title: Effects of four instruments on coronal pre-enlargement by using cone beam computed tomography.
abstract: BACKGROUND
  This ex vivo study used cone beam computed tomography to evaluate the amount of dentin removal from the distal wall of the mesial canal of human mandibular first molars caused by 4 instruments used to flare the cervical third.
  
  
  METHODS
  Thirty-two mesial roots were divided into 4 groups prepared by using ProTaper, K3, Gates-Glidden, or LA Axxess. The dentin thickness of the distal cervical wall of mesial canals was measured before and after the preparation by using computed tomography and Adobe Photoshop software.
  
  
  RESULTS
  There was no statistically significant difference between the study groups (P > 05).
  
  
  CONCLUSIONS
  All the instruments used for cervical preparation seemed to be safe and did not damage the dentin structure of the distal wall of mesial root canals of mandibular molars.
authors.affiliation: School of Dentistry, Universidade de Caxias do Sul (UNICSUL), Caxias do Sul, RS, Brazil.
authors.forename: Cintia Mussoline
authors.initials: CM
authors.lastname: Sanfelice
authors.forename: Fernanda Botega
authors.initials: FB
authors.lastname: da Costa
authors.forename: Marcus Vinícius
authors.initials: MV
authors.lastname: Reis Só
authors.forename: Fabiana
authors.initials: F
authors.lastname: Vier-Pelisser
authors.forename: Carlos Alexandre
authors.initials: CA
authors.lastname: Souza Bier
authors.forename: Fabiana Soares
authors.initials: FS
authors.lastname: Grecca
mesh_terms: D054893:Cone-Beam Computed Tomography; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D004869:Equipment Safety; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008963:Molar; D018915:Root Canal Preparation / Q000295:instrumentation*; D018709:Statistics, Nonparametric; D019237:Tooth Cervix