title: Comparison of third generation versus fourth generation electronic apex locators in detecting apical constriction: An in vivo study.
abstract: OBJECTIVE
  The aim of this in vivo study was to compare the accuracy of Root ZX and Raypex 5 in detecting minor diameter in human permanent single-rooted teeth.
  
  
  METHODS
  Thirty-one patients with completely formed single-rooted permanent teeth indicated for extraction were selected for the study. Crown was flattened for stable reference point and access cavity prepared. Working length was determined with both apex locators. A 15 K file adjusted to that reading was placed in the root canal and stabilized with cement. The tooth was then extracted atraumatically. Following extraction apical 4 mm of root was shaved. The position of the minor diameter in relation to the anatomic apex was recorded for each tooth under stereomicroscope at ×10. The efficiency of two electronic apex locators to determine the minor diameter was statistically analyzed using paired sample t-test.
  
  
  RESULTS
  The minor diameter was located within the limits of ±0.5 mm in 96.6% of the samples with the Root ZX and 93.2% of the samples with Raypex 5. The paired sample t-test showed no significant difference.
  
  
  CONCLUSIONS
  On analyzing the results of our study it can be concluded that Raypex 5 was as effective as Root ZX in determining the minor diameter.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Dayanandasagar College of Dental Sciences, Bengaluru, Karnataka, India.
authors.forename: D V
authors.initials: DV
authors.lastname: Swapna
authors.affiliation: Department of Endodontics and Cosmetic Dentistry, AL Rahba - (John Hopkins) SEHA - Hospital, Abu Dhabi, UAE.
authors.forename: Akash
authors.initials: A
authors.lastname: Krishna
authors.affiliation: Department of Conservative Dentistry and Endodontics, KLE VK Institute of Dental Sciences, Belgaum, Karnataka, India.
authors.forename: Anand C
authors.initials: AC
authors.lastname: Patil
authors.affiliation: Department of Conservative Dentistry and Endodontics, Dayanandasagar College of Dental Sciences, Bengaluru, Karnataka, India.
authors.forename: K
authors.initials: K
authors.lastname: Rashmi
authors.affiliation: Department of Conservative Dentistry and Endodontics, Dayanandasagar College of Dental Sciences, Bengaluru, Karnataka, India.
authors.forename: Veena S
authors.initials: VS
authors.lastname: Pai
authors.affiliation: Department of Conservative Dentistry and Endodontics, Dayanandasagar College of Dental Sciences, Bengaluru, Karnataka, India.
authors.forename: M A
authors.initials: MA
authors.lastname: Ranjini
keywords: Minor diameter; Raypex 5; Root ZX