Use of laser energy during endodontic surgical procedures

Abstract

To the Editor: Permit me to make a few comments regarding the paper entitled “The effect of CO2 laser irradiation on PDL cell attachment to resected root surfaces” by Fayad et al (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;97:518-23). I applaud them for their attempt to use laser energy during endodontic surgical procedures. Since their aim was to investigate the attachment of PDL cells to laser-irradiated tooth structure, I believe that their choice of using the CO2 wavelength was less than ideal. Their introduction states that “laser irradiation can effectively remove the smear layer and expose collagen fibers on the root surface, which can influence clinical healing by enhancing the PDL attachment….” This is true, but only of one specific wavelength—the Er.YAG wavelength, not CO2. They concluded, “despite the FDA approval for hard tissue applications, the present study strongly suggests caution with respect to apical surgery,” yet the CO2 wavelength is NOT approved for any hard tissue applications. Only the Er.YAG and Er.Cr.YSGG wavelengths are approved for hard tissue. They further conclude that “residual char layers resulting from laser irradiation or improper choice of parameters may inhibit reattachment of soft tissue to root surfaces,” yet multiple studies have shown that even though CO2 wavelength chars root surfaces, the Er.YAG laser does not produce a char layer on hard tissue. Israel and Cobb1.Israel M. Cobb C. Rossmann J. Spencer P. The effects of CO2, Nd:YAG, and Er.YAG lasers with and without surface coolant on tooth root surfaces—an in vitro study.J Clin Periodontol. 1997; 24: 595-602Google Scholar investigated the effects of CO2, Nd.YAG, and Er.YAG laser on root surfaces. Their results showed that the Er.YAG laser was the only wavelength that gave the following results: removal of the smear layer and exposure of the collagen matrix with no evidence of charring, melting, or surface cracking. Schwarz et al2.Schwarz F. Sculean A. Berakdar M. Szathmari L. Georg T. Becker J. In vivo and in vitro effects of an Er.YAG laser, a GaAlAs diode laser, and scaling and root planing on periodontally diseased root surfaces: a comparative histologic study.Lasers Surg Med. 2003; 32: 359-366Google Scholar studied the effects both in vitro and in vivo of an Er.YAG laser on periodontally diseased root surfaces. They concluded that the Er.YAG laser removed calculus from root surfaces on a level equivalent to that provided by an ultrasonic scaler with no cracks or thermal effects. No less an authority, the Research, Science and Therapy Committee of the American Academy of Periodontology concluded that “the Er.YAG laser has demonstrated the best application of laser use directly upon hard tissue, leaving the least thermal damage and creating a surface that suggests biocompatibility for soft tissue attachment.”3.Rossmann J. Lasers in periodontics.J Periodontol. 2002; 73: 1231-1239Google Scholar This report, and others,4.Yamaguchi H. Kobayashi K. Osada R. Sakuraba E. Nomura T. Arai T. Effects of irradiation of an Er.YAG laser on root surfaces.J Periodontol. 1997; 68: 1151-1155Google Scholar, 5.Schwarz F. Putz N. Georg T. et al.Effects of an Er.YAG laser on periodontally involved root surfaces: an in vivo and in vitro SEM comparison.Lasers Surg Med. 2001; 29: 328-335Google Scholar, 6.Schwarz F. Sculean A. Berakdar M. Georg T. Reich J. Becker J. Clinical evaluation of an Er.YAG laser combined with scaling and root planing for non-surgical periodontal treatment: a controlled prospective clinical study.J Clin Periodontol. 2003; : 26-34Google Scholar, 7.Schwarz F. Aoki A. Sculean A. et al.In vivo effects of an Er.YAG laser, an ultrasonic system and scaling and root planing on the biocompatibility of periodontally diseased root surfaces in cultures of human PDL fibroblasts.Lasers Surg Med. 2003; 33: 140-147Google Scholar give ample documentation that the Er.YAG laser may be the ideal wavelength to use when attempting to reattach PDL cells to tooth structure. I believe that a repeat of the experimental protocol by Fayad et al using the Er.YAG wavelength would give results that would validate the results shown by the 7 papers listed in the references. The effect of CO2 laser irradiation on PDL cell attachment to resected root surfacesOral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and EndodonticsVol. 97Issue 4PreviewThe effect of CO2 laser irradiation on PDL attachment to resected root ends was evaluated. Full-Text PDF In replyOral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and EndodonticsVol. 98Issue 5PreviewTo the Editor: Full-Text PDF