title: Activation of ethylenediaminetetraacetic acid by a 940 nm diode laser for enhanced removal of smear layer.
abstract: Laser enhancement of ethylenediaminetetraacetic acid with cetrimide (EDTAC) has previously been shown to increase removal of smear layer, for middle-infrared erbium lasers. This study evaluated the efficiency of EDTAC activation using a near-infrared-pulsed 940 nm laser delivered by plain fibre tips into 15% EDTAC or 3% hydrogen peroxide. Root canals in 4 groups of 10 single roots were prepared using rotary files, with controls for the presence and absence of smear layer. After laser treatment (80 mJ pulse(-1) , 50 Hz, 6 cycles of 10 s), roots were split and the apical, middle and coronal thirds of the canal were examined using scanning electron microscopy, with the area of dentine tubules determined by a validated quantitative image analysis method. Lasing EDTAC considerably improved smear layer removal, while lasing into peroxide gave minimal smear layer removal. The laser protocol used was more effective for smear layer removal than the 'gold standard' protocol using EDTAC with sodium hypochlorite (NaOCl). In addition, lasers may also provide a benefit through photothermal disinfection. Further research is needed to optimise irrigant activation protocols using near-infrared diode lasers of other wavelengths.
authors.affiliation: School of Dentistry, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Manfred
authors.initials: M
authors.lastname: Lagemann
authors.forename: Roy
authors.initials: R
authors.lastname: George
authors.forename: Lei
authors.initials: L
authors.lastname: Chai
authors.forename: Laurence J
authors.initials: LJ
authors.lastname: Walsh
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000528:radiation effects; D003786:Dental Pulp Cavity / Q000187:drug effects* / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects / Q000648:ultrastructure; D004492:Edetic Acid / Q000031:analogs & derivatives* / Q000528:radiation effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000528:radiation effects; D007091:Image Processing, Computer-Assisted; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000528:radiation effects* / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation; D016369:Smear Layer / Q000188:drug therapy*; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D019227:Tooth Apex / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D002593:Cetrimonium Compounds; D012388:Root Canal Irrigants; C033443:EDTAC; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D012973:Sodium Hypochlorite; D000077286:Cetrimonium
keywords: EDTA; diode laser; endodontics; irrigants; lasers; smear layer