Dental drill

An elbow (English: contra -angle hand piece ), simplistically called by the layman drills, is an angled preparation instrument, with the works of the dentist in the patient's mouth. The angle between the base and head ( see illustrations) is normally 30 °. In the head, depending on the operation of different rotary instruments can be clamped. The stem of these instruments has a diameter of either 2.35 mm ( RA shaft ( right -angle with manual lock ) ) or 1.6 mm ( FG shank ( friction grip = static friction ) ).

Models

Except elbow heads which accommodate rotating instruments are available for special operations ( preparation of root canals ) also elbows or elbow heads with other movements available: stroke, reciprocal ( alternating, changing) rotation with different rotation angles ( Giromatic ® contra-angle handpieces ) and combinations of stroke - reciprocal and rotational movements. Also available also elbows with a torque limiting available or those that generate vibrations.

All of the modern dental equipment elbows are placed directly on the electrically driven maintenance-free micro-motor. These couplings are standardized, so it can be combined with models of different manufacturers. The connection to the treatment unit, controlled by the motor and the angle pieces with compressed air and cooling water to be supplied, is provided by a hose. This is either controlled by a foot switch or by default.

Most corner pieces are provided with optical fibers, whose cold light source is integrated into the micro-motor.

Usually special angles can be used with a very low speed and high torque for the processing of bone pain associated with implants. These infusion bottle can be connected with a physiological saline solution for cooling.

Speeds

A micromotor normally provides up to 40,000 min -1 ( rev / minute). Different translations on the elbow and the head of a speed range is covered up to a total of 200,000 min -1.

The different translations are marked by colored markings on the elbows:

Application

According to operation can drill ( eg: round drill, fissure ), diamonds (actually tipped with diamond granules of different size and shape steel shafts ), abrasives (corundum ) or rubber polishers are clamped into the elbow. For surgical measures milling can be used ( according to Lindemann ) and internally cooled implant drills. Also parapulpal pins are screwed by machine.

For excavating ( removal of carious dentin) a speed between 1000 and 1500 min-1 min-1 is recommended for preparing ( grinding ) of enamel and dentin to receive a crown was given if selected the maximum speed. It should be noted that the pulling power of the combination of micro-motor / angle is substantially greater than that of a dental turbine.

For dental work (corrections ) to dental prostheses a non-angled handpiece is to be preferred, because they are more robust and the clamped instruments have a longer shaft HP ( handpiece ).

Care

After each use, the angle must be sterilized. For this, the instrument is removed and the elbow is washed with water, oiled and then sterilized in a special pouch in the autoclave. The instruments must be kept sterile until the next use. Alcohol should not be used as a penetration decomposed necessary for the mechanics lubricants and can lead to defects.

Hygiene regulations in Germany

The Robert Koch Institute is responsible for the hygienic guidelines for physicians on the basis of legal requirements. It stipulates clearly that all instruments ( handpieces, turbines ) must be sterilized after each patient contact. The data used in the sterilization autoclave must meet EU standards EN 13060-1 and 13060-2, Class B in this case.