Different ball bearings are used in a variety of dental instruments, such as turbines, contra-angles, motors and more. They are the key element that determines how smoothly the instrument runs, how long it lasts, and how quietly it operates.
In general, ball bearings are divided into two groups, depending on their speed of rotation. The speed is measured with RPM (revolutions per minute) – a measure which describes how many turns are completed in one minute around a fixed axis:
- Bearings with RMP from 100,000 to 500,000 are called HighSpeed bearings
- Bearings with RPM from 25,000 to 100,000 are called LowSpeed bearings.
The operation of a dental turbine is highly dependent on the choice of high-speed ball bearings. When selecting bearings, one must pay close attention to:
(1) the configuration of bearings,
(2) type of balls and cages,
(3) the manufacturer,
as these factors directly affect the turbine’s performance, durability, and noise level.
(1) Configuration
Ball bearings are available in Radial contact configuration (Deep Groove Ball Bearings or DGBB) or Angular contact configuration (Angular Contact Ball Bearings or ACBB).
The main difference between the angular and radial bearings is in the raceway geometry type and the way the balls make contact in those raceways which defines the support of load from axial and radial direction.
Radial contact ball bearings (deep groove) are suitable for both low speed and high speeds applications and are primarily built to carry radial loads at high speed. They can also withstand axial forces in both directions to some extent witch makes them versatile and convenient to use. Any significant axial load will force the balls against the groove edges, causing high stress, slippage and rapid wear as radial contact ball bearings have a relatively small contact angle (≈0–8°) compared to angular contact ball bearings.
Angular contact ball bearings are designed to handle combined loads, both radial and axial. Thanks to their raceway geometry, they have a higher contact angle (15° to 40°). That allows them to carry these loads more efficiently and with less stress on the balls and races. However, due to the special shape of the raceway, they can carry axial forces in only one direction. To handle axial loads in the opposite direction, a second bearing must be in pair. This design provides smoother operation, greater stability, and longer service life in high-speed applications where axial forces are also present.
(2) Ceramic or Steel Balls
High speed ball-bearings are available with Hybrid Ceramic balls, which include hardened steel rings and silicon nitride (ceramic) balls, and with Steel balls, which have steel rings and steel balls.
The advantage of using a hybrid ceramic ball bearing is that it runs cooler and extends bearing life. Ceramic balls are harder, smoother, lighter, and more wear resistant than stainless steel. They generate less bearing wear and lubricant degradation, produce lower internal bearing temperatures, and increase the bearing’s speed capabilities. Also, the ceramic bearing operates better than an all-steel ball bearing in low-lubrication conditions.
The benefits of Ceramic Angular contact bearings are:
- Longer lubricant service life
- Lower operating temperatures
- Increased speed rating
- Reduced weight
- No impact on assembly processes
- High stiffness
- Longer life
- Lower noise level (up to 25%)
Torlon or Phenolic
In high-speed dental turbines, the ball retainer (cage) is equally critical. It keeps the balls evenly spaced and minimizes friction and heat. Advanced cage materials such as Torlon® and Phenolic are traditionally favored. Today Torlon is used more often because it combines exceptional strength, high temperature resistance and dimensional stability. Phenolic remains valued for its light weight and natural lubricating properties, yet Torlon’s superior toughness, chemical resistance and consistent manufacturing quality make it the more durable and reliable choice for modern high-speed bearings.
(3) Manufacturer
When buying aftermarket dental turbines or dental bearings you have to pay attention on the bearing’s origin. There are many providers of dental bearings offering bearings of unknown origin. Those bearings mostly come from questionable productions or are produced for low standard markets. We strongly recommend you to ask providers of dental turbines which ball bearings do they assemble on turbines or sell.
We offer rotors assembled with top quality ball bearings, which are produced by Myonic, the producer of bearings for Original Equipment Manufacturers, like Kavo and W&H. Bearings can also be purchased as a stand-alone product.
Summary
For high-speed dental turbines the top choice bearing would be hybrid ceramic angular contact bearing with a Torlon cage from a trusted Manufacturer.
This setup runs cooler and quieter, tolerates both radial and axial loads, survives repeated autoclave cycles, and delivers the longest service life.
If budget is a key consideration, high-quality deep-groove radial bearings can still offer solid performance and represent a good price to performance compromise.
