Advantages and Disadvantages of Electric Micromotor Dental Units

Electric micromotor dental units are available alone, as slow speed handpieces for polishing and drilling, or combined with an ultrasonic scaler.

How It Works
The electric micromotor dental unit can polish or cut. The handpiece is driven by an electric motor in the handle. The polishing cup, or bur, can variably rotate from 0 to 30,000 rpm and go forward or reverse. It provides a very high torque. The handpiece can take a prophy angle, with polishing cups, or a contra-angle, with various attachments, including RA burs and polishing cups. Only a few units have a water-cooling facility.

Long HP burs can also be used in the nose cone (when the prophy angle is removed). They are used principally for trimming small herbivore cheek teeth.

Advantages
Relatively inexpensive, compared with an air driven unit.
Generally small, compact and mobile.

Disadvantages
Very slow in dental terms therefore extremely limited efficiency.
Burs 'walk off' teeth during cutting, due to slow speed.
Handpieces vibrate and heat up after a few minutes.
The torque is high. This is an advantage when polishing but a severe disadvantage for drilling tissues which will not be removed (e.g. bones).