title: Evaluation of the antimicrobial effect of Er:YAG laser irradiation versus 1% sodium hypochlorite irrigation for root canal disinfection.
abstract: This laboratory study evaluated Er:YAG laser antibacterial action in infected root canals. Forty-eight maxillary central incisors were used. After canal preparation, the teeth were autoclaved and divided into four groups: (1) non-treated teeth (control group); (2) teeth treated with NaOCl; (3) teeth irradiated with Er:YAG laser (7 Hz, 100 mJ, 80 pulses/canal, 11 sec) to the working length; (4) teeth irradiated similarly to, but 3 mm short, of the apex. The root canals from Groups 2, 3 and 4 were inoculated with 4 bacteria: Bacillus subtillus, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus, together with Candida albicans, and maintained for 24 h at 37 degrees C. All suspensions were adjusted to tube 2 of the MacFarland scale. The intracanal material was then collected with sterile paper points, which were placed in the canals for 5 min and then immersed in 5 ml of BHI medium. This was then seeded onto agar and stained by Gram's method. The NaOCl solutions and the Er:YAG laser irradiation to working length were effective against all five micro-organisms; however, 70% of the specimens irradiated 3 mm short of the apex remained infected.
authors.affiliation: Faculty of Dentistry, Universidade de Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Fernanda M
authors.initials: FM
authors.lastname: Perin
authors.forename: Suzelei C
authors.initials: SC
authors.lastname: França
authors.forename: Yara T C
authors.initials: YT
authors.lastname: Silva-Sousa
authors.forename: Edson
authors.initials: E
authors.lastname: Alfredo
authors.forename: Paulo C
authors.initials: PC
authors.lastname: Saquy
authors.forename: Carlos
authors.initials: C
authors.lastname: Estrela
authors.forename: Manoel D
authors.initials: MD
authors.lastname: Sousa-Neto
mesh_terms: D000538:Aluminum Silicates; D001412:Bacillus subtilis / Q000187:drug effects / Q000528:radiation effects; D002176:Candida albicans / Q000187:drug effects / Q000528:radiation effects; D015169:Colony Count, Microbial; D003786:Dental Pulp Cavity / Q000382:microbiology*; D004203:Disinfection / Q000379:methods*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000528:radiation effects; D004871:Erbium; D006801:Humans; D053685:Laser Therapy; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000528:radiation effects; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D018915:Root Canal Preparation; D012973:Sodium Hypochlorite / Q000627:therapeutic use*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000528:radiation effects; D019227:Tooth Apex / Q000382:microbiology; D015019:Yttrium
chemical_list: D000538:Aluminum Silicates; D012388:Root Canal Irrigants; D015019:Yttrium; D004871:Erbium; D012973:Sodium Hypochlorite