by William Greider, DMD, MAGD

I cannot imagine my practice without lasers. My goal has always been to achieve better dentistry through the best technology available. Like most dentists, I enjoy new gadgets and am always on the lookout for things that can improve my work. At the same time, I also take pride in taking an objective, hard look at the latest and greatest “hightech” dental equipment so I can separate hype and fantasy from the reality of any actual benefits to me and my patients. This is not always easy, and indeed my own closets have their share of items that turned out to be too good to be true. But we learn from our mistakes and continually try to minimize them.

The idea of using lasers for hard tissue dentistry has instant appeal for patients and dentists: no drill, shots, vibration, or unpleasant sound. I had already been an avid air abrasion user, and I still am for the times when it is the best tool in certain instances. I had been using a Premier diode laser for several years when the company finally received the first FDA approval for a hard tissue laser. As promised, their Aurora diode laser was a huge success in my practice, and I was among the first to check out their Centauri erbium hard tissue laser in 1997. But the machine had many technical problems, sometimes failing in the middle of a procedure. At other times, it would just cut so slowly, or some patients would experience pain at settings others would not even flinch at. Was the difference due to me, the machine, or the patients? Unfortunately, the machine was simply too unreliable for me to progress enough along a learning curve to figure things out. The fiber delivery failed often, and the machine was complicated to inspect and set up on a daily basis. It appeared that this technology was not quite there yet; and, disappointed, I returned the machine. But other US manufacturers were conducting clinical trials, and I kept hearing about success in Europe with an erbium laser by KaVo. I figured there must be something to this, and I hoped somebody would get it right.

My next laser I tried was the Millennium made by Biolase, the second company to get FDA approval for a hard tissue laser. This was a huge improvement. The laser was large and boxlike; some people called it a “Zamboni.” It also had a fiber delivery system that was more like a garden hose than a fiber. But it was fairly reliable, had a hand piece that looked like a traditional high speed, and once I got used to its characteristics I started to figure out what worked and what didn’t. In a relatively short period of time I got to the point where it was fairly quick to make preps, and my patients needed anesthesia less and less. Plus, I started doing soft tissue surgery that I used to refer out. I was more productive and both patients and my staff loved it! I knew that this technology was here to stay for me. The promise of the Premier had finally given rise to a piece of equipment that really could deliver on the goods, and it turned out to be one of the best investments I ever made.

The Millennium was not perfect. The stiff fiber and large right angled handpiece made it sometimes hard to access certain areas in the mouth, especially with small children. It was big and difficult to move around. It occasionally had technical problems, but Biolase was always quick to offer help and support. I like to think I may have had some influence on the improved design of the next generation laser from Biolase, the “Waterlase,” which I got in 2001. The new Waterlase is much smaller and uses a lighter and more flexible fiber delivery system. This is very important to be able to use it as much as I need to in my practice.

Recently, Biolase has begun promoting the Waterlase to the public and the dental community very aggressively for many different clinical procedures. Like the Millennium, the Waterlase is promoted by the company as a device that cuts with energized water instead of the laser light itself. I always had a little problem with that concept, trying to figure out the physics of that. Both have exactly the same effect clinically. Technically, the Biolase lasers use Er,Cr:YSGG at 2.78 microns compared to the 2.94 micron output of the Er:YAG of Premier, KaVo, and all of the other hard tissue lasers I am aware of. They all use a similar water spray for hard tissue, but the other companies claim that it is primarily the laser light that is responsible as the cutting mechanism. There are laser properties such as spot size, energy, pulse duration and repetition rate that are all also important factors in how they work. Whatever the real mechanisms, however, if they work clinically as promised, the future of dentistry looks very good to me.

While no dental instrument is the best solution for every procedure or patient, I know that the hard and soft tissue laser is by far the best single equipment purchase I have ever made. Still, my quest to provide better dentistry continues above everything else, and it is very important to objectively question the claims of the manufacturers.

In the past year, I have been very fortunate to have had the opportunity to extensively use in my practice the other two hard and soft tissue lasers currently being sold in the US, the Opus Duo from OpusDent and the DELight™ from Hoya ConBio (formerly Continuum Biomedical). Now that the state of the art in laser dentistry is coming of age and companies are making machines that work effectively, competition among the manufacturers is producing continued improvement in design, performance, and reliability. The promise of kinder, more patient-friendly, and truly better dentistry is a reality with these hard and soft tissue lasers. With estimates easily exceeding a thousand units in the US, and the recent growth of several laser-based dental educational organizations, dentists are seeing a resurgence of interest in these lasers. The US FDA seems to be very comfortable, compared to a few years ago, in clearing new procedures for these remarkable machines, without requiring extensive clinical trials from the manufacturers. This is due primarily to the nature of these lasers’ mid-infrared wavelengths that ablate, or vaporize, biological tissues with very little, if any, collateral thermal damage. Dedicated soft tissue lasers have very different wavelengths and work by not only vaporizing the tissue, the deeper penetration also cauterizes it. More care must be taken since the penetration of the laser beam may cause deeper thermal damage that may not be immediately apparent.

All of these erbium-type lasers hold the promise of being the best of both worlds, and as their reliability is increasing, more and more dentists are finally able to learn how to use them to their fullest capabilities. This in turn facilitates the ability of manufacturers to improve the capabilities of the machines to match the needs of the dentists. Depending on the nature of the practice, some laser capabilities may be more attractive to a potential user than others. Unfortunately, what is missing, however, are published, objective, clinical comparisons of the various machines. Ultimately, there are significant differences among the machines that should be taken into account if one is deciding which one to get. I hope the following information from my experience over the past few months is useful.

The OpusDent laser has the immediate and obvious advantage of having two different laser outputs, Er:YAG and CO2. This adds both cost and complexity to the laser system. However, some soft tissue surgical applications of the CO2 laser really cannot be duplicated by any other laser. The CO2 laser is one the oldest types of dental laser, with many being sold by several companies in the early 90’s, and Opus is the only company still offering it. It is a laser that cuts and coagulates quite well, but it also has a history of causing thermal injuries if not used correctly. Among all the dental lasers out there today, the CO2 probably requires the most care and training by the doctor in order to use it correctly. In my opinion, the CO2 laser has limited appeal to the average general dentist. The other big differences for this laser are that it works only with a 220 volt input and that both laser outputs are via optical waveguides, or tubes, rather than a fiber. The input is not a problem if they provide you with a transformer with the laser. The optical waveguides are like long straws that deliver the laser energy by reflecting the light along the inside of it. This type of delivery system can deliver the maximum energy per pulse as long as the tubing is rather straight and not bent too much. Bending causes the energy to vary significantly which sometimes makes it awkward to complete a planned procedure. The bending also tends to reduce the lifetime of the delivery system. As a consequence, OpusDent seems has made the delivery system rather stiff and short. This can work successfully, however, the learning curve includes managing the location and position of both the laser and the patient. Also, I found the control portion of the laser a bit cumbersome and slow, even though I really liked the ability to change the repetition rate. As a cutter of healthy occlusal enamel, this laser is impressive when it is used with their large 1 mm diameter tip. Sometimes this can be a big advantage, but it is somewhat offset by the bending restrictions. The water spray emits from the handpiece and is similar to the Waterlase. I often felt that it was difficult to cut small, conservative preps with this delivery system. This is a matter a choice that a prospective buyer should look at carefully Overall, I used the laser in my practice for approximately 8 months.

I have had most of my experience with Biolase’s old Millennium, and then more recently with their latest version of the Waterlase. The lasers are fixed at 20 pulses per second and then the energy per pulse is varied up and down to a maximum of 6 watts, or 300 mJ per pulse, depending on the procedure. The water is adjusted on a scale of 0 to 100%, again depending on the procedure. There are a wide variety of tips that are used for different procedures. Like the Opus, the right angle handpiece mimics the traditional dental handpiece in look and feel, and the water spray emits from the handpiece all around the straight tip which is inserted into the handpiece.

I have to say that in some ways the fiber delivery of the new Waterlase is somewhat less reliable than my old Millennium, possibly due to the fact that the new fiber is so much thinner and more flexible. However, I also need to say again that for the most part the company has been very quick and responsive in taking care of any problems with the machine.

Overall, I preferred the Waterlase to the OpusDent primarily because of the ease of use of the delivery system, the smaller size, and the somewhat simpler use of the control panel. The cutting ability of the Opus can be better on occlusal surfaces, but this is not usually accompanied with patient compliance. The repetition rate of the Opus can be varied somewhat, and this does offer some advantages for different procedures. Also, I admit that I am not a big fan of the CO2 laser for most soft tissue procedures. The erbium wavelength does accomplish most of the soft tissue procedures that I would do with the CO2 and with much less risk. When I do need a dedicated soft tissue laser, I can use one of my other lasers.

My most recent experience has been with the DELight™ Erbium:YAG laser from Hoya ConBio. This machine has been the most pleasant surprise to me. Initially, I had planned to use the machine for only a short while in order to compare it to the Waterlase. Purposely, I scheduled patients with procedures that might be “difficult,” including several teenagers and others who would be the first to mention discomfort.

My first clue that the DELight™ was a little different than the others was the installation process, or the lack of it. The laser arrived in a cardboard packing crate on a wooden pallet. When the sales rep arrived and began uncrating the laser, I was impressed with the level of simple, yet well-engineered ways that the laser and accessories were packed. No technician ever came to install the laser; everything was done by the sales rep. He said he always installed the demos himself; after all he carried one around in his car just for such purposes. Every other hard tissue laser I had ever used needed the blessing of a skilled technician before it could be deemed fit to use reliably. Initially, my staff was perhaps more impressed than I was – I would be the one blamed by patients if anything did not go smoothly.

The first patient I had scheduled to treat with the DELight™ seemed to be very comfortable with everything we did. For other patients, I often asked whether we could try a different laser. They were usually agreeable, and we stopped and walked over to the Waterlase to begin another prep. In some cases, I would change lasers on the same tooth. It was intriguing that, for whatever reason, patients were generally more comfortable with the DELight™ and expressed a preference to be treated with it. Sometimes, I suspected that it may simply have been due to the louder popping noise from the Waterlase rather than any real pain perception. In any case, the preference for the DELight™ was clear from the patients’ view.

Cutting soft tissue was also surprising with the DELight™. I had always assumed that the slightly better penetration of the Er,Cr:YSGG wavelength resulted in better hemostasis compared to that of the Er:YAG lasers. Indeed, I got that perception with the Premier laser and the OpusDent laser that I used on patients. However, I had never done a good side by side comparison, which I now started doing with the DELight™ and the Waterlase. In virtually all cases where I could keep it “apples to apples” as far as patient and procedure selection, the DELight™ seemed to result in less bleeding. The tendency to bleed with any of the lasers is always present with hyperemic or inflamed tissue. This is true even with the dedicated soft tissue lasers. However, in every case where I could make a good comparison with the Waterlase, the DELight™ bled less. In many cases, with both lasers, there would be no little to no bleeding at all, and I would say that the post-operative comfort and healing results were identical and excellent. All of the lasers are a good choice for most gingivectomies, frenectomies, troughing and simply carefully shaving away some tissue. Perhaps the better hemostasis with the DELight™ is due to other factors such as repetition rate or pulse duration.

Cutting speed is definitely an area where technique and experience play a large role in achieving success. This was true for me, and I hear that repeated over and over from other hard tissue laser dentists. As I got more experience with the characteristics of the lasers, I was able to finish all types of preps more efficiently, and with less use of anesthesia. One common thread with this is that because the light does the cutting, there is very little tactile response from the handpiece and seeing the progress of the prep becomes very important. This is an area where the curved tip of the DELight™ makes a very big difference. Not only does the thin curved tip allow better visual access, but the water spray emerges from a metal cannula near the target, and the spray is more controlled around the tip itself. I would estimate that because of this the DELight™ needs probably one fourth of the water to cut hard tissue effectively. I use 3.5X loupes; and, with the DELight™, I was able for the very first time to see indirectly as the laser cuts the prep. The others, with only right angled handpieces, have the spray emerging from the handpiece and have much more overspray. This makes vision with a mirror almost impossible. I am sure this contributes to a more optimized technique for cutting preps where direct vision may be impossible. When the 80 degree curved tip is still not optimum for a certain target, there is an optional right angled attachment for the DELight™; although I found myself usually preferring the curved tips. The cannula also seemed to have a beneficial effect on the durability of the tip. I have yet to break one after successfully treating over a hundred patients. A bonus is that I have been able to easily polish the tips back to almost new condition after several procedures.

In conclusion, I am extremely grateful for the opportunity to have tried all of these lasers under clinical conditions that I believe were sufficient in quantity and in comparative quality to give a fair assessment of pluses and minuses. Clearly, there is a need for this as hard tissue laser dentistry expands and more dentists are able to deliver a better experience to their patients and to themselves. I have no financial interest in either Opus or Hoya ConBio, although I am a shareholder of Biolase. Hard tissue laser dentistry has come to a stage where it is an investment that I think more dentists will be willing to make. This type of comparison shopping will only make it better, and I encourage all who are interested to try to take this route. In my experience with these three lasers, the DELight™ performed better overall on the procedures that I do; but there are many factors involved in making such an expensive decision, such as service, training, and after sale support.

As an epilogue, after the agreed upon three days of testing, the sales rep drained the DELight™ and recrated it to ship back to the Midwest to continue using it as his demo. The next morning the freight company arrived and off it went. After a short but intense period of thinking that I wanted to continue using the laser, I called the company, and they returned it later that day. The DELight™ arrived back in the crate and my dental assistant, by herself, managed to unpack it, set it up, and calibrate it with only telephone help from the sales rep who had returned home! I used it successfully on patients that same day. I did not think that was even remotely possible with a hard tissue laser; but as I said earlier, progress here is being made, and I hope it continues. I still have the laser.

About the Author

A graduate of the University of Pennsylvania School of Dentistry, Dr. Greider has been in private practice in Ft. Myers, Florida for over 20 years. He was among the first dentists in the US to use a hard tissue laser when Premier received the first FDA clearance in 1997. Since that time he has lectured for Biolase and has had extensive clinical experience with the Waterlase Er,Cr:YSGG laser, the OpusDent Er:YAG laser, and the Hoya ConBio Er:YAG DELight™.