Reports & Studies

LEDs in dentistry - the possibilities of a new technology

Dr. Peter Tschoppe and Prof. Dr. Andrej M. Kielbassa on LEDs in general and on Alegra in particular. Department for Restorative Dentistry and Periodontology, Charité Center 3 for Dental, Oral and Maxillary Medicine, Charité - Universitätsmedizin Berlin, Germany (Charité University Hospital)

These days innovative instruments are available to the dentist which help to ensure effective treatments that are also gentle on the tooth enamel.

The quality of dental treatment depends largely on how well the structures to be treated can be recognised. Treatment in the posterior jaw region in particular requires a good overview of the working area. A restricted view and inadequate lighting rank among the most challenging problem areas here. Targeted preparation that is gentle on tooth enamel and precise work can be hindered as a result.
Good lighting during treatment means fewer interruptions, as essential visual inspections using external light sources are not required. This allows for treatment that is not only especially gentle but also time-efficient. Effective lighting of the treatment area is therefore a fundamental prerequisite for a high quality and time-efficient treatment.

In light of this, handpieces and contra-angles with light are the most common aids for lighting the working area. In the past, motor-operated fibre optics on handpieces and contra-angles were sometimes available on the market.

At the IDS 2007, W&H showcased itself as the first manufacturer of instruments with LED technology. An innovative generator technology followed shortly afterwards: a generator was integrated into the instrument in order to produce energy for the LED.

Alegra contra-angle handpieces with LED+ and generator
Alegra contra-angle handpieces with LED+ and generator

Alegra contra-angle handpiece

The Alegra contra-angle handpiece that we tested produced daylight quality LED light from motor speeds of 9,000 rpm using an integrated generator. This new generator technology independently produces the energy necessary for the LED light source. The higher the speed of the motor, the brighter the light produced.

LED contra-angle handpieces from W&H are compatible with any motor with ISO connection. This means that these instruments are not dependent on the motor used and therefore no further investment is required. Furthermore, LED lights have a lifespan over 10 times longer than that of halogen bulbs. The LED contra-angle handpieces are sterilizable and thermo washer disinfectable. They therefore meet the RKI (Robert Koch Institute) guidelines for applications which require sterilization. Instrument preparation is simple, which ensures the safety of both dentist and patient.


The instruments produce daylight quality LED light with a colour temperature of 5,500 kelvin. The human eye is accustomed to daylight and can best perceive contrasts at this colour temperature (Fig. 1). Thus this colour temperature supports stress-free work. In addition to the light quality, the brightness and size of the illumination area also allow for comfortable work (Fig. 1). The light intensity increases with the speed of the motor; even at a low speed a good light intensity is achieved and detailed illumination is ensured. This precise illumination ensures that even at a low motor speed treatments can be carried out without complications. The only disadvantage of light production that is dependent on a generator is that light cannot be produced when the motor is not running. As a result, checking the prepared area is only possible using an external light source.

The contra-angle handpiece fits well in the hand thanks to its ergonomic design (Fig. 1), which also ensures comfortable, quiet operation and delicate preparation, even at higher motor speeds and even if there is a large amount of resistance. Despite the integrated generator, the noise level is as low as with other modern contra-angle handpieces. The integrated LED with its own generator in the instrument is an advantage, as it can be used with normal, conventional sterilizable micro motors. The integrated generator means that the Alegra contra-angle handpiece can produce LED light independently from the motor used. This makes it possible for the contra-angle handpiece to be used in various areas of treatment. Thanks to the large range of contra-angle handpieces available with different transmission ratios (4:1 to 1:4.5), the right contra-angle handpiece exists for every application in the field of restorative dentistry and prosthetics.

Closing remarks

The new LED generator technology allows for an independent, detailed illumination of the treatment area with fantastic light quality. This enables the dentist to see structures even in posterior jaw regions which are difficult to access and can help the dentist work precisely.

Contact information:

OA Dr. Peter Tschoppe
Department for Restorative Dentistry and Periodontology
CharitéCentrum 3 für Zahn-, Mund- und Kieferheilkunde
Charité - Universitätsmedizin Berlin
Assmannshauser Str. 4-6
14197 Berlin