Air vs. electric, through a zirconia crown. Dr. John Flucke demonstrates how torque changes the pressure, rhythm, and feel of cutting through a demanding restorative material.
If you have ever sectioned a zirconia crown, you know the challenge all too well. But if you’re using an air handpiece, it might be even more difficult.
This side-by-side demonstration compares an air-driven handpiece with a Bien-Air electric handpiece during bonded zirconia crown removal. The difference comes into focus once the bur meets resistance.
On the air-driven side, cutting follows a repeated cycle of contact, slowdown, and recovery. On the electric side, the cut is more continuous, with less need to lean into the bur. The difference comes down to available torque.
About this demonstration. This demonstration was originally designed to showcase the effectiveness of electric compared with air-driven handpieces when cutting through zirconia crowns. Every crown is different, and this was not a scientific study. At the end of the day, the goal is education: helping clinicians understand how air and electric handpieces can differ in their cutting performance.
In this demonstration, the air-driven cut involves more leaning into the bur. The electric handpiece advances through the zirconia with a lighter touch.
The air-driven cutting pattern includes repeated pauses to let the bur regain speed before re-engaging. The electric cutting pattern is a more continuous machining motion through the crown.
The distinction becomes apparent when the bur contacts the material. Greater available torque supports the electric handpiece’s more continuous cutting motion in this demonstration.
Speed tells you how quickly the bur rotates. Torque is the turning force available to overcome resistance. A high rotational speed before contact does not, by itself, tell you how a handpiece will behave during a cut.
The air-driven handpiece in the demonstration spins up to approximately 400,000 RPM before contact. As it engages the zirconia, it slows. Cutting then becomes a repeated sequence: release pressure, let the bur regain speed, and engage again.
The Bien-Air electric handpiece works through the zirconia without the same repeated recovery pattern in this demonstration. Its available torque supports a different cutting rhythm: fewer interruptions and a lighter touch.
The question is how the bur performs when it meets resistance.
Leaning harder on the bur changes more than the feel of the cut. In the air-driven portion of this demonstration, heavy pressure is accompanied by slight movement of the bur. The explanation in the video connects that extra force to stress on the turbine’s tightly fitted internal components—adding wear and potentially contributing to turbine damage that requires servicing.
That is another reason the lighter touch matters. In this comparison, the electric handpiece’s available torque supports progress through the zirconia with less need to lean into the bur. The practical takeaway is to let the cutting performance do the work, rather than compensate for a slowing bur by pushing harder.
The side-by-side view makes the difference easier to recognize. Here are the cutting patterns to watch for:
The handpiece is one part of the setup. This demonstration uses SS White burs designed for zirconia removal. Pairing the handpiece with a bur made for the material being cut is an essential part of the comparison.
The samples are two extracted teeth mounted in stone blocks, prepared for crowns, and fitted with zirconia crowns bonded using Shofu’s BeautyCem SA. Even after sections are removed, portions of the crowns remain bonded.
That distinction matters when watching the procedure. Sectioning the zirconia and releasing the bonded fragments are separate parts of crown removal; cutting through a crown does not necessarily make every piece come away immediately.
For dentists accustomed to releasing and re-engaging an air-driven handpiece, the electric cutting motion may feel different. This comparison shows what that change can look like: progress through zirconia with less pressure and fewer interruptions.
The demonstration offers a useful way to think about handpiece performance: pay attention to the behavior of the bur during contact, the effort needed to advance the cut, and the rhythm of the work.
In this zirconia demonstration, Bien-Air electric supports a more continuous cut with less need to lean into the bur.
Explore Bien-Air electric systems and high-speed attachments for your restorative workflow.
