Journal of the American Dental Association Letter

Letter by Dr. Eric Linden published in the Journal of the American Dental Association (JADA) taking issue with misleading conclusions in an article regarding laser periodontal therapy

Downloaded from on June 30, 2011 796 JADA 142(7) July 2011

I appreciate the efforts of Dr. Mark Thomas and Dr. Kathy Shafer in their February JADA article, “Insufficient Evidence That Pulsed Nd:YAG Laser Treatment Is Superior to Conventional Nonsurgical Therapy in the Treatment of Periodontal Disease” (JADA 2011;142[2]: 194-195). The manufacturer of a Nd:YAG pulsed laser used in a Food and Drug Administration–cleared protocol1 says that the laser assisted new attached procedure has more than 400 periodontist clients (R. Gregg, president and owner, Millennium Dental Technologies, written communication, April 1, 2011). I have been utilizing this protocol as a surgical modality in our full-time practice of periodontics for several years now, and lecture extensively on the clinical results we have been achieving by using scrupulous clinical, radiographic and digital photography. We are currently preparing for publication.

However, I think that the summary article has inaccurate and misleading conclusions. I am quite surprised that JADA even published a review article that the authors themselves labeled “evidence quality poor.” It is important to state that this review article is addressing the nonsurgical use of the Nd:YAG laser. The original systemic review on which this article is based appeared in Journal of Periodontology in July 2009.2 It is significant to reveal the following inconsistencies about this review article:

  1. It attempts to compare different treatment methodologies such as Nd:YAG as
    • (a) mono – therapy,
    • (b) included with scaling and root planing or
    • (c) in the treatment of furcations only.
  2. Each study used different treatment protocols, varying from 60 seconds to 180 seconds of laser application per tooth.
  3. Fiber diameters varied from one study to the next; thus, there were different energy densities at the fiber tip.
  4. Only two of the eight studies cited identified fluence (energy per unit of surface area).3,4 Fluence is the only way of comparing one study to another. The two that noted fluence varied by 127 percent in the amount of energy applied.
  5. More than 90 percent of the articles involving laser periodontal therapy in the literature were not included in this review.

There is no question, even among those of us using the Nd:YAG laser in periodontal therapies, that more good quality research is needed. But using the existing research inappropriately in this manner clarifies nothing, but simply adds to the confusion.

It is significant to note that the authors did not discuss the standardized FDA-cleared protocol nor the landmark human histology study by Yukna and colleagues,5 which showed connective attachment in the absence of a long junctional epithelium in all specimens in the human study.

The article that Dr. Thomas and Dr. Shafer wrote really doesn’t have scientific validity for any conclusion other than a biased review of the articles the authors thought should be included.

The studies that were picked were not standardized, did not follow the FDA clearance and had very inconsistent variables from a statistical point of view.

In fact, multicenter studies are currently in progress to compare the different modalities of periodontal treatment to the Nd:YAG FDA-cleared laser protocol. Ironically, I am a graduate of the University of Kentucky, Division of Periodontics, where this review article originated and where I recently lectured at the School of Dentistry about the use and benefits of the Nd:YAG laser, showing numerous successful clinical cases using this laser as a surgical modality.

I hope that readers of JADA will understand and appreciate the benefits of laser periodontal therapy in the years ahead by evaluating sound clinical and research studies.

Eric Linden, DMD, MSD
Practice Specializing in Laser Periodontal Therapy, Periodontics, and Dental Implants
Offices in
Manhattan & Woodcliff Lake, N.J.

  1. Food and Drug Administration. Summary of safety and effectiveness information: Periolase Dental Laser System—premarket notification, Section 510(k). Jan. 17, 2003. “ k030290.pdf”. Accessed Apr. 8, 2011.
  2. Slot DE, Kranendonk AA, Paraskevas S, Van der Weijden F. The effect of a pulsed Nd:YAG laser in non-surgical periodontal therapy. J Periodontol 2009;80(7):1041-1056.
  3. de Andrade AK, Feist IS, Pannuti CM, Cai S, Zezell DM, De Micheli G. Nd:YAG laser clinical assisted in Class II furcation treatment. Lasers Med Sci 2008;23:341-347.
  4. Radvar M, MacFarlane TW, MacKenzie D, Whitters CJ, Payne AP, Kinane DF. An evaluation of the Nd:YAG laser in periodontal pocket therapy. Br Dent J 1996;180:57-62.
  5. Yukna RA, Carr RL, Evans GH. Histologic evaluation of an Nd:YAG laser-assisted new attachment procedure in humans. Int J Periodontics Restorative Dent 2007;27(6):577-587.