Tag Archives: dental turbine

  • Practice Tips #91: Failed Turbines

    A failing handpiece can be due to several factors. After diagnosis, a failed turbine is often the culprit. There are several reasons why a turbine may fail. Below are some of the most common causes:

    1. Incorrect Air Pressure. The air pressure from the junction box into the dental unit needs to be set at 80psi. The drive air pressure from your dental unit going into the handpiece should be set between 35psi and 40psi (37psi is a good pressure setting). If you do not know what your drive air pressure is, you can find out using a handpiece pressure gauge. See more in Practice Tip #23.
      practice-tip-#91_hp-with-gauge
    2. Improper Handling. Dropping your handpiece, especially on a hard surface can cause dents to appear in the head of your handpiece. These dents point inward into the cavity where the turbine is seated. When the turbine spins, the impeller will hit these dents causing damage to the impeller as the dents act like speed bumps and in turn will cause the bearings to go out of alignment. Some dents can be removed using a cavity reamer. See more in Practice Tip #40.
      practice-tip-#91_hp-with-reamer_v2
    3. Poor Handpiece Maintenance. If the handpiece is not flushed clean before sterilization, the debris that has built up in the cavity will harden and can prevent the turbine from spinning properly. You still need to flush and sterilize your handpiece after every use. See more in Practice Tip #45.
      practice-tip-#91_handpiece-lubrication Handpieces are shown connected to a handpiece lubrication system (see #HF-403)
    4. Excessive Side Load. Excessive side load usually happens during crown preparation. When doing a crown prep, make sure you use a fresh bur (diamond burs are normally better suited than carbides). If you use a dull bur while doing a crown prep, the bur will not cut properly and the excessive pressure put on the bur will cause the rear bearing on the turbine to fail. Let the bur do the cutting -- minimal pressure should be applied. If you find that extra pressure is needed to get the bur to cut, you need to change burs, as this is a sign that the bur has become dull. See more in Practice Tip #66.
      practice-tip-#91_bad-bur-vs-good-bur_v2 Notice that the old bur (one on top) looks worn and dull, while the new bur (one on the bottom) looks coarse.

    Your dental handpiece is one of your most utilized instruments in the office and will need some TLC every day. Improper use and poor maintenance can lead to expensive repairs or total handpiece replacements later down the road. Hopefully, these tips will assist you in limiting premature turbine failures in the future.

  • Quick Tip Tuesday #40: Handpieces

    Handpiece choices will vary dentist to dentist, but luckily there are a lot to choose from. Narrowing down handpieces will depend on what you are using them for and personal preference. This dentist had an issues with turbines. There could be multiple reasons for this.

    Quick-Tip-Tuesday_#40_Q&A

    We can't stress this enough. Dental handpiece maintenance is crucial. You don't want to replace expensive turbines or other handpiece parts all of the time from simply not cleaning your handpiece. See more helpful customer questions. Also, check out our practice tips for even more free dental technical support.

  • Practice Tips #70: Get Your 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 Tips #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. For further explanation of the components, check out Practice Tips #22.

    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 will be made 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 good reliability. They are manufactured in large quantities for dental turbines and many other industries so cost is comparatively low. As these turbines incorporate metal bearings in metal housings, they require lubrication. Most handpiece lubricants on the market are designed to withstand the rigors of sterilization, but these turbines should still be lubricated every time they are used (see our handpiece maintenance products here). Lubrication 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:

    • Using a lube free material (i.e. ceramic)
    • 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 they aren’t manufactured in quantities like the standard bearings), so they will 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 to be cleaned after every use and before sterilization.

    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 will run at higher rpm than stainless bearings and are better able to handle higher air pressure (they typically require in excess of 40 psi drive air pressure). The higher rpm can help these turbines cut faster so some practitioners feel they perform better (naturally, this is subjective).

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