Once upon a time, there was a handpiece company named Midwest, now owned by Dentsply Sirona. As dentists started to appreciate the convenience of auto-chuck mechanisms, Midwest decided to incorporate such a mechanism into their handpieces. Rather than relying on the simple push button that had found favor in the industry, Midwest decided to do something different and patented a lever (Power Lever™). As the user pulled on the end of the lever, the opposite end would push on the actuator to open the chuck of the turbine, so one could remove or insert a bur. As the mechanism was patented, this prevented the after-market from simply copying the design and providing lower cost alternatives.
The core turbine was, however, still easily copied and provided by other sources. As dentists began using these after-market turbines, they started looking to the after-market to replace old worn end caps as well. Since after-market suppliers couldn’t manufacture a Power Lever™ cap (as it was patented), the after-market provided push button caps instead. These worked very well, fit the existing turbines, and addressed complaints of the lever tearing gloves (which some users experienced). Tradition autochuck handpieces could now be used with either a lever end cap or a push button. Either way, the turbine was the same, so replacement was kept simple. One could freely move between after-market brands and the OEM.
As time went on, Midwest realized that some people preferred a push button. Enter the XGT: a new and improved version of Midwest’s Tradition with a thicker, more ergonomic handle. The XGT also featured a push button chucking mechanism. While the XGT had the same size head as the Tradition, it did not use the same turbine. In order to accommodate their push button cap, Midwest altered the turbine slightly, so it had two flanged bearings to properly seat into their end cap. This feature further set the XGT apart from the existing Tradition design.
With the success of the XGT, Midwest was then able to offer the XGT turbine and cap as a retro-fit to their Tradition handpieces, allowing conversion to a push button. Eventually, Midwest started offering the Tradition handpiece brand new with their push button cap and turbine.
Meanwhile, the after-market continued to sell and make the standard “L” type turbine, as well as push button caps to match it. By doing so, this meant that there were now TWO different “push button” turbines and end caps for use with the Midwest Tradition. Currently, both designs still exist and are available. If you need a replacement turbine for a push button Midwest Tradition handpiece, you need to know the origin of your end cap.
NOTE: If the handpiece was originally purchased from Midwest as a push button, it has the original XGT style cap and uses the XGT turbine. If the handpiece was converted to a push button using an after-market cap, it still uses the “L” type turbine.
The distinguishing feature of the two turbines is the rear (“end”) bearing. On the original "L" turbine, it is a smooth bearing. The push button cap used with this will accept the narrow smooth bearing. The newer turbine produced by Midwest and first used on their XGT handpiece has a flanged rear bearing (with a lip). The push button cap for this turbine is made to accommodate this different bearing.