestige.  You can clean the tongue with any of the other modes.  You don’t need a specialist mode.  It is just shorter in running time really.  Plus, it accompanies the tongue brush that comes included.

In fact, rarely do you actually need any extra modes. But in some instances, they can be useful.  The sensitive and gum health modes are most useful. They are slower and less powerful, offering a less intense option.

Because the brushes are both from Sonicare, the way the cleaning does work is the same.

We have a detailed guide to Sonicare brushing modes available if you want to learn more.

One key difference here is how you change the modes.

On the DCS, you change the mode by pressing the lower of the 2 buttons on the brush handle.  You press this before turning the toothbrush on.  You keep pressing to cycle through the modes until you have the one you need selected.

With the 9900, you have to change it from the smartphone app.  There is no other option. You can’t switch between clean and white mode without using the application. There is a method to this madness, even if it is a bit frustrating.

What this means is you will only know which cleaning mode is set on the Prestige by going via the app.  Whereas the DCS has labels on the handle.

The Prestige comes with 1 x A3 Premium All-in-One brush head included in the box.

The DCS comes with 4 different brush heads.  They are 1 x C3 Premium Plaque Control, 1 x G3 Premium Gum, Care, 1 x W3 Premium White & 1 x TongueCare+ tongue brush.

The A3 brush head was launched at the same time as the Prestige.  This is 4 years after the DCS and the heads that come supplied with it.

There is some logic and some evidence to support the need for different styles of brush heads. The reality is though, they are not as important as some think.  Using a brush head called ‘whitening’ isn’t (generally speaking) going to make a radical difference to your tooth colour.  The differences are normaly minimal and not clinically significant.  It is a little more complicated than this, but I intend not to explain why now.

This is generalised.  But for most people, it makes more sense to select and stick with 1 style of brush heads.

It makes things easier to understand and more cost effective.

This is the whole intention and logic behind the A3 brush head.

No longer do you need 3 brush heads that do different things, the A3 does them all. It has been designed to remove plaque effectively, promote healthier gums and whiten teeth.

Sonicare’s independent tests have shown that this head removed 20x more plaque than a manual brush. It can achieve 100% stain reduction versus a manual toothbrush (in a lab test) for whiter teeth. And over a 6 week period, it can achieve 15x healthier gums vs a manual toothbrush.

Compared to the C3 and G3 brush heads that come with the DiamondClean Smart, this is 10x more plaque removal. This is quite a significant improvement.

To me, in use, the A3 felt more intense and the clean thorough.

Now, to be fair the C3 and G3 are still excellent brush heads and clean the teeth very well.   Don’t worry too much about this difference. Consider opting for the A3 brush head if you can.

All of the brush heads work with almost all the Sonicare brush handles.  They are compatible and interchangeable.  So the C3 & G3 brush heads can be used on the Prestige and the A3 brush head can be used on the DCS.

Brush heads should be replaced with either model on average every 3 months.

Both models allow you to track the brush heads usage via the smartphone application. 

This is done very intelligently via the RFID chip built into the brush heads.

The chip in the head is detected up by the handle and tracked.  Once used for 3 months, a light on the brush handle is lit orange/amber to alert you. This is clever and very useful for giving that visual reminder to change the brush head. This is part of a technology Sonicare calls BrushSync.

Another subtle difference is with the DCS. The cleaning mode is changed based on the brush head you attach.  For example, fitting the W3 Premium White head to the DCS handle would change the mode to white+.  This feature does not exist on the Prestige.

Both brushes have a built-in timer and pacer. These help encourage you brush your teeth for the dentist recommended 2 minutes.

Both brushes have a visible pressure sensor built-in too.

The Prestige does benefit from a couple of extra features.

If the pressure sensor is activated on the Prestige for too long, it will automatically change the brushing intensity.  This means the power of the brush reduces.  It can change the intensity from high, all the way to low if required.   Called ‘adaptive intensity’ this is not a feature found on the DCS.

The principle here is to help protect your teeth and gums.  It is trying to avoid you doing any unnecessary damage and educate you to brush better, for your own benefit.

It is all part of a broader technology called SenseIQ.  

The light ring will be lit yellow if it detects the brush handle/head is being moved too rapidly.  This is the scrubbing sensor.  The handle will also vibrate when the sensor is activated. This is switched off by default but can be activated from the app.

Both brush handles have a built-in, rechargeable Lithium-Ion battery.  It is not user removable.  

Sonicare claims with each brush a 2 week battery life on a full charge.  This is based on 1 user brushing their teeth twice a day for 2 minutes.

My own hands-on testing achieved 3.5 weeks with the DCS and 4 weeks with the Prestige.  In both instances, this is based on using the standard clean mode. 

The battery icon on the brush handle gives some feedback on the charge remaining. 

The battery charge light is illuminated as follows:

• A solid white LED means a full battery.
• A flashing white LED means a medium battery.
• A flashing white LED and three beeps mean a low battery.
• A flashing white LED and five beeps mean no brushing sessions left, you need to charge the toothbrush.

With the Prestige, the app reports the precise percentage (%). For example 47%. You do not get this with the DCS.

Both toothbrushes come with a charging stand included in the box.  They are similar, yet different.

Both stands are made up of 2 parts.  You have a base plate and then an extra component that sits on top.

With the DCS this is a glass item and with the Prestige it is a plastic frame, known as a ‘puck’.

The glass holder of the DCS looks and feels more premium.  It is heavier and bulkier.  The brush actually leans in the glass and doesn’t stand upright to charge.

A cable is hardwired into the charging plate of the DCS.  At the other end is a power adapter suitable for Australian bathrooms.

A full charge can take up to 24 hours.

The 9900 takes up to 16 hours to charge

Unlike the DCS the 9900’s charging stand has a USB cable hardwired into it.  There is a male USB Type A connector at the end. 

Couple this with the USB power adapter (supporting 100-240v) and you can charge in a bathroom. Or forget the adapter and charge via a USB socket on a laptop, computer, wall socket or battery bank for example.

The DCS charging solution looks classier. The Prestige charger is the more practical option.

As is common with premium brushes like this, both come with travel cases.

The Prestige case holds the handle and 1 brush head. The DCS case holds the handle and 2 heads. Given the type of head included with the Prestige, this isn’t the biggest surprise.

I am undecided on which case I actually prefer.

For a long time, I have raved about the DCS case.  This is because it has a USB cable hardwired into it.  

The cable wraps into the housing at the base of the case. The USB Type-A male connector at the other end is always present.

With the Prestige, there is no cable hardwired into it.  And there is no place to store it in the case.  The USB cable is detachable.  Meaning it is easy to forget or mislay the cable.

But, the case itself has a USB Type C connector on it.  A very current connection. It is futureproofed and makes charging wherever you are easy.

The Prestige case is slimmer and a little more stylish. It has been wrapped in vegan leather. It has a little strap built in to hold onto the case.

Both cases do the job. Both cases are far better than the competition.  The 9900 Prestige case is sleeker and a more practical option for a regular traveller.

Now I want to move on to the smart technology these 2 brushes offer.

Both use the same Sonicare app, which is available for free on both Android and iOS devices.

I do want to add a bit of a disclaimer here.  The software is updated and can be changed at any point.  I am writing about the software that is available at the time the Prestige launched in Spring 2021.

Since the DCS launched 4 years ago the software has evolved quite a lot.

Fundamentally, both brushes and the software do the same thing.  The intention is to track, log, analyse and educate.

Sensors in the brush handle track key information.  This includes how long you brush for, how often and what pressure you use.

This is then relayed back to the smartphone application and analysed.  Based on what it tracks it gives feedback and offers visual charts and icons.  These in turn inform and educate you on what you can work on to become better at taking care of your teeth and gums.

There is more to the application, but do check out the accompanying written reviews to learn more.

Whilst not essential, it is advisable, to use the brushes in real-time with the application.  It will guide you around the mouth and give you feedback on-screen during and post brushing.

3D mouth maps are generated from coverage, pressure and scrubbing data. They help give you clear visualisations.  For example, you will be able to see in which areas of the mouth you brushed with too much pressure. Or you will see if you missed certain tooth surfaces.

If you don’t use the brush in real-time with the application, data is stored on the brush handle.  It is then shared with the application, next time they connect.

Both models log pressure, scrubbing and coverage, even when not used in real-time.

But, the Prestige can display this data in a 3D mouth map.  The DCS can’t for offline brushing sessions.  The Prestige is better equipped for sync in the background too.

It is useful that the Prestige does this, but you have to be obsessed with your oral care for this to matter.  The underlying data is still synced back to the application.  It can still chart your progress, good or bad. It is still able to give you plenty of actionable feedback.

I am not downplaying what the Prestige has to offer. I am being realistic that for most it isn’t going to make a huge difference for the vast majority.

The Prestige is working towards helping you dial in your oral care routine more than the DCS.  

And last, but by no means least.  Included in the box with the DCS is a bottle of antibacterial spray.  This is designed to be used with the tongue cleaning brush.  This is not provided with the Prestige.

Does one clean better than the other?

No.

Both brushes have the same brush motor. It offers a sonic cleaning action with up to 31,000 brush strokes or 62,000 movements per minute.

When used correctly both offer a fantastic clean to the teeth and gums.

Yet, there is an argument that the Prestige can clean the teeth better.  This is because of the A3 Premium All-in-One brush head provided.

Clinical research showed the A3 Premium could remove 20x more plaque than a manual brush. Whereas the C3 and G3 provided with the DCS can remove only 10x. Thus the Prestige is better.

This is a bit of a moot point when you discover the A3 head is compatible with the DCS. Meaning this is not a benefit exclusive to the Prestige.  The difference is the A3 comes in the box with the Prestige and not the DCS.

There is no study that directly compares the C3/G3 brush heads from Sonicare with the A3.  

How these clinical differences play out in ‘real world use’ may be a little different.

For most people there is more to be gained from making sure you are doing the following:

• Brushing with the correct technique
• Brushing for the right amount of time
• Brushing for the right number of times per day

Worry more about these things than the particular brush head.

Only when you have perfected the above, might you want to worry about the brush head.

Given the choice, it might be best to invest in the A3 Premium brush head for the DCS.  

I do want to also mention the app here.

Technically, the Prestige logs and presents to you more brushing data than the DCS.  In theory, at least this extra data could educate and motivate you to brush your teeth better than if using the DCS.

In reality, the DCS still has tons of useful information. 

The 9900 encourages stronger oral care habits. It makes it harder to change brushing modes and brush heads. This way you focus on brushing.

Together these things in theory might make you better at cleaning your teeth. And in time achieve better results.  In practice, actually tracking and determining the difference is not possible. Plus a great deal rides on your personal mentality to oral care.

Is one better priced than the other?

Yes. The DiamondClean Smart is lower than the Prestige 9900.

The retail price of the Prestige is $499 compared to the $469 of the DiamondClean Smart 9700. A difference of $30.

However, the actual selling price tends to be a little different. You can generally save a few dollars or up to as much as 20% off if you are lucky.

The average selling price of the Smart is $400 whilst the newer Presitge is around $480.

This is a premium of $80 for the Prestige. 

Be aware. The DCS has been on the market for a little over 4 years at the time of the Prestige launching in the Spring of 2021.

Prices are always subject to change.  They can vary significantly from one seller to another. The DCS may be subject to extra price promotions because it is the ‘older’ model.

To give a more accurate cost comparison you need to factor in the cost of replacement brush heads.

We do this here at Electric Teeth over a 3 year period to give a benchmark for comparison.

As a rough guide, based on 1 user over a 3 year period you are looking at a daily cost of $0.56 for the 9900 Prestige. The daily cost for the DiamondClean Smart is $0.46. So the more cost effective option is the DiamondClean Smart.

It is your decision.  Pay a price you are happy with and can justify, but do so knowing the difference between these models.

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.