title: The ability of different nickel-titanium rotary instruments to induce dentinal damage during canal preparation.
abstract: The purpose of this study was to compare the incidence of dentinal defects (fractures and craze lines) after canal preparation with different nickel-titanium rotary files. Two hundred sixty mandibular premolars were selected. Forty teeth were left unprepared (n = 40). The other teeth were prepared either with manual Flexofiles (n = 20) or with different rotary files systems: ProTaper (Dentsply-Maillefer, Ballaigues, Switzerland), ProFile (Dentsply-Maillefer), SystemGT (Dentsply-Maillefer), or S-ApeX (FKG Dentaire, La Chaux-de-Fonds, Switzerland) (n = 50 each). Roots were then sectioned 3, 6, and 9 mm from the apex and observed under a microscope. The presence of dentinal defects was noted. There was a significant difference in the appearance of defects between the groups (p < 0.05). No defects were found in the unprepared roots and those prepared with hand files and S-ApeX. ProTaper, ProFile, and GT preparations resulted in dentinal defects in 16%, 8%, and 4% of teeth, respectively. Some endodontic preparation methods might damage the root and induce dentinal defects.
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University, UNESP, Araraquara, SP, Brazil.
authors.forename: Carlos Alexandre Souza
authors.initials: CA
authors.lastname: Bier
authors.forename: Hagay
authors.initials: H
authors.lastname: Shemesh
authors.forename: Mário
authors.initials: M
authors.lastname: Tanomaru-Filho
authors.forename: Paul R
authors.initials: PR
authors.lastname: Wesselink
authors.forename: Min-Kai
authors.initials: MK
authors.lastname: Wu
mesh_terms: D001641:Bicuspid; D003722:Dental Alloys; D003762:Dental Instruments / Q000009:adverse effects*; D003786:Dental Pulp Cavity / Q000293:injuries; D003804:Dentin / Q000293:injuries*; D006801:Humans; D009532:Nickel; D018915:Root Canal Preparation / Q000009:adverse effects* / Q000295:instrumentation*; D014025:Titanium; D014082:Tooth Fractures / Q000209:etiology; D014092:Tooth Root / Q000293:injuries*
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium