Factors influencing transfer accuracy of cone beam CT-derived template-based implant placement

Accuracy of Static Computer-Assisted Implant Placement in Narrow Ridge by Novice Clinicians

OBJECTIVE

 This study aimed to evaluate the accuracy and clinical impact of implant placement by novice implant clinicians in the narrow anterior ridge by fully guided (FG), pilot-guided (PG), and freehand (FH) placements.

MATERIALS AND METHODS

 A maxillary surgical model with missing incisors and a narrow ridge was designed. Two implants were planned in the lateral incisor locations to receive screw-retained implant prosthesis. Fifteen novice implant clinicians placed implants according to every placement. Angle, vertical and horizontal platform, and horizontal apex deviations from the planned implant were measured. The clinical impact evaluation aimed to relate the position of each placed implant to (1) periimplant bone dimension after implant placement and (2) the prosthesis retention mechanism.

RESULTS

 The FG implants were more accurate than PG implants at the angle (p = 0.001) and maximum horizontal apex deviations (p = 0.001), and were more accurate than FH implants for all comparisons (p = 0.001). The PG implants were superior to FH implants at the maximal horizontal platform deviation (p = 0.001). All FG implants were fully covered with bone and could be restored with screw-retained prostheses. One PG implant (3.3%) had fenestration at the apex, and one PG implant (3.3%) could not be restored with screw-retained prosthesis. Seven FH implants (23.3%) had fenestration at the apex, and one FH implant (3.3%) suffered from dehiscence. Seven FH implants (23.3%) were not restorable with screw-retained prosthesis.

CONCLUSION

 For novice clinicians, a significantly greater accuracy was observed for FG placement, followed by PG and FH placements. FH implants experienced significant compromise of periimplant bone dimension and the prosthesis retention mechanism.

A simple method to identify implant sites in totally edentulous arches: a pilot study with thermo-printed templates used with cone beam computed tomography

BACKGROUND

All dental implants must be placed following radiological, clinical and aesthetic indications in compliance with prosthetic principles avoiding iatrogenic damage to patients. In implantology, among the key choices, to obtain predictable results, it is essential to establish (by cone beam computed tomography [CBCT]) the sites where to insert the implants; these sites must be identified, during the surgical phase, in the oral cavity. Surgical guides represent a valid aid especially in complex cases that require multiple implants. For some clinical conditions, expert operators choose the free hand technique during which identifying the chosen implant sites on CBCT in the oral cavity is more difficult.

METHODS

This experimental study is based on the use of thermo-molded mask as an alternative to surgical guides when the freehand technique is adopted in totally edentulous patients. These innovative masks, containing radiopaque references, are initially worn by patients during the execution of the CBCT, and later during surgery to identify the implant sites in the oral cavity.

RESULTS

The procedure described proved to be very useful and able to increase the precision of the freehand technique even if it does not provide information on the inclination of the implants. The metal references help clinical identification of the implant site.

CONCLUSIONS

Our thermo-molded masks, in particular clinical conditions, could represent a valid and economical alternative to the classic surgical guide. The described procedure does not increase costs for the patient and significantly increases the precision in inserting the implants during free-hand techniques.

Accuracy of static computer-aided implant surgery (S-CAIS) using CAD-CAM surgical templates fabricated from different additive manufacturing technologies

STATEMENT OF PROBLEM

Different 3D printers are available for guided implant surgery, but studies that evaluate their source of errors and their cost-effectiveness are lacking.

PURPOSE

The purpose of this in vitro study was to compare the accuracy of different 3-dimensional (3D) printed surgical templates made using different additive manufacturing technologies and to evaluate the effect of implant location on the accuracy of fully guided implant placement.

MATERIAL AND METHODS

Fifty partially edentulous maxillary typodonts with edentulous sites in the right second premolar (SP), right lateral incisor (LI), left central incisor (CI), and left first molar (FM) locations were scanned and printed from the standard tessellation language (STL) datasets. The study compared 5 groups for the fabrication of implant surgical templates: Varseo S-Bego (Bego), Polyjet-Stratasys (Poly), Low Force Stereolithography-FormLabs (LFS), P30+-Straumann (P30), and M2-Carbon (M2). After fully guided implant placement, the typodont was scanned, and the 3D implant positions were compared with the master model by superimposing the STL files. Descriptive statistics were calculated for groups and subgroups, and comparisons among the groups and subgroups were conducted via 2-way mixed analysis of variance, Tukey honest significant difference, and post hoc Bonferroni tests (α=.05).

RESULTS

The results were site specific and not consistent within each group. For angle deviation, the within-group analysis for P30 demonstrated significantly lower values for implants positioned at site SP (1.4 ±0.8 degrees) than for sites LI (2.3 ±0.7 degrees; P=.001) and CI (2.3 ±0.8 degrees; P=.007). For 3D offset at base for implant CI, LFS was significantly higher than Bego (P=.002), Poly (P=.035), or M2 (P=.001); P30 was also significantly higher than Bego (P=.014) and M2 (P=.006). LFS had a significantly higher 3D offset at the tip than Bego (P=.001) and M2 (P=.022) for implant CI.

CONCLUSIONS

The choice of 3D printer seemed to influence fully guided implant surgery in terms of the final implant position compared with initial implant planning. However, although statistically significant differences were present across groups, all additive manufacturing technologies were within clinically acceptable values.

Comparison of the Accuracy of Pilot Drill-Guided and Fully Guided Implant Surgery With Dynamic Navigation: In Vitro Model Study

The aims of the present study are to measure and compare dental implant deviations with fully guided and pilot drill-guided protocols using dynamic navigation systems in polyurethane models. The pilot drill-guided group was determined to be the study group and included 12 implant applications. In this group, the pilot hole was drilled with navigation guidance, and the procedure was completed freehandedly. In the control group, all drilling and implant placement steps were performed using the navigation system, and a total of 12 implants were placed. The pre- and postoperative images were compared to calculate the magnitude of implant deviation. The quantitative data of the 2 groups were compared using the independent-samples t test and Mann-Whitney U test. The analyses revealed that the length of the procedure differed significantly between the 2 groups (P < .001). The procedure duration was significantly shorter in the study group. The entry deviation values of the 2 groups were not significantly different (P = .079). The analysis revealed the apex deviation to be higher in the study group than in the control group (P = .003). However, the 2-dimensional vertical apex deviation values of the implants were not significantly different between groups (P = .068). Angular deviation was determined to be significantly higher in the study group (P < .001). In the present study, all implants were successfully placed in the models using a dynamic navigation system. The results of this study may be useful for future clinical studies.

A prediction method and evaluation for assessing guide-supported dental implant accuracy

Functional and esthetic results require accurate implant placement. We aimed to develop a predictive method for assessing dental implant accuracy, and to evaluate the cumulative system influence of surgical guides. A mathematical model was constructed to determine the influence of surface changes on a specific point, using Jacobian matrix expressions. Tooth-supported guides with a specific locating surface were designed for model verification. Ten guides were fabricated for in vitro virtual implant accuracy tests. Locating surface errors of 0.15 mm caused significant deviations in implant positioning. Tooth-supported guide location errors significantly impacted implant accuracy, emphasizing the need for precise guide placement.

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.

Implant position accuracy using dynamic computer-assisted implant surgery (CAIS) combined with augmented reality: A randomized controlled clinical trial

Background/purpose

Computer-assisted implant surgery (CAIS) is increasingly performed to reduce deviations in implant position. Dynamic CAIS or navigation systems provide instant display of implant drilling instruments and patient positions directly on the computer monitor. Augmented reality (AR) technology allows operators to visualize real-time information projected onto the lenses of AR glasses. Although AR is being used in medical applications, there are few clinical studies on applying AR glasses to dental implants. The purpose of this randomized clinical study was to compare the accuracy of implant position using the dynamic CAIS with and without AR glasses.

Materials and methods

Twenty patients who needed a single dental implant were randomly divided into two groups: combined dynamic CAIS with AR glasses (AR glasses group, n = 10) and dynamic CAIS without AR glasses (non-AR glasses group, n = 10). Three-dimensional (3D) deviations of implant platform, apex and angular deviations were measured and analyzed using independent t-tests (P < 0.05).

Results

The 3D angular deviations in the AR glasses and non-AR glasses groups were 1.47 ± 1.01° and 2.42 ± 0.76°, respectively. Mean 3D entry point and apical deviations were 0.75 ± 0.45 mm and 0.87 ± 0.45 mm in the AR glasses group, whereas the non-AR glasses group were 1.11 ± 0.44 mm and 1.18 ± 0.50 mm, respectively. There was no statistically significant difference between the two groups.

Conclusion

Implant position accuracy using dynamic CAIS with AR glasses was similar to dynamic CAIS without AR glasses during a single implant placement.

Accuracy of dental implant placement with CAD-CAM 3D printed and conventional thermoplastic surgical pilot guides: A clinical comparative trial

STATEMENT OF PROBLEM

Dental implant placement is routinely guided by using 2-dimensional radiographs and thermoplastic surgical guides (CTGs), which may lack accuracy. Three-dimensionally (3D) printed surgical guides (3DGs) have been recommended to improve accuracy. However, they require additional training on specific technology. The current knowledge on indications for CTGs and 3DGs is limited.

PURPOSE

The purposes of this clinical comparative trial were to compare the accuracy of implant placement using a CTG or 3DG pilot surgical guide (3DGp) and to evaluate clinical outcomes related to the surgical procedure.

MATERIAL AND METHODS

Patients planned for a single implant were recruited and assigned to either the CTG or 3DGp group. The ideal implant position was determined through virtual treatment planning using intraoral digital scans and cone beam computed tomography (CBCT). Deviations were determined by superimposing the postsurgical digital scans and the virtually planned implant position. The Mann Whitney U Test was performed for each measure (α=.05). A linear regression model was performed to estimate and control for the effect of covariables.

RESULTS

Twenty participants were recruited (10 CTG and 10 3DGp). Mean initial ISQ values were 69 ±13 and 76 ±8 for the CTG and 3DGp group, respectively. There was no significant difference in primary (P=.15) or secondary (P=.383) stability between the CTG and 3DGp groups. Data revealed minimal deviations for both groups (P>.05). Bone type (P=.026) and secondary stability (P=.031) had a significant effect on angular deviation.

CONCLUSIONS

CTG accuracy was similar to that of 3DGp. Reduced angular deviation was noted in the presence of softer bone type and higher secondary stability.

Accuracy of markerless registration methods of DICOM and STL files used for computerized surgical guides in mandibles with metal restorations: An in vitro study

STATEMENT OF PROBLEM

Digital imaging and communications in medicine (DICOM) files together with surface scans must be accurately registered in virtual implant planning software programs to match real-life dimensions and ensure correct plan transfer through computer-aided manufactured surgical guides.

PURPOSE

The purpose of this in vitro study was to evaluate the accuracy of 3 different registration methods of DICOM data with and without metal restorations and a metal artifact reduction (MAR) tool for surface scans.

MATERIAL AND METHODS

Thirteen dentate mandibles were assigned to each group of this study (n=39). Baseplate wax was adapted to the bone surfaces of each mandible, and 5 radiopaque markers were attached. A desktop scanner was used to obtain control scans. The groups of metal-free mandibles (MFM) and mandibles with metal restorations (MRM) were scanned to obtain DICOM data without a MAR tool. Additional DICOM data for the MRM were obtained with the MAR tool (MRM-MAR). Point-based registration (PBR), best-fit registration (BFR), and automatic registration (AR) were used to align standard tessellation language (STL) and DICOM data, and 3 data sets were exported. Radiographic markers on each data set were compared with those on the control scan, and positional deviations were calculated and statistically evaluated with 1-way ANOVA followed by multiple pairwise comparisons, independent samples t test, and 2-way ANOVA (α=.05).

RESULTS

Within each group, PBR had the lowest deviation values with statistical significance in the MFM and the MRM-MAR groups (P<.001). AR showed failure in the MRM and the MRM-MAR groups. Statistically significant differences were found on comparing the average deviations among the 3 groups for PBR only (P<.001). No association was found between deviation values and the presence or absence of metal restoration, while a positive association was found with the type of registration method (P<.001).

CONCLUSIONS

PBR had the highest accuracy level compared with AR and BFR methods. An increase in the number of calculations resulted in more deviation values. The MAR tool had a positive effect on PBR in mandibles with metal restorations.

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.

A randomized clinical trial on the accuracy of guided implant surgery between two implant-planning programs used by inexperienced operators

STATEMENT OF PROBLEM

Various static implant planning software packages have been developed for the purpose of static computer-assisted implant surgery. However, how different software programs affect the accuracy of implant placement is unclear.

PURPOSE

The purpose of this clinical study was to evaluate and examine the difference in posterior implant positioning between the planned and placed positions when inexperienced operators, following a fully guided implant surgery protocol, used 2 static implant planning software packages.

MATERIAL AND METHODS

Twenty-four participants who needed single posterior implant placement were randomly divided into 2 groups based on the used implant planning software program (coDiagnostiX, n=12; Implant Studio, n=12). The dataset of the placed implant position, generated by digitizing the implant impression, was superimposed on the planned implant position. The number of horizontal, angular, and vertical deviations of the placed implants were measured for each software package and statistically analyzed with the independent t test (α=.05).

RESULTS

The coDiagnostiX group presented with a mean horizontal deviation at the entry point (DE) of 1.07 ±0.36 mm, mean angular deviation (DA) of 3.52 ±1.64 degrees, and mean depth deviation (DD) of -0.71 ±0.29 mm, while the mean DE, mean DA, and mean DD in the Implant Studio group were 0.97 ±0.33 mm, 3.77 ±2.16 degrees, and -0.84 ±0.30 mm, respectively. Statistically, no significant differences were found between coDiagnostiX and Implant Studio programs for all these results (P>.05).

CONCLUSIONS

Acceptable accuracy of implant positioning can be expected by inexperienced operators if they follow the guidelines of either of the 2 software packages. Both the coDiagnostiX and Implant Studio programs showed similar results, with a shallower than planned implant depth of 0.71 and 0.84 mm, respectively.

Influence of surgeon experience on implant placement in guided surgeries: A systematic review and meta-analysis of randomized clinical trials

STATEMENT OF PROBLEM

Guided surgical techniques in implant dentistry use virtual planning to accurately position implants. Understanding the effect of a surgeon's experience on guided surgery is essential to ensure successful outcomes.

PURPOSE

The purpose of this systematic review and meta-analysis of randomized clinical trials was to evaluate the influence of a surgeon's experience on the accuracy of implant positioning in guided surgery for completely or partially edentulous patients.

MATERIAL AND METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, searches were conducted in the PubMed, Scopus, Web of Science, EMBASE, Cochrane Library, SciELO, and nonpeer-reviewed literature databases. Studies that met the population, intervention, control, and outcome (PICO) strategy were included: a completely or partially edentulous maxilla or mandible, guided surgery performed by experienced and inexperienced surgeons, and assessing implant positioning accuracy. A random-effects meta-analysis with a 95% confidence interval was conducted using Stata 15.1. The risk of bias was assessed with the Cochrane risk-of-bias tool for randomized trials (RoB2), and evidence certainty was evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tool. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42022302288).

RESULTS

Three articles from 2017 to 2020 encompassing 43 participants (22 men and 21 women) with a mean age of 61.2 years and a total of 150 implants were included. No significant difference was found between experienced and inexperienced surgeons in terms of angular, cervical, or apical deviations of the implants (95% confidence interval, P<.05). The difference between surgeons regarding positioning accuracy was less than 0.01 degrees for angular deviation, 0.35 mm for apical deviation, and 0.16 mm for cervical deviation. Low heterogeneity was observed for angular deviations (Q P=.021, I2=34%, and t2<.001) and cervical deviations (Q P=.18, I2=45%, and t2=.064). High heterogeneity was observed for apical deviations (Q P<.001, I2=87% and t2=.522). The overall bias risk was moderate, with the evidence certainty ranging from low to moderate.

CONCLUSIONS

In guided surgery, the surgeon's experience did not significantly impact the occurrence of deviations in implant positioning.

Evaluation of the accuracy of fully guided implant placement by undergraduate students and postgraduate dentists: a comparative prospective clinical study

PURPOSE

This study aimed to assess the accuracy of implant placement through three-dimensional planning and fully guided insertion, comparing outcomes between undergraduate and postgraduate surgeons.

METHODS

Thirty-eight patients requiring 42 implants in posterior single-tooth gaps were enrolled from the University Clinic for Prosthodontics at the Martin Luther University Halle Wittenberg and the Department of Prosthodontics, Geriatric Dentistry, and Craniomandibular Disorders of Charité University Medicine, Berlin. Twenty-two implants were placed by undergraduate students (n = 18), while 20 implants were placed by trainee postgraduate dentists (n = 5). Pre-operative intraoral scans and cone beam computed tomography images were performed for implant planning and surgical template fabrication. Postoperative intraoral scans were superimposed onto the original scans to analyze implant accuracy in terms of apical, coronal, and angular deviations, as well as vertical discrepancies.

RESULTS

In the student group, two implant insertions were performed by the assistant dentist because of intraoperative complications and, thus, were excluded from further analysis. For the remaining implants, no statistically significant differences were observed between the dentist and student groups in terms of apical (p = 0.245), coronal (p = 0.745), or angular (p = 0.185) implant deviations, as well as vertical discrepancies (p = 0.433).

CONCLUSIONS

This study confirms the viability of fully guided implant placement by undergraduate students, with comparable accuracy to postgraduate dentists. Integration into dental education can prepare students for implant procedures, expanding access and potentially reducing costs in clinical practice. Collaboration is essential for safe implementation, and future research should explore long-term outcomes and patient perspectives, contributing to the advancement of dental education and practice.

TRIAL REGISTRATION

DRKS, DRKS00023024, Registered 8 September 2020-Retrospectively registered, https://drks.de/search/de/trial/DRKS00023024 .

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.

Accuracy in static guided implant surgery: Results from a multicenter retrospective clinical study on 21 patients treated in three private practices

PURPOSE

To evaluate the accuracy of a static computer-assisted implant surgery (s-CAIS) system across different private practices.

METHODS

This retrospective clinical study was based on data retrieved from 21 patients who received 61 implants between 2018 and 2020 in 3 private practices run by surgeons with extensive experience with s-CAIS. All patients were treated using the same s-CAIS system, planning software, template manufacturing process, and surgical guides. The standard tessellation language (STL) file of the intraoral scan of the fixture taken immediately after implant placement was matched with that of the preoperative plan for comparisons of preoperative and planned implant positions with postoperative and actual implant positions. The study outcomes were linear and angular deviations between the planned and actual implant positions.

RESULTS

No surgical or postsurgical complications occurred. The overlap of the two STL files resulted in a mean angular deviation of 2.94° The mean linear deviation at the implant shoulder was 0.73 mm, and that at the apex was 1.06 mm. The mean vertical deviations at the implant shoulder and the apex were 0.29 mm and 0.01 mm, respectively.

CONCLUSION

All cases showed satisfactory accuracy within the limits of this study (small number of patients and retrospective design). These results might be related to the use of a standardized digital workflow by experienced operators.

STATEMENT OF CLINICAL RELEVANCE

The study shows that careful control of each step, from data acquisition to final execution, is key for the accuracy of stent-guided systems.

Accuracy and patient-centered results of static and dynamic computer-assisted implant surgery in edentulous jaws: a retrospective cohort study

OBJECTIVES

This study aimed to compare implant positioning accuracy and patient-centered results between static and dynamic computer-assisted implant surgery (s-CAIS and d-CAIS) in edentulous jaws.

MATERIAL AND METHODS

The current study retrospectively evaluated a total of 110 implants placed in 22 fully edentulous patients via s-CAIS or d-CAIS (n = 11). The accuracy of implant positioning was assessed by measuring the implant's angular deviation and deviation at the platform and apex from the preoperative design postoperatively. Patient-centered results, including preoperative and intraoperative patient-reported experiences and postoperative patient-reported outcomes, were extracted from the medical records. The nested t test and chi-square test were used to compare accuracy and patient-centered results between s-CAIS and d-CAIS postoperatively.

RESULTS

The implants in the s-CAIS group showed significantly smaller angular deviation (2.32 ± 1.23°) than those in the d-CAIS group (3.87 ± 2.75°). In contrast, the platform and apical deviation were significantly larger in s-CAIS (1.56 ± 1.19 mm and 1.70 ± 1.09 mm, respectively) than d-CAIS (1.02 ± 0.45 mm and 1.00 ± 0.51 mm, respectively). Furthermore, the implants in the s-CAIS group deviated significantly (p < 0.001) more toward the coronal direction than those in the d-CAIS group. Notably, all patients in the s-CAIS group reported an obvious foreign body sensation during surgery, representing a significant difference from the d-CAIS group.

CONCLUSIONS

Compared to s-CAIS, d-CAIS is a reliable technique for the placement of multiple implants in fully edentulous patients with less linear deviation and less foreign body sensation.

TRIAL REGISTRATION

The retrospective study was registered on the Chinese Clinical Trial Registry on August 8th, 2022, with registration number No. ChiCTR2200062484.

CLINICAL RELEVANCE

Despite the increasing use of computer- assisted implant surgery in fully edentulous patients, clinical evidence comparing implant positioning accuracy and patient-centered results between static and dynamic CAIS systems is scarce. Our study demonstrated that compared to s-CAIS, d-CAIS is a reliable technique for the placement of multiple implants in fully edentulous patients with less linear deviation.

Hybrid Navigation Technique for Improved Precision in Implantology

The hybrid navigation technique involves the merging of the Dynamic navigation (DN) system (Navident, Claronav, Canada) and static navigation technique (3Shape, Copenhagen, Denmark). Combining the advantages of both techniques, devising a protocol of hybrid navigation will be advantageous to eliminate the difficulties faced by operators in using either methods separately. Three patients requiring dental implants were included in this study. This requires the cone beam computed tomography (CBCT) (Digital Imaging and Communications in Medicine (DICOM) data) and intra-oral scan (Standard Tessellation Language (STL) format) data for the accurate planning of the implant positions in both the static and dynamic approaches. The steps carried out were repeated for each of the patients, the accuracy of the implant placement was verified postoperatively by merging the CBCT data pre and post through the Evalunav software (NaviDent, Claronav). The accuracy of the implants placed were assessed based on the mesio-distal, bucco-lingual, apical deviations in distance and in angulation. The semi-robotic DN and static guide combination as a hybrid technique is an interesting method to improve the accuracy of flapless implant surgeries and can be used in cases where the anatomical landmarks are determinant factors for the implant placement.

A digital strategy for intraoperative acquisition of actual drill position and rapid assessment of bony preparation accuracy using an intraoral scanner

A digital workflow to acquire actual position of the drill and assess bony preparation accuracy intraoperatively was described. Based on the widely used intraoral scanner, this digital workflow was a relatively practical and economical option for digital intraoperative measurement. As a result, it could help the clinician in accurate verification and immediate correction of the drill position and consequently facilitating the accurate implant placement in implant surgery.

Accuracy assessment of implant placement with versus without a CAD/CAM surgical guide by novices versus specialists via the digital registration method: an in vitro randomized crossover study

BACKGROUND

Many studies demonstrated that surgical guides might reduce discrepancies compared with freehand implant placement. This randomized crossover study aimed to assess the effects of approaches, practitioners' experience and learning sequences on the accuracy of single tooth implantation via digital registration method. No similar study was found.

METHODS

This in vitro randomized crossover study enrolled 60 novice students (Group S) and 10 experienced instructors (Group I). Sixty students were randomly and evenly assigned to two groups (Group SA and SB). In Group SA, 30 students first performed single molar implant on a simulation model freehand (Group SAFH), and then with a CAD/CAM surgical guide (Group SASG). In Group SB, another 30 students first performed guided (Group SBSG) and then freehand (Group SBFH). Ten instructors were also divided into Group IAFH/IASG (n = 5) and IBSG/IBFH (n = 5) following the same rules. The accuracy of implant placement was assessed by the coronal and apical distance (mm) and angular (°) deviations using the digital registration method. T tests and nonparametric tests were used to compare the results among different groups of approaches, experience and sequences.

RESULTS

For students, the coronal and apical distance and the angular deviations were significantly lower in surgical guide group than freehand group in total and in learning freehand first subgroup, but for learning surgical guide first subgroup the apical distance deviation showed no significant difference between two approaches. For students, the angular deviation of freehand group was significantly lower in learning surgical guide first group than learning freehand first group. For instructors, the coronal and apical distance and angular deviations showed no significant difference between two approaches and two sequences. For freehand approach, the coronal and apical distance and the angular deviations were significantly higher in student group than instructor group, while not significantly different between two groups for surgical guide approach.

CONCLUSIONS

For novices, using a surgical guide for the first implant placement may reduce the potential deviations compared with freehand surgery, and may reach a comparable accuracy with that of specialists. For simple single molar implantation, the surgical guide may not be significantly helpful for experienced specialists.

Accuracy of full-guided vs. pilot-guided implant insertion - A prospective laboratory study in fifth-year dental students

BACKGROUND

Education of undergraduates in implant dentistry has been extended. In order to assess the correct implant position, the accuracy of implant insertion using templates for pilot-drill guided and full-guided implant insertion was examined in a laboratory set-up in a cohort of undergraduates.

METHODS

After three-dimensional planning of the implant position in partially edentulous mandibular models, individual templates for the pilot-drill guided or full-guided implant insertion in the region of the first premolar were produced. A total of 108 dental implants were inserted. The results of the radiographic evaluation of the three-dimensional accuracy were statistically analyzed. Furthermore, the participants completed a questionnaire.

RESULTS

The deviation of the three-dimensional angle of the implants inserted fully guided was 2.74 ± 1.49 degrees compared to 4.59 ± 2.70 degrees for pilot-drill guided. The difference was statistically significant (p < 0.01). The returned questionnaires revealed a high interest in oral implantology and a positive evaluation of the hands-on course.

CONCLUSIONS

In this study, the undergraduates benefited from applying full-guided implant insertion considering the accuracy in this laboratory examination. However, the clinical effects are not clear as the differences are within a small range. Based on the returned questionnaires, the implementation of practical courses in the undergraduate curriculum should be encouraged.

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.

Clinical study of precision analysis and deviation control of a domestic guide plate-assisted edentulous implant surgery

PURPOSE

To evaluate the accuracy of a domestic digital implant guide plate to assist edentulous implant surgery, analyze the sources of deviation, and reduce the deviation of the guide plate.

METHODS

In total, 14 edentulous patients were selected, and 100 implant sites were measured. The preoperative cone beam computerized tomography (CBCT) data were imported into the software to design and fabricate the guide plate. After implant surgery,the data were imported for 3D reconstruction and alignment model was exported into the Geomagic Studio software for deviation measurement.

RESULTS

Analysis of the overall accuracy of the domestic guide plate showed deviation of the implant neck center, horizontal direction, implant base center, depth, and angle of 0.83 ± 0.27 mm, 0.39 ± 0.17 mm, 1.11 ± 0.35 mm, 0.45 ± 0.19 mm, and 3.16 ± 1.73°. There were not statistically significant difference (p>0.05) between the tooth/mucosa-supported guide plate and the mucosa-supported, mandibular guide plate and maxillary, vertical implantation and inclined, anterior implant sites and posterior teeth. There was a statistically significant difference (p<0.05) between the use of the modified non-pressure plate tool box and the pressure plate tool box.

CONCLUSION

First, the domestic implant guide plate can significantly improve the accuracy and efficiency in edentulous implant surgery. Second, the accuracy of the tooth/mucosa-supported guide plate is higher than mucosa-supported guide plate. Third, the accuracy of the new tool box without pressure plate is improved.

Accuracy of intraoral real-time navigation versus static, CAD/CAM-manufactured pilot drilling guides in dental implant surgery: an in vitro study

Background

Nowadays, 3D planning and static for dynamic aids play an increasing role in oral rehabilitation of the masticatory apparatus with dental implants. The aim of this study is to compare the accuracy of implant placement using a 3D-printed drilling guide and an intraoral real-time dynamic navigation system.

Methods

A total of 60 implants were placed on 12 partially edentulous lower jaw models. 30 were placed with pilot drilling guides, the other half with dynamic navigation (DENACAM^®). In addition, implant placement in interdental gaps and free-end situations were investigated. Accuracy was assessed by cone-beam computed tomography (CBCT).

Results

Both systems achieved clinically acceptable results, yet more accurate results regarding the offset of implant base and tip in several spatial dimensions were achieved using drilling guides (each p < 0.05). With regard to angulation, real-time navigation was more precise (p = 0.0016). Its inaccuracy was 3°; the template-guided systems was 4.6°. Median horizontal deviation was 0.52 mm at base and 0.75 mm at tip using DENACAM^®. When using the pilot drill guide, horizontal deviation was 0.34 mm in the median and at the tip by 0.59 mm. Regarding angulation, it was found that the closer the drill hole was to the system's marker, the better navigation performed. The template did not show this trend (p = 0.0043; and p = 0.0022).

Conclusion

Considering the limitations of an in vitro study, dynamic navigation can be used be a tool for reliable and accurate implantation. However, further clinical studies need to follow in order to provide an evidence-based recommendation for use in vivo.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40729-022-00430-6.

Linear dimensional accuracy of stereolithographic surgical guide after chemistry and physics sterilization

OBJECTIVES

The purpose of this study was to evaluate the dimensional stability of prototyped surgical guides after autoclave and 2% glutaraldehyde sterilization processes.

MATERIAL AND METHODS

Twenty prototyped surgical guides were prepared and submitted to two sterilization processes (n = 10): Physics - sterilization by autoclave (saturated water vapor under pressure, temperature of 126 to 130 °C, pressure of 1,7 at 1.9 kgf/cm², 16 min); Chemistry - sterilization by 2% glutaraldehyde for 10 h. Six pre-established points were measured in the prototyped surgical guides, before and after sterilization, using a digital caliper rule. The comparisons were made using orthogonal contrasts using the linear model of mixed effects (random and fixed).

RESULTS

there are no significant differences between autoclave and glutaraldehyde 2% (p>0.05) there are significant differences after autoclave sterilization (p<0.05) and there are not significant differences after 2% glutaraldehyde sterilization (p>0.05).

CONCLUSION

autoclave promoted dimensional alteration of the prototyped surgical guides, and the chemical sterilization by glutaraldehyde 2% did not cause dimensional alteration of the prototype surgical guides, being a favorable choice for sterilization.

CLINICAL SIGNIFICANCE

the sterilization of surgical guides can be performed through the chemical process with 2% glutaraldehyde without changing the linear precision of the prototype surgical guides.

Assessment of Deviations of Implants Installed with Prototyped Surgical Guide and Conventional Guide: In Vitro Study

OBJECTIVE

 The study aimed to assess the angular and linear deviations of implants installed in mannequins aided by surgical guides produced with the techniques of dual tomography (DT), model-based tomography (MT), and nonprototyped guide.

MATERIALS AND METHODS

 Implants were installed in mannequins of a partially edentulous maxilla and divided into three groups: Group C (n = 20), implants installed using the conventional technique with flap opening and conventional guide; Group DT (n = 20), implants installed using guided surgery with the dual tomography technique; and Group MT (n = 20), implants installed using the model-based tomography technique. After implant installation, the mannequin was subjected to a computed tomography (CT) to measure the linear and angular deviations of implant positioning relative to the initial planning on both sides.

RESULTS

 There was a higher mean angular deviation in group C (4.61 ± 1.21, p ≤ 0.001) than in groups DT (2.13 ± 0.62) and MT (1.87 ± 0.94), which were statistically similar between each other. Similarly, the linear deviations showed group C with the greatest discrepancy in relation to the other groups in the crown (2.17 ± 0.82, p = 0.007), central (2.2 ± 0.77, p = 0.004), and apical (2.34 ± 0.8, p = 0.001) regions.

CONCLUSION

 The techniques of DT and MT presented smaller angular and linear deviations than the conventional technique with the nonprototyped guide. There was no difference between the two-guided surgery techniques.

Duration, deviation and operator's perception of static computer assisted implant placements by inexperienced clinicians

INTRODUCTION

This study measured the duration, deviation and operator's perception of implant placement by fully guided (FG), pilot-guided (PG) and freehand (FH) protocols by postgraduate students with minimal implant experience.

MATERIALS AND METHODS

Twenty postgraduate students participated in the study. Half of them placed single anterior (S-Ant) and single posterior (S-Post) implants, and the other half placed anterior (B-Ant) and posterior (B-Post) implants in a wide edentulous area. The PG placement involved surgical guides that only controlled pilot drilling, whilst the FG placement controlled all the drilling steps and implant placement. The duration of implant placement and the operator's perception (ease of drilling, ease of implant placement and operator's preference) were measured. The deviations of placed implants were quantified by measuring the trueness and angulation deviations in relation to the planned implants.

RESULTS

The PG placement was the quickest for inserting implants, followed by FG and FH placements, respectively (p < .05). The location of the implant had influenced the duration of implant placement only for the PG placement. In relation to ease of drilling, ease of implant placement and operator's preference, there was no significant difference amongst the different placement protocols or implant locations. The FG placement was associated with least deviations, followed by PG and FH placements, respectively (p < .05).

CONCLUSIONS

In the hands of postgraduate students with minimal implant experience, FG and PG placements reduced the implant placement duration in comparison with FH placement. The FG placement was consistently more accurate followed by PG placement.

An In Vitro Study of the Reproducibility of the Drilling Access of Digitalized Surgical Guides Generated via Three Different Implant Planning Software Programs

Several implant planning software programs are widely use in implant treatments, but there has been no evidence of how different software programs affect the accuracy of static surgical guides used for implant placement. Thus, in this in vitro study, we aimed to compare the accuracy of static surgical guides that were prefabricated from three different software programs, including Implant Studio (Program A) (3Shape®, Copenhagen, Denmark), coDiagnostiX® (Program B) (Straumann®, Basal, Switzerland), and Blue Sky Plan (Program C) (Blue Sky Bio®, LLC, Libertyville, IL, USA). A total of 90 drillable polyurethane models were used as samples in this in vitro study; 30 study models were used to plan the same implant positions and design the surgical guides by each software program (n = 30) and then 90 implants were placed in the models using the surgical guides. The outcomes of the surgical guide accuracy were autonomically measured by the evaluation tool in the coDiagnostiX® (Straumann®, Basal, Switzerland) software program. The deviations between the planned and placed implants were automatically evaluated as three-dimensional and angular deviations. The mean three-dimensional implant position deviations from the implant platform of Program A, Program B, and Program C were 0.55 ± 0.25 mm, 0.52 ± 0.31 mm, and 0.56 ± 0.22 mm, respectively. The mean three-dimensional implant position deviations from the implant apex of Program A, Program B, and Program C were 0.72 ± 0.37 mm, 0.73 ± 0.4 mm, and 0.9 ± 0.46 mm, respectively. The mean depth deviations of Program A, Program B, and Program C were 0.19 ± 0.13 mm, 0.31 ± 0.32 mm, and 0.31 ± 0.22 mm, respectively. The mean angulation deviations of Program A, Program B, and Program C were 1.72 ± 0.88 degrees, 2.05 ± 1.24 degrees, and 2.74 ± 1.81 degrees, respectively. The results indicated that there were no significant differences among the three-dimensional positions at the implant platform, the three-dimensional positions at the implant apex, and the depth deviations between all three groups. However, it was found that there was a significant difference in the angular deviation of the implant position between the three groups (p = 0.02). The mean angular deviation of Program C was significantly greater than the Program A group (p = 0.001). In terms of the deviation directions of the implant platform and implant apex for the three groups, most of the deviations of a larger magnitude were toward the mesio-buccal direction. No matter which program was used to plan the implant position, deviations between the placed implant position and the planned position still occurred. Therefore, when planning implant positions with any implant planning software program, one must take into account an implant position deviation.

Comparison of the accuracy of two different dynamic navigation system registration methods for dental implant placement: A retrospective study

BACKGROUND

Dynamic navigation approaches are widely employed in the context of implant placement surgery, with registration being integral to the accuracy of such navigation. Relatively few studies to date, however, have compared different registration approaches, and such a comparison has the potential to guide the development of more accurate and reliable clinical registration methodology.

PURPOSE

This study was developed to compare the accuracy of dynamic navigation-based dental implant placement conducted using either U-tube or cusp registration methods.

MATERIALS AND METHODS

Medical records from all patients that had undergone implant surgery between August 2019 and October 2020 in the First Clinical Division of the Peking University Hospital of Stomatology were retrospectively reviewed, with 64 patients and 99 implants ultimately meeting with study inclusion criteria. Implant placement accuracy was gauged via the superimposition of the planned implant position in preoperative cone-beam computed tomography (CBCT) images with the true postoperative implant position in postoperative CBCT images. Accuracy was measured based upon the angular deviation, entry deviation (3-dimensional [3D] deviation in the coronal aspect of the alveolar ridge), and apex deviation (3D deviation in the apical area of the implant) when comparing these two positions.

RESULTS

The angular deviation, entry deviation, and apex deviation of all analyzed implants were 3.29 ± 0.17°, 1.29 ± 0.07 mm, and 1.43 ± 0.08 mm, respectively, while in the cusp registration group these respective values were 3.25 ± 1.58°, 1.28 ± 0.60 mm, and 1.34 ± 0.63 mm as compared to 3.35 ± 1.78°, 1.30 ± 0.78 mm, 1.55 ± 0.9 mm in the U-tube group, respectively. No significant differences in accuracy were observed when comparing these two registration techniques.

CONCLUSION

Dynamic computer-assisted surgical systems can facilitate accurate implantation, and both the U-tube and cusp registration methods exhibit similar levels of accuracy. As the cusp registration technique can overcome some of the limitations of the U-tube strategy without the need for an additional registration device, it may be more convenient for clinical use and warrants further research.

Additively Manufactured Surgical Implant Guides: A Review

Static computer assisted implant surgery (s-CAIS) is an integral part of the digital workflow in implant dentistry and provides the link between the virtual planning environment and surgical field. The accuracy of s-CAIS is influenced by many cumulative factors including the fit of the template which is related to the manufacturing process. This critical review provides an overview of the current research on additively manufactured surgical implant guides.

Digital vs. conventional workflow for one-abutment one-time immediate restoration in the esthetic zone: a randomized controlled trial

OBJECTIVES

To compare short-term outcomes after immediate restoration of a single implant in the esthetic zone with one-abutment one-time technique comparing a conventional (control) vs. a fully digital workflow (test).

MATERIALS AND METHODS

Eighteen subjects were randomly assigned to the two groups, and a digital implant planning was performed for all. In the test group, a custom-made zirconia abutment and a CAD-CAM provisional crown were prepared prior to surgery; implants were placed using a s-CAIS guide allowing immediate restoration after surgery. In the control group, the implant was placed free-handed using a conventional surgical guide, and a custom-made zirconia abutment to support a stratified provisional crown was placed 10 days thereafter, based on a conventional impression. Implant accuracy (relative to the planning), the provisional restoration outcomes, as well as PROMs were assessed.

RESULTS

The implant positioning showed higher accuracy with the s-CAIS surgical guide compared to free-handed surgery (angular deviation (AD): 2.41 ± 1.27° vs. 6.26 ± 3.98°, p < 0.014; entry point deviation (CGD): 0.65 ± 0.37 mm vs. 1.27 ± 0.83 mm, p < 0.059; apical deviation (GAD): 1.36 ± 0.53 mm vs. 2.42 ± 1.02 mm, p < 0.014). The occlusion and interproximal contacts showed similar results for the two workflows (p = 0.7 and p = 0.69, respectively). The PROMs results were similar in both groups except for impression taking with intra-oral scanning preferred over conventional impressions (p = 0.014).

CONCLUSIONS

Both workflows allowed implant placement and immediate/early restoration and displayed similar clinical and esthetic outcomes. The fully digital workflow was associated with a more accurate implant position relative to planning.

CLINICAL RELEVANCE

Our results show that both conventional and digital workflow are predictive and provide similar clinical outcomes, with extra precision provided by digitalisation.

Digital implantology—a review of virtual planning software for guided implant surgery. Part II: Prosthetic set-up and virtual implant planning

Background

Patient- and technology-related parameters influence the successful implementation of virtual implant planning and guided implant surgery. Besides data processing and computer aided design of drill guides as described in Part I, the possibilities and limitations for prosthetic set-up and virtual implant planning are essential (Part II).

Methods

The following software systems were examined using two different clinical situations for implant therapy: coDiagnostiX™, DentalWings, Canada (CDX); Simplant Pro™, Dentsply, Sweden (SIM); Smop™, Swissmeda, Switzerland (SMP); NobelClinician™, Nobel Biocare, Switzerland (NC); Implant Studio, 3Shape, Denmark (IST). Assessment criteria geared towards interfaces and integrated tools for prosthetic set-up and virtual implant planning.

Results

A software interface for an individual virtual prosthetic set-up was provided by two systems (CDX, IST), whereas the set-up of standardized teeth was provided by four systems (CDX, SIM, SMP, IST). Alternatively, a conventional set-up could be scanned and imported. One system could solely work with the digitization of a conventional set-up for virtual implant planning (NC). Stock abutments could be displayed for implant planning, but none of the tested software systems provided tools for the design of an individual abutment. All systems displayed three-dimensional reconstructions or two-dimensional cross-sections with varying orientation for virtual implant placement. The inferior alveolar nerve could be marked to respect a minimum distance between the nerve and the planned implant. Three implant planning systems provided a library to display more than 50 implant systems (CDX, SIM, IST), one system provided 33 implant systems (SMP) and one implant system provided 4 implant systems (NC).

Conclusion

Depending on the used software system, there are limited options for a virtual set-up, virtual articulators and the display of a virtual prosthetic set-up. The implant systems used by the clinician is important for the decision which software system to choose, as there is a discrepancy between available implant systems and the number of supported systems in each software.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02057-w.

Accuracy of dental implant placement with computer-guided surgery: a retrospective cohort study

Background

The aim of this study was to assess the accuracy of virtual planning of computer-guided surgery based on the actual outcomes of clinical dental implant placement.

Methods

This retrospective study enrolled patients among whom implant treatment was planned using computer-guided surgery with cone beam computed tomography (CBCT). The patients who received implant according to the guide with the flapless and flapped approach were classified as group 1 and 2, respectively, and the others who could not be placed according to the guide were allocated to the drop-out group. The accuracy of implant placement was evaluated with the superimposition of CBCT.

Results

We analyzed differences in the deviated distance of the entrance point and deviated angulation of the insertion of implant fixtures. With regard to the surgical approach, group 2 exhibited greater accuracy compared to group 1 in deviation distance (2.22 ± 0.88 and 3.18 ± 0.89 mm, respectively, P < 0.001) and angulation (4.27 ± 2.30 and 6.82 ± 2.71°, respectively, P = 0.001). The limitations of guided surgery were discussed while considering the findings from the drop-out group.

Conclusions

Computer-guided surgery demonstrates greater accuracy in implant placement with the flapless approach. Further research should be conducted to enhance the availability of guides for cases with unfavorable residual bone conditions.

Accuracy of static digital surgical guides for dental implants based on the guide system: A systematic review

In the present study, we tried to review the current literature, focusing on the effect of different guide systems on the accuracy of the digital surgical guides. A search in PubMed's database, without any date restriction, was performed using keywords based on the PICO question. 54 of the 2378 articles' were chosen for full-text assessment. Articles were screened using predetermined inclusion and exclusion criteria. 21 articles were included in the qualitative assessment. Descriptive analysis was performed for numeric parameters using mean ± standard deviation. Six types of guide systems were used in the included articles. The commonest guide system was SimPlant (45.64%) followed by NobleGuide (23.00%). The pooled mean angle deviation, global coronal deviation, and global apical deviation were 3.43 mm (95% CI = 2.96, 3.90), 1.16 mm (95% CI = 0.98, 1.24) and 1.35 mm (95% CI = 1.11, 1.59), respectively. The maximum mean(SD) of angle deviation, global coronal deviation, and global apical deviation happened in Stent Cad 4.1(1.86) degrees, NobleGuide 1.86(0.56) mm, and OnDemend3d 1.56(1.48) mm, respectively. Although a final statement could not be made on which system is better, it is certain that the software affects the deviation and could be as important as the implant itself. CLINICAL SIGNIFICANCE: The choice of guide systems used for the production of static guide systems which was studied in this article could affect the accuracy of the implant placement procedure.

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.

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.

Failure rates associated with guided versus non-guided dental implant placement: a systematic review and meta-analysis

Objective

The purpose of the systematic review and meta-analysis was to evaluate implant failure rates and their association with guided and free-hand implant placement techniques.

Materials and methods

A literature search was conducted across PubMed, Medline via Ovid, Cochrane database, and Google Scholar. The search was completed in September 2020. Series of meta-analyses were conducted to compare implant failure rates with guided and free-hand techniques.

Results

A total of 3387 articles were identified from the electronic search. After applying the inclusion criteria, eight articles were selected for qualitative assessment and four for quantitative synthesis (meta-analysis). The included studies had a risk ratio of 0.29 (95% CI: 0.15, 0.58), P < 0.001 for the use of guided implant placement. Implant failure rates were affected by the different placement techniques indicated by the test for overall effect (Z = 3.53, P = 0.0004). The incidence of implant failure in guided surgery versus free-hand surgery was found to be 2.25% and 6.42%, respectively.

Conclusion

Both guided and free-hand implant placement techniques resulted in a high implant survival rate. However, implant failure rates were almost three times higher in the free-hand implant placement category. A guided implant placement approach is recommended for a successful outcome.

A Retrospective Study on the Transferring Accuracy of a Fully Guided Digital Template in the Anterior Zone

The accuracy of implant placement with a fully guided digital template can be influenced by many factors, such as arch difference, alveolar bone density, timing of implant placement and open flap. The purpose of this article was to evaluate the factors presumptively affecting the accuracy of implant placement assisted by the fully guided template in the anterior zone. In 40 patients with missing anterior teeth, a total of 52 implants were placed with tooth-borne, fully guided templates after CBCT evaluation, in West China Hospital of Stomatology, Sichuan University. After overlapping the pre-and post-operative DICOM data, measurements were taken in the dental implant planning software (Nobel Clinician^®) to calculate linear and angular deviations between virtual placement plan and actual implant placement. Grouping was categorized according to three factors that possibly have an influence on accuracy: arch type (maxilla/mandible), timing of implant placement (immediate/delayed), surgical technique (open flap/flapless). The data was analyzed with independent sample t-test (p < 0.05). The results showed that the apical, coronal, depth and angular mean deviations of implant positions in anterior zone were 1.13 ± 0.39 mm, 0.86 ± 0.33 mm, 0.41 ± 0.66 mm, 3.32 ± 1.65° with the fully guided templates. The accuracy at apex level, coronal level and the angulation were similar between the maxilla and mandible, and the magnitude of all four deviations between immediate and delayed implantation, open flap and flapless technique were small. No statistically significant difference was observed (p > 0.05). Whereas there was significant difference in depth deviation between maxilla and mandible (p < 0.05). Conclusively, the implant site, alveolar bone density, timing of implant placement and surgical techniques merely compromise the implant placement accuracy under the assistance of a fully guided template.

Three-dimensional accuracy of partially guided implant surgery based on dental magnetic resonance imaging

OBJECTIVES

To measure in vivo 3D accuracy of backward-planned partially guided implant surgery (PGIS) based on dental magnetic resonance imaging (dMRI).

MATERIAL AND METHODS

Thirty-four patients underwent dMRI examinations. Tooth-supported templates were backward planned using standard dental software, 3D-printed, and placed intraorally during a cone beam computed tomography (CBCT) scan. Treatment plans were verified for surgical viability in CBCT, and implants were placed with guiding of the pilot drill. High-precision impressions were taken after healing. The 3D accuracy of 41 implants was evaluated by comparing the virtually planned and definitive implant positions with respect to implant entry point, apex, and axis. Deviations from the dMRI-based implant plans were compared with the maximum deviations calculated for a typical single implant.

RESULTS

Twenty-eight implants were placed as planned in dMRI. Evaluation of 3D accuracy revealed mean deviations (99% confidence intervals) of 1.7 ± 0.9mm (1.2-2.1mm) / 2.3 ± 1.1mm (1.8-2.9 mm) / 7.1 ± 4.8° (4.6-9.6°) for entry point / apex / axis. The maximum deviations calculated for the typical single implant surpassed the upper bounds of the 99% CIs for the apex and axis, but not for the entry point. In the 13 other implants, dMRI-based implant plans were optimized after CBCT. Here, deviations between the initial dMRI plan and definitive implant position were only in part higher than in the unaltered group (1.9 ± 1.7 mm [0.5-3.4 mm] / 2.5 ± 1.5 mm [1.2-3.8 mm] / 6.8 ± 3.8° [3.6-10.1°] for entry point / apex / axis).

CONCLUSIONS

The 3D accuracy of dMRI-based PGIS was lower than that previously reported for CBCT-based PGIS. Nonetheless, the values seem promising to facilitate backward planning without ionizing radiation.

Computer-assisted surgery in medical and dental applications

INTRODUCTION

Computer-assisted surgery (CAS) is a broad surgical methodology that utilizes computer technology to both plan and execute surgical intervention. CAS is widespread in both medicine and dentistry as it allows for minimally invasive and precise surgical procedures. Key innovations in volumetric imaging, virtual surgical planning software, instrument tracking, and robotics have assisted in facilitating the transfer of surgical plans to precise execution of surgical procedures. CAS has long been used in certain medical specialties including neurosurgery, cardiology, orthopedic surgery, otolaryngology, and interventional radiology, and has since expanded to oral and maxillofacial application, particularly for computer-assisted implant surgery.

AREAS COVERED

This review provides an updated overview of the most current research for CAS in medicine and dentistry, with a focus on neurosurgery and dental implant surgery. The MEDLINE electronic database was searched and relevant original and review articles from 2005 to 2020 were included.

EXPERT OPINION

Recent literature suggests that CAS performs favorably in both neurosurgical and dental implant applications. Computer-guided surgical navigation is well entrenched as standard of care in neurosurgery. Whereas static computer-assisted implant surgery has become established in dentistry, dynamic computer-assisted navigation is newly poised to trend upward in dental implant surgery.

The implant position accuracy between using only surgical drill guide and surgical drill guide with implant guide in fully digital workflow: a randomized clinical trial

BACKGROUND

To evaluate and compare accuracy in position and inclination of a single-tooth implant placement using tooth-supported surgical drill guide (SDG) and surgical drill guide with implant insertion guide (SDIG) in fully digital workflow.

MATERIALS AND METHODS

Thirty partially single edentulous patients were recruited. After randomization, participants were divided into 2 groups equally. The first group underwent implant placement through SDG only, while the second group was subjected to SDIG. All procedure proceeded under a fully digital workflow as the combination of digital scanning from an intraoral scanner, 3D radiographic images from cone-beam computed tomography (CBCT), implant planning software, and a 3D manufacturing machine. A post-operative CBCT was performed to compare the deviations (7 parameters) between planned and actual implant positions.

RESULTS

The mean global deviations at the shoulder and apex were 0.74 ± 0.36 and 1.29 ± 0.61 mm, respectively in the SDG group and 0.48 ± 0.22 mm and 0.71 ± 0.31 mm, respectively in the SDIG group. Likewise, the other parameters in the SDIG group showed fewer deviations than SDG for all measurements. Statistically significant differences were indicated by all parameters except for the horizontal deviation at the implant shoulder (p < .05).

CONCLUSION

In single-tooth implant placement with a tooth-supported guide using a computer-assisted (static) system with the SDIG could reduce deviations of actual implant position when compared with using SDG only. Besides, guided implant surgery by fully digital workflow is a practical procedure and provides precise implant position regarding the prosthetic-driven concept.

Factors Influencing the Accuracy of Freehand Implant Placement: A Prospective Clinical Study

(1) Background: The objective of implant prosthetic restoration is to ensure the best possible rehabilitation of function and esthetics. Optimal positioning of the implant with regard to the bone availability, surrounding soft tissue, and prosthetic sustainability should be strived for during implant placement. The factors influencing freehand implant placement and the accuracy achieved with this procedure are investigated in this prospective clinical study. (2) Methods: Implants were placed in the single-tooth edentulous sites of the premolar and molar areas in 52 patients. Three-dimensional (3D)-planning was performed virtually prior to the freehand implant operation, and the desired position of the implant was provided to the surgeon. (3) Results: The deviations between the planned and the actually achieved position with freehand implant placement showed the following mean values and standard deviations: angle 8.7 ± 4.8°, 3D deviation at the implant shoulder 1.62 ± 0.87 mm, mesiodistal deviation 0.87 ± 0.75 mm, buccolingual deviation 0.70 ± 0.66 mm, and apiocoronal deviation 0.95 ± 0.61 mm. The type of jaw had a significant influence on accuracy. Major deviations were observed in the lower jaw. Furthermore, the timing of implant placement influenced the mesiodistal deviation and angular deviation; (4) Conclusions: Freehand implant placement demonstrated a higher level of deviation between the planned and actually achieved implant positions. In particular, the ranges showed a large spread. From a prosthetic point of view, there may be complications during the restoration of the prosthetic crown if the implant exit point is not optimally located or if the implants show a high angular deviation.

Does the macro design of an implant affect the accuracy of template-guided implantation? A prospective clinical study

Background

An implant prosthesis aims to ensure the best possible rehabilitation of function and esthetics following tooth loss. Template-guided insertion is used to achieve an optimal position of the implant with regard to prosthetic restorability, bone availability, and condition of the surrounding soft tissues. The accuracy of template-guided implant placement is subject to various influencing factors.

The clinically achievable accuracy depending on the macro design of the implant body was investigated in this prospective clinical study.

Material and methods

In this prospective clinical study, 20 implants were placed in 20 patients. The implant had a pronounced conical outer geometry (Conelog ProgressiveLine, Camlog Wimsheim, Germany). Data from a study using an implant with a distinct cylindrical outer geometry were used as a comparison group (Conelog ScrewLine, Camlog, Wimsheim, Germany). The clinically achieved implant position was compared with the planned position.

Results

The evaluation of the two-dimensional deviations in direction resulted in the following mean values (standard deviation) at the shoulder: 0.42 mm (0.33) in the buccolingual direction, 0.27 mm (0.25) in the mesiodistal direction, and 0.68 mm (0.55) in the apicocoronal direction. The mean angular deviation was 4.1° (2.3). The three-dimensional (3D) deviation was 0.94 mm (0.53) at the shoulder and 1.36 mm (0.62) at the apex of the implant.

Significant differences between implants with different macro designs were found in the apicocoronal direction. In connection to this, a significant 3D deviation was found at the implant shoulder.

Conclusions

Significant differences in height were found between the groups. The study had shown that the macro design of an implant has no influence on accuracy in all other directions. Overall, the implants showed a high level of accuracy and a low variation in values. The values were in the range determined by the template-guided insertion system in numerous other investigations. This provides good predictability of prosthetic rehabilitation.

Trial registration

German Register for Clinical Studies (DRKS-ID: DRKS000018939). Date of registration: November 11, 2019.

Multivariate analysis of causal factors influencing accuracy of guided implant surgery for partial edentulism: a retrospective clinical study

Abstract

Background

In dental implant treatment, the placement position of the implant body is important. The hypothesis is that there are factors that have a greater impact than the factors that have been studied so far.

Material and Methods

The deviation between planned and actually placed implants was measured three-dimensionally by modified treatment evaluation method in 110 patients who underwent implant placement with guided surgery for partial edentulism. Ten factors that seemed to affect errors in placement were selected: the type of tooth, type of edentulism, distance from the remaining teeth, the type of implant, implant length, number of implants, method of guidance, the number of teeth supporting the surgical guide, number of anchor pins, and presence or absence of a reinforcement structure. The effect of each factor that corrected each confounding was calculated using multivariate analysis.

Results

In this study, 188 implant bodies were set to target, and the errors measurement data of the implant position were as follows: average Angle, 2.5 ± 1.6° (95% CI 2.25–2.69); Base, 0.67 ± 0.37 mm (95% CI 0.62–0.72); and Apex, 0.92 ± 0.47 mm (95% CI 0.86–0.98). As the result of multivariate analysis, larger errors were present in the partially guided group than the fully guided group. The number of teeth supporting the surgical guide significantly influenced the error in placement position. The error caused by the number of anchor pins was significantly different for the Angle. Similarly, the presence of the reinforcement structure influenced the error significantly for the Angle.

Conclusions

It was suggested that the smaller errors could be present by performing guided surgery with full guidance and devising the design of the guide such as the number of teeth supporting the surgical guide, the setting of the anchor pin, and the reinforcement structure.

Accuracy of static computer-assisted implant placement in long span edentulous area by novice implant clinicians: A cross-sectional in vitro study comparing fully-guided, pilot-guided, and freehand implant placement protocols

BACKGROUND

To ensure accurate implant placement, surgical guides are used to control the steps of implant placement surgery.

PURPOSE

Evaluation of the accuracy of implant placement in long span edentulous area by novice implant clinicians according to fully-guided (FG), pilot-guided (PG), and freehand (FH) placement protocols.

MATERIALS AND METHODS

Maxillary surgical models with four missing teeth from the right first canine to the first molar were produced by 3-dimensional printing. Fourteen clinicians new to implant dentistry participated in the study, and each one of them inserted one canine and one molar implant for every implant placement protocol. All implant placement steps were completed in phantom heads to simulate the clinical situation. To evaluate the accuracy, the implant vertical, horizontal platform, horizontal apex, angle, and interimplant distance deviations from the planned positions were calculated.

RESULTS

With the exception of vertical deviation, the FG placement was clearly more accurate than the PG and FH placements for all the variables for canine and molar implants. The PG placement was significantly more accurate than the FH placement for the horizontal platform and apex deviations, and interimplant distance deviation. The FG placement did not show a significant impact of the location of the implant, or the horizontal deviations of the platform or the apex. The PG and FH placements showed increased deviation at the canine implant than the molar implant, and at the apex of the implants than the platform of the implants.

CONCLUSIONS

Within the limitations of this in vitro study, novice clinicians achieved a significantly more accurate implant position with FG placement, followed by PG and FH placements respectively. Therefore, a form of guided surgery is beneficial for novice clinicians.

Implant insertion using an orientation template and a full-guiding template - A prospective model analysis in a cohort of dentists participating in an implantology curriculum

BACKGROUND

Dental implantology has become an established option for treating tooth loss over the recent decades. Before inserting an implant in a clinical situation, theoretical and practical training is recommended. Different methods are available to give assistance in determining the correctly planned implant position. In this study, two different guiding methods were assessed considering their accuracy for implant insertion in a group of dentists.

METHODS

After three-dimensional planning of the implant positions, two surgical templates were manufactured as follows: in region 34 a stereolithographic template was used to perform a full-guided implant insertion, in region 44 a CAD/CAM milled template was used to determine the implant position and subsequently, perform a free-hand insertion. In total, 86 implants were placed in mandibular models by 43 dentists participating in a postgraduate curriculum. The differences between planned and achieved implant positions were measured and statistically analyzed.

RESULTS

The implants inserted fully-guided showed a lower deviation of the three-dimensional angulation (2.266 ± 1.443 degrees vs. 7.954 ± 4.372 degrees) and the cumulated mismatch of the implant position (0.547 ± 0.237 mm vs. 1.160 ± 0.427 mm) compared to the free-handed mode. For the angulation and the mismatch at the implant base the differences were statistically significant (p < 0.001).

CONCLUSIONS

Within the limits of the study it can be summarized that the full-guided implant insertion leads to a higher transfer accuracy compared to the free-hand method in a cohort of dentist inexperienced in dental implantology. However, the clinical effect has to be discussed as the study was performed using artificial mandibles and ideal conditions.

The accuracy of implant placement with computer-guided surgery in partially edentulous patients and possible influencing factors: A systematic review and meta-analysis

PURPOSE

To review the current clinical studies regarding the accuracy of implant computer-guided surgery in partially edentulous patients and investigate potential influencing factors.

STUDY SELECTION

Electronic searches on the PubMed and Cochrane Central Register of Controlled Trials databases, and subsequent manual searches were performed. Two reviewers selected the studies following our inclusion and exclusion criteria. Qualitative review and meta-analysis of the implant placement accuracy were performed to analyze potential influencing factors. Angular deviation, coronal deviation, apical deviation, and depth deviation were evaluated as the accuracy outcomes.

RESULTS

Eighteen studies were included in this systematic review, including six randomized controlled trials, nine prospective studies, and three retrospective clinical studies. A total of 1317 implants placed in 642 partially edentulous patients were reviewed. Eight studies were evaluated using meta-analysis. Fully guided surgery showed statistically higher accuracy in angular (P <0.001), coronal (P <0.001), and apical deviation (P <0.05) compared with pilot-drill guided surgery. A statistically significant difference (P <0.001) was also observed in coronal deviation between the bounded edentulous (BES) and distal extension spaces (DES). A significantly lower angular deviation (P <0.001) was found in implants placed using computer-aided design/computer-aided manufacturing (CAD/CAM) compared to the conventional surgical guides.

CONCLUSIONS

The edentulous space type, surgical guide manufacturing procedure, and guided surgery protocol can influence the accuracy of computer-guided surgery in partially edentulous patients. Higher accuracy was found when the implants were placed in BES, with CAD/CAM manufactured surgical guides, using a fully guided surgery protocol.

Accuracy of guided surgery using the silicon impression and digital impression method for the mandibular free end: a comparative study

Background

Implant treatment using guided surgery is becoming widespread in clinical dental practice. Furthermore, the development of digital technology has enabled the use of intraoral scanners (IOSs) to fabricate surgical guide plates. The objective of this study was to compare the accuracy of guided surgery using the silicone impression method with a three-dimensional (3D) scanner and the digital impression method with IOS for one side of the mandibular free end. In addition, we compared the accuracy of tooth-supported vs tooth/mucosa-supported surgical guide plates.

Results

The accuracy of the tooth-supported surgical guide plate using the new IOS method instead of the method of obtaining impressions with conventional silicone resulted in better measurements of 3D deviation at the crest, 3D deviation at the apex, and angular deviation. In terms of the accuracy of the tooth/mucosa-supported surgical guide plate, there were no significant differences in all measurements. The surgical guide plate using an IOS and the tooth/mucosa-supported surgical guide plate may enable more accurate guided surgery.

Conclusion

Tooth/mucosa-supported guided surgery involving preparation with an IOS may result in more accurate implant surgery.

In Vitro Comparison of Surgical Implant Placement Accuracy Using Guides Fabricated by Three Different Additive Technologies

Various three-dimensional (3D) printing technologies are commercially available on the market, but the influence of different technologies on the accuracy of implant-guided surgery is unclear. Thus, three printing technologies: Stereolithographic (SLA), Digital light processing (DLP), and Polyjet were evaluated in this study. An entire 30 polyurethane models replicated the clinical situation. Ten surgical guides were printed by SLA, DLP, and PolyJet. Then, implant-guided surgery was performed, and their accuracy outcomes were measured concerning angular deviation, 3D deviation at the entry point, and apex. On top of that, the total processing time was also compared. For the angular deviation, the mean deviation was not statistically significant among all technologies. For the 3D deviation, PolyJet was statistically more accurate than DLP (p = 0.002) and SLA (p = 0.017) at the entry point. PolyJet was also statistically more accurate than DLP (p = 0.007) in regards to 3D deviation at the apex. Within the limitation of this study, the deviations from the experiment showed that PolyJet had the best outcome regarding the 3D deviations at the entry point and at the apex, meanwhile, the DLP printer had the shortest processing time.

Use of dental MRI for radiation-free guided dental implant planning: a prospective, in vivo study of accuracy and reliability

OBJECTIVES

To evaluate the accuracy and reliability of dental MRI for static guided implant surgery planning.

MATERIALS AND METHODS

In this prospective study, a 0.4-mm isotropic, artifact-suppressed, 3T MRI protocol was used for implant planning and surgical guide production in participants in need of dental implants. Two dentists decided on treatment plan. Surgical guides were placed intraorally during a subsequent reference cone beam computed tomography (CBCT) scan. Inter-rater and inter-modality agreement were assessed by Cohen's kappa. For each participant, dental MRI and CBCT datasets were co-registered to determine three-dimensional and angular deviations between planned and surgically guided implant positions.

RESULTS

Forty-five implants among 30 study participants were planned and evaluated (17 women, 13 men, mean age 56.9 ± 13.1 years). Inter-rater agreement (mean κ 0.814; range 0.704-0.927) and inter-modality agreement (mean κ 0.879; range 0.782-0.901) were both excellent for the dental MRI-based treatment plans. Mean three-dimensional deviations were 1.1 ± 0.7 (entry point) and 1.3 ± 0.7 mm (apex). Mean angular deviation was 2.4 ± 1.5°. CBCT-based adjustments of MRI plans were necessary for implant position in 29.5% and for implant axis in 6.8% of all implant sites. Changes were larger in the group with shortened dental arches compared with those for tooth gaps. Except for one implant site, all guides were suitable for clinical use.

CONCLUSION

This feasibility study indicates that dental MRI is reliable and sufficiently accurate for surgical guide production. Nevertheless, more studies are needed to increase its accuracy before it can be used for implant planning outside clinical trials.

KEY POINTS

• An excellent reliability for the dental MRI-based treatment plans as well as agreement between dental MRI-based and CBCT-based (reference standard) decisions were noted. • Ideal implant position was not reached in all cases by dental MRI plans. • For all but one implant site surgical guides derived from dental MRI were sufficiently accurate to perform implant placement (mean three-dimensional deviations were 1.1 ± 0.7 (entry point) and 1.3 ± 0.7 mm (apex); mean angular deviation was 2.4 ± 1.5°).