Rotary electric toothbrushes :
Braun Oral B, Rotat-dent, Interplak
Modern conventional electric toothbrushes (the "rotary" brushes).
While sonic toothbrushes do represent a very technologically advanced form of electric toothbrush design, the recent generations of conventional electric toothbrushes, the "rotary" brushes (i.e., Braun Oral B, Interplak, Rotat-dent), have made great advances also.
Braun Oral B is a registered trademark of The Gillette Company. / Interplak is a registered trademark of The Conair Corporation. / Rotat-dent is a registered trademark of Professional Dental Technologies, Inc.
A) Rotary electric toothbrushes.
While encompassing a number of different individual designs, rotary electric toothbrushes are all similar by way of the fact that they each have a set of rotating bristles.
These bristles are either arranged in a circular format that rotates or oscillates, or else the individual tufts of bristles contained in the brush head each possess a spinning motion.
How fast do they spin?
In most cases these brushes generate between 3,000 and 7,500 brush strokes per minute but one manufacturer, Braun Oral B, has added a high frequency pulsating motion to enhance the cleaning action of their brush.
You'll find that rotary brushes comprise a large percentage of all electric toothbrushes sold today, both high-end and low-cost models.
How do they remove plaque?
The plaque-removing capability of rotary electric toothbrushes, similar as with all toothbrushes that came before them, relies on the scrubbing motion of the brush's bristles on a tooth's surface. (There is no disruption of dental plaque beyond where the bristles actually touch as there is with sonic brushes.)
However, different from previous generations of electric toothbrushes these brushes often possess some ability to reach into the interproximal (between the teeth) or subgingival (below the gum line) regions in the mouth to some degree.
Are they effective?
Studies involving rotary electric toothbrushes seem to have documented that these brushes may be superior to manual tooth brushing. (We discuss this topic in much greater detail here.)
These findings can probably be attributed to both the enhanced cleaning action of the bristle movements of these brushes, and the fact that the effective use of these brushes relies little on the dexterity of the individual using it.
B) The oscillating / pulsating rotary electric toothbrushes.
Electric toothbrushes that have both an oscillating and pulsating motion, such as the Braun Oral B "3D" model brushes, could certainly be considered to be examples of the pinnacle of conventional (non-sonic) electric toothbrush design.
These brushes have a round brush head that is capable of oscillating back and forth at a rate of 7,600 brush strokes per minute. In addition to this motion the Braun Oral B model has a pulsating action which creates movements somewhere between 20,000 and 40,000 pulses per minute, depending on the specific brush model.
Pulsating rotary electrics are not sonic toothbrushes.
Even with this intense high rate of movement the Braun Oral B "3D" brushes are not considered to be "sonic" type toothbrushes. We are unaware of any claims by the manufacture of a fluid dynamic clean action such as the one generated by sonic toothbrushes. The conventional mode of cleaning that is produced by these Braun Oral B brushes however (that cleaning produced by the toothbrush's bristles scrubbing a tooth's surface) is exceptional (per our van der Weijden et al reference).
Typically, you'll brush one tooth at a time.
Related to the relatively small brush head size of this design of brush, oscillating/pulsating toothbrushes are generally intended for use using a tooth-by-tooth technique, cleaning each side of one tooth before moving on to the next.
This is somewhat in contrast to sonic toothbrushes whose more conventional style brush head is intended to be manipulated more like a manual toothbrush.
C) Other rotary electric toothbrushes.
Previous decades have produced a variety of other rotary electric toothbrush designs. Some of these are:
a) Rota-dent brand toothbrushes.
The tiny brush heads found on Rota-dent electric toothbrushes possess a single rotating tuft of bristles fashioned in either a pointed or cup-shaped form. The cup-shaped brushes are intended for use on larger tooth surfaces while the pointed brushes have been designed for use between teeth.
b) Interplak brand toothbrushes.
Interplak electric toothbrushes are known as "counterrotational" toothbrushes. The brush head of an Interplak brush looks similar to a standard manual toothbrush but each individual tuft of bristles on the brush head rotates, in opposite direction as its neighbor.
The original generation of electric toothbrushes.
The first electric toothbrushes were primitive mechanized versions of manual toothbrushes. The brush stroke that was created by these brushes was a simple back and forth movement that attempted to simulate the scrubbing motion generated by brushing by hand.
The research studies involving this generation of electric toothbrushes were the ones where researchers found it difficult to show that the use of an electric toothbrush was superior to brushing with a manual one. Interestingly enough, even though this type of brush was first introduced about 60 years ago, this same design can still be found today in some of the inexpensive lower end electric toothbrushes that are sold.
Manual toothbrushes need no introduction. These are simply the hand-held, hand-manipulated toothbrushes we are all familiar with.
When a manufacturer designs a manual toothbrush one of their goals is to create a brush whose bristles have the ability to reach difficult areas, such as those areas in between teeth or on the side of teeth down by the gum line, more effectively than their competitor's brush.
Despite what you see advertised no one company's toothbrush head design has proven to be universally the most effective. Most studies have concluded that there is no significant change in brushing effectiveness when differences in bristle design, texture, or brush shape are evaluated.
However, for any one individual and related to their own specific situation and own individual brushing technique, one toothbrush design might be more effective or easier to use than another.
Brushing by hand takes some skill.
Manual tooth brushing can be very effective but it is extremely dependent on technique. The person brushing must:
- brush in the right directions, ...
- using the right motions, ...
- without too much force, ...
- for an appropriate amount of time (at least two minutes), ...
This is typically why so many people fail at brushing their teeth effectively with a manual toothbrush and therefore may benefit from using an electric.
"Soft" bristles are usually the appropriate choice.
Usually it's best to choose a manual toothbrush whose bristles have been categorized by its manufacturer as "soft." Toothbrushes having harsh bristles could possibly clean away dental plaque more readily than their counter parts designed with softer bristles, but a stiff brush would likely also damage or abrade soft oral tissues.
You just need to remember that dental plaque is soft. It simply requires brushing long enough, in the right areas, using an appropriate technique to dislodge it. Harsh scrubbing is not needed.