What’s the difference between a sonic and ultrasonic electric toothbrush?
Most of the brushes we review here at Electric Teeth are sonic, such as those from Oral-B and Philips. However, there is another type of brush to consider: the ultrasonic brush.
These are rarer to come across, but they do exist.
In this post, we’ll be taking a look at the key differences between the two types of brush, and there’s an infographic further down showing the two side by side.
Sonic Electric Toothbrush
To be classified as a sonic toothbrush, the motion or vibration from the brush has to be quick enough to produce a ‘humming’ sound that is within the audible range of the human ear (20 Hz to 20,000 Hz). Sonic brushes typically offer 12,000-24,000 oscillations or 24,000-48,000 movements per minute.
Sonic brushes rely on a sweeping motion alone to clean the teeth, the movement that they provide is often high in amplitude which means they offer larger sweeping brush stroke motions.
It is the bristles on the brush head that move at this speed to essentially brush away food particles and bacteria that sit on the teeth and gum line.
Sonic toothbrushes should not be confused with ultrasonic toothbrushes which operate at a much higher frequency and use ultrasound rather than the motion of the brush head to remove debris and bacteria.
Examples of a sonic brush include Oral-B’s range of electric brushes as well as Philips Sonicare range. You can see some of our reviews here.
Ultrasonic Electric Toothbrush
Ultrasonic toothbrushes, unlike sonic ones, do not rely on a physical motion to clean the teeth.
An ultrasonic toothbrush is one that uses a very high frequency of vibration referred to as ultrasound to remove plaque and bacteria from the teeth.
To be classified as such, the brush has to emit a wave of at least 20,000Hz or 2,400,000 movements per minute, considerably more than the very popular sonic technology.
Within the USA, the Food and Drug Association (FDA) actually specifies a minimum of 1.6MHz or 192,000,000 movements per minute.
The high frequency waves, but low in amplitude means the bacterial chains found in the mouth that make up plaque are broken up by the vibrations and can work as far as 5mm below the gumline. Essentially speaking the brush can clean the teeth simply by resting the brush on it.
An ultrasonic brush compared to the more commonly seen and used sonic brushes does not need a physical motion to clean the teeth surfaces and gumline.
However many ultrasonic brushes do also provide additional sonic vibration ranging from 9,000 to 40,000 movements per minute, in order to provide additional sweeping motion which removes food particles and bacterial chain remnants.
An example of an ultrasonic brush is the Megasonex (pictured above).
This video from YouTube gives a good explanation of what an ultrasonic toothbrush is and how it works:
A brief buying guide: who makes the best ultrasonic toothbrush?
Whilst ultrasonic toothbrushes have been shown on a limited scale to be effective (1 & 2) the reality is that few such toothbrushes are made and are available to buy today.
The market is dominated by sonic toothbrushes, notably those from the largest household brands.
There are several toothbrushes that suggest they are ultrasonic, using such words in the product title and description, but in fact they are just standard sonic toothbrushes, operating at up to 48,000 movements per minute rather than using ultrasound to achieve the cleaning.
It is my understanding that at the time of writing, the brands who do make true ultrasonic brushes are Megasonex, Smilex, and Emmi-Dent, so you’ll be best off choosing between these.
At the time of writing we couldn’t find any of these brushes available with US retailers, but we did see both Emmi-Dent on eBay and Megasonex on eBay, so at the moment in time it looks like this is your best bet if you want an ultrasonic toothbrush.
If you’re not specifically looking for ultrasonic, but rather a ‘standard’ electric toothbrush, check out our post that looks at the best sonic toothbrushes.
Best Ultrasonic toothbrush
Many people ask what is the best ultrasonic toothbrush?
I have not had hands-on with any ultrasonic brushes to date. Yet, despite this, for me, there isn’t a ‘best’ brush.
This is because your options are extremely limited and in reality, sonic toothbrushes tend to a more logical purchase.
They are more readily available, generally cheaper and provide noticeable brushing enhancement over a manual brush, therefore making the need or justification for an ultrasonic toothbrush much more difficult.
Comparison Infographic
To help summarise the key differences of sonic vs ultrasonic toothbrushes, we’ve put together the infographic below.
Do you know anything about the Mira Pet toothbrush for dogs? They advertise their product as an ultrasound brush which also includes a vibration setting. I would like to know if it is a true ultrasound toothbrush. Thank you.
Hi Karen.
We have not investigated pet toothbrushes, so I have not come across or used the Mira Pet toothbrush.
A quick look at their website doesn’t reveal much useful information. However, it does say 60 million oscillations per minute which would imply it was actually ultrasonic.
I too want to purchase one but am not finding any in the US
However I am pretty sure that a US type charger will work well maybe
Hi Brandy.
Was there a particular brand or model you were after?
I know emmi-dent are sold on Amazon.com
Thank you sooo much for this information, I was searching just for this for at least 2 years now.
If I would buy one, I’d definitely go for sonic. Ultrasound destroys also beneficial bacteria in mouth, which is bad for health – long term. Also Russian researchers have recently experimented with ultrasound a little bit. Ultrasound actually silence our DNA and we have actually not even a remote idea what would this mean for future generations (especially coz it’s used for watching the vulnerable fetus in womb, not to mention using it every day in our head / mouth).
must use special toothpaste?
No. Normal toothpaste is fine.
Megasonex is available in the UK on Amazon.co.uk
I wonder if there are any studies that determined if there is a higher risk of brain tumors with the ultrasonic machines?
I am not aware of such studies specifically in relation to brain tumors. I believe some studies have looked at the effects of the electromagnetic fields of such devices.
Hello Jon,
thank you for the great overview and toothbrush technology comparison.
Please allow a couple comments.
At least for one Ultrasonic toothbrush Emmi-dent, there is ample evidence of the effectiveness. Several clinical studies conducted in Germany by the University of Witten-Herdecke confirm the effectiveness of Emmi-dent in cleaning away harmful bacterial plaque. Different to other Ultrasonic devices, Emmi-dent’s patented Ultrasound piezo-chip is embedded right behind the bristles, closest to teeth and gums to maximum cleaning effectiveness. Importantly, and not mentioned in the article, are the fundamental technology advantages of Ultrasound vs. ordinary cleaning by brushing:
1) Zero abrasion and most gentle cleaning – because there is not brushing action and ultrasound toothpastes do not contain abrasive particles. Hence, teeth and gums are cleaned most gentle. Abrasion is a serious dental care challenge – often driven by wrong brushing techniques, and leading to receding gums and exposed tooth rootshttps://en.wikipedia.org/wiki/Abrasion_(dental) . Cleaning with Ultrasound eliminates this risk.
2) The 2nd big advantage over bristle cleaning is reach. Ultrasound generates millions of nano-size cleaning bubbles that reach into the tiniest crevices, gum pockets, fissures, behind braces and ultrasound waves are even penetrating the gums. Thereby, Ultrasound kills and cleans away bacteria in areas bristles cannot reach.
Last not least the good news that Emmi-dent is now available in the USA, with USA specification (110 Volt and power plug) – and I know this because I am the new distributor for Emmi-dent products in the US and Canada. 🙂
I hope this clarifies a bit the differences between abrasive mechanical brushing and gentle ultrasound cleaning. If you need any more information, I’d be happy to provide it to you.
BR
Frank Dreier
Please tell me more about the Emmident Ultrasound toothbrush! Thanks!
I am interested in purchasing this emmi dent US toothbrush…pls contact me.