Intraosseous Anesthesia Using Dynamic Navigation Technology.

INTRODUCTION: This study presents a novel method to deliver intraosseous anesthesia using dynamic navigation technology. The study aimed to evaluate its safety and 3-dimensional (3D) accuracy in comparison to traditional freehand injection of intraosseous anesthesia. METHODS: Six identical sets of 3D-printed surgical jaw models (TrueJaw; DELendo, Santa Barbara, CA) comprising simulated alveolar and dental anatomy with 54 interradicular sites were used in this study. The injection sites were equally distributed based on the range of the inter-radicular distance (ie, 1.5-2.5 mm, 2.5-3.5 mm, and 3.5-4.5 mm). A board-certified endodontist randomly completed intraosseous drilling at inter-radicular sites of varying distance using freehand technique and the Navident dynamic navigation system (ClaroNav, Toronto, Ontario, Canada) with the X-Tip system (Dentsply Sirona, York, PA). The rate of root perforation associated with inter-radicular distance was compared between the 2 groups using the Fisher exact test. Two-dimensional (2D) and 3D horizontal, vertical, and angulation discrepancies between the planned and dynamically navigated guide sleeves were digitally measured using superimposed cone-beam computed tomographic scans. Analysis of variance models were used to determine if the interdental distance was associated with the accuracy measures from the dynamic navigation system. The significance level was set at 0.05. RESULTS: The rate of root perforation was significantly higher for the freehand group than the dynamic navigation (22% vs 0%, P < .05). For dynamic navigation, the 2D entry deviation was 0.71 mm (95% confidence interval [CI], 0.56-0.87). The mean 2D horizontal deviation was 0.96 mm (95% CI, 0.79-1.14), and the mean 2D vertical deviation was 0.70 mm (95% CI, 0.55-0.84). The 3D deviation at the tip was on an average 1.23 mm (95% CI, 1.05-1.42). The overall 3D angular deviation was on average 1.36° (95% CI, 1.15-1.56). The inter-radicular distance was not significantly associated with any 2D or 3D discrepancies. CONCLUSIONS: Successful and accurate drilling of dynamically navigated intraosseous delivery occurred in 100% of injection sites irrespective of the inter-radicular distance. It was significantly safer in comparison to freehand intraosseous drilling to prevent injury of the roots of the adjacent teeth in close proximity.

Dynamically Navigated versus Freehand Access Cavity Preparation: A Comparative Study on Substance Loss Using Simulated Calcified Canals.

INTRODUCTION: The aim of this in vitro study was to compare the speed, qualitative precision, and quantitative loss of tooth structure with freehand and dynamically navigated access preparation techniques for root canal location in 3-dimensional-printed teeth with simulated calcified root canals. METHODS: Forty maxillary and mandibular central incisors (tooth #9 and tooth #25) were 3-dimensionally printed to simulate canal calcification. Under simulated clinical conditions, access preparations were randomly performed with contemporary freehand and dynamically navigated techniques. Qualitative precision and quantitative loss of tooth structure were assessed on postoperative cone-beam computed tomographic scans using ITK-SNAP open-source segmentation (http://www.itksnap.org/). The associations between jaw, technique, volume of substance loss, and operating time were determined using analysis of variance models with Tukey-adjusted post hoc pair-wise comparisons. The kappa statistic was used to determine agreement between 2 independent, blinded raters on the qualitative assessment of the drill path. The association between the technique and jaw and qualitative assessment scoring was compared using the Fisher exact test. The significance level was set at .05. RESULTS: Dynamically navigated accesses resulted in significantly less mean substance loss in comparison with the freehand technique (27.2 vs 40.7 mm3, P < .05). Dynamically navigated accesses were also associated with higher optimal precision (drill path centered) to locate calcified canals in comparison with the freehand technique (75% vs 45%, P > .05). Mandibular teeth were associated with a negligible difference in substance loss between the access techniques (19.0 vs 19.1 mm3, P > .05). However, qualitatively the freehand technique was still prone to 30% higher chance of suboptimal precision (drill path tangentially transported) in locating calcified canals. Overall, dynamically navigated accesses were prepared significantly faster than freehand preparations (2.2 vs 7.06 minutes, P < .05). CONCLUSIONS: Within the limitations of this in vitro study, overall dynamically navigated access preparations led to significantly less mean substance loss with optimal and efficient precision in locating simulated anterior calcified root canals in comparison with freehand access preparations.

3-Dimensional Accuracy of Dynamic Navigation Technology in Locating Calcified Canals.

INTRODUCTION: This study aimed to present a novel dynamic navigation method to attain minimally invasive access cavity preparations and to evaluate its 3-dimensional (3D) accuracy in locating highly difficult simulated calcified canals among maxillary and mandibular teeth. METHODS: Three identical sets of maxillary and mandibular 3D-printed jaw models composed of 84 teeth in their anatomic locations with simulated calcified canals (N = 138 canals) were set up on dental manikins. The Navident dynamic navigation system (ClaroNav, Toronto, Ontario, Canada) was used to plan and execute access preparations randomly with high-speed drills by a board-certified Endodontist. Two-dimensional (2D) and 3D horizontal, vertical, and angulation discrepancies between the planned and placed access preparations were digitally measured using superimposed cone-beam computed tomographic scans. Analysis of covariance models were used to evaluate the associations and the interaction between tooth type and jaw, the canal orifice depth, and the discrepancies between planned and prepared access cavities. The significance level was set at .05. RESULTS: The mean 2D horizontal deviation from the canal orifice was 0.9 mm, and it was significantly higher on maxillary compared with mandibular teeth (P < .05). The mean 3D deviation from the canal orifice was 1.3 mm, and it was marginally higher on maxillary teeth in comparison with mandibular teeth (P ≥ .05). The mean 3D angular deviation was 1.7 degrees, and it was significantly higher in molars compared with premolars (P < .05). The 3D and 2D discrepancies were independent of the canal orifice depths (P > .05). The average drilling time was 57.8 seconds with significant dependence on the canal orifice depth, tooth type, and jaw (P < .05). CONCLUSIONS: This study shows the potential of applying dynamic 3D navigation technology with high-speed drills to preserve tooth structure and accurately locate root canals in teeth with pulp canal obliteration.