title: Root canal centering ability of rotary cutting nickel titanium instruments: A meta-analysis.
abstract: OBJECTIVE
  To systematically review articles on canal centering ability of endodontic rotary cutting Nickel-Titanium (Ni-Ti) instruments and subject results to meta-analysis.
  
  
  METHODS
  A comprehensive search was initiated on canal centering ability of different rotary cutting Ni-Ti files such as Protaper, Hero Shaper, K3, Mtwo, Race, Wave One by selecting articles published in peer reviewed journals during 1991-2013 using "Pub Med" database. Inclusion and exclusion criteria were established. A data was created by tabulating: Author name, publication year, sample size, number of experimental groups, methods to evaluate canal centering ability, instrument cross section, taper, tip design, rake angle, mean and standard deviation. The data generated was subjected to meta-analysis.
  
  
  RESULTS
  Maximum studies were found to be conducted on mesiobuccal canal of mandibular 1(st) molar with curvature ranging from 15-60°. The difference in canal centering ability of different rotary cutting Ni-Ti instruments was not statistically significant.
  
  
  CONCLUSIONS
  All endodontic rotary cutting Ni-Ti instruments are capable of producing centered preparations. Protaper depicted the best centering ability. Computed tomography is an effective method of evaluating canal centering ability.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Teerthanker Mahaveer Dental College, Moradabad, Uttar Pradesh, India.
authors.forename: Mohan
authors.initials: M
authors.lastname: Gundappa
authors.affiliation: Department of Conservative Dentistry and Endodontics, Teerthanker Mahaveer Dental College, Moradabad, Uttar Pradesh, India.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Bansal
authors.affiliation: Department of Conservative Dentistry and Endodontics, Teerthanker Mahaveer Dental College, Moradabad, Uttar Pradesh, India.
authors.forename: Sarvesh
authors.initials: S
authors.lastname: Khoriya
authors.affiliation: Department of Periodontics, Teerthanker Mahaveer Dental College, Moradabad, Uttar Pradesh, India.
authors.forename: Ranjana
authors.initials: R
authors.lastname: Mohan
keywords: Centering ability; Ni-Ti rotary files; meta-analysis; systematic review