Learning curve of dynamic navigation-assisted zygomatic implant surgery: An in vitro study.

STATEMENT OF PROBLEM: Dynamic computer-assisted zygomatic implant surgery (dCAZIS) has been reported to provide clinical efficacy with high accuracy and low risk of complications. However, the learning curve before performing dCAZIS effectively is unknown. PURPOSE: The purpose of this in vitro study was to explore the learning curve of dCAZIS in dentists with different levels of experience in implant dentistry and navigation surgery. MATERIAL AND METHODS: Six senior dental students were randomly divided into 3 groups for initial training (FH-CI group: pretraining on freehand conventional implant surgery; FH-ZI group: pretraining on freehand ZI surgery; DN-CI group: pretraining on conventional implant surgery under dynamic navigation). Then, every operator conducted 6 repeated dCAZIS training sessions on edentulous 3-dimensional (3D) printed skull models and was asked to complete a self-report questionnaire after each training session. A total of 36 postoperative cone beam computed tomography (CBCT) scans with 144 ZI osteotomy site preparations were obtained and superimposed over the preoperative design for accuracy measurements. The operation time, 3D deviations, and results of the self-reports were recorded. Comparisons among groups were analyzed with independent-sample Kruskal-Wallis tests (α=.05), and correlations between study outcomes and the number of practices were calculated. RESULTS: Operator experience and increased practice times did not significantly affect the accuracy of dCAZIS (P>.05). However, the operation time varied among groups (P<.001), and significantly shortened with more practice, reaching 11.51 ±1.68 minutes at the fifth attempt in the FH-CI group (P<.001 compared with the first practice), 14.48 ±3.07 minutes at the third attempt in the FH-ZI group (P=.038), and 8.68 ±0.58 minutes at the sixth attempt in the DN-CI group (P<.001). All groups reached their own learning curve plateau stage within 6 practice sessions. As the number of practice sessions increased, the results from the self-report questionnaires gradually improved. CONCLUSIONS: Among dentists with different levels of experience in implant dentistry and navigation surgery, dCAZIS was found to have a learning curve with respect to operation time but not implant accuracy. Experience in ZI surgery had little impact on the learning curve of dCAZIS, but experience in navigation surgery was a key factor.

Accuracy of immediate dental implant placement with task-autonomous robotic system and navigation system: An in vitro study.

OBJECTIVES: The aim of this study was to compare the accuracy of dental implant placement in a single tooth gap, including the postextraction site and healed site, using a task-autonomous robotic system and a dynamic navigation system. MATERIALS AND METHODS: Forty partially edentulous models requiring both immediate and conventional implant placement were randomly divided into a robotic system group and a navigation system group. The coronal, apical, and angular deviations of the implants were measured and assessed between the groups. RESULTS: The deviations in immediate implant placement were compared between the robotic system and dynamic navigation system groups, showing a mean (±SD) coronal deviation of 0.86 ± 0.36 versus 0.70 ± 0.21 mm (p = .101), a mean apical deviation of 0.77 ± 0.34 versus 0.95 ± 0.38 mm (p = .127), and a mean angular deviation of 1.94 ± 0.66° versus 3.44 ± 1.38° (p < .001). At the healed site, significantly smaller coronal deviation (0.46 ± 0.29 vs. 0.70 ± 0.30 mm, p = .005), apical deviation (0.56 ± 0.30 vs. 0.85 ± 0.25 mm, p < .001), and angular deviation (1.36 ± 0.54 vs. 1.80 ± 0.70 mm, p = .034) were found in the robotic system group than in the dynamic navigation group. CONCLUSIONS: The position in both immediate and conventional implant placement was more precise with the task-autonomous robotic system than with the dynamic navigation system. Its performance in actual clinical applications should be confirmed in further trials.

Exploring training dental implant placement using static or dynamic devices among dental students.

BACKGROUND: Static computer-assisted surgery (s-CAIS) and dynamic computer-assisted implant surgery (d-CAIS) are the main digital approaches in guiding dental implant placement. PURPOSE: The aim of this study was to explore and compare the learning curves for s-CAIS and d-CAIS by beginners. MATERIALS AND METHODS: Three dental students used each dental model for drilling five positions with missing teeth. Operators performed the drilling test for five sets of dental models with an interval of 7 ± 1 days assisted by the d-CAIS system. After a six-month break, the same students performed the drilling test again in the same way but with the s-CAIS system. A total of thirty models were used, and 150 implants were inserted. The operation time and relative deviations were recorded and calculated. Correlations between various deviation parameters and attempts were tested with independent-samples Kruskal-Wallis tests. RESULTS: A significant difference between the two groups was found in the operation time (p < .001). For accuracy, the difference was found in the first attempt of coronal and apical deviations but disappeared as the training went on. As the practice progressed, improvement was evident in the d-CAIS group but not in the s-CAIS group. When reaching the plateau stage of the learning curve of the d-CAIS group (after five attempts), the influence of different methods of guidance was limited between the two groups. CONCLUSIONS: A learning curve effect was found in d-CAIS but not in s-CAIS in vitro tests by beginners. The operating procedure of dynamic navigated and static template-guided implant placement was easy to master.

The effect of anatomy on osteogenesis after maxillary sinus floor augmentation: a radiographic and histological analysis.

OBJECTIVES: To assess how anatomy and osteogenesis correlated with results of maxillary sinus floor augmentation (MSFA). MATERIALS AND METHODS: Patients with partial edentulism and advanced atrophy of the posterior maxillae (≤ 4 mm residual bone height, RBH) underwent MSFA with sole deproteinized bovine bone matrix (DBBM) through a lateral approach. After a 6 to 9-month healing period, bone core biopsies were obtained from the sites of implant insertion for histological evaluation. The correlations between anatomical and histomorphometric variables were analyzed in a multiple regression model. RESULTS: Forty-nine patients were recruited. One biopsy per patient was obtained from the augmented sinus. Thirty-seven bone core biopsies were intact and met the requirement for histomorphometry analysis. The mean (± standard deviation) percentages of vital bone (VB), remaining DBBM, and non-mineralized tissue were 18.25 ± 4.76%, 27.74 ± 6.68%, and 54.08 ± 6.07%, respectively. No statistically significant correlations were found between RBH and VB% (p = 0.44) or between sinus contour and VB% (p = 0.33). However, there was an inverse correlation between the sinus width (SW) and VB % (SW1: R2 = 0.13, p = 0.03; SW2: R2 = 0.15, p = 0.02). CONCLUSIONS: After a healing period of 6-9 months, wider sinuses augmented with DBBM alone tended to have a lower proportion of new bone formation, while RBH and sinus contour did not appear to affect osteogenesis after MSFA. CLINICAL RELEVANCE: This study emphasized the effect of anatomy on osteogenesis after MSFA. The result of the study may have an indication to the clinician that SW is a consideration when selecting the bone grafting material and deciding the healing period of MSFA.

The accuracy of a novel image-guided hybrid robotic system for dental implant placement: An in vitro study.

BACKGROUND: This in vitro study aims to evaluate the accuracy of dental implant placement by a novel image-guided hybrid robotic system for dental implant surgery (HRS-DIS). METHODS: The HRS-DIS with a 5 degree of freedom (DOF) serial manipulator and a 6 DOF Stewart platform was developed. To evaluate the accuracy of repeated drilling, the holes were prepared twice with a 2.2 mm drill. To evaluate the accuracy of dental implant placement, the entry, exit and angle deviations of dental implants were measured. RESULTS: Twenty-four holes were prepared twice, and mean (±SD) of diameters were measured as 2.2 ± 0.02 mm. A total of 160 dental implants were placed in 32 phantoms by HRS-DIS. The mean (±SD) of the entry, exit and angle deviation were 0.8 ± 0.54 mm, 0.87 ± 0.54 mm and 1.0 1 ± 0.44°, respectively. CONCLUSIONS: The results of the in vitro study preliminarily validated that the HRS-DIS could provide a high accuracy for dental implant surgery.

Accuracy of dental implant surgery using dynamic navigation and robotic systems: An in vitro study.

OBJECTIVES: To compare the accuracy of dental implant placement using a dynamic navigation and a robotic system. METHODS: Eighty three-dimensional (3D) printed phantoms, including edentulous and partially edentulous jaws, were assigned to two groups: a dynamic navigation system (Beidou-SNS) group and a robotic system (Hybrid Robotic System for Dental Implant Surgery, HRS-DIS) group. The entry, exit and angle deviations of the implants in 3D world were measured after pre-operative plans and postoperative cone-beam computed tomography (CBCT) fusion. A linear mixed model with a random intercept was applied, and a p value <.05 was considered statistically significant. RESULTS: A total of 480 implants were placed in 80 phantoms. The comparison deviation of the dynamic navigation system and robotic system groups showed a mean (± SD) entry deviation of 0.96 ± 0.57 mm vs. 0.83 ± 0.55 mm (p=0.04), a mean exit deviation of 1.06 ± 0.59 mm vs. 0.91 ± 0.56 mm (p=0.04), and a mean angle deviation of 2.41± 1.42° vs. 1 ± 0.48° (p<0.00). CONCLUSIONS: The implant positioning accuracy of the robotic system was superior to that of the dynamic navigation system, suggesting that this prototype robotic system (HRS-DIS) could be a promising tool in dental implant surgery. CLINICAL SIGNIFICANCE: This in vitro study is of clinical interest because it preliminarily shows that a robotic system exhibits lower deviations of dental implants than a dynamic navigation system, in dental implant surgery, in both partially and completely edentulous jaws. Further clinical studies are needed to evaluate the current results.