by John Jameson, DDS
Dr. John Jameson recently interviewed Robert Convissar, DDS, F.A.G.D, a renowned expert in the field of laser dentistry. In addition to his private practice, Dr. Convissar currently is Director of Laser Dentistry at New York Hospital Medical Center of Queens, NY, and serves as a dental materials and dental equipment evaluator for Clinical Research Associates, Provo, Utah. He has authored numerous articles on the subject of laser use in dentistry, including the textbook, Lasers and Light Amplification in Dentistry, and is a frequent speaker and educator at the Yankee Dental, Greater New York, and Academy of Laser Dentistry meetings.
Jameson: What changes have you seen recently in laser technology, specifically soft-tissue lasers?
Convissar: Ten years ago, we had a grand total of one wavelength, which was the NeodymiumYAG. The unit cost $50,000. Today, we have about a half-dozen wavelengths, and lasers can be purchased for as little as $10,000. Prices have come down tremendously, as have portability and size. We've seen an explosion in the number of wavelengths, and in the number of manufacturers that produce this technology.
Jameson: Of course, the differences in wavelengths have produced a myriad of clinical applications. Which lasers work best for certain procedures?
Convissar: Diode lasers are making tremendous inroads in general dentistry and periodontics. They're compact and portable; tabletop units can be moved from operatory to operatory with no trouble, and can do most of the work that larger units can do — gingivectomies, gingioplasties, troughing around crown margins, uncovering implants, and a whole multitude of other techniques. A diode can perform almost all of the soft tissue procedures that dentists use to treat their patients.
Jameson: What about hard-tissue procedures? What technologies are being used, and how are doctors using them?
Convissar: These days, the standard of excellence for hard-tissue procedures is the erbium wavelength. Opus Dent makes a unique instrument; it is a combined erbium and carbon dioxide unit — in short, it is two different lasers in one. It gives both hard-tissue ability and soft-tissue ability in one unit.
Another manufacturer that produces a wonderful erbium unit is Continuum Biomedical; their unit is outstanding for hard-tissue procedures.
Another important manufacturer is Biolase. This company makes a unit that is slightly different — an erbium/chromium laser. The wavelength is slightly different, but it also works on hard tissue to remove decay.
Erbium laser use is indicated for Class I occlusal decay, as well as Class III and Class V decay. It can be used on Class II decay if the marginal ridge is not intact, or if you get in through the embrasure. They essentially can be used for just about any classification of decay with the proviso that the decay is not recurrent underneath an amalgam filling. We still cannot remove amalgam fillings with a laser. However, composite fillings can be removed easily with a laser; so can glass ionomer fillings.
Jameson: What kind of investment is required to purchase a hard-tissue laser?
Convissar: It depends — practitioners may be able to find special promotions at certain times of the year. But a general average is anywhere from $45,000 to $50,000 for an erbium unit. Most of these units are very portable. They are about the size of a small filing cabinet but are on wheels and very easy to move from operatory to operatory with no problem.
Lasers offer some distinct advantages when compared with air abrasion. Most experienced air abrasion users will tell you that once they get into the tough, hard, leathery brown decay, air abrasion becomes much less efficient. The reverse is true with hard-tissue lasers. The softer the decay, and the more decalcified the material is, the quicker the erbium laser will pass through and ablate the material.
Jameson: Are there any extended, hands-on continuing education courses that deal specifically with laser usage?
Convissar: Not at this stage of the game, although some of the companies are planning to offer some instruction on disk. For now, dentists who purchase a laser unit can take full-day symposiums like those offered at various dental meetings around the country. Local dental societies also are a good source of instruction and technique.
Dentists are best served by joining an organization, such as the excellent Academy of Laser Dentistry. It's a worldwide organization; they offer some wonderful continuing-education courses, and their annual meeting always offers a strong slate of speakers, educators, and experts in the field. Their Web site is www.laserdentistry.org.
Jameson: You have the opportunity to consult and work with a variety of manufacturers and distributors of this technology. What are key points of research in this field, and what future applications can we expect for the dental practice?
Convissar: The most exciting, near-term development is in the field of endodontics. Erbium lasers have been proven to act as bactericidal instruments in root canals, remove the smear layer, and increase adhesion of epoxy-based root canal cements to the canal walls.
Hard-tissue lasers will undoubtedly be used for more and more procedures. Eventually, I expect they will be used for crown and bridge, laminate preparations, and other procedures. Specific delivery systems that will do those procedures are still under development — but they are definitely coming!
