title: Efficacy of LA Axxess burs, Gates Glidden drills and Protaper Sx in obtaining straight line access in mesiobuccal roots of mandibular first molars: A cone-beam computed tomography assessment.
abstract: OBJECTIVE
  This study aims at cone-beam computed tomography (CBCT) evaluation of the ability of Gates Glidden (GG) drills, Protaper Sx, and LA Axxess burs to produce a straight line access (SLA) in mesiobuccal canals of mandibular first molars.
  
  
  METHODS
  Forty-five freshly extracted mandibular teeth with a canal curvature of 10-20° were taken for the study and divided into three groups according to the instruments used for cervical preflaring: Group I (LA Axxess burs), Group II (GG drills), and Group III (Protaper Sx). Pre- and post-instrumentation CBCT images were evaluated for comparing the ability of GG drills, Protaper Sx and LA Axxess burs to produce an SLA in mesiobuccal canals of mandibular first molars.
  
  
  RESULTS
  There was no significant change (P= 0.06) in the angle in the preSLA images of LA Axxess Group I (12.37 ± 1.01), GG Group II (13.39 ± 1.74), and Protaper Sx Group III (13.90 ± 1.74). The mean decrease in the angle from preSLA to postSLA was significant for all the three groups (P= 0.0001). However, the mean change was highest in Group I (4.25 ± 1.14), followed by Group II (3.28 ± 1.22) and Group III (2.89 ± 1.53).
  
  
  CONCLUSIONS
  LA Axxess burs were the most effective in reducing the coronal curvature and produced a straighter access to apical third compared to GG Drills and Protaper Sx.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Promila
authors.initials: P
authors.lastname: Verma
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Rhythm
authors.initials: R
authors.lastname: Bains
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: A P
authors.initials: AP
authors.lastname: Tikku
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Chandra
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Shibha
authors.initials: S
authors.lastname: Mehta
keywords: Cervical preflaring; coronal curvature; straight line access