title: Influence of lasing parameters on the cleaning efficacy of laser-activated irrigation with pulsed erbium lasers.
abstract: Laser-activated irrigation (LAI) using erbium lasers is an irrigant agitation technique with great potential for improved cleaning of the root canal system, as shown in many in vitro studies. However, lasing parameters for LAI vary considerably and their influence remains unclear. Therefore, this study sought to investigate the influence of pulse energy, pulse frequency, pulse length, irradiation time and fibre tip shape, position and diameter on the cleaning efficacy of LAI. Transparent resin blocks containing standardized root canals (apical diameter of 0.4 mm, 6% taper, 15 mm long, with a coronal reservoir) were used as the test model. A standardized groove in the apical part of each canal wall was packed with stained dentin debris. The canals were filled with irrigant, which was activated by an erbium: yttrium aluminium garnet (Er:YAG) laser (2940 nm, AT Fidelis, Fotona, Ljubljana, Slovenia). In each experiment, one laser parameter was varied, while the others remained constant. In this way, the influence of pulse energy (10-40 mJ), pulse length (50-1000 μs), frequency (5-30 Hz), irradiation time (5-40 s) and fibre tip shape (flat or conical), position (pulp chamber, canal entrance, next to groove) and diameter (300-600 μm) was determined by treating 20 canals per parameter. The amount of debris remaining in the groove after each LAI procedure was scored and compared among the different treatments. The parameters significantly (P < 0.05, Kruskal-Wallis) affecting debris removal from the groove were fibre tip position, pulse length, pulse energy, irradiation time and frequency. Fibre tip shape and diameter had no significant influence on the cleaning efficacy.
authors: Department of Restorative Dentistry and Endodontology, Dental School, Ghent University, De Pintelaan 185/P8, B-9000, Gent, Belgium.
authors: Maarten A
authors: MA
authors: Meire
authors: Department of Restorative Dentistry and Endodontology, Dental School, Ghent University, De Pintelaan 185/P8, B-9000, Gent, Belgium.
authors: Sophie
authors: S
authors: Havelaerts
authors: Department of Restorative Dentistry and Endodontology, Dental School, Ghent University, De Pintelaan 185/P8, B-9000, Gent, Belgium. Roeland.DeMoor@Ugent.be.
authors: Roeland J
authors: RJ
authors: De Moor
mesh_terms: D003786:Dental Pulp Cavity / Q000473:pathology / Q000528:radiation effects; D006801:Humans; D053844:Lasers, Solid-State; D012390:Root Canal Therapy / Q000379:methods*; D007507:Therapeutic Irrigation; D014092:Tooth Root / Q000473:pathology / Q000528:radiation effects
keywords: Erbium laser; Fibre tip shape; Laser-activated irrigation; Pulse energy; Pulse length; Root canal irrigation