抄録
Proper endodontic access cavity （AC） preparation is crucial for the long-term success of root canal treatment. However, achieving proper AC preparation remains challenging, particularly for novice clinicians. Static navigation with optical scan （SNOS） is a technique developed to guide AC preparation using static superimposition of preoperative cone-beam computed tomography data with intraoral scanner （IOS） data. This in vitro study aimed to evaluate the efficacy of SNOS in improving the precision of AC preparation. A total of 40 dental residents were included in this study and randomly assigned to either the control group （freehand with reference model check, n＝20） or the SNOS group （n＝20）. AC preparation was performed using simulated maxillary first molar models. The SNOS group used the navigation system to visualize the drilling status. The volumes of overprepared area （OPA） and underprepared area （UPA） relative to the reference standard were determined using postoperative IOS scans, and the number of perforations was recorded. Data were analyzed using Student’s t-test （α＝0.05）. The mean OPA volume was significantly lower in the SNOS group than in the control group （p＝0.040）. No significant difference in UPA volume was observed between the two groups （p＝0.206）. Two perforations were observed in the control group, whereas none were observed in the SNOS group. These findings indicate that the SNOS system is an effective and safe tool for improving the accuracy of AC preparation. The use of SNOS significantly reduced the incidence of overpreparation and eliminated the risk of perforation. This cost-effective static navigation approach has significant potential as a training and chairside aid for enhancing the quality of endodontic treatment.
