title: Smear layer removal efficacy of different irrigating solutions: a comparative scanning electron microscope evaluation.
abstract: OBJECTIVE
  Comparative evaluation of cleaning efficacy of smear layer removal by different irrigating solutions such as 2.5% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) with 2.5% NaOCl, 10% citric acid with 2.5% NaOCl and 1% tetracycline Hydrochloride (HCl) with 2.5% NaOCl for smear layer removal in the apical third of root canal.
  
  
  METHODS
  In vitro material science study.
  
  
  METHODS
  Seventy-five single rooted permanent maxillary central incisor teeth were subjected to standardized root canal instrumentation (crown down technique). The teeth were randomly divided into five groups with 15 teeth in each groups: (1) Normal saline (n = 15) (2) 2.5% NaOCl (n = 15) (3) 17% EDTA + 2.5% NaOCl (n = 15) (4) 10% citric acid + 2.5% NaOCl (n = 15) (5) 1.0% tetracycline HCL + 2.5% NaOCl (n = 15). After final irrigation, the teeth were prepared for scanning electron microscope analysis to evaluate the cleaning of apical third of radicular dentine to determine the presence or absence of smear layer.
  
  
  METHODS
  The results were analyzed by nonparametric statistical analysis techniques. Kruskal-Wallis test, Mann-Whitney test and Chi-square tests were carried out.
  
  
  RESULTS
  There was no significant statistical difference in the efficacy of smear layer removal when 2.5% NaOCl was compared with 17% EDTA with 2.5% NaOCl, 10% citric acid with 2.5% NaOCl and 1% tetracycline HCl with 2.5% NaOCl in apical third of root canals.
  
  
  CONCLUSIONS
  The present study suggests that irrigating agents, citric acid and tetracycline HCl can be used as an alternative to EDTA for the removal of smear layer in endodontics.
authors.forename: B
authors.initials: B
authors.lastname: Ahir
authors.forename: V
authors.initials: V
authors.lastname: Parekh
authors.affiliation: Department of Dentistry, GMERS Medical College and Hospital, Gandhinagar, Gujarat, India.
authors.forename: M K
authors.initials: MK
authors.lastname: Katyayan
authors.forename: P A
authors.initials: PA
authors.lastname: Katyayan
mesh_terms: D019343:Citric Acid / Q000494:pharmacology; D003786:Dental Pulp Cavity / Q000187:drug effects* / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects / Q000648:ultrastructure; D004492:Edetic Acid / Q000627:therapeutic use; D006801:Humans; D007180:Incisor / Q000187:drug effects / Q000648:ultrastructure; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011897:Random Allocation; D012388:Root Canal Irrigants / Q000494:pharmacology*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D016369:Smear Layer / Q000648:ultrastructure*; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013752:Tetracycline / Q000494:pharmacology; D019227:Tooth Apex / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D012388:Root Canal Irrigants; D019343:Citric Acid; D004492:Edetic Acid; D012973:Sodium Hypochlorite; D013752:Tetracycline