(PO22) Reliability of the Tactile Method During the Exploration of the Apical Foramen of Permanent Teeth with Necrotic Pulps and Open Apices

Abstract: This research assessed the inter-observer agreement and precision of the Tactile Method (TM) during the orthograde exploration of the apical terminal portion of permanent teeth with necrotic pulps and open apices. This observational clinical study included nine non-vital teeth with incomplete root development from nine patients. Two observers analyzed the pre-operative CBCT scans to determine the distance between the incisal reference point and the apical terminal portion at four apical measurement points: buccal, lingual, distal, and mesial. The shortest of these points was considered the tomographic working length (TWL) and was used as the control group. Subsequently, canal accesses and light chemo-mechanical brushing of the main canals were performed, followed by radiographic working length (RWL) establishment. Two different operators applied the TM using a #25 manual K-file (Dentsply Maillefer, Ballaigues, Switzerland) pre-curved at the tip at a 90° angle. The same four apical measurement points were explored, and the tactile method working length (TMWL) was determined. Inter-observer agreement was assessed using the Bland-Altman method. The Wilcoxon signed-rank and Student's t-tests analyzed the correlation between methods (p ≤ 0.05). The measurements conducted for TM and TWL showed a high level of agreement (0.486 and -0.144 mm, respectively). In comparison to the control group (TWL) and TMWL, RWL showed no significant correlation (p < 0.001 and p = 0.0068, respectively). The TM demonstrated a reliable level of inter-observer agreement and could prove valuable when dealing with permanent teeth exhibiting non-vital pulps and open apices, especially in cases with radiographic evidence of external inflammatory apical resorption.