Comparative Analysis of Endodontic Apical Sealing Using Imaging Methods

Objectives: To compare in vitro the aspect of the endodontic apical sealing using optical coherence tomography (OCT) and computerized microtomography (µCT).
Methods: Forty-five uniradicular teeth with round canals instrumented with reciproc system, divided into groups (n=15) following the obturation protocols: GCL (Lateral condensation), GCTM (thermomechanical compaction) and GCU (single cone). Samples were scanned using µCT (parameters: 80 kV, 222 µA, and resolution of 11µm), OCT (parameters: SSOCT, 1300nm and axial resolution of 12µm), and periapical digital radiography. The images were analyzed by a calibrated examiner and a blind examiner using ImageJ, measuring the boundary of the obturation apical sealing, and fissures when present. Categorical and metric data were submitted to inferential analysis and the validity of the OCT as a diagnostic test was assessed with sensitivity and specificity tests.
Results: The work length average remained constant for all obturation techniques and image methods. OCT showed adequate sensitivity (97%) and specificity (73%) to detect fissures in the apical sealing in comparison to µCT. Both image methods found a higher number of fissures for lateral condensation technique (µCT p=0.011/ OCT p=0.002).
Conclusions: OCT can be used for apical obturation fissure assessment and the lateral condensation technique revealed more fissures with larger dimensions.