Histologic evaluation of an Nd:YAG laser-assisted new attachment procedure in humans.
Howard E. Strassler, DMD
Yukna RA, Carr RL, Evans GH. Int J Periodontics Restorative Dent. 2007;27:577-587.
This report presents histological results in humans following a laser-assisted new attachment procedure (LANAP) for the treatment of periodontal pockets. Six pairs of single-rooted teeth with moderate to advanced chronic periodontitis associated with subgingival calculus deposits were treated. A bur notch was placed within the pocket at the clinically and radiographically measured apical extent of calculus. All teeth were scaled and root planed with ultrasonic and hand scalers. One of each pair of teeth received treatment of the inner pocket wall with a free-running pulsed neodymium-yttrium-aluminum garnet (Nd:YAG) laser to remove the pocket epithelium, and the test pockets were lased a second time to seal the pocket. After 3 months, all treated teeth were removed en bloc for histologic processing. LANAP treated teeth exhibited greater probing depth reductions and clinical probing attachment level gains than the control teeth. All LANAP treated specimens showed new cementum and new connective tissue attachment in and occasionally coronal to the notch, whereas five of the six control teeth had a long junctional epithelium with no evidence of new attachment or regeneration. There was no evidence of any adverse histologic changes around the LANAP specimens. These cases support the concept that LANAP can be associated with cementum-mediated connective tissue attachments and apparent periodontal regeneration of disease root surfaces in humans.
The primary goal of periodontal treatment is regenerating the supporting tissues. The desire in regenerative therapy is to provide for clinical results for new connective tissue attachment, as well as regeneration of cementum, periodontal ligament, and alveolar bone. Currently, results of successful cases are very limited. To demonstrate histologic evidence for proof of regeneration, guidelines were established in the 1996 World Workshop in Periodontics. Currently, most treatments that demonstrate proof of new attachment and regeneration are associated with surgically implanted devices or materials. The authors of this article present a novel approach and demonstrate histologic evidence of gingival reattachment using a Nd:YAG laser. Sulcular/pocket epithelium removal has been the basis for curettage, excisional new attachment procedures (ENAP), and the replaced Widman Flap procedure to set up the environment for new connective tissue attachment, but these procedures would not be expected to influence new bone formation. This well-designed study reported on histologic wound healing after use of the LANAP surgery for periodontal pockets. The LANAP procedure was described as using the fiber tip of the laser directed parallel to the root surface and moving laterally and apically along the pocket wall, eventually reaching close to the base of the pocket to remove the epithelial lining of the pocket. Root debridement was accomplished with ultrasonic and hand instrumentation. Three months later, the teeth were removed with bone and soft tissue attachment in a block section for histologic examination (these teeth had been treatment planned for extraction as part of the overall restorative treatment plan). The evidence of this study demonstrated consistent positive histologic responses in periodontal pockets in humans treated with the LANAP. Regeneration of the cementum mediated new attachment, and, occasionally, apparent periodontal regeneration following the protocol described with a free-tuning pulsed Nd:YAG laser was demonstrated.
Howard E. Strassler, DMD
Professor and Director of Operative Dentistry
Department of Endodontics, Prosthodontics and Operative Dentistry
University of Maryland Dental School, Baltimore, Maryland