title: A retrospective clinical study of incidence of root canal instrument separation in an endodontics graduate program: a PennEndo database study.
abstract: This study investigated the incidence of hand and rotary instrument separation (IS) in the endodontics graduate program at the University of Pennsylvania between 2000 and 2004. In 4,865 endodontic resident cases the incidence of hand and rotary IS was 0.25% and 1.68%, respectively. The odds for rotary IS were seven times more than for hand IS. The probability of separating a file in apical third was 33, and 6 times more likely when compared to coronal and middle thirds of the canals. The highest percentage of IS occurred in mandibular (55.5%) and maxillary (33.3%) molars. Furthermore, the odds of separating a file in molars were 2.9 times greater than premolars. Among the ProFile series 29 rotary instruments, the .06 taper # 5 and # 6 files separated the most. There was no significant difference in IS between the use of torque controlled versus nontorque controlled handpieces, nor between first and second year residency.
authors.affiliation: Department of Endodontics, The Robert Schattner Center, University of Pennsylvania, School of Dental Medicine, Philadelphia, Pennsylvania 19104-6030, USA. miqbal@pobox.upenn.edu
authors.forename: Mian K
authors.initials: MK
authors.lastname: Iqbal
authors.forename: Meetu R
authors.initials: MR
authors.lastname: Kohli
authors.forename: Jessica S
authors.initials: JS
authors.lastname: Kim
mesh_terms: D001641:Bicuspid / Q000473:pathology; D015331:Cohort Studies; D019992:Databases as Topic; D003786:Dental Pulp Cavity / Q000473:pathology; D004499:Education, Dental, Graduate; D004708:Endodontics / Q000193:education; D004867:Equipment Design; D004868:Equipment Failure; D006801:Humans; D007396:Internship and Residency; D008963:Molar / Q000473:pathology; D010414:Pennsylvania; D011336:Probability; D012189:Retrospective Studies; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000706:statistics & numerical data; D012399:Rotation; D013499:Surface Properties; D019227:Tooth Apex / Q000473:pathology; D019415:Torque