Reliability of sealer penetration measurement methods and assessment of dentine penetrability after endodontic retreatment: A correlation in vitro study

This study evaluated the reliability of sealer penetration measurement methods used with confocal laser scanning microscopy in correlation with the percentage of residual root filling and examined the effect of residual root-filling material on dentine penetrability after retreatment. Extracted teeth were randomly divided into different groups according to the obturation sealer used (n = 6); BioRoot RCS; MTA Fillapex; Bio-C and AH Plus. Root-filling material was removed before the secondary chemo-mechanical preparation and obturation using fluorescein labelled AH Plus. Multiple micro-computed tomography scans were obtained followed by confocal laser scanning microscopy to measure the penetration of the labelled sealer into the dentinal tubules using four different methods. Measuring sealer penetration into radicular dentine using the penetration percentage method was found to be the most reliable. Dentine penetrability during retreatment did not seem to be affected by the type of residual root-filling material.