An electric toothbrush

The first Broxodent brand electric brush was invented in Switzerland in 1954 by Dr. Philippe-Guy Vaugh. They began to be produced in Switzerland, and then in France for the company Broxo SA. The device was powered by a home AC network. Initially, electric toothbrushes were created for people with limited motor skills, as well as for patients with orthodontic bracket systems.

The Broxo electric brush was introduced in the USA in 1959 by ER Squibb and Sons Pharmaceuticals and sold under the brand name Broxo-Dent or Broxodent. In the 1980s, Squibb transferred the Broxodent line of distribution rights to Somerset Labs to Bristol Myers / Squibb.

The first cordless Automatic Toothbrush was introduced by General Electric in the 1960s. She did not have a cord and she had a nickel-cadmium battery . Despite portability, the brush was quite voluminous, about the size of about two type D batteries for flashlights. Nickel-cadmium batteries of the time suffered from a “ memory effect ." The General Electric brush was sold with a charging stand, in which it had to be upright and constantly charged, which negatively affected this type of nickel-cadmium battery. Batteries had a short lifespan and were not replaceable.

The use of alternating current in a device in a humid bathroom environment was problematic. In the early 1990s, the American private UL testing lab and the Canadian CSA Standards ceased to certify appliances with a wire for use in the bathroom. In new devices, manufacturers had to use transformers to make the brush work at a low voltage (usually −12, 16 or 24 volts). The requirements of the standards of many countries provide for the mandatory presence of an RCD in the bathroom (for example, from the 1980s in the USA in the outlets of new buildings).

In the 1990s, there were problems with certification of the original Broxodent design. In addition, battery brushes began to seriously compete with this design. Broxo SA is still producing its low-voltage model, but in limited quantities due to the emergence of major competitors Philips Sonicare and Braun .

The first ultrasonic toothbrush was patented in 1992 under the Ultima brand, later Ultrasonex, and in the same year received US FDA approval for daily home use. Initially, Ultima had only ultrasonic action, but after a couple of years a motor was added to the Ultrasonex design for additional mechanical sound vibration. Currently, there are several brands of ultrasonic brushes combining ultrasonic and mechanical action.

Electric brushes can be divided into 2 categories, depending on the movement of the bristles: up-down vibration (for example, Sonicare) or back and forth movements (for example, Oral B).

The brushing technique with vibrating toothbrushes is similar to the manual brushing technique, and brushing with the back and forth bristles of the bristles involves a slow movement from tooth to tooth. ^[one]

Electric toothbrushes can also be classified according to the speed of the bristles: standard, sonic and ultrasonic . If the movements of the bristles (and not the motor) are audible to the human ear (20Hz - 20,000Hz) - this brush is considered sonic. Movement beyond the ears of the human ear is an ultrasonic brush. Some ultrasonic brushes (e.g. Megasonex and Ultreo) have both sonic and ultrasonic effects.

The development of sound technology was the next step towards improving the cleaning properties and reducing the abrasive effect on hard tooth tissues. Its main difference is the creation of a dynamic fluid flow (a mixture of water, saliva and toothpaste) due to the oscillatory movements of the bristles with a certain frequency and amplitude. According to research results, a sonic toothbrush is able to remove more than 70% of plaque when the ends of the bristles are located at a distance of 2-3 mm from the surface being cleaned [1]. Thus, this technology ensures the effective removal of plaque in the interdental spaces and under the gum, minimizing the likelihood of injury to hard tissues of teeth and periodontal tissues. In clinical studies, a more pronounced cleansing effect of sonic toothbrushes was established compared to manual ones [2].

High sound speed ensures the formation of a uniform foam from paste, saliva and oxygen, this mixture allows you to effectively and carefully clean your teeth from all sides, including hard to reach places. Due to the creation of an irrigation effect, plaque cleansing occurs gently, without effort, without injuring tooth enamel.

The villi, performing micromotion with sound frequency, carefully massage the gums, thereby enhancing the microcirculation of the blood and preventing gum disease.

According to the results of clinical studies, when using CS Medica sound brushes, the cleaning efficiency of smooth and proximal tooth surfaces increases, contamination by pathogenic microorganisms decreases (without affecting the stability of the microbiocenosis of the gingival sulcus), hygiene indices improve, gum inflammation decreases (according to the GI index) ^[2] .

The bristles of most brushes are made of modern high-quality hypoallergenic synthetic material nylon (dupont). The excellent shape of the nozzles allows you to choose the right one for differentiated care: daily cleansing, cleansing of inaccessible places, with a whitening and firming effect. For example: the whitening bristles of the nozzle are impregnated with polishing particles of calcium carbonate to effectively remove surface staining, as well as sodium fluoride compound to strengthen tooth enamel.

Children's electric sonic toothbrushes are designed specifically for children, work at a lower frequency of vibrational movements (16,000 - 18,000), and their soft bristles do not injure the enamel of children's teeth. Children's brushes have a bright attractive design and additional functions that not only increase motivation for cleaning, but also contribute to the formation of a child’s good habit of maintaining oral hygiene.

Most modern electric brushes have a battery.

The latest developments in the field of oral hygiene are ultrasonic brushes based on the action of an ultrasonic wave. A brush is considered ultrasonic if it generates a sound wave of frequency from 20,000 Hz, which equals 2,400,000 movements per minute. The US FDA has approved an ultrasonic frequency of 1.6 MHz (192,000,000 revolutions per minute) for use in electric brushes.

Ultrasonic brushes vibrate at a very high frequency , but with a small amplitude of motion. These sound waves break the chains of bacteria that make up plaque and damage their method of attachment to the surface of the teeth even at a distance of 5 mm. ^[3]

Some toothbrushes, such as Emmi-Dent, only generate ultrasound. Other ultrasonic brushes, such as Ultreo and Megasonex, additionally generate mechanical vibrations from 9,000 to 40,000 movements per minute, typical of sonic brushes. The sweeping movements of the bristles help remove food particles and the remains of bacterial chains. The mechanical vibration of the bristles in these brushes has a much lower amplitude of motion than in sound brushes, since their effectiveness is based more on ultrasound rather than on mechanical action.

Due to the similarity of the names “sound” and “ultrasound”, people often confuse sonic brushes with ultrasonic ones. If the brush operates at a frequency of less than 20,000 Hz (2,400,000 movements per minute) - this is a sound one. The name is due to the fact that the frequency of movement of the bristles (for example, 31,000 movements per minute equal to 258 Hz) falls into the range of human hearing. Toothbrushes operating at a frequency beyond the human hearing range of more than 20,000 Hz (2,400,000 movements per minute) are considered ultrasonic. Today, most ultrasonic brushes operate at a frequency of 1.6 MHz, since this frequency was approved by the US FDA more than 20 years ago and its effectiveness and safety has been confirmed by numerous scientific studies around the world.

There is an opinion that electric brushes are more effective than manual brushes, since they are less dependent on the user's cleaning technique. Some dentists believe that they help children overcome the fear of visiting a dentist. Independent studies have shown that most electric brushes are not more efficient than manual brushes, if used properly. ^{[4] [5]} Some studies have shown that brushes with reciprocating movements of the bristles can be more effective than manual ones. ^{[4] [6] [7]} Studies have shown that the brushing technique, as well as the time spent, is much more important than choosing the brush itself. Users with disabilities have difficulty cleaning their back teeth, so dentists find electric brushes more convenient and effective for this category of users. ^[8] A recent Cochrane review provided new evidence on the benefits of electric brushes over manual brushes. Plaque decreased by 11% and inflammation with gingivitis decreased by 6% after one to three months of use, and after more than three months of use, by 21% and 11%, respectively. ^{[9] The} ultrasound generated by ultrasonic brushes is able to break the plaque-forming chains of bacteria ( Streptococcus mutans ), damage their shell and destroy their method of attachment to the enamel surface at a distance of 5 mm from plaque. ^[3]

The effectiveness of the electric brush depends not only on its action and proper use, but also on the condition of the bristles. ^[10] Most manufacturers recommend changing nozzles every 3-6 months or as the bristles wear.

Modern electric brushes operate at low voltage - no more than 12 volts. Some have transformers , but most have a built-in rechargeable battery or batteries located in the brush housing and protected against moisture to prevent damage to the electronics. Early models with nickel-cadmium batteries had metal contacts on the chargers. In modern brushes, the battery is charged by induction.

Timer

Many modern electric brushes have a timer that gives a sound signal or interrupts the action, usually after 2-3 minutes of operation and every 30 seconds. This is due to the order and time of brushing your teeth - with 2 minutes, give 30 seconds for every quarter of the tooth area.

Display

Some electric brushes have a liquid crystal display for counting time and emoticons to encourage optimal cleaning. ^{[11] [8]}

Push Sensor

Excessive pressure when brushing your teeth can damage the enamel and gums. Some toothbrushes have a sensor that protects the user from excessive pressure. There are two types of pressure sensor: one makes a sound and the other stops the brush.

Ultrasound Indicator

Since ultrasound exists beyond the limits of human hearing and the amplitude of movement is not noticeable, the user cannot determine its presence. Therefore, for clarity, ultrasonic brushes are equipped with a built-in ultrasound indicator.

Cleaning Modes

Most sound brushes have different operating modes and brushing intensities: a mode for sensitive teeth, for teeth whitening, and in some for tongue cleaning.

Some electric brushes combine ultrasonic and mechanical sound action, which reduces or completely eliminates vibration. Since the amplitude of the ultrasonic movement is imperceptible, a vibration-free mode is recommended for patients who have undergone oral surgery, or who poorly tolerate mechanical vibration, but who want to have a high level of cleaning quality.

[1] .Stanford CM, Srikantha R., Wu CD Efficacy of the Sonicare toothbrush fluid dynamic action on removal of human supragingival plaque. // J. Clin. Dent. - 1997. - V. 8 (1). - P. 10-14.

[2]. Abdusalamova B.F. Clinical and laboratory assessment of the effectiveness of various toothbrushes: Abstract. diss ... candidate of medical sciences / M., 2010 .-- 24 p.

[3]. Kuzmina I. N., Lapatina A. V., Pazdnikova N. K., Abdusalamova B. F. Clinical and laboratory rationale for the use of sound technology in hygienic oral care. // Dental Forum.- 2015.- No. 2.- S.12-19.