Detection of dentinal cracks after root-end resection: an ex vivo study comparing microscopy and endoscopy with...

Dentinal cracks are occasionally observed at the cut root face after root-end resection in apical surgery. The objective of this ex vivo study was to evaluate and compare the efficiency of visual aids to identify root-end dentinal cracks.

Twenty-six extracted human molars were decoronated, and the root canals were instrumented and filled. The apical 3 mm of the roots were resected, and the cut root faces were assessed with microscopy at x16 and x24 magnification and with endoscopy at x8 and x64 magnification (four visual aids). Roots were then duplicated for inspection with scanning electron microscopy. The presence, type, and location of cracks were registered by a blinded observer, with the scanning electron microcopy serving as the reference. The percentages of correct identification of dentinal cracks were then statistically compared among the four test configurations.

Endoscopy x64 showed the highest sensitivity for crack identification, irrespective of the applied methodology (ie, per root and per crack). However, higher scores of false-positive cracks (lower specificity) were found with endoscopy x64 than with the other tested visual aids. The correct detection and location of complete canal cracks (55.3%, 52.6%, 68.4%, and 78.9%) were higher than the detection of incomplete canal cracks (42.2%, 42.2%, 52.0%, and 64.7%) using the four tested visual aids (microscopy at x16 and x24 magnification and endoscopy at x8 and x64 magnification, respectively). Only one of five intradentin cracks was identified with endoscopy x64.

Overall, endoscopy x64 proved the most accurate visual aid for the identification of dentinal cracks after root-end resection in extracted human teeth; however, it also provided the most false identifications.