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Medically Reviewed
Published: 22 May 2023

Oral-B Smart 4 4000 review

Author: Jon Love (Leave a comment)
Medical reviewer: Dr Gemma Wheeler, BDS
Oral-B Smart 4 4000 review 1

The cheapest Oral-B with Bluetooth, not that you need it

star star star star

The grippy and slim Smart 4 4000 is a solid brush. It has the features dentists recommend, cleans the teeth well and lasts 2 weeks on a full charge.

Although you can pair with an app to log your brushing data, you only get limited insight into how well you are brushing.


Slim grippy handle


2 variants – 1 with & 1 without travel case


2 week battery life


No cleaning mode icons/labels


Use Bluetooth to log brushing habits in the app

Also worth considering

Oral-B's iO Series 6 has real-time tracking which provides more useful feedback on your brushing habits, allowing meaningful improvements to be made quicker.

Alternatively, forgo the non-essential Bluetooth features and opt for the more affordable Pro 2 2000.

Oral-B iO Series 6 (iO6)
Oral-B iO Series 6 (iO6)
Oral-B Smart 4 4000 review 2 Oral-B Smart 4 4000 review 2 Oral-B Smart 4 4000 review 2 Oral-B Smart 4 4000 review 2 Oral-B Smart 4 4000 review 2

How the Oral-B Smart 4 looks, feels and works

Between brands and even different ranges from the same brand, the design and feel of a brush in hand can differ, however, most have a fairly slim, rounded profile to them.

Oral-B has always done, in my mind, a pretty decent job when it comes to the look and feel of the brushes.

Could they do away with some of the plastic construction? Yes, they probably they could.  However, I think the look of the Pro and Smart models are actually a nice blend of design and everyday practicality.

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The Oral-B 4000 is an all white design.  A gloss white plastic body is finished with a soft touch rubber grip that runs down the front of the brush handle.  On many other models this a bolder colour to give it a bit more character and more eye catching, the Smart 4 4000 looks quite clinical.

Despite this, it is grippy and has a series of ridges around the power button that help hold and guide you to the controls of the brush.  On the back of the handle is a harsher but still practical series of grips.  Raised plastic notches give the fingers sticking points on the upper half of the handle.

For me, these are small practicalities that make a big difference in everyday life.

Virtually at the top of the brush handle in between the contoured grips is the power button that is white in colour with a grey/black power icon on it.  The contrasting colour of the icon helps it stand out against all the white body.

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You don’t want a button that is too easily activated or too firm, thankfully that is not the case on the 4000.  It has a nice resistance when pressed.  Not too soft that it can be accidentally activated, but not too firm it is difficult to press.  Good even for those with limited dexterity in my opinion.

The lower third of the brush handle has the Bluetooth, Oral-B and Braun logo in grey/black as well as a battery and charging icon below them.

These icons are transparent and have an LED light behind them that illuminate at certain times.

There are 2 parts to the brush, the handle I have been describing.  This has all the clever bits of technology in.

Sealed inside, these parts are protected from water and moisture.  This means that the brush is water resistant and can be rinsed under a tap and used in a shower.

The likelihood is that it would survive, but I strongly advise you avoid submerging the brush below water, for example in a bath or sink.  A rinse is fine, but the brush does not need to sink to the bottom of a bowl of water.

The second is the detachable brush head, I will explain a lot more about this shortly.

If you take a look at the very bottom of the brush handle, there is a recess, into which the pin on the charging stand connects to.  A charging stand is provided.

The brush is able to stand upright without the stand.

Right at the top of the brush handle is a metal prong, this is what the brush head connects to and feeds the power from the brush motor.

Just below this metal prong on the rear side of the handle is the pressure sensor.

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Are you familiar with a pressure sensor?

If not, in this case, it is a plastic panel that is a red/orange colour, it sweeps up over and down the neck of the handle.

When you brush, sensors within the brush detect if you are applying too much force to your teeth.  When it detects this, it activates the pressure sensor.

This means that the LED sat behind the panel lights up.  You get a bright red light that you won't fail to notice.

At the same time as the LED pressure sensor illuminates, you should also notice that the speed of the brush head will decrease and the sound of the motor will change.  This is nothing to worry about.  It is programmed to do this, until such time as the pressure is relieved.

You see, applying too much pressure when brushing is a big issue and it causes more damage than you might think.  Excessive pressure can damage the gums and cause wear on your teeth.  A brush need only skim the surface of the tooth and gums. So, the brush reduces the power to protect your teeth.

Just relieve the pressure and the light will go out and the motor power up again.  Just remember to let the bristles essentially glide across the tooth surfaces.

If you activate it often, don’t worry all that much, over time you will learn and avoid doing lasting damage to your teeth.  Just imagine if you didn’t have it...

The Oral-B Pro 2 2000 has 2 cleaning modes, the Pro 3000 has 3 cleaning modes, the Smart 5 5000 has 5 cleaning modes, so as you would imagine the Smart 4 has 3 cleaning modes….Yes, I know, I can't quite figure that out either.

The 3 cleaning modes are:

  • Daily Clean
  • Sensitive
  • Whitening

Remember the order of these, you will need to refer to this in a moment.

Unlike the Pro 3 3000 the Smart 4 is a bit smarter, as the name implies.  More on this shortly.

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Each of the 3 cleaning modes work slightly differently, with differing levels of oscillations, rotations and pulsations to achieve different cleaning effects on the teeth.

For example, Sensitive mode reduces the number of movements to be softer on the teeth and gums.

You can find much more detail on each mode and how they compare in our article, Oral-B cleaning modes explained.

What I find somewhat odd is that Oral-B have not included a Gum Care or Sensitive brush head with the 4000. Would that not make sense to pair with the sensitive cleaning mode?!

To activate each cleaning mode, you have to use the power button on the front of the brush.

Remember the list above, this is the order of the cleaning modes.

Press the power button once to turn it on.  Daily Clean mode will launch.

Press it again to change the mode to Sensitive.

Press it a third time to activate Whitening mode.

A fourth time will turn the brush off.

You can press and hold the button for 2 seconds at any point to power it off.

This makes sense, but there are 2 issues in particular that I have with the way in which this has been configured.

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The first is that to change to any of the cleaning modes, you first have to power the brush on and the second is you need to remember the order.

I suspect over time you will learn this, but wouldn’t some icons or LED’s be helpful to show the mode.  The more premium Smart 6 and Genius range offer them.

Ideally, a way of selecting the mode prior to actually turning the brush on would be the solution.  This is not available, not even on the premium Genius 9000 model.

Most Sonicare brushes allow you to do this though.

Another small but significant thing to remember is; put the brush in your mouth before powering on and changing modes otherwise the toothpaste might go flying across the room.

Buy the Genius 9000 and although you have to power the brush on to change the cleaning mode, if you have changed the mode, it will remember it.  Next time you power the brush on, it will begin in that mode.  The Oral-B Smart 4000 electric toothbrush does not do this.

I understand why though.  If it did, there is no way of showing what mode it is on, unless you use the app.

When using the Bluetooth connectivity, the app will show the cleaning mode.  I will explain the connectivity option in more detail shortly.

Despite the criticisms of the way in which the cleaning modes are presented, I do love the clean that an Oral-B brush offers. Studies have suggested Oral-B’s oscillating and rotating technology is superior, but there are studies that side with Sonicare.

It is a little harsher/aggressive feeling than a Sonicare or Colgate brush.  Whilst this is not exactly the best way of rating a clean of the teeth, it really feels like it has done something. I prefer it.

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The handle offers some 16 days of battery life and is lightweight.

When the battery built into the brush begins to deplete, the charging icon will flash Red.

You do not get anything more detailed from the handle.

It would be nice if you had a green light to suggest a good amount of remaining charge or yellow for less than 50% for example, but no such luck.

Even better would be a little LED display that showed the exact battery percentage (%).  Or in the case of the Smart 4, the app picked up the information.

The battery icon will flash green when the brush is on charge.

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In the box with the Smart 4 you get 3 styles of brush head.

  • 1 x CrossAction
  • 1 x FlossAction
  • 1 x 3D White

There is a range of more than 6 different styles of brush heads you could use on the Smart 4.

The heads are interchangeable, so you can select your preferred head and use it with any of the cleaning modes, although some work best with particular modes.

To fit or remove the brush head simply align the metal with the hole in the shaft of the brush head and push the two together until you hear and feel them clip into place.

Pull the two apart to release them.

It is important for your oral health to replace your toothbrush head every 3 months or sooner if your bristles are frayed.

Official Oral-B brush heads are recommended and they all have something known as indicator bristles.  These are Blue coloured bristles that will over a 3 month period gradually discolour.

When they are a very pale blue or white it is time to change.  It is a clever reminder system.

Would you like to know more about the brush heads, the styles, how they work and the aftermarket options?  I recommend you take a look at my Ultimate Guide to Oral-B brush heads.

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Most cleaning modes on this brush run for 2 minutes.

If you did not already know, this is generally the recommended brushing time. 2 minutes, twice a day.

If you didn’t know this or are guilty of not brushing for as long as you should, the Smart 4 can help in 2 ways.

The first is the built-in timer and quadpacer.

Imagine your mouth broken up into 4 sections. Upper right, upper left, lower right and lower left.

You should spend 30 seconds cleaning each section.  The pacer helps you keep an even brushing time on these 4 sections.

At 30 second intervals, the brush will provide an audible warning via a slight pause in the brush motor at to tell you to change quadrant. Once the 2 minutes are up 3 brief pauses in the brush motor will be heard and felt.

Brushing for the full 2 minutes is very important, but just as important if not more so is the right technique. Make sure you learn how to clean your teeth properly.  

The second was in which it helps is through the more powerful Bluetooth connectivity and smartphone app.

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The idea behind this connectivity is to encourage you to brush for the right amount of time and evenly.

To take advantage of this smart feature you need an Android or iOS smartphone and Bluetooth 4.0 on your phone.

Download the appropriate app and install it on your phone.

You can download from iTunes here and Google Play Store here.

As good as the app is, I feel this may also be one of the negatives as some will not see the point of using it or find it more hassle than it's worth.  You don’t have to if you don’t want to.

If you feel you won’t use it, you may want to consider if the Pro 2 2000 is for you, you will be paying for a feature you won't necessarily use otherwise.

It takes a bit of practice to get in a routine of having your phone with you when brushing.  If you forget it or don’t have it to hand, don’t worry.  The handle will store the data for the last 20 cleans and sync this to the app, the next time it connects.

It is also worth knowing that the Bluetooth connectivity works only for one user.  If you share the brush handle with a partner, this will mess up the data.  If you and other family members all want to track with the app, you need your own brush handle.

The app is very comprehensive with lots of options. It gives you all you need though to not only effectively brush your teeth, but to log the cleans and motivate you.

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There are features like integration with your calendar so you can see your days' agenda, news, tips and tricks, so you stay interested when cleaning your teeth.

At times I have found these distracting, you may want to customise the settings to avoid some notifications.

You can also set personalised modes which can disable cleaning modes on the brush handle too.

Sadly the app does not show the battery power of the brush handle.

The main feature of the app is the on screen timer and guide that shows you where to brush and how well you have brushed.

Whilst not essential, it would be nice if Oral-B included some form of smartphone stand with the 4000.

If you want to make best use of the smart features, you need to have the phone to hand. Holding it for 2 minutes whilst you brush can be frustrating.

It need not be a suction cup holder like the Genius 9000 comes with, but a countertop option would be a nice alternative. It would only cost a few dollars extra.

The idea being, launch the Oral-B app, sit the phone in the stand and you can now see the timer and how well you are cleaning, plus all the useful advice.

Whilst not all choose to or like you use their phone in the bathroom (water & electrics) the dock would give somewhat of a more suitable home to the phone and encouraged the use of the smart element of the brush.

With this said, maybe this is what encourages you to look at the more premium models that do include something similar.

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Aside from the aforementioned 3 brush heads, the Smart 4 comes with a brush head storage compartment included in the box.  

This is a moulded piece of plastic that clips around the charging stand that is also provided.

It is essentially a tray with 4 recesses into which a brush head can be laid. A translucent lid then closes down over them protecting the heads from dust and debris. But, importantly allowing ventilation so the heads can dry out.

It is a handy accessory if you like to use multiple heads or share the handle with other people.

The charging stand is fairly self explanatory, but I explain more about this in the battery section of the review.

There are 2 variants of the Smart 4. 1 comes with a travel case, the other doesn't.

The model numbers are the same and the packaging looks the same, but what you get in the box is different.

The variant with the case is primarily sold via Shaver Shop for the same price as the one without a case.

I think this is worth picking up, because should you travel, go on vacation etc, it helps protect the handle and head.

You get an impressive 180 days to try the Smart 4 with Oral-B's money back guarantee. It is essentially like a trial, whereby you can buy and try the brush.  Should you not like it you can return it for a refund.  This is particularly useful if you are unsure whether an electric toothbrush is for you.

In the unlikely event, something goes wrong, there is as standard a 24 month warranty is provided with the 4000.  

Summary of design, usability, clean & general use

Slim and comfortable brush to hold and use
Looks good
3 cleaning modes (Daily Clean, Whitening and Sensitive)
2 brush heads included (2 x CrossAction (4000N) or 2 x Sensitive/SensiClean (4000S))
Alternative brush heads available
Brush head stand for 2 heads included
Overall inferior package to the older SmartSeries 4000
Need to switch the brush on to change cleaning modes
No way to easily tell which mode is being used
Built-in quad pacer and 2 minute timer tells you when to change quadrant and finish brushing
16 day battery life, but no percentage indicator for clear feedback of remaining power
Bluetooth connectivity with an app for logging and coaching
Not all will find the app useful
Can support tracking for only 1 user per brush handle
No smartphone stand or travel case included
Water resistant and can be used in the shower
2 year warranty as standard, register online for a free additional year
Money back guarantee option for 180 days

Battery life

The introduction of the Smart 4 brought an upgrade on battery life compared to previous models.

Up until now, Oral-B has been producing brushes that have offered far inferior battery life when compared to the competition.

However, they have managed to remain strong and essentially get away with it, because the price has often been more favourable.

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There is the reality that most of us don’t need over a weeks battery life, but there is something to be said for having the ability to take a brush away on vacation and not having to worry about charging it!

To date, with the exception of the Genius brushes, all others used a battery type known as Nickel Metal Hydride (NiMH).  Although okay, this battery technology has really been superseded by Lithium-Ion (Li-Ion) batteries. These are the types of batteries we find in our smartphones.

As a result of this change, the Smart 4 and other models now have a battery life more fitting of the current climate.

The older SmartSeries 4000 offers 7 days use or 28 minutes of actual usage time.

With the Oral-B Smart 4, this has more than doubled.

In my testing, we were able to get 66 minutes of usage time from the brush, which equates to 16 days use.

The 16 days we measured is based on one user brushing twice a day for 2 minutes.

Various conditions may affect this quoted usage time, but safe to say you are getting at least double the performance, yet despite the battery change the physical size of the brush handle has not altered.

Some Sonicare and Colgate models do actually achieve up to 3 weeks, but Oral-B are now much much closer in their capabilities.

On the brush handle are 2 icons that light up, a battery icon and a charger icon.

When the battery is low, it is the charging icon that will flash red.

Sit the brush on the provided charging stand and the battery icon will flash green.

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Made of plastic, the charging stand has a prong on the top, on which the Smart 4 will sit to be recharged.  This aligns with the recess in the base of the Smart 4 brush handle.

This charger has a power cable that will connect to a power socket found in a bathroom.  The 2 pin connector works on 220-240v.

It usually takes up to 15 hours to recharge the brush fully.  It is a relatively slow charge that is pushed to th

Summary of battery life

Newer Lithium-Ion battery technology used
66 minutes of usage time or 16 days usage based on 2 cleans a day
Can be left on the charger
Takes up to 15 hours to charge fully
A charger is included in the box
The status icon flashes green when charging and red when the battery is low
Works on 220-240 volts
Competition still offer up to 3 weeks usage

Price & where to buy

Most products are given a recommended retail price (RRP) by the manufacturer, the Smart 4 4000 is no exception.

The RRP here is $199.

This is not the most ludicrous given some of the RRP’s for other brushes, but it is still more than you should pay.

To put it into perspective, you can quite often purchase Oral-B brushes for up to 50% off.

This appears to be no different with the Smart 4 4000 and you should therefore expect to pay around $100.

Prices will vary from store to store.  Quite often online retailers will have the best price, but promotions run by high street stores at certain times of the year will see them come inline or cheaper than other retailers.

Ultimately, pay a price you deem fair and are happy to pay, but spending over $120 and you should question the value, given the other brushes available for the price.

This brush like every other requires replacement brush heads for each user every 3 months.  Replacement heads can be purchased in various pack sizes, but each head typically works out at around $7.

Here at Electric Teeth, we like to calculate the approximate cost of ownership over a 3 year period to try and give you a guide to what it would cost, as well as a benchmark for other brushes.

Using the average cost of $100 for the brush, plus the cost of a further 9 brush heads over 3 years, the total ownership cost comes in at $163 or $0.15 per day.

At full price this would cost $262 or $0.24 per day.

This price does exclude the cost of water, toothpaste and electric to charge it. This also assumes one user as well as some other assumptions, but you get a rough idea.

You can bring the cost down further if you were to share it with other members of your household.  All you need do is invest in extra brush heads.

Please note that all prices quoted are approximates and should be used only as a guide during your decision process.

Summary of price & where to buy

Recommended retail price of $199
Generally available with 50% or more off RRP; circa $100
Works out at around $0.15 per day over 3 years
Share brush handle with another user to extend the value

My thoughts on reliability and repairability

We would all love the products we buy to last forever.

Sadly, this is not the case, but many products do last for a reasonable amount of time and we have read many stories of users enjoying 5+ years from their Oral-B electric toothbrush.

Every brush that we test, we check over for obvious signs of weakness or defects.

Oral-B Smart 4 4000 review 32

The very nature of being an electronic item with moving parts does indeed make the brush susceptible to failure.  However, the reliability of Oral-B products tend to be very good.

With the Smart 4 4000, a 2 year/24 month warranty is included as standard from the time you buy the brush.

Therefore should the brush fail within the first 2 years of ownership you are covered.

You do too have the 180 money back guarantee, which allows you to return it, even if its not faulty!

For 99.9% of users there will be years of hassle free brushing, but should you be one of the 0.01% where inevitably something does go wrong, Oral-B do not leave you high and dry.

You can get full details of the warranty and the associated process here.

The Smart 4 uses a handle design that has been tried, tested and perfected over many years and I really can’t find any obvious faults with it.  It is well built and solid in hand.

I know from past experience that most Oral-B models will survive a few falls to the bathroom floor, in most instances.

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Dr. Gemma Wheeler has looked in detail at the environmental impact of electric toothbrushes. Our guide to eco-friendly dental health offers advice on steps you can take to reduce your own impact.

With regards to the Smart 4000 specifically; it has a few more extras in the box, which some might not use and find unnecessary. The brush head holder is only any use if you use multiple heads or share the handle with others. The different head styles might too be surplus to requirement, if you have a preferred style.

As a smart toothbrush it increases the component usage.

It has not been designed to be easily repaired by yourself. Trying to replace parts like the battery will likely break the brush. This makes it more likely to be discarded rather than repaired if broken.

While Oral-B has partnered with schemes such as TerraCycle in some countries, it does not yet have its own recycling scheme for used brush heads or faulty products.

Its brush heads are made from petroleum-based plastic, which uses up the planet’s finite resources compared to using plant-based plastics.

Summary of reliability, long term use & sustainability

Oral-B has extensive expereince in the dental care market
Established warranty & support networks
Comes with a 2 year warranty
Toothbrush feels well built
A few extras in the box which might be surplus to requirement
Smart features require additional components
Not designed to be easily repaired
No own schemes to recycle brush heads or faulty products
Plastics of the handle & head made from petroleum-based plastic


I give the Smart 4 4000 a rating of 4 out of 5.

It is a solid electric toothbrush that will serve you well.

There is no denying that this brush cleans the teeth and mouth well.  

It offers a pretty decent battery life, whilst also looking fairly good and feeling slim in hand.

2 versions, one with and one without a travel case is less than ideal. Go for the travel case included option if you can.

The problem if you can call it that, is it potentially feels a bit lost in the Oral-B range.

Yes, it is the cheapest smart toothbrush. However, you don't need this, so the likes of the Pro 2 2000 become more appealing.

Should you really then want a smart brush, models like the Genius range do offer just that bit more, which might be worth the extra spend.

Size guide

  • Toothbrush height with head - 23.5cm / 9.3 inches
  • Toothbrush height without head - 19.5cm / 7.7 inches
  • Width - 2.3cm / 0.9 inches
  • Depth/thickness - 2.9cm / 1.1 inches
  • Weight with head - 129g / 4.6oz
  • Weight without head - 123g / 4.3oz
  • Package weight - 500g / 17.6oz


  • 75dB

Country of manufacture

  • Germany
Author: Jon Love
Medical reviewer: Dr Gemma Wheeler, BDS

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