title: Comparative evaluation of the antibacterial effects of intracanal Nd:YAG laser irradiation: an in vitro study.
abstract: The purpose of this study was to determine if the Nd:YAG laser was capable of disinfecting contaminated root canals in vitro. Eighty canals of extracted single-rooted teeth were prepared to size 35 K-file. The teeth were sterilized with ethylene oxide gas and then inoculated with Bacillus stearothermophilus. Eight groups were treated as follows: 1, sterility control; 2, positive control, no treatment; 3, hand instrumentation with sterile water filling chamber; 4, hand instrumentation with NaOCl (5.25%) filling chamber; 5, ultrasonic instrumentation with sterile water; 6, ultrasonic instrumentation with NaOCl; 7, laser exposure with sterile water; and 8, laser exposure with NaOCI. All instrumentation times were 1 min. Teeth were then flushed with 1.0 ml of sterile water onto blood agar plates, and the number of colony forming units were determined. Results indicate that: (i) all groups treated with NaOCI effectively inhibited the growth of B. stearothermophilus; (ii) hand and ultrasonic instrumentation with sterile water did not effectively disinfect root canals; and (iii) the Nd:YAG laser was effective in inhibiting the growth of B. stearothermophilus. The effects of the Nd:YAG laser on other bacteria more commonly found in root canal systems should be evaluated.
authors.affiliation: Department of Endodontics, University of Detroit-Mercy School of Dentistry, Michigan 48093, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Fegan
authors.forename: H R
authors.initials: HR
authors.lastname: Steiman
mesh_terms: D000704:Analysis of Variance; D015169:Colony Count, Microbial; D003786:Dental Pulp Cavity / Q000382:microbiology; D001411:Geobacillus stearothermophilus / Q000187:drug effects / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D009354:Neodymium; D012388:Root Canal Irrigants / Q000494:pharmacology; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013171:Spores, Bacterial / Q000528:radiation effects; D014464:Ultrasonic Therapy
chemical_list: D012388:Root Canal Irrigants; D009354:Neodymium; D012973:Sodium Hypochlorite