title: Laser welding method for removal of instruments debris from root canals.
abstract: The purpose of this study was to clarify the viability of a novel method for removing debris from broken instruments from root canals using a laser apparatus. Laser welding was performed on stainless steel or nickel titanium files using an Nd:YAG laser. Retention force between the files and extractors was measured. Increase in temperature on the root surface during laser irradiation was recorded and the irradiated areas evaluated with a scanning electron microscope. Retention force on stainless steel was significantly greater than that on nickel titanium. The maximum temperature increase was 4.1°C. The temperature increase on the root surface was greater in the vicinity of the welded area than that at the apical area. Scanning electron microscopy revealed that the files and extractors were welded together. These results indicate that the laser welding method is effective in removing debris from broken instruments from root canals.
authors.affiliation: Department of Endodontics, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502, Japan. hagi@joy.hi-ho.ne.jp
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Hagiwara
authors.forename: Masataka
authors.initials: M
authors.lastname: Suehara
authors.forename: Rie
authors.initials: R
authors.lastname: Fujii
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kato
authors.forename: Kan-ichi
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Oda
mesh_terms: D001831:Body Temperature; D003722:Dental Alloys / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000473:pathology*; D004868:Equipment Failure; D005547:Foreign Bodies / Q000628:therapy; D006358:Hot Temperature; D006801:Humans; D053844:Lasers, Solid-State; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry; D055100:Optical Fibers; D044367:Phase Transition; D018915:Root Canal Preparation / Q000295:instrumentation*; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D019227:Tooth Apex / Q000502:physiology; D014092:Tooth Root / Q000502:physiology; D014896:Welding / Q000295:instrumentation / Q000379:methods*
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium