Computer-assisted Implant Surgery Research Articles

Complete-Arch Implant Rehabilitation with the Aid of Computer-Assisted Implant Surgery and Transitional Implants: A New Digital Approach

This case report describes a new digital workflow for computer-assisted implant surgery in an edentulous patient using transitional implants to support a fixed surgical template and interim prosthesis. The accuracy of the final implant position using the described protocol was evaluated and compared to the outcomes obtained using other types of surgical templates. This novel digital approach appears to enhance the accuracy of implant positioning for edentulous patients and seems to be comparable to a tooth-supported surgical template.

Accuracy of Different Surgical Guide Designs for Static Computer-Assisted Implant Surgery: An In Vitro Study.

The aims of this study were to evaluate the effect of (1) the different surgical guide designs and (2) implant placement location on the accuracy of fully guided implant placement in single edentulous sites using an in vitro study model. Forty-five partially edentulous models were scanned and divided into 3 groups: group 1, tooth-supported full-arch surgical guide; group 2, 3 different tooth-supported shortened surgical guides (SSGs); and group 3, tooth-supported full-arch surgical guide with a crossbar. All surgical guides were printed and used for fully guided implant placement. A total of 180 implants (60 per group) were placed, and scan bodies were positioned on all models, and postoperative surface scan files (STL) files were obtained. Superimposition of preoperative and postoperative STL files was performed, and the accuracy of implant position was evaluated. The interaction between group and implant location was statistically significant for angle, 3D offset at the base, and at the tip (P < .001). The post-hoc tests showed a statistically significantly higher deviation for group 2 compared to group 3 for all outcomes for implants #4 (P < .05) and #7 (P < .05). There was also a statistically significant difference in all outcomes between groups 1 and 3 for implant #7 (P < .05). All surgical guide designs presented satisfactory performance with clinically acceptable levels of deviation. However, SSGs presented higher accuracy for guided implant placement in a single-edentulous site, whereas a full-arch surgical guide with a crossbar presented superior outcomes when 2 or more guided implants were placed simultaneously.

Comparison of Dental Surface Image Registration and Fiducial Marker Registration: An In Vivo Accuracy Study of Static Computer-Assisted Implant Surgery.

This study compared the accuracy of static computer-assisted implant surgery (sCAIS) planned through dental surface image registration and fiducial marker registration. Stone models of 30 patients were converted into digital dental casts by using a desktop scanner. Cone-beam computed tomography (CBCT) was performed and superimposed to the digital dental casts with two methods: matching the dental surface images or matching the fiducial markers on a stereolithographic radiographic template. Following the implant planning, stereolithographic surgical guides were fabricated, and 56 fully guided implants were inserted by the same doctor. Deviations between planned and inserted implants were measured and compared using postoperative CBCT images. After adjustment for other potential influencing factors, compared with the fiducial marker registration group, significantly larger mean lateral deviations were noted in the dental surface registration group at both the implant platform and apex (p = 0.0188 and 0.0371, respectively). However, the mean lateral deviations for the dental surface registration (0.83 ± 0.51 mm at implant platform and 1.24 ± 0.68 mm at implant apex) were comparable to the literature. In conclusion, our findings indicate that although sCAIS planned using dental surface image registration was not statistically as accurate as that using fiducial marker registration, its accuracy was satisfactory for clinical use.

Comparison of the accuracy of implant placement using different drilling systems for static computer-assisted implant surgery: A simulation-based experimental study.

Different designs of surgical drilling systems have been developed for the purpose of static Computer-Assisted Implant Surgery (sCAIS), but there is at present little understanding of how design principles affect the accuracy of implant placement. The aim of this in vitro study was to compare the accuracy of implant placement among five drilling systems of sCAIS in a controlled experimental setting. Twenty-five 3D printed models with two edentulous bilateral premolar spaces were allocated to five different drilling systems: group A: sleeve-in-sleeve, group B: sleeve-in-sleeve with self-locking, group C: mounted sleeve-on-drill, group D: integrated sleeve-on-drill with metal sleeve in the guide, group E: integrated sleeve-on-drill without metal sleeve. Models were scanned with CBCT and optical scanner. All implants were digitally planned and 10 implants placed with sCAIS in each group. Postoperative 3D deviation of placed vs planned position was measured by means of platform, apex and angular deviation. Data was analyzed using Kruskal-Wallis test (P ≤ .05). Pairwise comparisons were tested with Dunn's test with adjusted P values. The overall platform deviation ranged from 0.42 ± 0.12 mm (group B) to 1.18 ± 0.19 mm (group C). The overall apex deviation ranged from 0.76 ± 0.22 mm (group B) to 1.95 ± 0.48 mm (group D). The overall angular deviation ranged from 2.50 ± 0.89 degree (group B) to 5.30 ± 1.04 degree (group E). Group A and B showed significantly less angular deviation than groups D and E (P < .05). There was no statistically significant differences in all parameters between group A and B, as well as between group D and E (P > .05). Significant differences were found with regards to accuracy among the five sCAIS systems tested, suggesting that the drilling protocol, the devices used and the design principles of the guides could influence the accuracy of implant placement.

The Influence of Surgical Experience and Bone Density on the Accuracy of Static Computer-Assisted Implant Surgery in Edentulous Jaws Using a Mucosa-Supported Surgical Template with a Half-Guided Implant Placement Protocol—A Randomized Clinical Study

The aim of our randomized clinical study was to analyze the influence of surgical experience and bone density on the accuracy of static computer-assisted implant surgery (CAIS) in edentulous jaws using a mucosa-supported surgical template with a half-guided implant placement protocol. Altogether, 40 dental implants were placed in the edentulous jaws of 13 patients (novice surgeons: 18 implants, 6 patients (4 male), age 71 ± 10.1 years; experienced surgeons: 22 implants, 7 patients (4 male), age 69.2 ± 4.55 years). Angular deviation, coronal and apical global deviation and grey level measurements were calculated for all implants by a blinded investigator using coDiagnostiX software. 3DSlicer software was applied to calculate the bone volume fraction (BV/TV) for each site of implant placement. There were no statistically significant differences between the two study groups in either of the primary outcome variables. There was a statistically significant negative correlation between angular deviation and both grey level measurements (R-value: −0.331, p < 0.05) and BV/TV (R-value: −0.377, p < 0.05). The results of the study suggest that surgical experience did not influence the accuracy of implant placement. The higher the bone density at the sites of implant placement, the higher the accuracy of static CAIS.

Comparison of the accuracy of implant position for two-implants supported fixed dental prosthesis using static and dynamic computer-assisted implant surgery: A randomized controlled clinical trial.

Computer-assisted implant surgery (CAIS) can facilitate accuracy of single implant placement, but little is known with regards to parallelism between multiple implants. To compare the accuracy of position and parallelism of two implants, using static and dynamic CAIS systems. Thirty patients received two implants (60 implants) randomly allocated to two different CAIS systems. Optimal implant position and absolute parallelism was planned based on preoperative cone beam CT (CBCT). Patients received implants with a surgical guide (static CAIS, n = 30) or real-time navigation (dynamic CAIS, n = 30). Implant three-dimensional deviation and parallelism was calculated after surgery. The mean 3D deviation in the static and dynamic CAIS group at implant platform were 1.04 ± 0.67 vs 1.24 ± 0.39 mm, at apex were 1.54 ± 0.79 vs 1.58 ± 0.56 mm and angulation were 4.08° ± 1.69° vs 3.78° ± 1.84°, respectively. The angle deviations between two placed implants (parallelism) in static and dynamic CAIS groups were 4.32° ± 2.44° and 3.55° ± 2.29°, respectively. There were no statistically significant differences in all parameters between groups. Static and dynamic CAIS provides similar accuracy of the 3D implant position and parallelism between two implants.

Accuracy of implant position when placed using static computer-assisted implant surgical guides manufactured with two different optical scanning techniques: a randomized clinical trial

Data from cone beam computed tomography (CBCT) and optical scans (intraoral or model scanner) are required for computer-assisted implant surgery (CAIS). This study compared the accuracy of implant position when placed with CAIS guides produced by intraoral and extraoral (model) scanning. Forty-seven patients received 60 single implants by means of CAIS. Each implant was randomly assigned to either the intraoral group (n=30) (Trios Scanner, 3Shape) or extraoral group (n=30), in which stereolithographic surgical guides were manufactured after conventional impression and extraoral scanning of the stone model (D900L Lab Scanner, 3Shape). CBCT and surface scan data were imported into coDiagnostiX software for virtual implant position planning and surgical guide design. Postoperative CBCT scans were obtained. Software was used to compare the deviation between the planned and final positions. Average deviation for the intraoral vs. model scan groups was 2.42°±1.47° vs. 3.23°±2.09° for implant angle, 0.87±0.49mm vs. 1.01±0.56mm for implant platform, and 1.10±0.53mm vs. 1.38±0.68mm for implant apex; there was no statistically significant difference between the groups (P>0.05). CAIS conducted with stereolithographic guides manufactured by means of intraoral or extraoral scans appears to result in equal accuracy of implant positioning.

Influence of surgical guide support and implant site location on accuracy of static Computer-Assisted Implant Surgery.

To investigate the effect of surgical guide support and implant site location on the accuracy of static Computer-Assisted Implant Surgery (sCAIS) in partially edentulous patients. 375 replica implants were inserted in 85 study models. Surgical implant placement was done using static 3D printed surgical guides, which were designed to be supported either by all the teeth present in the model (full arch), or by 4-teeth), 3-teeth or 2-teeth. Each study model included threesingle-tooth gap (STG) situations; one extraction socket site and two implants placed in a distal extension situation. Preplanned and postoperative implant positions were compared using the treatment-evaluation tool in digital software. 3-dimensional and angular deviations were measured. Statistical analysis was done using ANOVA, and pairwise t tests and Bonferroni-Holm's adjustment were applied as a post hoc test. Accuracy of surgical guides used in sCAIS was significantly affected by the number and type of teeth used for its support. Guides supported by 4 teeth were not significantly different from accuracy of full-arch-supported guides (p>.05). Guide support by posterior teeth was associated with an increased level of accuracy, when compared to anterior teeth guide support. Implants placed in extraction sockets were associated with significantly higher 3D and angular deviation values (p<.05), and surgical guides with a distal extension situation resulted in significantly higher deviation values (p<.05). The number and location of teeth supporting the surgical guide can significantly influence the accuracy of sCAIS, with 4 teeth providing equal accuracy to full-arch guides in (STG) situations.

The accuracy of single-tooth implants placed using fully digital-guided surgery and freehand implant surgery.

This randomized controlled clinical trial (RCT) aimed to compare the accuracy of implant positions between static computer-assisted implant surgery (CAIS) and freehand implant surgery in a single edentulous space. Sites with single edentulous spaces and neighbouring natural teeth were randomized into static CAIS or freehand implant surgery groups. In both groups, digital implant planning was performed using data from cone beam computed tomography (CBCT) and surface scans. In the static CAIS group, a surgical guide was produced and used for fully guided implant surgery, while in the freehand group, the implants were placed in a freehand manner. Postoperative CBCT was used for nine measurements representing the deviations in angles, implant shoulders and apexes between planned and actual implant positions. Fifty-two patients received 60 single implants. The median (IQR) deviations in angles, shoulders and apexes were 2.8 (2.6)°, 0.9 (0.8)mm and 1.2 (0.9)mm, respectively, in the static CAIS group, and 7.0 (7.0)°, 1.3 (0.7)mm and 2.2 (1.2)mm, respectively, in the freehand group. Statistically significant differences were found in 6 out of nine measured parameters using Mann-Whitney U test (p<0.05). Static CAIS provided more accuracy in implant positions than freehand placement in a single edentulous space.

The accuracy of static vs. dynamic computer-assisted implant surgery in single tooth space: A randomized controlled trial.

The aim of this RCT was to compare the accuracy of implant placement between static and dynamic computer-assisted implant surgery (CAIS) systems in single tooth space. A total of 60 patients in need of a single implant were randomly assigned to two CAIS groups (Static n=30, Dynamic n=30) and implants were placed by one surgeon. Preoperative CBCT was transferred to implant planning software to plan the optimal implant position. Implants were placed using either stereolithographic guide template (Static CAIS) or implant navigation system (Dynamic CAIS). Postoperative CBCT was imported to implant planning software, and deviation analysis with the planned position was performed. Primary outcomes were the deviation measurements at implant platform, apex, and angle of placement. Secondary outcome was the distribution of the implant deviation into each 3D direction. The mean deviation at implant platform and implant apex in the static CAIS group was 0.97±0.44mm and 1.28±0.46mm, while that in the dynamic CAIS group was 1.05±0.44mm and 1.29±0.50mm, respectively. The angular deviation in static and dynamic CAIS group was 2.84±1.71 degrees and 3.06±1.37 degrees. None of the above differences between the two groups reached statistical significance. The deviation of implants toward the mesial direction in dynamic CAIS group was significantly higher than that of the static CAIS (p=0.032). Implant placement accuracy in single tooth space using dynamic CAIS appear to be the same to that of static CAIS. (Thai Clinical Trials Registry TCTR20180826001).

The Accuracy of Computer-Assisted Implant Surgery Performed Using Fully Guided Templates versus Pilot-Drill Guided Templates

Purpose. Computer-assisted stereolithographically guided surgery allows an ideal implant placement for prosthetic restoration. Two types of stereolithographic templates are currently available: a fully guided template and a pilot-drill guided template. The purpose of this study was (i) to evaluate the accuracy of implant insertion using these types of surgical templates and (ii) to define parameters influencing accuracy. Materials and Methods. 20 patients were enrolled and divided into 2 study groups: in group A, implants were placed using CAD-CAM templates with fully guided sleeves; in group B, implants were placed with a template with only pilot-drill guided sleeves. Pre- and postoperative computed tomographies were used to measure differences between final positions of implants and virtually planned positions. Three linear discrepancies (coronal, apical, and depth) and two angular ones (buccolingual and mesiodistal) were measured. Correlations between accuracy and jaws of interest, implant length and diameters, and type of edentulism were also analysed. Results. A total of 50 implants were inserted in 15 patients using CAD-CAM templates: 23 implants in group A and 27 in group B. The mean coronal deviations were 1.16 and 1.11 mm (P = 0.35), respectively; the mean apical deviations were 1.65 and 1.71 mm (P = 0.22); the mean depth deviations were 0.95 and −0.68 mm (P = 0.032); the mean buccolingual angular deviations were 4.16° and 6.72° (P = 0.042); and the mean mesiodistal ones were 2.81° and 5.61° (P = 0.029). In addition, the accuracy was statistically influenced only by implant diameter for coronal discrepancy (P = 0.035) and by jaw of interest for mesiodistal angulation (P = 0.045). Conclusion. Fully guided implant surgery was more accurate than pilot-drill guided surgery for different parameters. For both types of surgery, a safety margin of at least 2mm should be preserved during implant planning to prevent damage to nearby anatomical structures.

The influence of guided sleeve height, drilling distance, and drilling key length on the accuracy of static Computer-Assisted Implant Surgery.

The aim of this study was to evaluate the effect of guided sleeve height, drilling distance, and guided key height on accuracy of static Computer-Assisted Implant Surgery (sCAIS). Pre and post-operative positions of implants placed in duplicate dental models were compared and recorded after placement of implants according to a standardized treatment planning and execution sCAIS protocol. Guided sleeve heights: 2 mm, 4 mm, 6 mm and guided key heights: 1 mm and 3 mm were equally randomized in six test groups with varying implant lengths (10-16 mm) and surgical drilling protocols. The mean crestal and apical three-dimensional (3D) deviation, as well as the angular deviation were calculated for each group. Data was analyzed using multivariate analysis anova. P values less than .05 were considered statistically significant. All P values of post-hoc tests were corrected for multiple testing using Bonferroni-Holm's adjustment method. 3D implant positioning accuracy was not significantly affected by the difference in sleeve height alone or by the implant length alone (P > .05). However, 3D and angular deviation values became significantly higher as the total drilling distance below the guided sleeve increased and significantly became lower as the guided key height above the sleeve increased. 18 mm drilling distance resulted in a significantly higher deviation, when compared to 14 mm or 16 mm drilling distances, irrespective of sleeve height or implant length (P < .01). 3 mm key height resulted in significantly less 3D deviation than 1 mm key height (P < .01). Decreasing the drilling distance below the guided sleeve, by using shorter sleeve heights or shorter implants can significantly increase the accuracy of sCAIS.

Papilla Formation in Response to Computer-Assisted Implant Surgery and Immediate Restoration.

This retrospective analysis was undertaken to evaluate the effect of immediate implant restoration using a computer-assisted technique in partially edentulous sites on interimplant and intertooth bone level stability and papilla formation. Nine partially edentulous patients received a total of 23 implants that supported immediately placed implant restorations. Planning was accomplished using a radiographic guide, which allowed visualization of the emergence profile from the platform of the implant to the cervical of the planned restoration. Guided implants were placed according to the manufacturer's instructions, and restorations were screw retained directly to the implant. Multiple implants were splinted at surgery with autopolymerizing resin. Measurements were made at a mean of 545 days (range 288-958) postoperatively on the basis of radiographs and photographs. Measures were: (1) distance from bone crest to platform, (2) bone crest to contact point, (3) interimplant distance at the outer diameter of the platform, and (4) papilla from highest point to a reference line. At follow-up time, the bone ridge was located higher than the implant platform (mean 0.57 mm) compared to implants whose interimplant distance was less than 3 mm (mean 0.27 mm). Mean increase of the bone level between insertion and approximate 1-year follow-up was 0.047 mm. The mean distance from the contact point to bone was 2.39/3.93 mm postoperatively, resulting in 91/71% papilla fill between implants and between implant and adjacent tooth, respectively. Computer-assisted surgery with the preplanned immediate restoration seems to be an effective method to minimize bone loss at the implant platform resulting in support for papilla.

Full Arch Restoration with Computer-Assisted Implant Surgery and Immediate Loading in Edentulous Ridges with Dental Fresh Extraction Sockets. One Year Results of 10 Consecutively Treated Patients

There is a growing need for patients to be rehabilitated with a fixed, implant-supported prosthesis immediately after surgery. The present study aims to describe the results of a modified prosthetic and surgical protocol of computer-assisted implant insertion and immediate loading in edentulous jaws with extraction sockets. Ten patients were consecutively treated with a modified computer assisted implant surgery protocol and screw-retained provisional metal-acrylic prosthesis prepared ahead of surgery and delivered immediately. Overall, 60 implants (Nobel Replace Tapered Groovy) were inserted, of which 22 were inserted in fresh extraction sockets. Definitive prosthesis was delivered after 6-12months. Outcome measures were radiographic marginal bone-level changes, survival of implants, and patient satisfaction. The follow-up period was of at least 12months. All the patients felt comfortable and none withdrew from the study. No implants were lost, resulting in a cumulative survival rate of 100%. Radiological estimation showed a mean peri-implant marginal bone loss of 1.4±0.3mm. No other complications, biological or mechanical, were recorded. In all cases, patients appeared to be very satisfied with the aesthetic and function. Within the limitations of this study, our data seem to validate this surgical and prosthetic protocol with valid functional and aesthetic results when applied in selected cases.