Bactericidal effect of erbium YAG laser on periodontopathic bacteria

Abstract

Background and Objective Recently Erbium (Er) YAG laser has been developed for dentistry. It may be suitable for periodontal therapy. This study examined the bactericidal effect of the Er: YAG laser on periodontopathic bacteria in vitro. Study Design/Materials and Methods After spreading the bacterial suspension of Porphyromonas gingivalis or Actinobacillus actinomycetemcomitans on agar plates, a single pulse laser was applied to the agar plates at the energy density of 0.04–2.6 J/cm2. The growth of the bacterial colonies on the lased agar plates was examined after anaerobic culture. P. gingivalis colonies were also individually exposed to the single pulse laser at the energy of 1.8–10.6 J/cm2. The colony forming unit of the irradiated colonies were counted. Results Growth inhibitory zones were found at the irradiated sites at the energy of about 0.3 J/cm2 and higher. The survival ratios of the viable bacteria in the lased P. gingivalis colonies decreased significantly at the energy of 7.1 and 10.6 J/cm2, as compared with that of the control. Conclusion These findings suggest that the Er:YAG laser has a high bactericidal potential at a low energy level. © 1996 Wiley-Liss, Inc.