Real-Time Guided Endodontics with a Miniaturized Dynamic Navigation System Versus Conventional Freehand Endodontic Access Cavity Preparation: Substance Loss and Procedure Time.

Introduction: This study aimed to evaluate substance loss and the time required for access cavity preparation (ACP) using the conventional freehand method (CONV) versus a miniaturized dynamic navigation system of real-time guided endodontics (RTGE) in an in vitro model using 3-dimensional-printed teeth.

Methods: Nine human anterior maxillary teeth were selected and micro-computed tomographic scanned. Root canals were virtually reduced to 2 mm below the cementoenamel junction. The teeth were digitally duplicated and mirrored to yield 6 different models with 6 single-rooted teeth each. The models were 3-dimensionally printed using radiopaque resin and consecutively mounted on a dental mannequin for ACP. Two operators with 12 and 2 years of clinical experience, respectively, received 6 models (36 teeth) each and performed ACP on half of the models using RTGE (after digital planning) and CONV on the other half 2 weeks later. The time was recorded. Postoperative substance loss was measured by cone-beam computed tomographic imaging. The differences in time and substance loss between the methods and operators were evaluated by the t test.

Results: Overall, substance loss was significantly lower with RTGE than CONV (mean = 10.5 mm vs 29.7 mm), but both procedures took a similar time per tooth (mean = 195 vs 193 seconds). Operator 1 (more experienced) achieved significantly less substance loss than operator 2 with CONV (mean = 19.9 vs 39.4 mm) but not with RTGE (mean = 10.3 vs 10.6 mm).

Conclusions: RTGE is a practicable, substance-sparing method performed in comparable time as CONV. Moreover, RTGE seems to be independent of operator experience.