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Innovative wavelengths in endodontic treatment
Author(s) -
Schoop Ulrich,
Kluger Wolf,
Dervisbegovic Selma,
Goharkhay Kawe,
Wernisch Johann,
Georgopoulos Apostolos,
Sperr Wolfgang,
Moritz Andreas
Publication year - 2006
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.20331
Subject(s) - dentin , root canal , laser , enterococcus faecalis , endodontics , dentinal tubule , dentistry , materials science , irradiation , biomedical engineering , chemistry , medicine , optics , escherichia coli , biochemistry , physics , nuclear physics , gene
Background and Objectives The sanitation of the root canal system and the adjacent dentin has always been a key requirement for successful endodontics. In recent years, various laser systems have provided a major contribution to this aim, namely the Nd:YAG‐, the 810 nm Diode‐, the Er:YAG‐, and the Er,Cr:YSGG laser. Numerous studies could prove their efficiency within the endodontic procedure. Recently, two new wavelengths have been introduced to the field of oral laser applications: The KTP laser emitting at 532 nm and the 980 nm diode laser. The present in vitro investigation was performed to evaluate the effects of these laser systems focusing on their antibacterial effect in deep layers of dentin and their impact on the root canal dentin. Study Design/Materials and Methods Two‐hundred slices of root dentin with a thickness of 1 mm were obtained by longitudinal cuts of freshly extracted human premolars. The samples were steam sterilized and subsequently inoculated with a suspension of either Escherichia coli or Enterococcus faecalis . After the incubation, the samples were randomly assigned to the two different laser systems tested. Each laser group consisted of two different operational settings and a control. The dentinal samples underwent “indirect” laser irradiation through the dentin from the bacteria‐free side and were then subjected to a classical quantitative microbiologic evaluation. To assess the temperature increase during the irradiation procedure, additional measurements were carried out using a thermocouple. To assess the impacts on the root canal walls, 20 additional samples underwent laser irradiation at two different settings and were subjected to scanning electron microscopy. Results Microbiology indicated that both laser systems were capable of significant reductions in both test strains. At an effective output power of 1 W, E. coli was reduced by at least 3 log steps in most of the samples by the tested wavelengths, with the best results for the KTP laser showing complete eradication of E . coli in 75% of the samples. E. faecalis , a stubborn invader of the root canal, showed minor changes in bacterial count at 1 W. Using the higher setting of 1.5 W, significant reductions of E. coli were again observed with both laser systems, where the lasers were capable of complete eradication of E. faecalis to a significant extent. There was no significant relation between the temperature increase and the bactericidal effect. Conclusions The present study demonstrates that both wavelengths investigated could be suitable for the disinfection of even the deeper layers of dentin and equal the results achieved by established wavelengths in state‐of‐the‐art endodontics. Lasers Surg. Med. 38:624–630, 2006. © 2006 Wiley‐Liss, Inc.