Comparing the accuracy and active drilling time of robot-assisted and dynamic navigation systems in access cavity preparation: an in vitro study

This in vitro study aims to compare the accuracy and active drilling time of an autonomous robot-assisted system (RAS) and a dynamic navigation system (DNS) during access cavity preparation in extracted single-rooted human teeth. Sixty-four sound, single-rooted human extracted teeth were randomly assigned to either the RAS or the DNS group ( n = 32 per group). Under simulated clinical conditions, an experienced endodontist performed access cavity preparation on the specimens using the allocated system for each group. Postoperative cone beam computed tomography (CBCT) images were superimposed on preoperative images and compared with planned pathways to quantify deviations between planned and actual pathways, namely coronal deviation, apical deviation, and angular deflection. Additionally, we compared tooth substance loss, active drilling time, and procedure failures between the two groups. Coronal deviation, angular deflection, and substance loss in the RAS group were significantly lower than those in the DNS group ( p < 0.05). In both anterior teeth and premolar subgroups, the RAS group exhibited lower angular deflection ( p < 0.001) and substance loss ( p < 0.01) than the DNS group. Both systems achieved a 93.75% success rate in locating root canals. Four structurally damaged specimens (two in each group) were recorded as procedural failures and excluded from the accuracy analysis. Within the limitations of this in vitro study, the RAS demonstrated higher technical accuracy and superior tooth structure preservation than the DNS during access cavity preparation in extracted single-rooted teeth.