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User Report Dr. Grant Dean - Primea Advanced Air
Completing intricate work like crown preps is made simpler and quicker.
Nowadays, the challenges during preparations for prosthetics restauration are diverse. Combining precise top quality preparations and high safety with efficient operations is among the desired goals. Excellent Ergonomics, good light conditions in the oral cavity, as well as simple and intuitive handling are requirements for dental devices and instruments.
The new W&H Primea Advanced Air turbine handpiece can fulfil all these expectations. The high performance turbine, which has been awarded the Austrian National State Prize for innovation, combines the benefits of an electric motor with those of a turbine handpiece: precisely setting the recommended rotary bur speed according to material and process step and the constant removal rate with increasing pressure on the bur during preparation are among the Primea Advanced Air´s great achievements.
Meeting different speed recommendations: accurately, constantly and with a single device
All bur manufacturers recommend predefined speeds for the optimum performance of their instruments. Dental burs are designed with different flute angles, cutting characteristics specific to the task for which they are designed [1]. Rotations per minute (rpms) will vary depending on the OD (Outside Diameter) of the blade and material to be cut [2] and on vibration characteristics [3]. To improve blade life and help reduce wreckage [2], reduce heat generation and maximize efficiency [3] and tactile sense [4] it is important to run blades at the appropriate RPMs [2] and follow the bur manufacturer´s specifications of speed [1]. By accurately adjusting the Primea in accordance with these recommended speeds, the user can get a much better clinical performance out of the bur. In the following user case, Dr. Dean reports on his workflow and how using the Advanced Air technology has modified it.
For instance, the Australian dentist uses 180,000 rotations per minute to complete the initial shaping of the restoration, then reduces the speed to 100,000 rpm for more intricate shaping, and sometimes even as low as 60,000 rpm to get a super-smooth finish. He completes each step with a single bur, which is no problem for the Primea Advanced Air turbine, due to adjustment of the speed (see figure 1). The speed can be adjusted quickly and easily on the display.
Adjusting the speed in this way ensures very good cutting efficiency which is impossible to achieve by using the foot control to supervise a conventional air-driven turbine handpiece. Dr. Dean gives an example of how this has expanded the range of his treatments: “I reduced the speed to control the bur cutting a GI (glass ionomer) restorative placed in the distal of an upper tooth. It was difficult to place. I therefore added surplus material, so I could trim back to the tooth shape. Using the 60,000 rpm speed, I have far greater control and can avoid the bur ‘burrowing in’ to the restorative – I could even use the root surface as a ‘guide’ to ensure a seamless margin without any effect on the root surface.”
It is also possible to perform a preparation with a constant bur speed, regulated on the device. With conventional air-driven turbine handpieces, increasing pressure during preparation was associated with decreasing performance but the Primea Advanced Air adds constant performance during increased load just as used with electric motors and speed increasing contra angles.
After setting the required or recommended rotary speeds for the various applications on the module’s display, a sensor in the turbine head continuously measures the bur’s actual rotary speed on the tooth. The bur is then aligned with the rotary speed set. As soon as the speed threatens to slow, the control module adjusts the air supply immediately to ensure constant removal. In addition to the “Power” mode with constant rotary speed, there is also a “Tactile mode” for allowing a defined loss of speed when loaded performed with even greater control and even more minimally invasively.
Better results for patients and dentists
Not only does this new technology enable Dr. Dean to work in a more precise, straightforward, faster and safer way, it also guarantees a smoother cutting pattern and result for the patient. “With a conventional turbine, loading of the bur slows the bur speed down. The consequent foot pedal ‘feathering’ that we all do, creates an uneven cutting pattern. Sometimes the bur will bounce or walk across the preparation creating uneven cutting depths. I found this almost never happens with Primea: completing intricate work like crown preps is made simpler and quicker,” the Australian dentist explains. “Especially bulk amalgam removal is now much faster with the Primea Advanced Air. I have used a number of different bur types and shapes (both tungsten and diamond) – the Primea turbine does not slow down with any of them! I have gone back to an old favourite bur (JET FG TC 330), simply because I am used to the small instruments working part which supports my MID (minimal intervention dentistry) philosophy,” Dr. Dean points out happily.
“The new W&H 5x Ring LED+ system (RK-97 L) reduces reflection from moist surfaces and offers me perfect interpretation of the tooth surface, which is among others crucial for a minimally invasive performance as well. Due to superior distribution of the light, shadows are non-existent.”
The lightweight of a turbine, the design of the handpiece with its advantageous weight distribution and non-slip surface render the devices highly ergonomic. Furthermore, the W&H Roto Quick coupling system RQ-24 allowing a 360° handpiece rotation without twisting the hose support an ergonomic operation.
Quiet treatment despite high performance
Arranging the treatment to be as quiet as possible without high-frequency noise helps to create a very positive atmosphere for the patient. “A conventional turbine’s free-running speed is 350,000 rpm or more. The Primea turbine is set to the application speed (i.e. 180,000 rpm) and is therefore far quieter, and the pitch is far lower – which must be more convenient for the patient’s experience and which I certainly appreciate too! I’ve always linked the pitch/noise of the turbine to the performance, i.e. the higher the noise, the higher the cutting speed. Not any more! Tremendous cutting performance but at a lower speed means less noise pollution and creates a far more pleasant atmosphere for me, my staff and the patient,” Dr. Dean says happily.
Dr. Grant Dean is dental head and practice owner of the “Central Dental Group” in Wodonga, Australia. With the establishment of the “Central Dental Group” in 2008, Dr. Dean has been able to continue his commitment to dentistry in an environment that aims to provide the best in patient care.
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References
- Elias K, Amis AA, Setchell DJ. The magnitude of cutting forces at high speed. J Prosthet Dent. 2003 Mar;89(3):286-91.
- Manual of the UKAM Industrial Superhard Tools Division of LEL Diamond Tools International, Inc., Valencia, CA 91355 USA
- Vaughn RC, Peyton FA. The influence of rotational speed on temperature rise during cavity preparation. J Dent Res. 1951 Oct;30(5):737-44.
- Krejci I, Lutz F, Boretti R. Resin composite polishing—filling the gaps. Quint Int 1999;30(7):490-495.
- W&H Dentalwerk Bürmoos GmbH
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