title: Dentinal crack formation during root canal preparations by the twisted file adaptive, ProTaper Next, ProTaper Universal, and WaveOne instruments.
abstract: BACKGROUND
  The aim of this study was to compare the incidence of root cracks after root canal instrumentation with the TF Adaptive, WaveOne, ProTaper Next, and ProTaper Universal systems.
  
  
  METHODS
  Seventy-five extracted mandibular central incisors with mature apices and straight root canals (<5°) were selected and kept in distilled water. The root canals were instrumented by using the ProTaper Universal, ProTaper Next, WaveOne, and TF Adaptive systems. All the roots were horizontally sectioned 3, 6, and 9 mm from the apex with a low-speed saw under water cooling. The slices were then viewed through a stereomicroscope at ×25 magnification. The samples were photographed with a camera to determine the presence of dentinal cracks.
  
  
  RESULTS
  The control group had no cracks, and the difference between the control group and the experimental groups was statistically significant (P < .001). The ProTaper Next and TF Adaptive systems produced significantly less cracks than the ProTaper Universal and WaveOne systems in the apical section (3 mm) (P < .05).
  
  
  CONCLUSIONS
  Under the study conditions and within the limitations of this study, it can be concluded that the ProTaper Universal, ProTaper Next, WaveOne, and TF Adaptive instruments can result in dentinal cracks.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey. Electronic address: dtertu@windowslive.com.
authors.forename: Ertuğrul
authors.initials: E
authors.lastname: Karataş
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Hicran Ateş
authors.initials: HA
authors.lastname: Gündüz
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Damla Özsu
authors.initials: DÖ
authors.lastname: Kırıcı
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Arslan
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Meltem Çolak
authors.initials: MÇ
authors.lastname: Topçu
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Kübra Yeşildal
authors.initials: KY
authors.lastname: Yeter
mesh_terms: D003762:Dental Instruments / Q000009:adverse effects; D003786:Dental Pulp Cavity / Q000503:physiopathology; D003804:Dentin / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D007180:Incisor / Q000503:physiopathology* / Q000601:surgery; D018915:Root Canal Preparation / Q000009:adverse effects* / Q000295:instrumentation; D019227:Tooth Apex / Q000503:physiopathology / Q000601:surgery; D014082:Tooth Fractures / Q000209:etiology / Q000503:physiopathology*; D014092:Tooth Root / Q000503:physiopathology* / Q000601:surgery
keywords: Dentinal crack; ProTaper Next; Twisted File Adaptive