Practice Tips #70: Get Your (Handpiece) Bearings

The turbine is the heart of the high-speed handpiece and bearings are the heart of the turbine. Bearings are the most common failure point of a turbine and are often the primary differentiator between one turbine and another.

Way back in Practice Tip #22, “High-speed Handpiece Design,” we covered all of the components that make up a complete bearing assembly. For ease of reference, we’ve included the diagram of a bearing assembly below.

Handpiece Bearing Design

Bearing Materials

Today, we’re going to look at some of the different bearing materials and designs on the market. Many turbines use stainless steel bearings that require lubrication. The balls, inner ring, outer ring, and shield are all made of stainless steel. The ball cage consists of a polymer. There are a few more variations within this broad category and different types of polymers for the cage, but all these permutations require lubrication.

Stainless steel bearings have been in use for decades and are a proven design with good performance and reliability. Because they manufacture in large quantities for dental turbines and many other industries, this keeps costs comparatively low.

Lubricated vs. Lube Free

As these turbines incorporate metal bearings in metal housings, they require lubrication. Most handpiece lubricants on the market withstand the rigors of sterilization, but these turbines need lubrication after every use. See our handpiece maintenance products here. Lubricate after using and before sterilization is generally adequate, but consult the manufacturer of your turbine and lubricant to determine if post sterilization lubrication is required as well.

Many turbines currently on the market are advertised as “lube free.” There are 2 primary methods of manufacturing lube free bearings:

  1. Using a lube free material (i.e. ceramic)
  2. Pre-greasing the bearings and sealing them to “lock” the grease in (sometimes referred to as Life Time Lube or LTL)

LTL bearings are still the same basic stainless steel design, so they share many of the features of standard stainless bearings. The greasing and sealing process adds to the cost (and not manufactured in quantities like the standard bearings), so they add to the cost of the turbine or handpiece that uses them. The sealing process, also, prevents debris from getting into the center of the bearing assembly and on the actual steel balls, so maintenance is a little easier. Nonetheless, these bearings (or, more accurately, turbines that incorporate these bearings) still need cleaning after every use and before sterilization.

Ceramic Handpiece Bearings

Last of all, there are ceramic bearings. Ceramic bearings are actually made of a ceramic silicon nitride, so they have a very smooth low-friction surface. The low-friction surface removes the need for lubrication and also minimized heat build-up during use. They, also, withstand high temperatures very well, so they withstand repeated sterilization better than stainless steel bearings.

Both LTL and ceramic bearings run at higher rpm than stainless bearings and handle higher air pressure. They typically require in excess of 40 psi drive air pressure. The higher rpm helps these turbines cut faster, so some practitioners feel they perform better.

In summary, the materials and techniques used to manufacture lube free bearings are more costly than standard stainless bearings. Lube free bearings (or the turbines that incorporate them) often cost twice as much as turbines that need lubrication. It’s up to the practitioner if the advantages are worth the expense.

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