Air Abrasion

Cincinnati Ohio Dentist: Thomas K. Hedge D.D.S., F.A.C.E.
The Profitable Dentist
September 1998

Air abrasion is a very hot topic at dental meetings today. Thirty-four percent of dentists surveyed have an interest in purchasing this technology in 1998. There are more machines and people lecturing on the topic than ever before. The lectures cover the history of air abrasion dating back to the forties up to the present. They usually do not cover a review of the air abrasion devices available. Usually there is only one machine referenced. This is also usually a very expensive machine. There are over twenty air abrasion machines currently available on the market ranging from under $1000 to over $17,500.

The issue is further clouded by the addition of curing lamps and suction units. I feel that there is enough controversy with laser or high power curing that this option should not be considered. There is some new information John Kanka is presenting research in his current lecture that indicates that our everyday curing lights are too powerful for certain situations and that a slow cure results in the best bond and composite cure. Therefore if you follow Dr. Kanka’s thinking, there is absolutely no indication for laser curing. On the other hand, Bill Dickerson loves lasers. He cites a study where he cures composite in anesthetic carpules with a laser and an everyday curing light. Afterward he adds a caries stain to the sides of the carpule to demonstrate that no leakage occurs around the laser cured specimen, but the everyday light leaks considerably. John Kanka carefully dissects this study and points out many weaknesses in the scientific method. Who is right? Who knows, but I wouldn’t be buying a curing lamp with my air abrasion unit until more definitive research is performed. With respect to buying a separate suction unit, I don’t feel that they are necessary. If you do purchase an air abrasion unit and later feel that it is making too much of a mess, then get one.

I have been using an air abrasion unit for about two months now. I waited until recently to make the purchase a machine because I just couldn’t spend $15,000 on a dental toy that seemed to have limited applications. I have found it to be the treatment of choice for virgin Class I and Class V caries. It is fast, painless and conservative. I have also found it to be very useful as a third handpiece. When removing an old amalgam I use the high speed hand piece first, followed by the slow speed or the air abrasion unit for recurrent decay. Often, after the removal of old amalgam, there is a layer of tooth structure that is stained from the amalgam. It is usually not carious and removal with the high speed is not warranted. A quick two-second burst with air abrasion is usually sufficient to remove this stain. This situation is usually seen on the facial surface of upper bicuspids with two surface amalgams. When there is a deep base or decay there is no better way to remove it than using air abrasion. Air abrasion removes an even layer, which helps to decrease the operator’s mental anxiety of exposing the pulp. Wouldn’t it be interesting if one of the dental unit manufacturers, like ADEC put one of these air abrasion units right in the unit next to the high speed? Applications beyond this are usually a stretch of practicality.

I purchased the Micadent unit powered by a minitank filled with nitrogen for about $1,500. It is definitely not as sleek or pretty as some of the other units, but I have an extra $13,500 dollars in my checking account. Patients never actually see the unit or tank anyway so the aesthetic benefit would be for me anyway.

The minitank is about two feet tall and is refilled by a large nitrogen tank that is kept in our tank room with nitrous oxide and oxygen. The mini tank seems to last through twenty or more preparation. Nitrogen is a clean, dry source of propellant that will provide up to 160 lbs of pressure. Most of the other manufacturers provide propellant with either a separate compressor at considerable additional cost, or by a quick disconnect to your office compressor. One of the disadvantages often cited about the latter technique is that the air is of questionable dryness and not at a great enough pressure. I feel that the nitrogen minitank is a great concept and would adapt to any of the air abrasion systems at a considerable cost savings.

I had the advantage of comparing the Danville Prepstar to my Micadent unit last month when the Danville representative was in town. The Prepstar unit sells for $2695 and is the second least expensive unit on the market. These two units are both small table top units and can be carried from operatory to operatoty. The Prepstar is considerably larger that the Micadent, but this does not matter from a practical point of view.

The Prepstar unit is a sleek modern design with a European look. The controls and pressure gauge are easy to access and read on the front panel. The operator has control of both abrasive flow and pressure to determine cut speed and minimize powder overspray. The air pressure on the Prepstar can be adjusted prior to use, as the pressure guage constantly reads the pressure. The Micadent unit must be activated to read the pressure guage. This means that you are spraying powder somewhere while you are adjusting the pressure. Ironically, I spray mine into the Danville Engineering Microcab while adjusting the pressure.  The pneumatic foot switch turns on and cuts off the air abrasive stream instantly when you remove your foot from the switch. The Prepstar also has a built in high efficiency two-stage filtration dessicant in line.

The Micadent unit is of a more industrial design, but is very small. There is only one control for air pressure and the gauge faces straight up and is somewhat hard to read. The foot switch on the Micadent unit has a delay on turning on and cutting off the flow so you need to be careful to wait until the flow stops so you don’t prep adjacent teeth. There is no filtration or desiccant with this unit, but it is not necessary with the nitrogen propellant.

Handpieces for both units are small and lightweight. Both handpieces and nozzles can be unscrewed and autoclaved. The nozzles on the Prepstar are longer and more delicate in design, thus allowing better visualization of the tooth preparation.

The two units are both very nice. For an extra $1200 you get the ability to control powder flow, instant on and off and some other nice features with the Prepstar. I would use the nitrogen minitank to power either unit.

The only clinical recommendation that I have is that rubber dam usage is critical. The rubber dam protects adjacent teeth and keeps the powder out of the patient’s mouth. An application of topical anesthetic around the gingivae of the tooth to be clamped is usually sufficient to prevent any discomfort.

The benefits of using air abrasion are clear to the dental team, however, it is, perhaps, even more important that the patient understand the benefits. I have found the best way to be using the CAESY system. We recently installed the new DVD version in each of our clinical computers. The module on air abrasion has full motion video showing a traditional drill preparing a tooth and an air abrasion handpiece gently melting away the decay. This CAESY module goes on to explain all of the benefits of the air abrasion technique, such as elimination of microfractures, lack of heat buildup, and a reduced need for anesthetic.

There are a lot of research and development costs, marketing costs, and sales commissions to recover in the business of air abrasive sales. We , the consumer dentist, need to carefully evaluate the cost and benefits of the various systems. Is a $15,000 system really that much better than a $1500 dollar system? You make the call, but the $13,500 in my checkbook sure feels good!