Guidance means accuracy: A randomized clinical trial on freehand versus guided dental implantation

Prevalence of Dental Implant Positioning Errors: A Radiographic Analysis

Objectives Implant placement errors remain a persistent challenge, leading to complications such as peri-implant bone loss, neurosensory issues, and, in severe cases, implant failure. This study evaluates the prevalence and characteristics of dental implant positioning errors in patients treated at the Dental University Hospital. Methods: A sample of 500 cone-beam computed tomography (CBCT) scans was used to assess implants for positioning errors, including thread exposure, proximity to anatomical structures, and violations of inter-implant and implant-tooth distances. Results: A total of 56.6% of the implants exhibited positioning errors, with the maxillary posterior region being the most commonly affected area (51.6%). The most frequent errors observed were thread exposure (37.7%) and implant proximity to the maxillary sinus (27.7%). Statistical analysis revealed significant correlations between implant positioning errors and anatomical location, underscoring the need for meticulous preoperative planning and advanced imaging. While factors such as patient age, implant length, and diameter were analyzed, no statistically significant differences were found in error prevalence based on sex or demographic variables. Conclusions: This study highlights the importance of combining clinical expertise with advanced imaging modalities like CBCT to minimize implant positioning errors and improve patient outcomes. Future research should focus on refining surgical techniques and evaluating the impact of the implants' design and patient-specific factors on the accuracy of placements.

Freehand vs. computer-aided implant surgery: a systematic review and meta-analysis-part 1: accuracy of planned and placed implant position

OBJECTIVES

This systematic review aimed to investigate and compare the accuracy of free-hand and computer-aided implant surgery (CAIS) approaches in dental implant placement.

MATERIAL AND METHODS

The PICO question as follows: In patients receiving dental implants, does computer-aided implant surgery superior in accuracy compared to non-computer-aided implant surgery? The primary outcome was angular deviation between the planned and placed position of the implant. An electronic search was made to identify all relevant studies reporting the accuracy of CAIS approaches and freehand for dental implant placement. The data were extracted in the descriptive description, and a meta-analysis of single means was performed to estimate the deviations for each variable using a random-effects model.

RESULTS

Out of 1609 initial articles, 55 were selected for data extraction. The mean value of angular, entry, and apex deviations were 7.46°, 1.56 mm, and 2.22 mm for freehand, 5.94°, 1.13 mm, and 1.43 mm for pilot drill-sCAIS, 2.57°, 0.72 mm, 0.88 mm for fully guided-sCAIS (fg-sCAIS), and 3.67°, 1.01 mm, and 1.36 for dynamic CAIS (dCAIS), respectively. Significant differences were found between the freehand and CAIS approaches (p < 0.04). Fg-sCAIS was significantly more accurate than dCAIS systems at the entry (p < 0.001).

CONCLUSIONS

Compared to the freehand approach, both sCAIS and dCAIS improve implant placement accuracy, with angular deviations ranging from 2° to 6°. Detailed planning is crucial for CAIS, particularly for fg-sCAIS, which demonstrated the highest accuracy than others. As apex deviations of 1 to 2 mm have been observed in CAIS approaches, a 2-mm safety margin should be implemented to minimize surgical risks.

Surgical protocol affecting robotic implant accuracy: Ex-vivo study

OBJECTIVES

A randomized controlled study was conducted to compare the accuracy of three different robotic-computer aided implant surgical protocols (fully guided surgery, partially guided surgery performed by a novice surgeon, and partially guided surgery conducted by an experienced surgeon) under the same conditions.

METHODS

A total of n = 81 implants were placed in porcine ribs according to three different protocols (n = 27 implants per group). All cases were digitally planned, and the final implant positions were captured through cone-beam computed tomography and compared to the planned positions. The primary outcome variable was angular deviation. The secondary outcome variables were global, horizonal, and vertical deviations at the coronal and apical levels.

RESULTS

In terms of implant insertion, the novice surgeon exhibited significantly larger angular deviation compared to both the experienced surgeon and the robot, with no significant difference observed between the latter two. Regarding vertical deviation, the robot showed worse performance than both surgeons, though no significant difference was found between the novice and experienced surgeons.

CONCLUSIONS

For novice surgeons, using the robot to guide the whole process of implantation can obtain smaller angular deviation, while the vertical deviation may increase; for experienced surgeons, using the robot to guide only the osteotomy process and adopting a freehand implant insertion manner can obtain smallest angular and vertical deviation.

CLINICAL SIGNIFICANCE

This study highlights the potential of improving angular precision for novice surgeons through a fully guided surgical protocol, while a partially guided approach may optimize both angular and vertical precision for experienced surgeons, offering tailored strategies based on surgical expertise.

The Use of Robotics in Implant Dentistry

The integration of robotics in medicine and surgery marks a pivotal shift in the way modern health care delivers care. Robotics technology is not only capable of augmenting human capabilities but also improving the quality of surgical interventions. Initially designed to enhance precision in complex surgeries, robotics has made significant advancements in orthopedics, soft tissue surgery, and, more recently, implant dentistry.

Accuracy in dental implant placement: A systematic review and meta-analysis comparing computer-assisted (static, dynamic, robotics) and noncomputer-assisted (freehand, conventional guide) approaches

STATEMENT OF PROBLEM

Computer-assisted implant placement has been reported to provide better accuracy, particularly in complex situations, while noncomputer-assisted approaches remain effective for more straightforward procedures. However, comprehensive evidence comparing these approaches across various clinical scenarios is limited. Evaluating factors such as cost-effectiveness, edentulous span, and clinician expertise is essential for optimizing treatment planning.

PURPOSE

The purpose of this systematic review and meta-analysis was to compare the accuracy of dental implant placement between computer-assisted and noncomputer-assisted workflows.

MATERIAL AND METHODS

A systematic search of the PubMed, Embase, and Scopus databases (up to August 2024) was conducted using keywords related to surgery, computer-assisted techniques, and dental implants. The primary outcomes were angular, 3-dimensional (3D)-coronal, and 3D-apical deviations. Studies were selected based on predefined inclusion and exclusion criteria, and quantitative meta-analysis was performed.

RESULTS

Forty-five studies met the inclusion criteria. In clinical studies, meta-analysis showed a mean difference (MD) of 0.65 mm (95% CI: 0.56 to 0.74; P<.001) for global coronal deviation, 1.10 mm (95% CI: 0.95 to 1.20; P<.001) for global apical deviation, and 3.87 degree (95% CI: 3.31 to 4.44; P<.001) for angular deviation, favoring the computer-assisted implant workflow, based on 22 studies. In in vitro studies, the MD was 0.45 (95% CI: 0.36 to 0.54; P<.001) for global coronal deviation, 0.63 mm (95% CI: 0.50 to 0.76; P<.001) for global apical deviation, and 3.60 degree (95% CI: 2.66 to 4.54; P<.001) for angular deviation, favoring the computer-assisted implant workflow, with data from 23 studies. Among the navigation systems, robotic-assisted implant surgery (r-CAIS) achieved the highest clinical accuracy across all metrics compared with noncomputer-assisted techniques.

CONCLUSIONS

Overall, computer-assisted implant workflows significantly improved the accuracy of implant placement, with r-CAIS demonstrating the highest accuracy in clinical scenarios. However, factors such as cost-effectiveness, edentulous span, and clinician expertise must be considered, as conventional methods remain suitable alternatives in certain straightforward situations. These findings highlight the importance of tailored treatment planning to optimize the outcomes of implant-supported prostheses.

Impact of Cantilever Length on the Accuracy of Static CAIS in Posterior Distal Free-End Regions

BACKGROUND

Implant placement accuracy in the distal free-end posterior region is often compromised, increasing the risk of damage to adjacent anatomical structures and negatively affecting restoration function, occlusal loading, and aesthetics.

OBJECTIVES

This study aimed to assess the accuracy of implant placement using static computer-assisted implant surgery (CAIS) in the posterior distal free-end partially edentulous area with varying cantilever lengths and to evaluate the correlation between cantilever length and implant deviations.

MATERIALS AND METHODS

A prospective observational study involved 40 patients with 72 posterior implant sites, divided into three groups: 1-unit cantilever (1-UC; distal free-end with a mesial neighboring tooth), 2-unit cantilever (2-UC; one-tooth space from the mesial neighboring tooth), and control (single-tooth space with both mesial and distal neighboring teeth). Implants were placed using fully guided static CAIS, and accuracy was assessed by comparing angular and linear deviations at the implant platform and apex using post-operative CBCT scans. The correlation between cantilever length and implant deviations was analyzed.

RESULTS

The 2-UC group exhibited significantly higher angular deviations (5.01° ± 2.41°) compared to the 1-UC (3.60° ± 1.92°, p = 0.033) and control groups (2.62° ± 1.13°, p < 0.001). The 3D deviations at both the platform and apex were also significantly greater in the 2-UC group (1.15 ± 0.38 mm, 1.74 ± 0.53 mm, respectively) than in the 1-UC (0.86 ± 0.35 mm, p = 0.001; 1.30 ± 0.47 mm, p = 0.002) and control groups (0.72 ± 0.30 mm, p < 0.001; 1.04 ± 0.38 mm, p < 0.001). Deviations in the cantilever groups predominantly trended towards the buccal and apical directions. Additionally, positive correlations were found between cantilever length and implant deviations at both the platform (R = 0.306, p = 0.034) and apex levels (R = 0.294, p = 0.042).

CONCLUSION

Cantilever length in posterior implant positions significantly affects the accuracy of implant placement using static CAIS. Implants positioned at a 2-unit cantilever or with lengths exceeding 10 mm are more prone to deviating from the planned positions.

The Influence of Guiding Concept on the Accuracy of Static Computer-Assisted Implant Surgery in Partially Edentulous Cases: An In Vitro Study

Background and Objectives: Static Computer-Assisted Implant Surgery (sCAIS) can be performed with different drill guiding systems. This study aimed to compare the accuracy of two guiding concepts of sCAIS in partially edentulous cases. Materials and Methods: Forty polyamide models of partially edentulous maxillae with seven implantation sites were fabricated. In total, 140 replica implants were placed with keyless (KL) and drill-key (DK) guiding systems using static, full-arch, tooth-supported surgical guides. Three-dimensional crestal and apical, angular and vertical deviations from the planned implant positions were compared using Mann-Whitney U and Kruskal-Wallis H tests. Intergroup homogeneity of variance homogeneity was examined using Levene's test to assess the precision. Results: Overall median 3D crestal and apical deviations of implants placed in the KL group were significantly higher compared to the DK group (0.86 mm [0.63-0.98] vs. 0.72 mm [0.52-0.89], p = 0.006 and 1.26 [0.98-1.52] vs. 1.13 [0.70-1.45], p = 0.012). In the subgroup analysis, implants placed with a KL system showed higher 3D crestal (p = 0.029), 3D apical (p < 0.001) and angular (p < 0.001) deviations in the extended anterior area, higher 3D crestal (p < 0.001) deviations in the proximal posterior single-tooth gap and higher vertical (p < 0.001) deviations in the distal site of free-end situation. Contrarily, the KL group showed lower 3D crestal (p = 0.007), 3D apical (p < 0.001), angular (p < 0.001) and vertical (p = 0.003) deviations in the distal posterior single-tooth gap, lower 3D apical (p = 0.007) and angular (p = 0.007) deviations in the distal site of free-end situation and lower vertical (p = 0.019) deviations in the proximal site of free-end situation. Conclusions: The deviations of both guiding concepts did not exceed the recommended safety margins. Statistically significant differences in deviations were found between two guiding concepts. Guiding concepts with superior accuracy varied across different sites of implantation.

Clinical added value of 3D printed patient-specific guides in orthopedic surgery (excluding knee arthroplasty): a systematic review

INTRODUCTION

Patient-specific guides (PSGs) provide customized solutions and enhanced precision. However, the question remains: does clinical evidence support the added value of PSGs? This study critically appraises, summarizes, and compares the literature to assess the clinical value of PSGs in orthopedic surgery.

MATERIALS AND METHODS

PubMed and Embase were used to search for studies reporting on randomized controlled trials (RCTs) that compared the use of PSGs with a control group for an orthopedic intervention, excluding knee arthroplasty. The risk of bias was assessed using the Cochrane risk-of-bias tool (RoB 2). The clinical value was expressed as patient reported outcome measures (PROMs), complications, accuracy, surgery duration, blood loss, and radiation exposure. Relative and absolute differences were determined, and whether these were negative or positive for using PSGs.

RESULTS

From 6310 studies, 27 RCTs were included, covering various interventions. The studies' heterogeneity prevented meta-analysis. Six (22.2%) of the included articles scored low risk of bias. Significant differences in the benefit of PSGs were reported across all included metrics: 32.2% in PROMs, 22.7% in complications, 69.8% in accuracy, 42.1% in surgery duration, 46.7% in blood loss, and 93.3% in radiation exposure. No significant negative differences were found in any of the studies.

CONCLUSION

PSGs generally show superior outcomes for accuracy and radiation exposure across multiple intervention types, while the reduction in complications was primarily significant in spinal fusion surgery. For PROMs, complications in other treatments, surgery duration, and blood loss, there may be clinical added value but future well-designed RCTs are needed to provide stronger evidence.

Assessment of hard tissue changes after horizontal guided bone regeneration with the aid of deep learning CBCT segmentation

OBJECTIVES

To investigate the performance of a deep learning (DL) model for segmenting cone-beam computed tomography (CBCT) scans taken before and after mandibular horizontal guided bone regeneration (GBR) to evaluate hard tissue changes.

MATERIALS AND METHODS

The proposed SegResNet-based DL model was trained on 70 CBCT scans. It was tested on 10 pairs of pre- and post-operative CBCT scans of patients who underwent mandibular horizontal GBR. DL segmentations were compared to semi-automated (SA) segmentations of the same scans. Augmented hard tissue segmentation performance was evaluated by spatially aligning pre- and post-operative CBCT scans and subtracting preoperative segmentations obtained by DL and SA segmentations from the respective postoperative segmentations. The performance of DL compared to SA segmentation was evaluated based on the Dice similarity coefficient (DSC), intersection over the union (IoU), Hausdorff distance (HD95), and volume comparison.

RESULTS

The mean DSC and IoU between DL and SA segmentations were 0.96 ± 0.01 and 0.92 ± 0.02 in both pre- and post-operative CBCT scans. While HD95 values between DL and SA segmentations were 0.62 mm ± 0.16 mm and 0.77 mm ± 0.31 mm for pre- and post-operative CBCTs respectively. The DSC, IoU and HD95 averaged 0.85 ± 0.08; 0.78 ± 0.07 and 0.91 ± 0.92 mm for augmented hard tissue models respectively. Volumes mandible- and augmented hard tissue segmentations did not differ significantly between the DL and SA methods.

CONCLUSIONS

The SegResNet-based DL model accurately segmented CBCT scans acquired before and after mandibular horizontal GBR. However, the training database must be further increased to increase the model's robustness.

CLINICAL RELEVANCE

Automated DL segmentation could aid treatment planning for GBR and subsequent implant placement procedures and in evaluating hard tissue changes.

Comparison of tooth substance loss and angle deviation in access cavity preparation using guided endodontics and conventional method in calcified canals - An in vitro study

Aims

This study aimed to evaluate the accuracy of access cavity preparation using guided endodontics (GE) and conventional technique (CT) in calcified canals.

Subjects and Methods

Twenty teeth with calcification up to middle third were collected after scanning through RadioVisioGraphy (RVG). Preoperative cone-beam computed tomography (CBCT) scan was done and samples were randomly divided into two groups of ten samples each on the basis of method of access cavity preparation. Group 1: Access cavity was prepared by CT, Group 2: Access cavity was prepared by GE. 3D template and corresponding guide drill were made for group 2 samples after performing optical surface scans. After access cavity preparation, postoperative CBCT scanning was performed for all samples. The amount of tooth structure loss and angle deviation were calculated using Sidexis Software.

Statistical Analysis Used

The data were analyzed using IBM SPSS Statistics, version 22. A t-test compared tooth structure loss and angle deviation between groups, and a one-way ANOVA calculated tooth structure loss in multiple directions for both groups (P < 0.001).

Results

Our study found that the mean tooth volume loss (17.19 mm3 ± 06.11 standard deviation [SD]) and angle deviation (4.82° ±01.66 SD) in GE was significantly less (P < 0.001) as compared to mean tooth structure loss (38.85 mm3 ± 19.07 SD) and angle deviation (13.16° ±2.34 SD) by CT.

Conclusion

GE is more accurate and conservative than CT in management of calcified canals.

The Accuracy of Dental Implant Placement With Different Methods of Computer-Assisted Implant Surgery: A Network Meta-Analysis of Clinical Studies

OBJECTIVE

Computer-assisted implant surgery (CAIS) has been introduced as a tool to aid in reaching a more accurate implant position. The aim of this network meta-analysis was to compare all the available CAIS techniques and obtain collective evidence on the method that offers the highest accuracy compared to freehand implant placement.

MATERIALS AND METHODS

Database search was done in PubMed, Scopus, and Cochrane library in addition to extensive search in the gray literature and related systematic reviews, aiming to find clinical studies that compared any CAIS technique with another, or with freehand implant placement. The outcomes evaluated were angle, platform, and apex deviation. The search process ended on March 18, 2024.

RESULTS

Thirty-three studies were included. All CAIS techniques (static with partial or full guidance, dynamic with partial or full guidance, the combination of static and dynamic CAIS) showed significantly less deviation than freehand implant placement, except for the static CAIS with guidance for the pilot drill only. The combination of static and dynamic CAIS ranked best among all other methods. Based on the GRADE system, the certainty of evidence in the outcomes of the meta-analysis was judged as low or moderate.

CONCLUSIONS

The current study demonstrates that computer-assisted implant surgery provides significantly higher accuracy in implant placement, with the combination of static and dynamic CAIS being the most precise. Nevertheless, future studies are needed, considering the different types, locations, and extents of edentulism in the analyzed investigations, as well as the necessity of obtaining stronger evidence.

TRIAL REGISTRATION

PROSPERIO number: CRD42023482030.

Influence of supporting teeth quantity of surgical guide on the accuracy of the immediate implant in the maxillary central incisor: an in vitro study

INTRODUCTION

Guided surgery for immediate anterior implants aims to reduce the time required for aesthetic and functional immediate loading. However, the limited surface area of anterior teeth for guide stabilization may affect the accuracy of implant positioning. This in vitro study evaluated the effect of the number of supporting teeth on the accuracy of immediate implants in the maxillary central incisor region.

METHODS

28 replica implants were inserted into 28 upper jaw models, simulating immediate post-extraction sockets of tooth 11. Based on the number of supporting teeth, the implants were categorized into G1 (four adjacent teeth) and G2 (six adjacent teeth). The planned and actual implant positions were compared using the evaluation module of the implant planning software. Angular and 3D deviations were measured as the primary outcomes. Statistical analysis was performed using the two-sample t-test, with p-values less than 0.05 defined as statistically significant.

RESULTS

Between group G1 and G2, angular deviation was measured at 4.63 ± 0.71° and 3.59 ± 0.97°, respectively, while the implant apex 3D deviation was 2.08 ± 0.21 mm for G1 and 1.40 ± 0.27 mm for G2. These differences were statistically significant (p = 0.003 and p < 0.001, respectively). Other discrepancy variables in G2 demonstrated lower values but were not statistically significant compared to G1.

CONCLUSION

The number of supporting teeth for the surgical guide can influence the accuracy of immediate implant surgery. While both four-teeth and six-teeth supports demonstrated acceptable clinical implant accuracy, a surgical guide supported by six teeth can enhance implant precision.

Accuracy of full-guided versus half-guided implant procedures carried out with digital implant planning software by students as part of a university curriculum

BACKGROUND

This in vitro study investigated whether full-guided (FG) or half-guided (HG) implant placement is more suitable for beginners and to what extent the use of the coDiagnostiX (CDX) (10.5, Straumann Group, Basel, Switzerland) implant planning software proves useful in teaching.

METHODS

Twenty students planned implant positions with CDX which were then placed in a model using printed drill templates in the sense of FG implantation (group 1) and HG implantation (group 2). The implant positions could be compared with those of the reference model, and deviations could be determined. The results were tested for significance using the t-test for independent samples for groups 1 and 2. A total of 32 students subsequently completed a questionnaire about the software. Cronbach's α was also calculated to check the reliability of the questions for the individual subject areas.

RESULTS

In both groups the greatest deviation occurred along the y-axis in the vestibular direction. It measured 1.390 mm in group 1 and 1.570 mm in group 2. Comparing both groups, there were significant deviations along the y-axis (p = .013), along the z-axis (p = .049), and in the total deviation (p = .031). The questionnaire was evaluated in design, with 95% positive answers. In contrast, the evaluation of the area of time and effort resulted in only 55% positive responses. Overall, experience with the software was rated as positive by 74%.

CONCLUSIONS

Group 1 achieved more accurate results, especially along the y-axis in the vestibular direction. In both groups, the implants were placed too deep. The questionnaire indicated a software with high usability and is therefore very suitable for teaching. If clinically feasible, beginners should prefer full-guided implant placement.

From Tradition to Technology: Robotic Artificial Intelligence in Dental Implantology

Dynamic navigation and haptic robotic systems are revolutionizing dentistry by significantly improving implant placement precision, especially in the maxillofacial region where safeguarding nerves, vessels, and vital structures is crucial. This article examines the impact of X-Guide dynamic navigation and Yomi robotics on implant surgery outcomes, comparing these technologies to traditional freehand methods. The X-Guide dynamic navigation system and Yomi robotics have both been proven to enhance accuracy, with both achieving mean deviations of around 1 mm from pre-planned positions. However, the high costs associated with these technologies may limit access for many practitioners. Despite these challenges, both systems facilitate the completion of complex cases with minimal deviations. In addition, their applications are expanding beyond implantology into areas like endodontics, further demonstrating their potential in modern dental practices.

Accuracy of guided dental implant surgery using a fully digital workflow: A case series

STATEMENT OF PROBLEM

Computer-guided implant surgery facilitated by intraoral scanning may enhance the efficiency of the digital workflow. However, it is necessary to assess technique accuracy to evaluate the accuracy of implant placement.

PURPOSE

The purpose of this clinical study was to evaluate the accuracy of a virtual computer-aided design and computer-aided manufacturing (CAD-CAM) static guided surgery technique associated with intraoral scanning in partially edentulous participants by analyzing the overlap among preoperative and postoperative cone beam computed tomography (CBCT) scans, virtual planning, and the guided surgery performed.

MATERIAL AND METHODS

Eleven partially edentulous participants underwent CBCT and intraoral scanning (TRIOS3). Data were integrated into a software program (ImplantViewer 3.5) for the virtual planning of implants and 3-dimensional (3D) printing of the prototype CAD-CAM surgical guide. A total of 18 implants were placed using the CAD-CAM static computer-aided implant surgery technique (Strong SW). After 15 days, postoperative CBCT scans were made and 4 variables (angular, coronal, apical, and vertical deviation) were measured to compare the virtually planned implants and the implants placed by analyzing the overlap between preoperative and postoperative of the virtual planning and guided surgery performed using the ImplantViewer 3.5 and Rhino 6 software programs.

RESULTS

Deviations were found in all parameters analyzed. The mean angular deviation was 2.68 ±1.62 degrees; mean coronal deviation, 0.82 ±0.44 mm; mean apical deviation, 1.14 ±0.44 mm; and mean vertical deviation, 0.62 ±0.44 mm.

CONCLUSIONS

The implants placed using the CAD-CAM static guided surgery technique associated with intraoral scanning in partially edentulous participants exhibited angular and linear deviations when compared with virtual planning implants. However, these deviations were not clinically significant.

Automatic Segmentation of the Jaws Used in Guided Insertion of Orthodontic Mini Implants to Improve Their Stability and Precision

Background and Objectives: With the goal of identifying regions with bicortical bone and avoiding root contact, the present study proposes an innovative technique for the simulation of the insertion of mini orthodontic implants using automatic jaw segmentation. The simulation of mini implants takes place in 3D rendering visualization instead of Multi-Planar Reconstruction (MPR) sections. Materials and Methods: The procedure involves utilizing software that automatically segments the jaw, teeth, and implants, ensuring their visibility in 3D rendering images. These segmented files are utilized as study models to determine the optimum location for simulating orthodontic implants, in particular locations characterized by limited distances between the implant and the roots, as well as locations where the bicortical structures are present. Results: By using this method, we were able to simulate the insertion of mini implants in the maxilla by applying two cumulative requirements: the implant tip needs to be positioned in a bicortical area, and it needs to be situated more than 0.6 mm away from the neighboring teeth's roots along all of their axes. Additionally, it is possible to replicate the positioning of the mini implant in order to distalize the molars in the mandible while avoiding the mandibular canal and the path of molar migration. Conclusions: The utilization of automated segmentation and visualization techniques in 3D rendering enhances safety measures during the simulation and insertion of orthodontic mini implants, increasing the insertion precision and providing an advantage in the identification of bicortical structures, increasing their stability.

Depth distortion and angular deviation of a fully guided tooth-supported static surgical guide in a partially edentulous patient: A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the depth distortion and angular deviation of fully-guided tooth-supported static surgical guides (FTSG) in partially edentulous arches compared to partially guided surgical guides or freehand.

MATERIAL AND METHODS

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the Open Science Framework (OSF). The formulated population, intervention, comparison, and outcome (PICO) question was: "In partially edentulous arches, what are the depth distortion and angular deviation of FTSG compared to partially guided surgical guides or freehand?" The search strategy involved four main electronic databases, and an additional manual search was completed in November 2023 by following an established search strategy. Initial inclusion was based on titles and abstracts, followed by a detailed review of selected studies, and clinical studies that evaluated the angular deviations or depth distortion in FTSG in partial arches, compared to partially guided surgical guides or freehand, were included. In FTSG, two surgical approaches were compared: open flap and flapless techniques, and two digital methods were assessed for surgical guide design with fiducial markers or dental surfaces. A qualitative analysis for clinical studies was used to assess the risk of bias. The certainty of the evidence was assessed according to the grading of recommendations, assessment, development, and evaluations (GRADE) system. In addition, a single-arm meta-analysis of proportion was performed to evaluate the angular deviation of freehand and FTSG.

RESULTS

Ten studies, published between 2018 and 2023, met the eligibility criteria. Among them, 10 studies reported angular deviations ranging from -0.32° to 4.96° for FTSG. Regarding FTSG surgical approaches, seven studies examined the open flap technique for FTSG, reporting mean angular deviations ranging from 2.03° to 4.23°, and four studies evaluated flapless FTSG, reporting angular deviations ranging from -0.32° to 3.38°. Six studies assessed the freehand surgical approach, reporting angular deviations ranging from 1.40° to 7.36°. The mean depth distortion ranged between 0.19 mm to 2.05 mm for open flap FTSG, and between 0.15 mm to 0.45 mm for flapless FTSG. For partially guided surgical guides, two studies reported angular deviations ranging from 0.59° to 3.44°. Seven studies were eligible for meta-analysis, focusing on the FTSG in open flap technique, with high heterogeneity (I2 (95%CI) = 92.3% (88.7%-96.4%)). In contrast, heterogeneity was low in studies comparing freehand versus FTSG in open flap techniques (I2 (95%CI) = 21.3% (0.0%-67.8%)), favoring the FTSG surgical approach.

CONCLUSION

In partially edentulous arches, FTSG systems exhibited less angular deviation than freehand and partially guided surgical guides. Flapless surgical approaches were associated with reduced angular deviation and depth distortion, suggesting a potential preference for the FTSG method in these procedures.

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.

Computer-assisted and robotic implant surgery: Assessing the outcome measures of accuracy and educational implications

OBJECTIVE

This scoping review aimed to (1) critically evaluate the outcomes measures used to assess the accuracy of implant placement with Computer Assisted Implant Surgery (CAIS) and (2) review the evidence supporting the efficient implementation of CAIS in training and education of clinicians.

METHODS

A scoping literature review was conducted aiming to identify (a) clinical trials assessing accuracy of implant placement with CAIS, and (b) clinical trials or simulation/cadaver studies where CAIS was utilised and assessed for the training/education of clinicians. Studies since 1995 were assessed for suitability and data related to the outcomes measures of accuracy and educational efficacy were extracted and synthesised.

RESULTS

Accuracy of CAIS has been mainly assessed through surrogate measures. Individual clinical trials have not shown any difference between static and dynamic CAIS, but recent meta-analyses suggest an advantage of dynamic CAIS in reducing angular deviation. The combination of static and dynamic CAIS might offer higher accuracy than each of the two used alone. Dynamic CAIS is suitable for novice surgeons and might even have added value as an education tool for implant surgery, although mastering the technique requires longer training than static.

CONCLUSION

Meta-analyses of large samples, new and diverse outcomes measures, as well as benchmarking of levels of accuracy with specific clinical outcomes will help to better understand the potential and limitations of CAIS. Dynamic CAIS is suitable for novice operators, but educational interventions distributed over longer periods of time will be required for mastery of the process.

Current knowledge about stackable guides: a scoping review

PURPOSE

The rise of stereolithographic surgical guides and digital workflow, combined with a better knowledge of materials and loading principle, has enabled the placement of the temporary prosthesis at the time of implant placement. This scoping review aimed to assess the current knowledge available on stackable guides.

METHODS

The review focused on fully edentulous or requiring total edentulism patients. The procedure studied was the use of stackable guides for edentulous patients in order to place immediate temporary prostheses. The clinical endpoint was immediate placement of the provisional prosthesis after surgery combined with a prior bone reduction using a stackable guide.

RESULTS

12 case reports or case series articles met inclusion criteria, which did not allow an analysis by a systematic review. The included studies were case reports or case series. Most of the articles showed a base stabilized by 3 or 4 bone-pins, anchored in buccal or lingual part. Regarding the accuracy of bone reduction (ranged from 0.0248 mm to 1.98 mm) and implant placement when compared to planned, only 4 articles reported quantitative data. 11 articles showed an immediate loading with the transitional prosthesis after implant placement.

CONCLUSIONS

There are as yet no prospective or comparative studies on the efficiency of this technique. In a reliable way, stackable guides seem to be able to guide the practitioner from the flap elevation to the placement of the temporary screw-retained implant supported prosthesis. Given the lack of studies in this specific field of guided surgery, further studies are needed to confirm the clinical relevance of this technique.

Accuracy of the novel digital non-cross-arch surgical guides with integration of tooth undercut retention and screw-bone support for implant placement in mandibular free-end

BACKGROUND

Large cross-arch free-end surgical guides can obscure the visual field, compromising surgical accuracy due to insufficient stability at the free-end. This in vitro study aims to evaluate the accuracy of novel digital non-cross-arch surgical guides designed for implant placement at the mandibular free-end, incorporating tooth undercut retention and screw-bone support.

MATERIALS AND METHODS

A mandibular dental model lacking left molars was utilized to fabricate unilateral (cross-arch) tooth-supported surgical guides (GT I, n = 20). Subsequently, two additional types of surgical guides were fabricated: GT II (covering two teeth, n = 20) and GT III (covering three teeth, n = 20). These novel surgical guides were designed to utilize the undercut of the supporting teeth for retention and enhance stability with screw-bone support at the guide's free-end. Furthermore, 60 identical guiding blocks were assembled on the three types of surgical guides to facilitate the implants' insertion. On a phantom head, 120 implant replicas were placed at the Federal Dentaire Internationale (FDI) teeth positions #36 and #37 on the dental model, employing a combination of surgical guides and guiding blocks. To assess accuracy, planned and placed implant positions were compared using intraoral optical scanning. Discrepancies in angulation and linear deviations, including the coronal/apical 3D deviations, lateral deviation as well as depth deviation, were measured. Statistical analysis was performed using two-way ANOVA and Bonferroni test (α = 0.05).

RESULTS

GT I exhibited significantly largest discrepancies, including angular and linear deviations at the crest and apex at every implant site. Especially in depth, at implant site #36, the mean deviation value of GT I (0.27 ± 0.13 mm) was twice as large as GT III (0.13 ± 0.07 mm), and almost twice as large as GT II (0.14 ± 0.08 mm). However, at implant site #37, this deviation increased to almost a five-fold relationship between GT I (0.63 ± 0.12 mm) and II (0.14 ± 0.09 mm), as well as between GT I and III (0.13 ± 0.09 mm). No significant discrepancies existed between the novel surgical guides at either implant site #36 or #37.

CONCLUSION

This study provides a practical protocol for enhancing accuracy of implant placement and reducing the size of free-end surgical guides used at mandibular molar sites.

The three-dimensional stability and accuracy of 3D printing surgical templates: An In Vitro study

OBJECTIVE

To evaluate the three-dimensional (3D) stability and accuracy of additively manufactured surgical templates fabricated using two different 3D printers and materials.

MATERIALS AND METHODS

Forty surgical templates were designed and printed using two different 3D printers: the resin group (n = 20) used a digital light processing (DLP) 3D printer with photopolymer resin, and the metal group (n = 20) employed a selective laser melting (SLM) 3D printer with titanium alloy. All surgical templates were scanned immediately after production and re-digitalized after one month of storage. Similarly, the implant simulations were performed twice. Three-dimensional congruency between the original design and the manufactured surgical templates was quantified using the root mean square (RMS), and the definitive and planned implant positions were determined and compared.

RESULTS

At the postproduction stage, the metal templates exhibited higher accuracy than the resin templates (p < 0.001), and these differences persisted after one month of storage (p < 0.001). The resin templates demonstrated a significant decrease in three-dimensional stability after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05). No significant differences in implant accuracy were found between the two groups. However, the resin templates showed a significant increase in apical and angular deviations after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05).

CONCLUSION

Printed metal templates showed higher fabrication accuracy than printed resin templates. The three-dimensional stability and implant accuracy of printed metal templates remained unaffected by one month of storage.

CLINICAL SIGNIFICANCE

With superior three-dimensional stability and acceptable implant accuracy, printed metal templates can be considered a viable alternative technique for guided surgery.

A New Full Digital Workflow for Fixed Prosthetic Rehabilitation of Full-Arch Edentulism Using the All-on-4 Concept

(1) Background: Recent digital workflows are being developed for full-arch rehabilitations supported by implants with immediate function. The purpose of this case series is to describe a new digital workflow for the All-on-4 concept. (2) Methods: The patients were rehabilitated using the All-on-4 concept with a digital workflow including computerized tomography scanning, intra-oral scanning, and CAD-CAM production of the temporary prosthesis, with the 3D printing of stackable guides (base guide, implant guide, and prosthetic guide). The passive fit of the prostheses and the time to perform the rehabilitations were evaluated. (3) Results: The digital workflow allowed for predictable bone reduction, the insertion of implants with immediate function, and the connection of an implant-supported prosthesis with immediate loading. The time registered to perform the full-arch rehabilitations (implant insertion, abutment connection, prosthesis connection) was below 2 hours and 30 min. No passive fit issues were noted. (4) Conclusions: within the limitation of this case series, the digital workflow applied to the All-on-4 concept using stackable base-, implant-, and prosthetic guides constitutes a potential alternative with decreased time for the procedure without prejudice of the outcome.

Effect of guided implant placement learning experiences on freehand skills: A pilot study

OBJECTIVES

Guided implant systems can be used as a training approach for placing implants. This in vitro prospective randomized pilot study evaluated the learning progression and skill development in freehand placement of two implants supporting a three-unit fixed prosthesis on a simulation model among novice operators.

MATERIAL AND METHODS

Four senior dental students with no prior implant placement experience participated in the study. As a baseline, each student placed two mandibular and two maxillary implants by freehand technique on a simulation model. Sixteen consecutive guided placements using a static guide, dynamic navigation, and template-based guide followed totaling 32 guided implant placements into maxillary and mandibular models. Freehand implant placements before and after the various guided navigation attempts were compared to assess their impact on freehand skill. Metrics compared included surgical time, horizontal, vertical, and angulation discrepancies between the planned and placed implant positions measured on superimposed CBCT scans and analyzed with repeated measures regression with Tukey's adjusted pairwise comparisons (α = .05).

RESULTS

Before training with guided techniques, the average baseline freehand implant placement took 10.2 min and decreased to 8.2 after training but this difference was not statistically significant (p = .1670) There was marginal evidence of a significant difference in the 3D apex deviation with an average improvement of 0.89 mm (95% CI: -0.38, 2.16, p = .1120); and marginal evidence of a significant improvement in the overall angle with an average improvement of 3.74° (95% CI: -1.00, 8.48, p = .0869) between baseline and final freehand placement attempts.

CONCLUSIONS

Within the limitations of this pilot study, guided implant placement experiences did not significantly benefit or hinder freehand placement skills. Dental students should be exposed to various placement techniques to prepare them for clinical practice and allow them to make informed decisions on the best technique based on their skills and a given clinical scenario.

Accuracy of implant placement with computer-aided static, dynamic, and robot-assisted surgery: a systematic review and meta-analysis of clinical trials

This systematic review explores the accuracy of computerized guided implant placement including computer-aided static, dynamic, and robot-assisted surgery. An electronic search up to February 28, 2023, was conducted using the PubMed, Embase, and Scopus databases using the search terms "surgery", "computer-assisted", "dynamic computer-assisted", "robotic surgical procedures", and "dental implants". The outcome variables were discrepancies including the implant's 3D-coronal, -apical and -angular deviations. Articles were selectively retrieved according to the inclusion and exclusion criteria, and the data were quantitatively meta-analysed to verify the study outcomes. Sixty-seven articles were finally identified and included for analysis. The accuracy comparison revealed an overall mean deviation at the entry point of 1.11 mm (95% CI: 1.02-1.19), and 1.40 mm (95% CI: 1.31-1.49) at the apex, and the angulation was 3.51˚ (95% CI: 3.27-3.75). Amongst computerized guided implant placements, the robotic system tended to show the lowest deviation (0.81 mm in coronal deviation, 0.77 mm in apical deviation, and 1.71˚ in angular deviation). No significant differences were found between the arch type and flap operation in cases of dynamic navigation. The fully-guided protocol demonstrated a significantly higher level of accuracy compared to the pilot-guided protocol, but did not show any significant difference when compared to the partially guided protocol. The use of computerized technology clinically affirms that operators can accurately place implants in three directions. Several studies agree that a fully guided protocol is the gold standard in clinical practice.

Comparing accuracy in guided endodontics: dynamic real-time navigation, static guides, and manual approaches for access cavity preparation - an in vitro study using 3D printed teeth

OBJECTIVES

To assess root canal localization accuracy using a dynamic approach, surgical guides and freehand technique in vitro.

MATERIALS AND METHODS

Access cavities were prepared for 4 different 3D printed tooth types by 4 operators (n = 144). Deviations from the planning in angle and bur positioning were compared and operating time as well as tooth substance loss were evaluated (Kruskal-Wallis Test, ANOVA). Operating method, tooth type, and operator effects were analyzed (partial eta-squared statistic).

RESULTS

Angle deviation varied significantly between the operating methods (p < .0001): freehand (9.53 ± 6.36°), dynamic (2.82 ± 1.8°) and static navigation (1.12 ± 0.85°). The highest effect size was calculated for operating method (ηP²=0.524), followed by tooth type (0.364), and operator (0.08). Regarding deviation of bur base and tip localization no significant difference was found between the methods. Operating method mainly influenced both parameters (ηP²=0.471, 0.379) with minor effects of tooth type (0.157) and operator. Freehand technique caused most substance loss (p < .001), dynamic navigation least (p < .0001). Operating time was the shortest for freehand followed by static and dynamic navigation.

CONCLUSIONS

Guided endodontic access may aid in precise root canal localization and save tooth structure.

CLINICAL RELEVANCE

Although guided endodontic access preparation may require more time compared to the freehand technique, the guided navigation is more accurate and saves tooth structure.

Comparative evaluation of accuracy of implants placed with thermoplastic and three-dimensional-printed surgical guides: A randomized controlled trial

Background

The current study was planned to evaluate the accuracy of dental implant placement with two different types of surgical guides: Thermoplastic and three-dimensional (3D) printed.

Materials and Methods

A total of 32 implants were placed in 20 healthy, partially dentate individuals with an isolated single missing tooth. The implant sites were randomly allocated into two treatment groups: Group A (thermoplastic implant surgical guide, n = 16 implants) and Group B (3D printed implant surgical guide, n = 16 implants). All the cases in both groups were digitally planned according to a defined protocol, and a comparison of the planned and actual implant positions was performed using the medical image analysis software. The differences in the outcome variables, i.e., angular deviation (AD), 3D error at the entry, 3D error at the apex (3D EA), vertical deviation (VD), and composite deviation, were statistically analyzed.

Results

All the outcome variables showed improvements, but statistically significant improvement was shown by AD (P = 0.005), 3D EA (P = 0.01), and VD (P = 0.007). The mean and standard deviation (SD) for AD, (3D EA), and VD were 5.58° ±1.93°, 0.96 ± 0.32 mm, and 0.58 ± 0.36 mm, respectively, for group A. The mean and SD for AD, (3D EA), and VD were 3.94° ± 0.64°, 0.64 ± 0.35 mm, and 0.29 ± 0.13 mm, respectively, for group B (P < 0.05).

Conclusion

Within the limits of the study, dental implants placed using 3D-printed surgical guides were positioned clinically with greater accuracy, and fewer deviations were observed from their presurgical planned positions as compared to the thermoplastic surgical guides.

A comprehensive review and update on the current state of computer-assisted rehabilitation in implant dentistry

AIM

This paper provides a comprehensive review of the established concepts and newer developments related to computer-assisted implant rehabilitation.

METHODS

Two independent researchers searched the English literature published to 31st December 2023 in the PubMed/Medline database for primary and secondary research and related publications on computer-assisted implant planning, computer-assisted implant placement and computer-assisted implant restoration.

RESULTS

A total of 58,923 papers were identified, 198 relevant papers were read in full text and 110 studies were finally included. Computer-assisted implant rehabilitation was found to result in more precise implant positioning than freehand placement. Advantages include reduced trauma and surgery time; disadvantages include reduced primary implant stability and higher cost.

CONCLUSION

Computer-assisted surgery is particularly indicated in cases of critical anatomy, but may encounter limitations in terms of cost, restricted mouth opening, visibility and adjustment of the surgical guides and the need for prior familiarisation with the procedure. Nonetheless, this surgical technique reduces the post-implant placement complication rate.

Influence of the macrodesign of an implant and the sleeve system on the accuracy of template-guided implant placement: A prospective clinical study

STATEMENT OF PROBLEM

Three-dimensional (3D) implant planning facilitates determining the optimal position and number of implants, in terms of function and esthetics, by taking into account adjacent structures. Template-guided implant placement is an established procedure for implementing this planning, although the accuracy between the planned and the actual implant position is subject to many influences. The influences of the macrodesign of the implants and the sleeve materials used have rarely been investigated clinically.

PURPOSE

The purpose of this prospective clinical study was to investigate the accuracy of template-guided implant placement according to the macrodesign of different implants and the design of the drill sleeve.

MATERIAL AND METHODS

Implants were placed in 60 participants within 3 groups (n=20): tapered implant with a metal sleeve (T-MS), tapered implant with a polymeric sleeve (T-PS), and progressive tapered implant with a polymeric sleeve (XT-PS). After overlaying the 3D implant planning image with the postoperative intraoral scan, deviations were 2-dimensionally related to the implant shoulder (S) and the apex (A) in terms of height (2DHS/2DHA), mesiodistal (2DSmd/2DAmd) and buccolingual (2DSbo/2DAbo), as well as 3-dimensionally on the implant shoulder (3DS), on the apex (3DA), and on the axis deviation (Axis). The groups were compared by using the analysis of variance. The Tukey post hoc test was performed for normally distributed data to identify significant differences among groups (α=.05).

RESULTS

The errors for 2DSmd and 2DSbo were 0.26 to 0.40 mm across all groups. The 3DS group varied between 0.67 and 0.87 mm. No significant differences were found in terms of the material of the sleeves or the macrodesign of the implants (P>.05). Significant differences were found for 2DHS (P=.029) and 2DHA (P=.016) between the groups with the different sleeves. Group T-PS showed the least height deviation.

CONCLUSIONS

In terms of height deviation, significant differences were found among the groups, with deviations depending on the implant type and the sleeve type. Overall, the method showed a high level of accuracy, providing good predictability of the prosthetic rehabilitation.

Biomechanical performance of dental implants inserted in different mandible locations and at different angles: A finite element study

STATEMENT OF PROBLEM

Accurate implant placement is essential for the success of dental implants. This placement influences osseointegration and occlusal forces. The freehand technique, despite its cost-effectiveness and time efficiency, may result in significant angular deviations compared with guided implantation, but the effect of angular deviations on the stress-strain state of peri-implant bone is unclear.

PURPOSE

The purpose of this finite element analysis (FEA) study was to examine the effects of angular deviations on stress-strain states in peri-implant bone.

MATERIAL AND METHODS

Computational modeling was used to investigate 4 different configurations of dental implant positions, each with 3 angles of insertion. The model was developed using computed tomography images, and typical mastication forces were considered. Strains were analyzed using the mechanostat hypothesis.

RESULTS

The location of the implant had a significant impact on bone strain intensity. An angular deviation of ±5 degrees from the planned inclination did not significantly affect cancellous bone strains, which primarily support the implant. However, it had a substantial effect on strains in the cortical bone near the implant. Such deviations also significantly influenced implant stresses, especially when the support from the cortical bone was uneven or poorly localized.

CONCLUSIONS

In extreme situations, angular deviations can lead to overstraining the cortical bone, risking implant failure from unfavorable interaction with the implant. Accurate implant placement is essential to mitigate these risks.

Accuracy Comparison between Robot-Assisted Dental Implant Placement and Static/Dynamic Computer-Assisted Implant Surgery: A Systematic Review and Meta-Analysis of In Vitro Studies

Background and Objectives: The present systematic review and meta-analysis undertake a comparison of studies that examine the accuracy of robot-assisted dental implant placement in relation to static computer-assisted implant surgery (SCAIS), dynamic computer-assisted implant surgery (DCAIS), and freehand procedures. This study aims to provide a comprehensive understanding of the precision of robot-assisted dental implant placement and its comparative efficacy in relation to other placement techniques. Methods: The guidelines recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were used to organize and compose this review. Four electronic databases (PubMed, Web of Science, Scopus, and Cochrane) were systematically searched for pertinent articles. Articles were selected following the inclusion and exclusion criteria. Qualitative and quantitative analyses of the selected articles were performed. Results: The initial electronic search resulted in 1087 hits. Based on the inclusion and exclusion criteria, five articles were selected for qualitative analysis, out of which three were considered for quantitative analysis. Three parameters were considered for accuracy evaluation (angular, coronal, and apical deviation). The mean angular deviation was -1.22 degrees (95% CI, -1.06--1.39), the mean coronal deviation was -0.15 mm (95% CI, -0.24--0.07), and the mean apical deviation was -0.19 mm (95% CI, -0.27--0.10). Conclusions: The robotic implant system was found to have significantly lower angular deviations and insignificantly lower coronal and apical deviations compared to DCAIS. Within the limitations of this review, it can be concluded that robot-assisted implant placement in resin models permits higher accuracy compared to DCAIS and SCAIS systems. However, due to the limited number of comparative studies with high heterogeneity, the findings of this review should be interpreted with caution. Further research is necessary to confirm the clinical application of robotics in implant surgery.

COMPARISONS BETWEEN DIGITAL-GUIDED AND NONDIGITAL PROTOCOL IN IMPLANT PLANNING, PLACEMENT, AND RESTORATIONS: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

OBJECTIVES

The present study aimed to systematically review the current randomized clinical trials (RCTs) with respect to computer-aided design/computer-aided manufactured (CAD/CAM) techniques in the process of implant planning, placement, and rehabilitation.

MATERIALS AND METHODS

Four independent reviewers conducted an electronic and manual literature search using several databases, including the National Library of Medicine (MEDLINE-PubMed), Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE. Articles were included if they were RCTs involving the interventions regarding the computer-guided impression, placement, and manufacturing process. The outcomes of interest include clinical and patient-reported outcomes and time efficiency. A meta-analysis was conducted to evaluate the time efficiency, pain severity, accuracy of implant placement, and postsurgery marginal bone level.

RESULTS

A total of 39 and 25 articles were included in the qualitative and quantitative analysis, respectively. The results of the meta-analysis showed that significantly less time was spent performing the digital impression procedure than the conventional impression (P = .002). In addition, the average adjustment time of the final prosthesis was significantly less than the nondigital fabricated prosthesis (P = .0005). Computer-guided groups reported significantly lower painkiller consumption compared to control groups (P = .03).

CONCLUSIONS

Digital impressions and CAD/CAM procedures are time-saving and provide stable and predictable outcomes. Moreover, computer-guided surgery can effectuate an accurate implant placement and less postsurgery discomfort.

Analysis of the accuracy of a dynamic navigation system when performing dental implant surgery with transcrestal sinus floor elevation: A pilot study

Background/purpose

The success of transcrestal sinus floor elevation (TSFE) is primarily reliant upon the experience of the surgeon owing to the limited operative visibility. To evaluate the accuracy associated with the use of a dynamic navigation system when conducting posterior maxilla implant surgery with TSFE.

Materials and methods

Twenty-eight implants were placed in 28 patients requiring implantation in the posterior maxilla via a TSFE approach. The drills were used to access the planned position (within 1 mm of the bottom of the maxillary sinus floor) under dynamic navigation system. TSFE was then accomplished using osteotomes and a piezoelectric device. Lastly, the implant was inserted under the dynamic navigation. Three effective deviations between planned and actual implant placement were then measured including angular deviation (AD, degrees), entry point horizontal deviation (EPHD, mm), and apical point horizontal deviation (APHD, mm).

Results

The AD, EPHD, and APHD between the planned and actual implant placement were 3.656 ± 1.665°, 1.073 ± 0.686 mm, and 1.086 ± 0.667 mm, respectively. Premolar site AD values were less than those for molar sites (P = 0.004). No significant differences in these outcomes were observed in different surgeons. Obvious sinus perforation was not detected by immediate postoperative cone beam computed tomography imaging.

Conclusion

The accuracy associated with using a dynamic navigation system when conducting posterior maxilla implant surgery via a TSFE approach using piezoelectric devices was comparable. This technique thus achieved appropriate interventional precision and safety while decreasing the morbidity associated with the TSFE approach.

Accuracy of freehand versus guided immediate implant placement: A randomized controlled trial

PURPOSE

This randomized controlled trial (RCT) aimed to compare the accuracy of immediate implant placement with freehand and static guided surgery.

METHODS

An RCT was conducted on 61 subjects who received a total of 80 dental implants. The enrolled patients were randomly allocated to two groups: freehand surgery (control group, n = 40 implants) and static guided surgery with R2Gate® (Megagen, Gyeongbuk, South Korea, test group, n = 40 implants). Crestal and apical deviations in both mesiodistal and buccolingual dimensions, as well as depth and angular deviations, were calculated by comparing the three-dimensional (3D) position of the implant in the planning software with the final implant position, revealed by an intraoral scan of the fixture after placement. The Mann-Whitney test was used for comparative assessment.

RESULTS

In the freehand group (control), crestal deviations of 1.13 ± 0.89 mm and 1.00 ± 0.76 mm were found in the mesiodistal and buccolingual directions, respectively, versus 0.34 ± 0.26 mm (p<0.001) and 0.37 ± 0.24 mm (p = 0.03) in the static guided surgery group (test). Apical deviation was also higher in the freehand group (control) than in the static guided surgery group (test) in the mesiodistal (4.04 ± 1.90 mm vs. 0.97 ± 0.55 mm, p = 0.04) and buccolingual directions (3.46 ± 1.82 mm vs. 0.94 ± 0.67 mm, p = 0.02). Freehand surgery had greater angular deviation (6.09° ± 3.23) compared to guided surgery (0.83° ± 0.53, p = 0.02). However, depth deviation was similar in the freehand surgery group (2.24 ± 1.58 mm) and static guided surgery group (0.66 ± 0.43, p = 0.09).

CONCLUSIONS

Immediate implant placement with static guided surgery demonstrated better accuracy than freehand surgery.

STATEMENT OF CLINICAL RELEVANCE

Guided implant surgery showed fewer deviations compared to freehand surgery in fresh extraction sockets; therefore, the use of static guides should be given preference over the freehand modality.

Soft tissue dimensional change using customized titanium healing abutment in immediate implant placement in posterior teeth

BACKGROUND

The morphologic and dimensional alveolar bone is significant for resorption in the first 3 months after tooth removal because they restrict treatment outcomes with respect to function and esthetic. Following teeth extraction, the width and height of the alveolar ridge contour are reduced in both the horizontal and vertical dimensions. Following implant placement, the gingival morphology should be changed minimally compared to pre-extraction. Surrounding natural-like tissue is also an ultimate goal of the dental implant treatment, which is correlated with the cervical third contour on the anatomical tooth, for comfortable cleansing, food impaction avoidance, and esthetics.

PURPOSE

To evaluate the peri-implant soft tissue changes after immediate implant placement (IIP) with the use of a customized titanium healing abutment in the posterior teeth.

METHOD

Digital impressions using the intraoral scanner (MEDIT i500) were taken from 30 patients. Customized titanium healing abutments were designed and milled before extraction. Flapless extractions were done using surgical guides, 32 immediate implants placement were done in posterior areas, and healing abutments were placed. Soft tissues were scanned during pre-operation, and post-surgery during the 1st, 3rd, and 6th months. A 3D analysis program (Final Surface) evaluated the gingival margin distance, height, contour width, and volume in each period. SPSS was used to analyze the data with a p-value = 0.05. The between-time interval comparisons were done and the analysis was done using a Multivariate test.

RESULTS

Customized titanium healing abutments used in immediate implantation maintained optimal peri-implant mucosa. In intermittent periods, there was no significant reduction in all aspects of the margin distances and heights. During the entire period, the margin height reduction on the buccal, lingual, mesial, and distal was 0.63 mm, 0.93 mm, 0.08 mm, and 0.24 mm, respectively, and contour width reduction on the buccal, lingual, and buccolingual was 0.59 mm, 0.43 mm, and 1.03 mm, respectively. There was a significant reduction in the total buccolingual contour width in the 1st month and total volume in the 3rd to 6th months.

CONCLUSIONS

Immediate implant placement with customized titanium healing abutment can achieve the optimal peri-implant mucosa and this protocol is an alternative for soft tissue management.

Accuracy of dental implant placement with a robotic system in partially edentulous patients: A prospective, single-arm clinical trial

OBJECTIVES

This clinical study aimed to assess the accuracy of implant positions using a robotic system in partially edentulous patients.

MATERIALS AND METHODS

Twenty-eight partially edentulous patients received 31 implants using the robotic system. Deviations between the planned and placed implants were calculated after surgery. The deviations were compared with objective performance goals (OPGs) from reported studies of fully guided static computer-assisted implant surgery (CAIS) and dynamic CAIS. A multiple linear regression analysis was performed to investigate the possible effects of the type and side of the arch, implant location, and implant dimensions on the deviations.

RESULTS

The evaluation of 31 implants resulted in a mean angle deviation of 2.81 ± 1.13° (95% confidence interval (CI): 2.40-3.23°), while the 3D deviations at the implant shoulder and apex were 0.53 ± 0.23 mm (95% CI 0.45-0.62 mm) and 0.53 ± 0.24 mm (95% CI 0.44-0.61 mm), respectively. The upper limits of the 95% CI of 3D deviations were lower than those of the corresponding OPGs; however, the angle deviation was similar to that of the OPG. No statistically significant differences were found for the type and side of the arch, implant location, and implant dimensions to the deviations (p > .05).

CONCLUSIONS

The robotic system appears to achieve higher accuracy in implant positions than static and dynamic CAIS in partially edentulous patients (Chinese Clinical Trial Registry ChiCTR2300067587).

Accuracy of Zygomatic Implant Placement Using a Full Digital Planning and Custom-Made Bone-Supported Guide: A Retrospective Observational Cohort Study

The aim of the study was to evaluate the accuracy of zygomatic implant placement using customized bone-supported laser-sintered titanium templates. Pre-surgical computed tomography (CT) scans allowed to develop the ideal virtual planning for each patient. Direct metal laser-sintering was used to create the surgical guides for the implant placement. Post-operative CT scans were taken 6 months after surgery to assess any differences between the planned and placed zygomatic implants. Qualitative and quantitative three-dimensional analyses were performed with the software Slicer3D, recording linear and angular displacements after the surface registration of the planned and placed models of each implant. A total of 59 zygomatic implants were analyzed. Apical displacement showed a mean movement of 0.57 ± 0.49 mm on the X-axis, 1.1 ± 0.6 mm on the Y-axis, and 1.15 ± 0.69 mm on the Z-axis for the anterior implant, with a linear displacement of 0.51 ± 0.51 mm on the X-axis, 1.48 ± 0.9 mm on the Y-axis, and 1.34 ± 0.9 mm on the Z-axis for the posterior implant. The basal displacement showed a mean movement of 0.33 ± 0.25 mm on the X-axis, 0.66 ± 0.47 mm on the Y-axis, and 0.58 ± 0.4 mm on the Z-axis for the anterior implant, with a linear displacement of 0.39 ± 0.43 mm on the X-axis, 0.42 ± 0.35 mm on the Y-axis, and 0.66 ± 0.4 mm on the Z-axis for the posterior implant. The angular displacements recorded significative differences between the anterior implants (yaw: 0.56 ± 0.46°; pitch: 0.52 ± 0.45°; roll: 0.57 ± 0.44°) and posterior implants (yaw: 1.3 ± 0.8°; pitch: 1.3 ± 0.78°; roll: 1.28 ± 1.1°) (p < 0.05). Fully guided surgery showed good accuracy for zygomatic implant placement and it should be considered in the decision-making process.

Accuracy of partially and fully guided surgical techniques for immediate implant placement: An in vitro assessment

STATEMENT OF PROBLEM

Optimal implant positioning is essential to achieving predictable results. Computer-guided surgery has been reported to be an accurate technique for implant placement in healed sites, but the accuracy of guided techniques for immediate implant placement into fresh sockets is still unclear.

PURPOSE

The purpose of this experimental randomized split-mouth study in pig jaws was to determine the accuracy of partially and fully guided surgical techniques for immediate implant placement into fresh sockets and to compare 2 different methods of implant position deviations analysis.

MATERIAL AND METHODS

Twenty implants were installed in 10 pig jaws using 2 different techniques: partially guided (n=10) and fully guided (n=10). Cone beam computed tomography and digital scanning were performed before and after the surgical procedure to plan the virtual implant position and fabricate the surgical guide, as well as to determine implant position deviations. Two methods were used to evaluate implant deviations: tomographic and digital scanning. The Shapiro-Wilk test of normality was used. Deviation comparisons were carried out by using paired t tests (α=.05), and intraclass correlation coefficient (ICC) was computed to assess the agreement between the 2 methods of implant deviation analysis.

RESULTS

In the tomographic analysis, the partially guided technique resulted in significantly higher global apical and lateral coronal deviations (2.25 ±0.59 mm; 0.96 ±0.55 mm) than fully guided (1.52 ±0.89 mm; 0.75 ±0.52 mm) (P<.01 and P<.05, respectively). The analysis performed using digital scanning showed significantly higher angular, global apical, and lateral apical deviations in the partially guided (6 ±3.28 degrees; 2.49 ±1.03 mm; 2.16 ±1.07 mm) technique than in the fully guided (3.32 ±1.84 degrees; 1.5 ±0.58 mm; 0.98 ±0.67 mm) (P<.05). An ICC of 0.522 between the 2 methods of implant deviation analysis was obtained.

CONCLUSIONS

The partially guided technique was less accurate than the fully guided technique for immediate implant placement into fresh sockets. A moderate concordance was observed between cone beam computed tomography and digital scanning analyses, suggesting that more studies are required to validate and to define the most reliable method of measuring implant deviation.

Investigation on the application of digital guide templates guided dental implantation in China

BACKGROUND

The aim of this survey is to investigate the application of digital guide templates (DGTs) across China, and the views and attitudes of oral health professionals toward them.

METHODS

This survey was prepared, distributed, and collected by WJX. Chinese oral health professionals were invited to participate in it. The basic information of respondents, the application of DGTs, and the views and attitudes toward their status quo and development were statistically described. Chi-square test was used to evaluate the correlation between the basic information of respondents and the application of DGTs as well as the views and attitudes toward them.

RESULTS

A total of 276 questionnaires were collected, of which 273 were identified as valid. 269 (98.5%) respondents were dental clinical workers, 204 (74.7%) were dental clinical implant workers, and 152 (55.7%) had been engaged in the implant industry for more than five years. The chi-square test showed that working years were significantly correlated with the half-guided, tooth-supported, and mucosa-supported DGTs (P < 0.05); and professional backgrounds and working years presented significant differences in the views and attitudes toward the status quo and development of DGTs (P < 0.05). The questionnaires also made a preliminary investigation and evaluation on the factors influencing accuracy, indications, doctors' recommendations and relevant training.

CONCLUSION

Most respondents held a positive attitude toward the accuracy and development of DGTs. This survey can point out the direction for the improvement of DGTs, and provide a reference for the study of factors affecting implant accuracy, the establishment of a training system, and the understanding of clinicians' current views on DGTs. Trial registration This survey was approved by the Ethics Review Committee of Chenghuaxinguanghua Dental Clinic (Approval NO. CDCIRB-D-2021-201).

Digital versus radiographic accuracy evaluation of guided implant surgery: an in vitro study

BACKGROUND

Cone-beam computed tomography (CBCT) is the most widely used method for postsurgical evaluation of the accuracy of guided implant surgery. However, the disadvantages of CBCT include radiation exposure, artifacts caused by metal implants, and high cost. Few studies have introduced a digital registration method to replace CBCT for evaluating the accuracy of guided surgery. The purpose of this study was to compare digital registration to conventional CBCT in terms of the capacity to evaluate the implant positioning accuracy of guided surgery.

MATERIALS AND METHODS

This in vitro study included 40 acrylic resin models with posterior single mandibular tooth loss. Guided surgery software was used to determine the optimal implant position; 40 tooth-supported fully guided drilling templates were designed and milled accordingly. After the guided surgery, the accuracies of the surgical templates were evaluated by conventional CBCT and digital registration. For evaluation by conventional CBCT, postsurgical CBCT scans of the resin models were performed. The CBCT data were reconstructed and superimposed on the implant planning data. For digital registration, we constructed a virtual registration unit that consisted of an implant replica and a scan body. Next, we obtained postsurgical optical scans of resin models with the scan body. The postsurgical implant position was identified by superimposition of the registration unit and optical scan data. The implant planning data and postsurgical implant position data were superimposed; deviations were reported in terms of distance for implant entry/apex point and in terms of angle for the implant axis. Interclass correlation coefficients (ICCs) and Bland-Altman plots were used to analyze the agreement between the two evaluation methods.

RESULTS

The ICCs between the two methods were 0.986, 0.993, and 0.968 for the entry point, apex point, and angle, respectively; all were significantly greater than 0.75 (p < 0.001). Bland-Altman plots showed that the 95% limits of agreement of the differences were - 0.144 to + 0.081 mm, - 0.135 to + 0.147 mm, and - 0.451° to + 0.729° for the entry point, apex point, and angle, respectively; all values were within the maximum tolerated difference.

CONCLUSION

Conventional CBCT and digital registration showed good agreement in terms of evaluating the accuracy of implant positioning using tooth-supported surgical templates.

Comparison between flapless-guided and conventional surgery for implant placement: a 12-month randomized clinical trial

OBJECTIVES

The study was aimed at comparing implants installed with guided and conventional surgery.

MATERIAL AND METHODS

Twenty-nine total edentulous patients were selected, and maxillary contralateral quadrants were randomly assigned to static computer-aided implant surgery (S-CAIS): flapless computer-guided surgery, and conventional surgery (CS): flap surgery with conventional planning. Tomography scans were performed at baseline and 10 days after the surgery for deviation measurement, and radiography was done at baseline and after 6 and 12 months, for peri-implant bone level (PIBL) analysis. Peri-implant fluid and subgingival biofilm were collected to evaluate bone markers and periodontal pathogens.

RESULTS

S-CAIS showed less linear deviation at the apical point and the midpoint and less angular deviation (p < 0.05), with greater depth discrepancy in the positioning of the platform (p < 0.05). Higher values of vertical PIBL were observed for the S-CAIS group at baseline (p < 0.05), while lower values of horizontal PIBL were observed for CS (p < 0.05). Bone markers and Tf presented higher levels in CS (p < 0.05). Flapless S-CAIS allowed smaller linear and angular deviations than the conventional technique.

CONCLUSION

However, PIBL was higher in S-CAIS; the conventional technique led to a greater angiogenic and bone remodeling activity by elevating the angiogenic levels and bone markers.

CLINICAL RELEVANCE

Evaluating the different implant insertion techniques can guide clinical and surgical regarding the accuracy, the release pattern of bone markers, and the peri-implant bone level.

TRIAL REGISTRATION

ReBEC-RBR-8556fzp.

Computer-Guided Surgery for Dental Implant Placement: A Systematic Review

Implant therapy is currently the treatment of choice for the replacement of missing teeth. Correct implant positioning is of vital importance. To this end, radiographic techniques providing 3D information and guided surgery techniques, both static and dynamic, have been developed. The primary objective of this work is to study whether placing dental implants in partially edentulous patients with guided surgery techniques results in less, equal or greater precision than placing them freehand. The secondary objectives are to gain an understanding of the advantages and disadvantages, indications, limitations, and complications of this type of surgery. A literature search was performed in Pubmed and BVS, and six randomized clinical trials meeting the marked inclusion criteria were included. The different guided surgery techniques were compared with each other and with the traditional method. Freehand surgery was found to be the least accurate, as the implants placed with this technique showed the largest deviations between the planned position and the final position, both when calculating the global (3D) deviation and when measuring the deviation in each of the axes (vertical, mesio-distal, bucco-lingual and lateral), and the angular deviation and voxel overlap. In contrast, the most accurate surgeries were fully guided and half-guided, with the smallest deviations between the planned and final implant position. With any guided surgery technique, more precise implant positioning is achieved than with freehand placement. Advantages include reduced trauma and surgery time; disadvantages include reduced primary implant stability and higher cost. This type of surgery is more indicated in cases of critical anatomy, but may encounter limitations in terms of cost, degree of buccal opening, visibility and adjustment of the guides and the need for prior familiarization with the procedure. Nevertheless, this surgical technique reduces the complication rate.

A Novel Approach to Guided Implant Surgery: A Technical Note

Computer-guided software and kits have significantly improved the clinical applications of implant surgery. Nonetheless, some technical problems are still in evidence during clinical procedures because of cumbersome surgical tools that can limit access to implant sites, mainly in posterior areas of the mouth in the presence of bulky anatomical structures and in patients with reduced mouth-opening capacity. The present paper aimed to present a novel approach to guided implant surgery, describing the technical characteristics of an innovative guided surgical kit made up of modified sleeves and modular surgical drills. The proposed guided surgical kit is based on a novel patented system of sleeves and modular burs, with an increased length of the metal sleeves and a reduced height of the drills. The innovative design of the proposed system would allow the clinician to position guided fixtures in all clinical situations; the reduced encumbrance would be particularly helpful to gain access to the posterior areas of both maxilla and mandible, which have limited inter-arch space, with an easy and user-friendly approach. The modular system could overcome anatomical limitations, such as reduced mouth-opening capacity, and permit clinicians to maintain the stability and integrity of the surgical templates, even in cases where there is very limited intermaxillary space.

Does guided level (fully or partially) influence implant placement accuracy at post-extraction sockets and healed sites? An in vitro study

OBJECTIVES

The aim of this study is to evaluate the effect of guide level on the accuracy of static computer-aided implant surgery (sCAIS) at post-extraction sockets and healed sites.

MATERIALS AND METHODS

A total of 30 duplicate dental models, with 300 potential implant sites, were used. All the models were equally randomized into three groups: fully guided (FG, n = 100), partially guided (PG, n = 100), and free handed (FH, n = 100) surgeries. After implant placement, the mean global, horizontal, depth, and angular deviations between the virtually planned and actual implant positions were measured automatically by a Python script within software Blender.

RESULTS

Both FG and PG surgeries showed significantly higher accuracy than FH surgery at post-extraction sockets and healed sites. In both sCAIS groups, there were nearly 50% more deviations from implants placed at sockets than those from delayed placement. For the immediate implant placement, the accuracy of sCAIS was significantly affected by the level of guidance. The FG group exhibited lower deviations than the PG group, with a significant difference in coronal global and horizontal deviations (p < .05). For the healed sites, two guided groups exhibited similar outcomes (p > .05).

CONCLUSIONS

sCAISs provide more accuracy than the free-handed approach in position transferring from planning to a model simulation. Full guidance can significantly increase the accuracy, especially at post-extraction sites.

CLINICAL RELEVANCE

Guided protocols showed significantly higher accuracy than free-handed surgery regardless of implantation timing, but both had nearly 50% more deviations in immediate implant placement.

Accuracy of commercial 3D printers for the fabrication of surgical guides in dental implantology

OBJECTIVES

To evaluate the accuracy of two different surgical guides (small extent = single implant and large extent = full arch) fabricated by five additive manufacturing technologies (SLA=Stereolithography, DLP= Digital Light Processing, FDM=Fused Deposition Modeling, SLS=Selective Laser Sintering, Inkjet).

METHODS

Overall, 72 guides (6 per type) were obtained with the different machines (SLA=Form2; DLP=Rapid Shape D40 and Cara Print 4.0; FDM=Raise 3D Pro2; SLS=Prodways P1000; Polyjet®=Stratasys J750). The guides were surface-scanned with an optical dental scanner, and the resulting files were compared with the initial design files using a surface matching software. Root Mean Square (RMS) and standard deviation were calculated, representing respectively trueness and precision. Kruskall-Wallis non-parametric test was used to compare trueness and precision between small-extent and large-extent guides and 3D printer by pairs. The threshold for significance was α=0.05, except for the comparison of printers by pairs where a Bonferroni-corrected level of 0.0033 was used.

RESULTS

Significant differences were observed for trueness and precision between small-extent and large-extent guides, regardless the printer except for DLP (trueness and precision) and SLS (precision). SLA, DLP and Polyjet® technologies showed similar results in terms of trueness and precision for both small-extend and large-extend guides (P>0.05).

CONCLUSIONS

The size affected the accuracy of CAD-CAM surgical guides. The different additive manufacturing technologies had a limited impact on the accuracy.

CLINICAL SIGNIFICANCE

This study is of clinical interest as it shows that the 3D printing technology (SLA/DLP) has a limited impact on 3D printed surgical guides accuracy. However, the size of the guide can have a significant impact, as small-extent guides were more accurate than large-extent guides.

Accuracy of static fully guided implant placement in the posterior area of partially edentulous jaws: a cohort prospective study

OBJECTIVE

A cohort prospective study was conducted to assess the three-dimensional positioning accuracy of the implant between pre-surgical and the final implant position using a static fully guided approach in the posterior area of the jaws.

MATERIALS AND METHODS

A total of 60 implants (30 patients) were digitally analyzed after superimposing the Digital Imaging and Communications in Medicine (DICOM) files obtained from the Cone Beam Computed Tomography (CBCT) pre- and post-implant placement. The software calculations included deviations at the implant shoulder and at the implant apex, global deviation (3D offset), and angle deviation. Statistical analysis was performed with α = 0.05.

RESULTS

Considering the total number of implants, mesiodistal, buccolingual, and apicocoronal mean deviations at the shoulder and implant apex were equal or below 0.21 ± 0.69 mm, and only the buccolingual mean deviation at the apex reached up to 0.67 ± 1.06 mm. The mesiodistal and apicocoronal deviations were not statistically significant at both the shoulder and apex levels of the implant. The mean total angular deviation was 5.62° ± 4.09. The main limitation of this surgical approach was the requirement for a wide mouth opening.

CONCLUSIONS

Static fully guided surgery for dental implant placement exhibits minimum deviations respect to presurgical planning. The main limitation in the posterior areas is the requirement for a wide mouth opening.

CLINICAL RELEVANCE

Even with minimum deviations clinically acceptable, precautions and safety margins must be respected when using static full-guided surgery to place dental implants.

The influence of crown coverage on the accuracy of static guided implant surgery in partially edentulous models: An in vitro study

OBJECTIVE

To evaluate the influence of crown coverage of surgical guides on the accuracy of static computer-assisted implant surgeries (sCAISs) in different partially edentulous situations.

METHODS

Acrylic models with five types of partially edentulous situations were fabricated in this study. In coDiagnostiX software (Dental Wings, Montreal, Canada), surgical templates were designed and fabricated with reduced crown coverage (RCC), standard crown coverage (SCC) and extended crown coverage (ECC). Then, fully guided implant placement into the acrylic models was performed by dental surgeons with more than 10 years of experience. In total, 120 models and 120 guides were manufactured, and 168 bone-level Straumann replica implants (4.1 × 10 mm, Institut Straumann AG, Basel, Switzerland) were inserted. Postoperative implant positions were scanned (Trios 3, 3 shape, Copenhagen, Denmark) and compared with the preplanned virtual positions via coDiagnostiX (Dental Wings, Montreal, Canada). The angular, coronal and apical deviations were measured and analyzed to evaluate the accuracy of implant insertion. Statistical analysis was performed using one-way ANOVA and Tukey's test.

RESULTS

For single tooth missing situations, the RCC group was similar to the SCC group and ECC group in anterior sites. In premolar or molar sites, the SCC and ECC groups had no statistically significant difference (p > .05), while the RCC group had more coronal and apical deviation (p < .05). For multiple teeth missing situations, there was no difference among the RCC, SCC and ECC groups (p > .05). No difference was found among the five edentulous situations with different CCs (p > .05).

CONCLUSION

The CC of templates can significantly affect the accuracy of guided surgeries when implants are inserted in a single gap at posterior sites. Templates with CC extended to the undercut line may be an optimal choice for static guided surgeries.

CLINICAL SIGNIFICANCE

The accuracy of static guided implant surgery can be influenced by the CC of templates, and proper CC with the guide covering extending to the undercut line may contribute to improved accuracy. CC should be taken into consideration when designing surgical templates.

Accuracy of digitally planned, guided apicoectomy with a conventional trephine and a custom-made endodontic trephine: An in vitro comparative study

PURPOSE

Static guided trephine apicoectomy has been developed as a less invasive and more accurate alternative to conventional freehand apicoectomy with drills. Overpenetration is a frequent issue with this procedure, which deteriorates accuracy and raises safety concerns. A safety improvement to address this problem is presented.

MATERIALS AND METHODS

Guided apicoectomies were performed in porcine mandibles with either a conventional bone trephine or a custom-made endo-trephine with built-in depth control. The deviation of the apical endpoint of the trephine from the digital surgical plan was analyzed. Overpenetration frequency was recorded.

RESULTS

Procedures performed with the custom trephine were significantly more accurate both along the x-axis and globally, but no significant difference was found for the y and z axes. Overpenetration frequency was 70% in the conventional trephine group versus 38% in the stop trephine group.

CONCLUSION

The results indicate that the lack of physical depth control can interfere with the accuracy (and safety) of these procedures to a significant extent, as visual cues (such as the depth markings on a conventional trephine) are insufficient to prevent overpenetration. Our results show that custom-made trephines with a built-in stop offer an optimal solution for this problem.

Accuracy of half-guided implant placement with machine-driven or manual insertion: a prospective, randomized clinical study

OBJECTIVES

To compare the accuracy of implant placement performed with either a surgical motor or a torque wrench as part of a half-guided surgical protocol.

MATERIALS AND METHODS

Implant insertion with half-guided surgical protocol was utilized by surgical motor (machine-driven group) or torque wrench (manual group) in the posterior maxilla. After the healing period, accuracy comparison between planned and actual implant positions was performed based on preoperative cone beam computed tomography and postoperative digital intraoral scans. Coronal, apical, and angular deviations, insertion time, and insertion torque were evaluated.

RESULTS

Forty patients were treated with 1 implant each; 20 implants were inserted with a surgical motor and 20 implants with a torque wrench. Global coronal and apical deviations were 1.20 ± 0.46 mm and 1.45 ± 0.79 mm in the machine-driven group, and 1.13 ± 0.38 mm and 1.18 ± 0.28 mm in the manual group (respectively). The mean angular deviation was 4.82 ± 2.07° in the machine-driven group and 4.11 ± 1.63° in the manual group. Mean insertion torque was 21.75 ± 9.75 Ncm in the machine-driven group, compared to 18.75 ± 7.05 Ncm in the manual group. Implant placement duration was 9.25 ± 1.86 s in the machine-driven group at a speed of 50 rpm, and 36.40 ± 8.15 s in the manual group.

CONCLUSION

No significant difference was found between the two groups in terms of accuracy and mean insertion torque, while machine-driven implant placement was significantly less time-consuming.

CLINICAL RELEVANCE

Optimal implant placement accuracy utilized by half-guided surgical protocol can be achieved with both machine-driven and torque wrench insertion.

TRIAL REGISTRATION

ID: NCT04854239.