title: Detection of residual obturation material after root canal retreatment with three different techniques using a dental operating microscope and a stereomicroscope: An in vitro comparative evaluation.
abstract: OBJECTIVE
  The study was designed to compare the efficiency of three different methods used for retreatment using a dental operating microscope (DOM) and a stereomicroscope and to evaluate and compare the two methods for detection of residual obturation material after retreatment.
  
  
  BACKGROUND
  The DOM can play an important role in the successful retreatment by detecting the remaining obturation material.
  
  
  METHODS
  Thirty extracted maxillary central incisors were collected and obturated after biomechanical preparation. The samples were divided into three groups depending on the method of retreatment: Group I, H-files; Group II, ProTaper Universal retreatment files; and Group III: H-files + Gates-Glidden drills, with 10 samples in each group. After retreatment, the samples were observed under a DOM for detection of residual obturation material. Later, the teeth were cleared and observed under a stereomicroscope for detecting the remaining filling material. The results were subjected to the Spearman's rank order test and other statistical analysis.
  
  
  RESULTS
  The maximum cleanliness of the root canal walls was seen in Group I while Group II showed the least. The difference between the mean scores obtained with a DOM and a stereomicroscope was statistically significant (P = 0.05).
  
  
  CONCLUSIONS
  None of the techniques could completely remove the obturation material. The root canal cleanliness is best achieved when retreatment is performed under a DOM.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Institute of Dental Sciences, Pilibhit Bypass Road, Bareilly, India.
authors.forename: Raju
authors.initials: R
authors.lastname: Chauhan
authors.forename: Ap
authors.initials: A
authors.lastname: Tikku
authors.forename: Anil
authors.initials: A
authors.lastname: Chandra