title: Efficacy of different irrigation techniques in the removal of calcium hydroxide from a simulated internal root resorption cavity.
abstract: OBJECTIVE
  To evaluate the efficacy of six irrigation techniques to remove calcium hydroxide (CH) from a simulated internal root resorption cavity.
  
  
  METHODS
  The root canals of 100 single-rooted teeth were prepared using the ProTaper system to size F5. The roots were split longitudinally, and standardized simulated internal root resorption cavities were prepared in the two root halves. The root halves were reassembled, and CH was placed into the root canals, with the exception of five teeth that served as the negative control group. Another five teeth (the positive control group) were not subjected to the CH removal procedure. Ninety teeth were randomly divided into six experimental groups (n = 15), according to the final irrigation techniques used: conventional syringe irrigation (CSI), CanalBrush (CB), passive ultrasonic irrigation (PUI), self-adjusting file (SAF) system, EndoActivator (EA), and apical negative pressure irrigation (EndoVac system). Five millilitres of 3% NaOCl and 17% EDTA were used in all experimental groups during the CH removal procedure. The amount of remaining CH was evaluated under a stereomicroscope at 20 ×magnification, using a 4-grade scoring system. The data were statistically compared using the Kruskal-Wallis and Mann-Whitney U-tests (P < 0.05).
  
  
  RESULTS
  Remnants of CH in simulated internal root resorption cavities were found in all experimental groups. SAF and PUI were superior to the other groups (P < 0.05); however, there was no significant difference between the SAF and PUI (P > 0.05). There were also no significant differences between the CSI, CB, EA and EndoVac groups (P > 0.05).
  
  
  CONCLUSIONS
  None of the irrigation techniques was able to completely remove CH from a simulated internal root resorption cavity.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: H S
authors.initials: HS
authors.lastname: Topçuoğlu
authors.forename: S
authors.initials: S
authors.lastname: Düzgün
authors.forename: K T
authors.initials: KT
authors.lastname: Ceyhanlı
authors.forename: A
authors.initials: A
authors.lastname: Aktı
authors.forename: K
authors.initials: K
authors.lastname: Pala
authors.forename: B
authors.initials: B
authors.lastname: Kesim
mesh_terms: D002126:Calcium Hydroxide / Q000302:isolation & purification*; D006801:Humans; D012391:Root Resorption; D007507:Therapeutic Irrigation
chemical_list: D002126:Calcium Hydroxide
keywords: calcium hydroxide; irrigation; simulated internal resorption cavity