title: Relative frequency of teeth needing conventional and surgical endodontic treatment in patients treated at a graduate endodontic clinic--a Penn Endo database study.
abstract: OBJECTIVE
  The objective of this study was to identify the most commonly retreated tooth at a postgraduate endodontics program and to compare this result with teeth requiring primary root canal treatment as well as those that required further surgical endodontic treatment.
  
  
  METHODS
  The study population consisted of 6,894 patients treated between 2000 and 2005 by endodontic postgraduate students at the University of Pennsylvania School of Dental Medicine. Data regarding tooth type and endodontic treatment rendered were obtained from the Penn Endo database.
  
  
  RESULTS
  Initial root canal treatment was most commonly done on mandibular molars. Anterior teeth were 1.411 times more likely to undergo NSRT than molars. Maxillary molars were 1.048 times more likely to undergo conventional retreatment than mandibular molars. Maxillary anterior teeth were 3.032 times more likely than mandibular molars to undergo surgical treatment.
  
  
  CONCLUSIONS
  Mandibular molars may most commonly receive initial root canal treatment but it is the anterior teeth that are more likely to undergo surgical and nonsurgical retreatment. Maxillary molars are more likely to receive surgical intervention than mandibular molars. These data call for further investigation into the reasons for such discrepancy.
authors.affiliation: Department of Endodontics, School of Dental Medicine, University of Pennsylvania, Robert Schattner Center, 240 South 40th Street, Philadelphia, PA 19104-6030, USA. miqal@pobox.upenn.edu
authors.forename: Mian
authors.initials: M
authors.lastname: Iqbal
authors.forename: Selina
authors.initials: S
authors.lastname: Chan
authors.forename: Joanna
authors.initials: J
authors.lastname: Ku
mesh_terms: D016208:Databases, Factual; D003740:Dental Clinics; D004499:Education, Dental, Graduate / Q000706:statistics & numerical data; D004708:Endodontics / Q000193:education*; D006801:Humans; D007180:Incisor; D008334:Mandible; D008437:Maxilla; D008963:Molar; D010414:Pennsylvania; D019233:Retreatment / Q000706:statistics & numerical data; D012184:Retrograde Obturation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012389:Root Canal Obturation / Q000706:statistics & numerical data*