title: Comparison of dentinal damage induced by different nickel-titanium rotary instruments during canal preparation: An in vitro study.
abstract: OBJECTIVE
  To compare dentinal damage caused by hand and rotary nickel-titanium instruments using ProTaper, K3 Endo, and Easy RaCe systems after root canal preparation.
  
  
  METHODS
  One hundred and fifty freshly extracted mandibular premolars were randomly divided into five experimental groups of 30 teeth each and biomechanical preparation was done: Group 1 with unprepared teeth; Group 2 were prepared with hand files; Group 3 with ProTaper rotary instruments; Group 4 with K3 rotary; Group 5 with Easy RaCe rotary instruments. Then, roots were cut horizontally at 3, 6, and 9 mm from apex and were viewed under stereomicroscope. The presence of dentinal defects was noted.
  
  
  METHODS
  Groups were analyzed with the Chi-square test.
  
  
  RESULTS
  Significant difference was seen between groups. No defects were found in unprepared roots and those prepared with hand files. ProTaper, K3 rotary, and Easy RaCe preparations resulted in dentinal defects in 23.3%, 10%, and 16.7% of teeth, respectively. More defects were shown in coronal and middle sections, and no defect was seen in apical third.
  
  
  CONCLUSIONS
  The present study revealed that use of rotary instruments could result in an increased chance for dentinal defects as compared to hand instrumentation.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Genesis Institute of Dental Sciences and Research, Ferozepur, Punjab, India.
authors.forename: Shiwani
authors.initials: S
authors.lastname: Garg
authors.affiliation: Department of Conservative Dentistry and Endodontics, Genesis Institute of Dental Sciences and Research, Ferozepur, Punjab, India.
authors.forename: Pardeep
authors.initials: P
authors.lastname: Mahajan
authors.affiliation: Department of Conservative Dentistry and Endodontics, Genesis Institute of Dental Sciences and Research, Ferozepur, Punjab, India.
authors.forename: Deepa
authors.initials: D
authors.lastname: Thaman
authors.affiliation: Department of Conservative Dentistry and Endodontics, Genesis Institute of Dental Sciences and Research, Ferozepur, Punjab, India.
authors.forename: Prashant
authors.initials: P
authors.lastname: Monga
keywords: Dentinal damage; hand files; rotary nickel-titanium files; stereomicroscope