Assessment of operator performance during dynamically guided osteotomy and root-end resection in endodontic microsurgery: A cross-sectional in vitro study.

[OBJECTIVES] To compare in vitro the magnitude of deviations, task-focused performance, and perspective on instrumentation of two operators with different levels of experience using computer-assisted dynamic navigation (C-ADN) systems during osteotomy/root-end resection (RER) in models mimicking thick bone layers overlying the apices.

[METHODS] Eight models with 15 tooth replicas each were assigned equally to two operators (experienced/less experienced). Pre- and post-operative cone-beam computed tomography images were superimposed using a C-ADN software to determine discrepancies between the planned and real trajectory of the trephine bur. Task-focused operator performance and subjective aspects derived from operator's perspective related to C-ADN were also analyzed. Statistical analysis was completed through parametric methods and Chi-square/fisher exact tests.

[RESULTS] Pearson correlation tests showed positive correlations between the distance from buccal cortical plate to root apex regarding deviation at apex, trephination depth, and visuomotor coordination time. The less experienced operator had significantly greater values of visuomotor coordination time, deviation at buccal entry point and apex, trephination depth, and angular deviation, as well as a significantly higher frequency of apex location failures, poor RER quality, and mishaps in comparison with those of the experienced operator, thus leading to a significantly higher task-focused performance for the experienced operator. Both operators improved the visuomotor task through diverse attempts, acknowledged enhanced situation awareness, surgical procedure quality, and patient safety associated to the use of C-ADN, and reported a positive impact on the developing and maintaining navigational skills. Concerns regarding perceived workload, mental demand, and usability difficulties were reported only by the less experienced operator.

[CONCLUSIONS] Dynamically guided osteotomy and RER prepared with trephine burs entail a subset of visuomotor skills requiring a special learning which may vary depending on the operator's experience and the procedure complexity as determined by dentoalveolar anatomy. Likewise, the perceived usability about C-ADN systems increases insofar the complexity of the user interface decreases and upsurge the earlier experience with these systems.

[STATEMENT OF CLINICAL RELEVANCE] This study shows that both the technical characteristics involved in the function of C-ADN systems and the subjective operators' perceptions are critical for the accuracy of task-focused performance during endodontic microsurgery.