Diagnostic accuracy of endoscopy in periradicular surgery - a comparison with scanning electron microscopy

Aim To compare the accuracy of endoscopic diagnostics with the scanning electron microscope (SEM) in evaluating elements of periradicular surgery. Methodology The material consisted of 22 extracted human molars, which were subjected to the following treatments: orthograde root-canal obturation, root-end resection and root-end cavity preparation with diamond-coated sonic microtips. After each step, the cut root face was inspected with an endoscope, and subsequently, the roots were duplicated for SEM evaluation. Endoscope findings were compared to those obtained with SEM serving as the 'gold standard with a blinded observer. The presence of the following structures was assessed including specificity and sensitivity: isthmuses, accessory canals, obturation gaps, microfractures and chipping of cavity margins. Results The specificity and sensitivity of the identification of isthmuses or accessory canals was 100% each for the endoscope compared to SEM. The sensitivity of identification of obturation gaps, crack formation or chipping ranged between 73 and 95% (except intradentine cracks with only 36% sensitivity). The specificity of the same parameters ranged between 77 and 100% for the endoscope compared to SEM. Conclusions With the exception of intradentine cracks, the endoscope accurately identified microstructures following root-end resection and root-end-preparation. The endoscope could be considered for use during intraoperative diagnostics in periradicular surgery.