OBJECTIVE: This study aims to evaluate the amount of distortion using computer-guided implant surgery with 3D printed surgical guides in limited edentulous spaces.
METHODS: 25 bone level self-tapping implants (Straumann® BL and BLT) were randomly inserted in either distal or intercalary posterior mandibular edentulism using a fully digital protocol and 3D printed surgical guides. Amount of inaccuracy was evaluated after superimposing the 3 coordinates of virtually planned and final implant images, which were obtained using intra-oral scans and scan bodies. Four evaluation parameters were considered: origo-displacement, error depth, apical displacement and angle between the planned and the placed implant.
RESULTS: The average of distortion was 0.71 mm for the origo-displacement, 0.36 mm for the error depth, 0.52 mm for the horizontal displacement and 3.34º for the error angle.
CONCLUSIONS: The major reason of exclusion was CBCT artifacts. Results of this study were aligned with the results of previous studies concerning partially edentulous spaces. CAD/CAM manufacturing process did not result in significant distortion whilst the biggest part of distortions originated from the surgical process. The learning curve in computer-guided implant surgery presented an important source of inaccuracy.

OBJECTIVE: This randomized clinical trial aimed to assess the feasibility of computer-assisted open exposure of palatally impacted canines.
METHODS: Patients aged 11-30 years who required orthodontic eruption for the full palatal impaction of their canines were included in this study. Exclusion criteria were psychosocial and dental contraindications of orthodontic treatment, congenital craniofacial disorders, and trauma in the patient\'s history in the vicinity of the surgical site. Virtual planning software was used to register the intraoral scans and cone-beam computed tomography data and to design a surgical template. In the test group, exposure of the canines was guided by a surgical template, whereas in the control group, the surgeon relied on the surgical plan to localize the impacted canine. The success of the intervention, duration of surgery, and complications, including excessive hemorrhage, damage to the canine or neighboring anatomical landmarks, and postoperative inflammation of the surgical site were assessed. Postoperative pain was reported by the patients using the visual analog pain scale (VAS).
RESULTS: Surgery was deemed successful in all patients in both groups. During healing, no complications were observed. The duration of surgery decreased significantly in the test group (4 min 45.1 s ± 1 min 8.4 s) compared to that in the control group (7 min 22.3 s ± 56.02 s). No statistically significant differences were observed between the VAS scores of the two study groups.
CONCLUSIONS: The application of virtual planning and static navigation is a viable approach for the open exposure of palatally impacted canines.
BACKGROUND: NCT05909254.
CONCLUSIONS: Computer-assisted surgery is a feasible method for open exposure of palatally impacted canines, which decreases the duration of surgery compared to the freehand method.

To evaluate the three-dimensional (3D) stability and accuracy of additively manufactured surgical templates fabricated using two different 3D printers and materials.
Forty surgical templates were designed and printed using two different 3D printers: the resin group (n = 20) used a digital light processing (DLP) 3D printer with photopolymer resin, and the metal group (n = 20) employed a selective laser melting (SLM) 3D printer with titanium alloy. All surgical templates were scanned immediately after production and re-digitalized after one month of storage. Similarly, the implant simulations were performed twice. Three-dimensional congruency between the original design and the manufactured surgical templates was quantified using the root mean square (RMS), and the definitive and planned implant positions were determined and compared.
At the postproduction stage, the metal templates exhibited higher accuracy than the resin templates (p < 0.001), and these differences persisted after one month of storage (p < 0.001). The resin templates demonstrated a significant decrease in three-dimensional stability after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05). No significant differences in implant accuracy were found between the two groups. However, the resin templates showed a significant increase in apical and angular deviations after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05).
Printed metal templates showed higher fabrication accuracy than printed resin templates. The three-dimensional stability and implant accuracy of printed metal templates remained unaffected by one month of storage.
With superior three-dimensional stability and acceptable implant accuracy, printed metal templates can be considered a viable alternative technique for guided surgery.

Digital workflows have become integral in orthodontic diagnosis and therapy, reducing risk factors and chair time with one-visit protocols. This study assessed the transfer accuracy of fully digital planned insertion guides for orthodontic mini-implants (OMIs) compared with freehanded insertion. Cone-beam computed tomography (CBCT) datasets and intraoral surface scans of 32 cadaver maxillae were used to place 64 miniscrews in the anterior palate. Three groups were formed, two using printed insertion guides (A and B) and one with freehand insertion (C). Group A used commercially available customized surgical templates and Group B in-house planned and fabricated insertion guides. Postoperative CBCT datasets were superimposed with the planning model, and accuracy measurements were performed using orthodontic software. Statistical differences were found for transverse angular deviations (4.81° in A vs. 12.66° in B and 5.02° in C, p = 0.003) and sagittal angular deviations (2.26° in A vs. 2.20° in B and 5.34° in C, p = 0.007). However, accurate insertion depth was not achieved in either guide group; Group A insertion was too shallow (-0.17 mm), whereas Group B insertion was deeper (+0.65 mm) than planned. Outsourcing the planning and fabrication of computer-aided design and computer-aided manufacturing insertion guides may be beneficial for certain indications; particularly, in this study, commercial templates demonstrated superior accuracy than our in-house-fabricated insertion guides.

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).
CONCLUSIONS: 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.
CONCLUSIONS: 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.

Although guided implant surgery is widely practiced, clinical studies examining the differences in accuracy between implanting systems that use the same surgical guide are currently lacking. This study aimed to evaluate and compare the effects of different dental implanting systems on positioning accuracy using a uniform type of stereolithographic surgical guide to account for cumulative errors in guide production. One hundred BEGO Semados® S implants (Group A) and ninety-one NobelActive® implants (Group B) were inserted into patients using the same type of guide. The accuracy was assessed by matching the preoperative and postoperative cone-beam computed tomography (CBCT). The implant shoulder, tip, depth and angular deviation were registered. Statistically significant differences between groups were  determined using student\'s t-test, bivariate correlation test and generalized estimating equation. The angular deviation was 3.16±1.74° in Group A and 2.58±1.41° in Group B (P=0.013 ); the depth deviation was 0.44±0.23mm in GroupA and 0.51±0.22mm in Group B (P=0.032). In terms of vertical accuracy, the Bego implant system is superior to the Nobel implant system using the same type of surgical guide, while the angle accuracy is opposite. Therefore, it is important to control the depth when using the template guided surgery in Nobel implant system. Similarly, angle control should be emphasized in Bego implant system. Measurements of the deviations provide the basis for a clinical reference that will be useful in preoperative analysis for improvement of the safety and accuracy of guided implant surgical procedures.

To evaluate the accuracy of a computer numerical control (CNC) milled surgical guide for implant placement in edentulous jaws.
Edentulous patients seeking implants treatment were recruited in this prospective cohort study. Radiographic guides with diagnostic templates were fabricated from wax-up dentures. Patients took cone-beam computed tomography (CBCT) wearing the radiopaque radiographic guides. Implant positions were virtually designed in the planning software based on the CBCT data, and the radiographic templates were converted into surgical guides using CNC milling technique. Forty-four implants were placed into 12 edentulous jaws following guided implant surgery protocol. Post-surgery CBCT scans were made for each jaw, and the deviations between the planned and actual implant positions were measured. Deviation of implant position was compared between maxilla and mandible, and between cases with and without anchor pins using independent t-test.
Nine patients (3 males and 6 females) with 12 edentulous jaws were recruited. The mean age of patients was 59.2 ± 13.9 years old. All 44 implants was placed without complication and survived, the mean three dimensional linear deviation of implant position between virtual planning and actual placement was 1.53 ± 0.48 mm at the implant neck and 1.58 ± 0.49 mm at the apex. The angular deviation was 3.96 ± 3.05 degrees. No significant difference was found in the deviation of implant position between maxilla and mandible (P = 0.28 at neck, 0.08 at apex), nor between cases with and without anchor pins (P = 0.87 at neck, 0.06 at apex).
The guides fabricated using the CNC milling technique provided comparable accuracy as those fabricated by Stereolithography. The displacement of the guides on edentulous arch might be the main contributing factor of deviation.
Chinese Clinical Trial Registry, ChiCTR-ONC-17014159 (July 26, 2017).

The aim of this prospective clinical study was to investigate differences between virtually planned and clinically achieved implant positions in completely template-guided implant placements as a function of the tooth area, the use of alveolar ridge preservation, the implant length and diameter, and the primary implant stability.
The accuracy of 48 implants was analyzed. The implants were placed in a completely template-guided manner. The data of the planned implant positions were superimposed on the actual clinical implant positions, followed by measurements of the 3D deviations in terms of the coronal (dc) and apical distance (da), height (h), angulation (ang), and statistical analysis.
The mean dc was 0.7 mm (SD: 0.3), the mean da was 1.4 mm (SD: 0.6), the mean h was 0.3 mm (SD: 0.3), and the mean ang was 4.1° (SD: 2.1). The tooth area and the use of alveolar ridge preservation had no significant effect on the results in terms of the implant positions. The implant length had a significant influence on da (p = 0.02). The implant diameter had a significant influence on ang (p = 0.04), and the primary stability had a significant influence on h (p = 0.02).
Template-guided implant placement offers a high degree of accuracy independent of the tooth area, the use of measures for alveolar ridge preservation or the implant configuration. A clinical benefit is therefore present, especially from a prosthetic point of view.
German Clinical Trial Register and the International Clinical Trials Registry Platform of the WHO: DRKS00005978 ; date of registration: 11/09/2015.

OBJECTIVE: The aim of this study was to investigate differences between the virtually planned and clinically achieved implant positions in completely template-guided implantations as a function of the type of edentulous space, the residual natural dentition, and the surgical implementation.
METHODS: Fifty-six patient cases with a total of 122 implants were evaluated retrospectively. The implantations were completely template-based. The data of the planned implant positions were overlaid with the actual clinical implant positions, followed by measurements of the 3D deviations in terms of coronal (xc) and apical distance, height (xh), and angulation (ang) and statistical analysis.
RESULTS: The mean xc was 1.2 mm (SD 0.7 mm); the mean xa was 1.8 mm (SD 0.9 mm), the mean xh was 0.8 mm (SD 0.7 mm); and the mean ang was 4.8° (SD 3.1). The type of edentulous space and the jaw (maxilla/mandible) had no significant effect on the results in terms of implant positions. The presence of an adjacent natural tooth at the time of implantation had a significant influence on xh (p = 0.04) and ang (p = 0.05). No significant differences were found regarding the surgical approach for any of the parameters examined.
CONCLUSIONS: The results of our study are in the same range as those of other studies. Template-guided implantation offers a high degree of accuracy even in the presence of different configurations of the residual dentition or different surgical approaches. A clinical benefit is therefore present, especially from a prosthetic point of view.
CONCLUSIONS: The clinically achievable accuracy can be described as sufficient for further prosthetic treatment, given the intrinsic and methodological tolerances, making prosthetic rehabilitation safe and predictable.

OBJECTIVE: To assess the accuracy of guided surgery (mucosa and bone-supported) compared to mental navigation or the use of a surgical template, in fully edentulous jaws, in a randomized controlled study.
METHODS: Fifty-nine patients (72 jaws), requiring four to six implants (maxilla or mandible), were consecutively recruited and randomly assigned to one of the following treatment groups; guidance via Materialise Universal(®)/mucosa, Materialise Universal(®)/bone, Facilitate™/mucosa, Facilitate™/bone, or mental navigation or a pilot-drill template. The precision was assessed by matching the planning computed tomography (CT) with a post-operative cone beam CT.
RESULTS: A significant lower mean deviation at the entry point (1.4 mm, range: 0.3-3.7), at the apex (1.6 mm, range: 0.2-3.7) and angular deviation (3.0°, range: 0.2-16°) was observed for the guiding systems when compared to mental navigation (2.7 mm, range: 0.3-8.3; 2.9 mm, range: 0.5-7.4 and 9.9°, range: 1.5-27.8) and to the surgical template group (3.0 mm, range: 0.6-6.6; 3.4 mm, range: 0.3-7.5 and 8.4°, range: 0.6-21.3°). Differences between bone and mucosa support or type of guidance were negligible. Jaw and implant location (posterior-anterior, left-right), however, had a significant influence on the accuracy when guided.
CONCLUSIONS: Based on these findings, guided implant placement appears to offer clear accuracy benefits.