A Preliminary Study on the Effects of the Nd:YAG Laser on Root Surfaces and Subgingival Microflora In Vivo

Abstract

The purpose of this study was to examine the effects of root preparation using the pulsed Nd:YAG laser, either alone or in combination with manual instrumentation. Study specimens consisting of 18 teeth with associated periodontal pockets from 8 different patients were treated as follows: 5 specimens were root planed with curets followed by laser exposure for 3 minutes using energy settings of 3.0 W at 20 pps; 2 specimens were root planed and then laser treated for 3 minutes using settings of 2.25 W and 20 pps; 4 specimens were treated by laser for 1 minute at settings of 1.75 W and 20 pps followed by root planing; 4 specimens were treated by laser only for 1 minute using settings of 1.75 W and 20 pps; and the remaining 3 teeth served as untreated controls. Both prior to and after completion of the laser and root planing treatments, microbiological samples were obtained from the treated pockets and submitted to a commercial laboratory for analysis of levels of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia. With the exception of two 7-day specimens, all others were extracted immediately post-therapy and processed for SEM examination. All treated specimens, regardless of treatment sequence, exhibited some degree of laser-induced root surface alteration. Notably, laser-treated calculus deposits were free of their characteristic surface layer of microbial plaque. Microbial sampling indicated a post-therapy reduction in levels of all 3 putative microbial pathogens compared to pre-treatment samples and control specimens. However, SEM examination revealed residual deposits of plaque and calculus in all treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of Er: YAG or Nd:YAG Laser Exposure on Fluorosed and Non-Fluorosed Root Surfaces: An <i>In vitro</i> Study

“…These observations provide cause for concern regarding potential thermal, pulpal damage in the clinical situation. 3) In case of open and closed PDL insertion sites in the cementum after Nd: YAG laser irradiation, a comparison between the fluorosed and non-fluorosed groups showed similar findings (p>0.05). Depending on the choice of laser parameter the effect on PDL insertion sites into cementum varied from total obliteration of insertion sites to little or no effect, the latter resulting in exposed and distinctly open sites.…”

Thermal and microstructural effects of nanosecond pulsed Nd:YAG laser irradiation on tooth root surface

“…In a similar in vivo study, Cobb et al (26) observed ineffective and patchy removal of deposits on the root surface, associated with areas of cratering and meltdown. A post-treatment decrease in microbial levels was also reported.…”

New processing technologies: an overview

“…component of the radiation and, sometimes, local transient heating. The delivery of light to packaging materials, food surfaces and to transparent liquid products, in short pulses of high intensity has been shown to be capable of inactivating vegetative and spore forms of micro-organisms in these environments (Dunn et al 1988) and in the medical area, particularly dentistry (Powell & Wisenart, 1991;Cobb et al 1992;Rooney et al 1994).…”