Learning Curve for Dynamic Navigation Procedure During Endodontic Management of Permanent Maxillary Anterior Teeth with Pulp Canal Calcification: A Risk-Adjusted Cumulative Summation (RA-CUSUM) Analysis of a Single Operator's Experience.

Introduction: The dynamic navigation system (DNS) in endodontics presents a significant learning curve. This cross-sectional study aimed to assess the number of cases required to achieve consistent performance in DNS-assisted treatment of maxillary anterior teeth with pulp canal calcification.

Methods: A series of DNS procedures were performed on 45 calcified maxillary anterior teeth with pulp necrosis by a single endodontist who had no prior clinical DNS experience. Pre-operative cone beam computed tomography (CBCT) was obtained. After trace registration and calibration, drilling was executed using a low-speed bur. Once the canal was located and scouted to the working length, a post-operative CBCT was taken immediately. Angular deviation (AD), linear deviation (LD), and operating time (OT) were measured. The learning curve was evaluated using the risk-adjusted cumulative sum (CUSUM) analysis method.

Results: The overall success rate in locating canals was 93.33% (95% CI 80.7, 98.3). The mean (±SD) for AD, LD and OT was 3.21 ± 2.23 degrees, 0.52 ± 0.33 mm and 34.14 ± 13.18 minutes, respectively. For AD, two distinct peaks were observed at the 5th and 18th cases, identifying three learning phases: Phase I (cases 1-5), Phase II (cases 6-18), and Phase III (cases 19-45). Similarly, LD exhibited peaks at the 13th and 28th cases. Two peaks for OT were identified at the 7th and 26th cases.

Conclusions: Achieving technical proficiency in locating calcified canals using DNS required approximately 18 to 28 cases, indicating a significant learning curve that must be overcome for optimal accuracy.