title: Root canal morphology and variations of mandibular premolars by clearing technique: an in vitro study.
abstract: OBJECTIVE
  The aim of this study was to compare internal anatomy between first and second mandibular premolars and to study different percentage variations of root canal morphology of mandibular premolars in Gujarat population based on Vertucci's classification by clearing technique.
  
  
  METHODS
  A total of 80 extracted intact permanent mandibular premolars (40 each mandibular first premolar and mandibular second premolar) with fully formed apices were collected. Access cavity was prepared with endo access kit, all samples were placed in 2.5% sodium hypochlorite for 48 hours, after that all samples were washed in running water for 2 hours. After washing, all samples were transferred to 5% nitric acid, for decalcification, for 72 hours, with the acid being changed every 24 hours and stirred once every 8 hours. All samples were washed in running water and dehydrated using ascending grades (70%, 80%, 90% and 100%) of isopropyl alcohol for 2 days. Finally, they were rendered transparent by immersion in methyl salicylate for 15 minutes and then India ink dye was injected into the access cavity. The anatomy of the root canal was observed and classified based on the Vertucci's classification.
  
  
  METHODS
  Parametric Z-test was used to compare the variation between mandibular first and second premolars.
  
  
  RESULTS
  In mandibular first premolar, type 1 was found in 20%, type 2 was 5%, type 3 was 5%, type 4 was 25%, type 5 was 12.5% and type 6 was 2.5% of total samples. Whereas, in mandibular second premolar, type 1 was found in 80% out of all samples, type 4 was 2.5%, type 5 was 17.5%. Type 2, type 3, type 6, type 7 and type 8 were not found in this study.
  
  
  CONCLUSIONS
  Mandibular first premolar showed higher variation (75%) compared to mandibular second premolar (37.5%).
  
  
  CONCLUSIONS
  The knowledge of variations in the root canal morphology of the mandibular premolars can enhance the level of endodontic treatment of mandibular premolars.
  
  
  BACKGROUND
  Root canal morphology, Vertucci's classification, Clearing technique. How to cite this article: Parekh V, Shah N, Joshi H. Root Canal Morphology and Variations of Mandibular Premolars by Clearing Technique: An in vitro Study. J Contemp Dent Pract 2011;12(4):318-321. Source of support: Nil Conflict of interest: None declared.
authors.affiliation: Department of Conservative and Endodontics, KM Shah Dental College and Hospital, Sumandeep VidyapeethWaghodia Road, Piparia, Vadodara, Gujarat, India. drchiragtaluja@yahoo.com
authors.forename: Vaishali
authors.initials: V
authors.lastname: Parekh
authors.forename: Nimisha
authors.initials: N
authors.lastname: Shah
authors.forename: Hardik
authors.initials: H
authors.lastname: Joshi
mesh_terms: D001641:Bicuspid / Q000033:anatomy & histology*; D002244:Carbon; D002965:Classification; D004396:Coloring Agents; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D016591:Histocytological Preparation Techniques; D006801:Humans; D007194:India; D008334:Mandible; D009811:Odontometry / Q000379:methods*; D014092:Tooth Root / Q000033:anatomy & histology*
chemical_list: D004396:Coloring Agents; C028433:chinese ink; D002244:Carbon