Root canal treatment of a dilacerated mandibular premolar using a novel instrumentation approach. A case report

To report on a novel method to instrument a dilacerated double-curved mandibular premolar.

A 45-year-old female was referred suffering from diffuse pain emanating from the mandibular right quadrant. The second premolar (tooth 45) was diagnosed with symptomatic irreversible pulpitis. The radiographic examination revealed a dilacerated S-shaped root configuration, with 2 severe curvatures of <2 mm radius. Under local anaesthesia and rubber dam isolation, a glide path was created until a size 10 K-file reached working length. Instrumentation to larger size was achieved with a novel approach using controlled memory files. The controlled memory files were pre-curved and passively inserted below the curvature until maximum frictional resistance. The motor was activated by maintaining light apical pressure, and the files were withdrawn from the canal. This procedure was repeated until each file could reach the working length. Chemical disinfection was achieved with positive syringe irrigation of 6% NaOCl, followed by 17% EDTA rinsing and manual dynamic gutta-percha activation of the irrigants. Canal filling was achieved using the continuous wave of condensation technique and thermoplasticized injectable gutta-percha backfill. The postoperative radiography revealed that the initial canal anatomy of the dilacerated double-curved root canal was preserved.