title: Frequency of Iatrogenic Errors through Root Canal Treatment Procedure in 1335 Charts of Dental Patients.
abstract: BACKGROUND
  Endodontic procedures such as root canal treatment would be at the risk of failure like other medical interventions due to any unsuitable conditions. This has a causative effect in making the procedure more complicated to resulting in weak prognosis finally. Technical errors such as ledge, perforation, obstruction, broken instrument, etc. make infection control too hard or impossible. The aims of this study are common errors frequency and types of root canal treatments focusing on defined groups of dental students in Qazvin, Iran.
  
  
  METHODS
  All the errors were divided into three major kinds of: (1) During providing access cavity, (2) cleaning and preparation and (3) canal obturation.
  
  
  RESULTS
  A total number of 1335 charts of the cases were studied in the field of root canal treatment. The whole number of charts, which reported errors was 880 (66%) while 455 (34%) error-free ones. The most frequent error in upper incisors was void with the rate of 50.9%, followed by overfilling (apical perforation) in 18.2%. The same errors were also most common for lower incisors in addition to imperfect cleaning.
  
  
  CONCLUSIONS
  The current study identified the least mistakes through the process of providing access cavity and instrumentation phase comparing obturation phase, which had the most frequent errors including void, overfilling and imperfect cleaning.
authors.affiliation: Assistant Professor, Department of Endodontics, Dental Faculty, Qazvin University of Medical Sciences, Qazvin, Iran.
authors.forename: Neda
authors.initials: N
authors.lastname: Haji-Hassani
authors.affiliation: Associate Professor, Department of Oral Medicine, Dental Faculty, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mahin
authors.initials: M
authors.lastname: Bakhshi
authors.affiliation: Post-Graduate Student, Department of Endodontics, Dental Faculty, Qazvin University of Medical Sciences, Qazvin, Iran.
authors.forename: Samaneh
authors.initials: S
authors.lastname: Shahabi
keywords: Endodontics; frequency; iatrogenic errors; root canal treatment