A clinically relevant accuracy study of computer-planned implant placement in the edentulous maxilla using mucosa-supported surgical templates

Accuracy of Implant Guided Surgery in Fully Edentulous Patients: Prediction vs. Actual Outcome-Systematic Review

Objectives: Examine deviations between the digitally planned and actual implant positions in clinical studies using static fully guided surgical guides. Identify potential associated factors and strategies to minimize their likelihood. Materials and Methods: This systematic review was conducted following the PRISMA checklist. The literature search was conducted in the PubMed® and Scopus® databases up to February 2024 following the PICOS search strategy. Clinical trials conducted between 2013 and 2024, evaluating the accuracy of static fully guided surgical guides placed in fully edentulous patients, were included. The studies had to assess at least two of the following parameters: angular deviation, cervical deviation, apical deviation, and depth deviation. Results: Out of the 298 articles initially searched, six randomized clinical trials and three clinical trials were included. All but one article used mucosa-supported guides; the remaining one used bone-supported guides. Apical deviations were more significant than cervical deviations, and implants tended to be placed too superficially. The greatest mean deviations were 2.01 ± 0.77 mm for cervical and 2.41 ± 1.45 mm for apical deviations, with the largest angular deviation recorded at 4.98 ± 2.16°. Conclusions: The accuracy of the surgical guide is influenced by various factors, including the technique of image acquisition and subsequent planning, guide support methods, and the adopted surgical protocol. Apical deviations are influenced by cervical and angular deviations. Additionally, deviations were more pronounced in the mandible. Further studies with similar methodologies are necessary for a more precise assessment of the different factors and for establishing safety margins.

Flapless Guided Dental Implant Surgery in a Systemically Compromised Patient: A Case Report

The use of surgical guides in implant treatment offers several advantages, including reduced surgery time, flapless procedures, and enhanced precision and reliability in implant placement. By utilizing tomography and scanning technologies, a patient's complete anatomical structure can be transferred into software in three spatial planes. This allows for the three-dimensional printing of surgical guides that ensure the accurate execution of the procedure. Traditional techniques and planning using two-dimensional imaging are now considered outdated compared to the precision offered by guided surgery. In this study, we present the case of a patient with multiple systemic health complications whose primary concern was the absence of teeth 15 and 35. For this patient, flap surgeries were contraindicated. Given the effectiveness of surgical guides, this method was chosen for planning and treatment. Single Implacil implants were successfully placed. Despite the limitations of this case report, the use of guided surgery proved to be more precise and effective in determining the location, direction, and inclination of the implants while simultaneously enhancing patient comfort.

Accuracy of an autonomous dental implant robotic system in partial edentulism: A pilot clinical study

OBJECTIVES

Robots are increasingly being used for surgical procedures in various specialties. However, information about the accuracy of robot-assisted dental implant surgery is lacking. This pilot clinical study aimed to investigate the accuracy of an autonomous dental implant robotic (ADIR) system in partially edentulous cases.

MATERIAL AND METHODS

The ADIR system was used to place a total of 20 implants in 13 participants. Implant deviation from the planned positions was assessed to determine accuracy. The entry, apex, and angular deviations were described as means ± standard deviation. A two-sample t test was used to compare implant deviation between the flap and flapless groups and between maxillary and mandibular implants (α = .05).

RESULTS

The entry, apex, and angular deviations were 0.65 ± 0.32 mm, 0.66 ± 0.34 mm, and 1.52 ± 1.01°, respectively, with no statistically significant difference between the flap and flapless approaches (P > .05). No adverse events were encountered in any of the participants.

CONCLUSIONS

DIR accuracy in this clinical series was comparable to that reported for static and dynamic computer-assisted implant surgery. Robotic computer-assisted implant surgery may be useful for dental implant placement, potentially improving the quality and safety of the procedure.

CLINICAL RELEVANCE

The findings of this study showed that the ADIR system could be useful for dental implant surgery.

Digital workflow for creating a coolant channel for direct irrigation through an implant surgical guide

Heat elicited during the osteotomy for implant placement may have a significant impact on the vitality of surrounding bone and on the healing capacity for osseointegration. This article describes a digital workflow for creating a coolant channel for the direct irrigation of the osteotomy site through an implant surgical guide. This technique can be particularly advantageous when the surgical guide restricts access for direct irrigation of the osteotomy site.

Clinical accuracy of partially guided implant placement in edentulous patients: A computed tomography-based retrospective study

OBJECTIVES

This retrospective study was intended to evaluate the clinical accuracy of partially guided template in guiding implant placement in edentulous patients.

METHODS

A total of 120 implants were placed in 24 patients with at least one completely edentulous arch with a partially guided system. Based on CBCT data, a repeatable method was used to measure linear and angular deviations of implants at 3D level in Mimics medical software. The influence of supporting tissue and implant region on the accuracy was assessed, followed by the evaluation of direction of linear deviations in biologically vital areas.

RESULTS

Linear deviations of all implants were 1.91 ± 0.68 mm, 1.47 ± 0.68 mm, and 1.02 ± 0.69 mm at apical, apical lateral, and apical vertical levels. When at the cervical, cervical lateral, and cervical vertical levels, the linear deviations were 1.53 ± 0.65 mm, 0.98 ± 0.53 mm, and 1.01 ± 0.69 mm, respectively. Angular deviation of all implants was 7.14 ± 3.41°. Implants guided by mucosa + tooth-supported templates showed higher linear deviations at apical vertical level (1.21 ± 0.72 mm vs. 0.86 ± 0.63 mm, p < .05) and cervical vertical level (1.18 ± 0.72 mm vs. 0.87 ± 0.63 mm, p < .05) than mucosa-supported templates, and implants in maxilla were found higher angular deviation than mandible (7.89 ± 3.61° vs. 6.29 ± 2.97°, p < .05).

CONCLUSIONS

The partially guided template served as clinically viable surgical assistance in implant placement in edentulous patients. When using mucosa + tooth-supported template or placing implants in maxilla, more caution was required, especially in biologically vital areas.

Reliability of a chairside CAD-CAM surgical guide for dental implant surgery on the anterior maxilla: An in vitro study

PURPOSE

This study evaluated the reliability of the chair-side CAD-CAM surgical guide (CSG) in the anterior maxilla by comparing its accuracy with the laboratory 3D-printed surgical guide (3DSG) and manual surgical guide (MSG) concerning different levels of dentists' surgical experience.

MATERIALS AND METHODS

Ten surgical guides of each type (MSG, 3DSG, and CSG) were fabricated on a control study model with missing right and left central incisors. Sixty implants were placed in 30 study models by two dentists (one inexperienced and one experienced) using three different types of surgical guides. Horizontal deviations at shoulder and at apex, vertical, and angular deviations were measured after superimposing the planned and placed implant positions in the software. Kruskal-Wallis and Mann-Whitney U tests were used to compare the accuracy of three types of surgical guides in each dentist group and the accuracy of each surgical guide between two dentists (α = .05).

RESULTS

There were no significant differences in any deviations between CSG and 3DSG, apart from angular deviation, for both dentists' groups. Moreover, both CSG and 3DSG showed no significant differences in accuracy between the two dentists (P > .05). In contrast, MSG demonstrated significant differences from CSG and 3DSG and a significant difference in accuracy between the two dentists (P < .05).

CONCLUSION

CSG provides superior accuracy to MSG in implant placement in the maxillary anterior region and is comparable to 3DSG at different levels of surgical experience, while offering the benefits of shorter manufacturing time and reduced patient visits.

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.

Comparison of the accuracy of implant position among freehand implant placement, static and dynamic computer-assisted implant surgery in fully edentulous patients: a non-randomized prospective study

The optimal implant position is a critical factor for long-term success in fully edentulous patients. Implants can be placed through conventional freehand, static computer-assisted implant surgery (CAIS), or dynamic CAIS protocols, but at present there is very limited clinical evidence on their accuracy in fully edentulous patients. This study was performed to evaluate the accuracy of implant placement using three protocols in fully edentulous patients. Thirteen patients received 60 implants with the freehand (n = 20), static CAIS (n = 20), or dynamic CAIS (n = 20) protocol. Postoperative cone beam computed tomography was utilized to evaluate the accuracy of implant placement in relation to the planned optimal position. The data were analysed by ANCOVA followed by Bonferroni analysis. The mean angular deviation (standard deviation) in the freehand, static CAIS, and dynamic CAIS groups was 10.09° (4.64°), 4.98° (2.16°), and 5.75° (2.09°), respectively. The mean three-dimensional deviation (standard deviation) at the implant platform in the freehand, static CAIS, and dynamic CAIS groups was 3.48 (2.00) mm, 1.40 (0.72) mm, and 1.73 (0.43) mm, while at the implant apex it was 3.60 (2.11) mm, 1.66 (0.61) mm, and 1.86 (0.82) mm, respectively. No difference in terms of accuracy was found between static and dynamic CAIS; both demonstrated significantly higher accuracy when compared to the freehand protocol in fully edentulous patients.

3D Printed and Bioprinted Membranes and Scaffolds for the Periodontal Tissue Regeneration: A Narrative Review

Numerous technologies and materials were developed with the aim of repairing and reconstructing the tissue loss in patients with periodontitis. Periodontal guided bone regeneration (GBR) and guided tissue regeneration (GTR) involves the use of a membrane which prevents epithelial cell migration, and helps to maintain the space, creating a protected area in which tissue regeneration is favored. Over the time, manufacturing procedures of such barrier membranes followed important improvements. Three-dimensional (3D) printing technology has led to major innovations in periodontal regeneration methods, using technologies such as inkjet printing, light-assisted 3D printing or micro-extrusion. Besides the 3D printing of monophasic and multi-phasic scaffolds, bioprinting and tissue engineering have emerged as innovative technologies which can change the way we see GTR and GBR.

Accuracy of Computer-Assisted Flapless Implant Placement by Means of Mucosa-Supported Templates in Complete-Arch Restorations: A Systematic Review

The aim of this study was to systematically review the current scientific literature regarding the accuracy of fully guided flapless implant positioning for complete-arch rehabilitations in edentulous patients and to assess if there was any statistically significant correlation between linear deviation at shoulder point, at apex point and angular deviation. The electronic and manual literature search of clinical studies was carried out using specified indexing terms. A total of 13 studies were eligible for qualitative analysis and 277 edentulous patients were rehabilitated with 1556 implants patients by means of fully guided mucosa-supported template-assisted flapless surgery. Angular deviation was 3.42° (95% CI 2.82–4.03), linear deviation at shoulder point 1.23 mm (95% CI 0.97–1.49) and linear deviation at apex point 1.46 mm (95% CI 1.17–1.74). No statistically significant correlations were found between the linear and angular deviations. A statistically significant correlation was found between the two linear deviations (correlation coefficient 0.91) that can be summarized by the regression equation y = 0.03080 + 0.8254x. Computer-assisted flapless implant placement by means of mucosa-supported templates in complete arch restorations can be considered a reliable and predictable treatment choice despite the potential effects that flapless approach could bring to the overall treatment.

Reducing errors in guided implant surgery to optimize treatment outcomes

Clinical considerations and treatment criteria in implant placement are constantly evolving. Prosthetically driven implant surgery has become the standard of care to improve short and long-term functional and esthetic outcomes. Therefore, implant position and angulation are planned according to the available bone, anatomical structures, and the requirements of the future prosthetic superstructure. In parallel with these developments, significant progress has been made in data imaging and different software technologies to allow the integration of data within a digital file format. Digitalization in implant surgery enables optimal planning of implant position, as well as the ability to transfer this planning to the surgical field-a process defined as "computer-supported implant planning and guided surgery." The aims of the present review are as follows: (a) to critically appraise the indications and potential "added value" of guided implant surgery, elaborating the main differences between dynamic and static guidance; and (b) to discuss the most important clinical considerations relevant for the different steps of the workflow that might influence the surgical outcome and to offer recommendations on how to avoid or reduce process errors in order to optimize treatment outcomes.

Guided Endodontics in Root Canals with Complex Access: Two Case Reports

This article reported two clinical cases in which the guided endodontics was used to perform the access to the root canals. The first case presents a 40-year-old female with a history of pain related to the left maxillary canine. After radiographic examination, the presence of severe calcification up to the apical third of the root canal, associated with a periapical radiolucency, was noted. In the second case, an 85-year-old male was referred to our service with pain upon palpation, at the right mandibular first molar. The radiographic images revealed the presence of endodontic treatment and a fiberglass post in the distal root canal, which was associated with extrusion of the filling material and a periapical lesion. The 3D-guides were planned based on cone beam computed tomography and intraoral digital scanning, which were aligned using a specific software. Therefore, implant drills could be guided up to the root canal length required for each case. In the first case, a surgical root canal was created and the patient was free of signs and symptoms after the treatment was completed. In the second case, it was observed that the fiber post was worn by the drill, allowing free access to the filling material. It was possible to perform the endodontic reintervention in a more predictable way and in less time. In both cases, the use of the guided endodontics allowed the preservation of a large part of the dental structure. The procedures were performed faster, without the occurrence of fractures and perforations.

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 Impact of Surgical Guide Fixation and Implant Location on Accuracy of Static Computer-Assisted Implant Surgery

PURPOSE

To evaluate the accuracy of static computer-assisted implant surgery (sCAIS) for tooth-supported free-end dental implantation with the aid/and without the aid of fixation pins to secure the surgical template through comparison between planned, 3D printed guide position and placement implant position.

MATERIALS AND METHODS

Thirty-two duplicated maxillary resin models were used in the present in vitro study. Digital planning was performed and fabrication of a surgical template that allowed implant placement on the distal extension edentulous site of the model (maxillary left side). A first optical scan was performed after fitting the surgical template on the model to assess the deviation at the surgical guide level. After placing implants in the model using the surgical guide, scan bodies were attached to the implants, and a second scan was performed to record the position of placed implants. The digital representations were later superimposed to the pre-operative scan and measurements of implant deviations were performed. Global (coronal and apical), horizontal (coronal and apical), depth and angular deviations were recorded between planned implant position, guide position, and placement implant position. Three-way ANOVA was used to compare implant location (#13, 14, and 15), fixation pin (with or without pin), and guide comparison (planned, guided, and placement).

RESULTS

Final implant placement based on the digital plan and based on the 3D printed guide were very similar except for depth deviation. Use of fixation pin had a statistically significant effect on the depth and angular deviation. Overall, without fixation pins and based on guide versus placement, mean global coronal (0.88 ± 0.36 mm), horizontal coronal (0.55 ± 0.32 mm), and apical (1.44 ± 0.75 mm), and angular deviations (4.28 ± 2.01°) were similar to deviations with fixation pins: mean global coronal (0.88 ± 0.36 mm); horizontal coronal (0.67 ± 0.22 mm) and apical (1.60 ± 0.69 mm); and angular deviations (4.53 ± 2.04°). Horizontal apical without pins (1.63 ± 0.69 mm) and with fixation pins (1.72 ± 0.70 mm) was statistically significant (p = 0.044). Depth deviation without pins (-0.5 ± 0.5 mm) and with fixation pins (-0.16 ± 0.62 mm) was also statistically significant (p = 0.005). Further analysis demonstrated that the final sleeve position on the 3D printed guide was on average 0.5 mm more coronal than the digital plan.

CONCLUSIONS

The use of surgical guides with or without fixation pins can provide clinically acceptable outcomes in terms of accuracy in implant position. There was a statistically significant difference in the accuracy of implant position when utilizing fixation pins only for horizontal apical and depth deviation. Additionally, a statistically significant difference between the planned and the 3D printed surgical guide when considering the sleeve position was detected.

Immediate Loading of Implants Placed by Guided Surgery in Geriatric Edentulous Mandible Patients

The aim of this study was to show the clinical outcomes of the immediate loading of implants inserted by guided surgery in edentulous mandible patients. Edentulous mandible patients were diagnosed with oral examination, cone beam computerized tomography and diagnostic casts for intermaxillary relations and treated with 8–10 implants for rehabilitation with guided surgery and immediate loading. After flapless surgery, implants were loaded with an immediate acrylic temporary prosthesis. After a period of six months, a ceramic definitive full-arch prosthesis was placed. A total of 22 patients (12 females and 10 males) were treated with 198 implants. Eleven patients (50%) had a previous history of periodontitis. Six patients (27.3%) were smokers. The follow-up was 84.2 ± 4.9 months. Clinical outcomes showed a global success rate of 97.5% of implants. Five implants were lost during the healing phase with provisional prosthesis. Twenty-two fixed full-arch rehabilitations were placed in the patients over the 193 remaining implants. Mean marginal bone loss was 1.44 mm ± 0.45 mm. Six patients (27.3%) showed some kind of mechanical prosthodontic complication. Eighteen (9.3%) of the 193 remaining implants were associated with peri-implantitis. The antecedents of peri-implantitis are critical elements for the survival of the implants. The loss of implants was significant in patients who smoked up to 10 cigarettes, compared to non-smokers. Peri-implantitis is one of the key elements in the long-term follow-up of implants and it was more manifest in smoking patients, and in those with a history of peri-implantitis. Marginal bone loss was more significant in smokers. Full-arch rehabilitation is presented as a predictable alternative with minor fatigue problems that are easily solvable.

Comparison of positioning accuracy between two different implant systems using mucosa-supported surgical templates: a retrospective clinical study

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.

Guided implant surgery workflow in edentulous patients: A precise and rapid technique

A new technique of guided implant surgery is presented. A conventional complete denture is converted into both tomographic and surgical guides and later into an interim implant-supported fixed prosthesis. A plate derived from a computed tomography scan becomes the physical link between the virtual planning and tube positioning device. Furthermore, the interim placement of mini-implants adjacent to the symphysis region stabilizes the guide throughout the guided surgery. This technique reduces treatment time and costs.

Accuracy of implant surgical guides fabricated using computer numerical control milling for edentulous jaws: a pilot clinical trial

Background

To evaluate the accuracy of a computer numerical control (CNC) milled surgical guide for implant placement in edentulous jaws.

Methods

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.

Results

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).

Conclusions

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.

Trial registration: Chinese Clinical Trial Registry, ChiCTR-ONC-17014159 (July 26, 2017).

Newly developed data-matching methodology for oral implant surgery allowing the automatic deletion of metal artifacts in 3D-CT images using new reference markers: A case report

PATIENTS

The patient was a 55-year-old woman with left upper molar free-end edentulism and 9 full cast metal crowns in her mouth. Three three-dimensional (3D) images were superimposed: a computed tomography (CT) image with the patient wearing the CT-matching template (CTMT) with six glass ceramic markers, which hardly generate any artifacts, on the template surface, and oral plaster model surfaces with and without CTMTs. Metal artifacts were automatically removed by a Boolean operation identifying unrealistic images outside the oral plaster model surface. After the preoperative simulation, fully guided oral implant surgery was performed. Two implant bodies were placed in the left upper edentulism. The placement errors calculated by comparing the preoperative simulation and actual implant placement were then assessed by a software program using the 3D-CT bone morphology as a reference. The 3D deviations between the preoperative simulation and actual placement at the entry of the implant body were a maximum 0.48 mm and minimum 0.26 mm. Those at the tip of the implant body were a maximum 0.56 mm and a minimum 0.25 mm.

DISCUSSION

In this case, the maximum 3D deviations at the entry and tip section were less than in previous studies using double CT.

CONCLUSIONS

Accurate image fusion utilizing CTMT with new reference markers was possible for a patient with many metal restorations. Using a surgical guide manufactured by the new matching methodology (modified single CT scan method), implant placement deviation can be minimized in patients with many metal restorations.

Accuracy of fully guided orthodontic mini-implant placement evaluated by cone-beam computed tomography: a study involving human cadaver heads

OBJECTIVES

The aim of this study was to evaluate the accuracy of fully guided orthodontic mini-implant (OMI) placements supported by tooth- (TBGs) or gingiva-borne silicone guides (GBGs) based on virtually superimposed lateral cephalograms on virtual plaster models.

MATERIALS AND METHODS

Lateral cephalograms and corresponding plaster models were virtually superimposed for the planning of OMI positions; fully guided TBGs and GBGs were fabricated (each, n = 10). A total of 40 OMIs were inserted in a paramedian position into the palate of 20 human cadavers. Postoperative cone-beam computer tomographies (CBCTs) were carried out, and an accuracy evaluation was performed by comparing preoperative planning models and postoperative CBCTs. Deviations of the axis, tip, centre of the shoulder and vertical position of each of the implants were evaluated. Furthermore, the transfer accuracy measured by postoperative CBCT scans were compared with the accuracy determined using an intraoral scanner.

RESULTS

A significant deviation between TBGs (2.81° SD 2.69) and GBGs (6.22° SD 4.26) regarding implant angulation was evaluated (p = 0.005). Implant tip and implant shoulder deviations revealed no statistical differences between the guides. Accuracy values of oral scans regarding vertical deviations were significantly more inaccurate when compared with CBCTs (p < 0.001).

CONCLUSIONS

The accuracy of an OMI position can be significantly increased by using a guide extension over the teeth. Vertical implant positions presented the lowest deviations. Postoperative oral scans and CBCTs represent diverging accuracy measurements when compared with virtual planning.

CLINICAL RELEVANCE

Users must keep in mind that despite virtual planning deviations, inaccuracies of a few millimetres may occur.

[Research advances in the use of digital surgical guides in implantology]

Dental implants have become the main choice for patients to fill in their missing teeth. A precise placement is the basis for a functional and aesthetic restoration. A digital surgical guide is a carrier that transfers the preoperative plan of dental implants to the actual surgery. This paper provides some references that can help clinicians improve the accuracy of implant surgery by stating the development, classification, advantages and disadvantages, and factors that affect the accuracy of digital guides.

Guided implant surgery risks and their prevention

Ideal implant placement may reduce surgical complications, such as nerve injury and lingual cortical plate perforation, and minimize the likelihood of functional and prosthetic compromises. Guided implant surgery (GIS) has been used as the means to achieve ideal implant placement. GIS refers to the process of digital planning, custom-guide fabrication, and implant placement using the custom guide and an implant system-specific guided surgery kit. GIS includes numerous additional steps beyond the initial prosthetic diagnosis, treatment planning, and fabrication of surgical guide. Substantial errors can occur at each of these individual steps and can accumulate, significantly impacting the final accuracy of the process with potentially disastrous deviations from proper implant placement. Pertinent overall strategies to reduce or eliminate these risks can be summarized as follows: complete understanding of the possible risks is fundamental; knowledge of the systems and tools used is essential; consistent verification of both diagnostic and surgical procedures after each step is crucial; proper training and surgical experience are critical. This review article summarizes information on the accuracy and efficacy of GIS, provides insight on the potential risks and problems associated with each procedural step, and offers clinically relevant recommendations to minimize or eliminate these risks.

Image analysis of immediate full-arch prosthetic rehabilitations guided by a digital workflow: assessment of the discrepancy between planning and execution

Background

A dentition with adequate function and esthetics is essential for the well-being and quality of life. A full implant-retained fixed prosthetics is an ideal solution for fully edentulous arch, however requires complex planning, surgical, and prosthetic procedure. With the help of digital workflow, it becomes a predictable and fast solution for the dentists and the patients. This retrospective study analyzed the most advanced surgical approach in full-arch rehabilitation with dental implants and immediate loading using digital workflow.

Methods

Patient records of fully edentulous jaws treated in four clinical centers in Warsaw, Poland, were evaluated. Computer-assisted planning and surgical template fabrication were done using the planning software coDiagnostiX™, based on a pre-op cone beam computed tomography (CBCT) and scanned data of a plaster model. A post-op CBCT was acquired after the placement of four to six implants by the guided system. The influence of different surgical variables on the discrepancy between planning and execution was analyzed, together with the biomechanical indices.

Results

A total of nine patient records were selected of 12 edentulous jaws treated with 62 implants. The overall mean three-dimensional (3D) offset at the implant base was 1.60 mm, at the tip 1.86 mm. The mean angle of deviation was 4.89°, the mean implant stability quotient (ISQ) 70.42, and the insertion torque 35.58 Ncm. The 3D offsets were influenced by the gender of the patient, treated jaw, the diameter, and length of the implant. The angle of deviation was affected only by the treated jaw. Insertion torque was influenced by the treated jaw, the age of the patient, the length of the implant, tooth type, and the side of the jaw.

Discussion

Bone quality of the patient and implant preparation procedure influenced the discrepancy between the planning and the execution of the digitally guided implant placement. Dense bone—mandible, posterior area, young age, and man—and multiple preparations of the implant bed—wider and longer implant—could be suggested as risk factors.

Conclusion

Digital workflow successfully enabled the immediate full-arch rehabilitation with a predictable outcome by different surgeons in multiple centers.

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

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

Accuracy, reproducibility, and dimensional stability of additively manufactured surgical templates

STATEMENT OF PROBLEM

Additively manufactured surgical templates are commonly used for computer-guided implant placement. However, their accuracy, reproducibility, and dimensional stability have not been thoroughly investigated with the different 3D printers and materials used for their fabrication.

PURPOSE

The purpose of this in vitro study was to evaluate the accuracy, reproducibility, and dimensional stability of additively manufactured surgical templates fabricated by using different 3D printers.

MATERIAL AND METHODS

Thirty surgical templates were designed and additively manufactured from 3 different 3D printers as follows: group SLA (n=10) was fabricated by using a desktop stereolithography (SLA) 3D printer and photopolymerizing resin; group PolyJet (n=10) was fabricated by using a PolyJet 3D printer and photopolymerizing resins; and group DMP (n=10) was fabricated by using a direct metal printing (DMP) system and Co-Cr metal alloy. All surgical templates were scanned by using a laser scanner within 36 hours of production and digitalized again 1 month later. All scanned files were compared with the corresponding designed files in a surface matching software program. The mean deviation root mean square (RMS, measured in mm, representing accuracy), percentage of measurement data points within 1 standard deviation of mean RMS (in %, representing reproducibility), and dimensional changes were determined and compared.

RESULTS

At the postproduction stage, group PolyJet was most accurate with the lowest RMS value of 0.10 ±0.02 mm and highest reproducibility with 93.07 ±1.54% of measurement data points within 1 standard deviation of mean RMS. After 1-month storage, group PolyJet_(1month) remained the most accurate with the lowest RMS value of 0.14 ±0.03 mm and the highest reproducibility value of 92.46 ±1.50%. For dimensional stability, group SLA versus group SLA_(1month) comparison showed a significant decrease in accuracy (RMS values of 0.20 ±0.08 mm versus 0.25 ±0.08 mm, P<.001) and reproducibility (88.16 ±3.66% versus 86.10 ±4.16%, P=.012). Group PolyJet versus group PolyJet_(1month) comparison only showed significant changes in accuracy (RMS values of 0.10 ±0.02 mm versus 0.14 ±0.03 mm, P=.011). Group DMP versus group DMP_(1month) comparison showed no significant changes in accuracy (RMS values of 0.19 ±0.03 mm versus 0.20 ±0.04 mm, P=.981) or reproducibility (89.77 ±1.61% versus 89.74 ±2.24%, P=1.000).

CONCLUSIONS

Printed resin surgical templates produced by using the PolyJet 3D printer showed higher accuracy and reproducibility than those produced by using the desktop SLA 3D printer and printed Co-Cr surgical templates at both the postproduction stage and after 1-month storage. The level of accuracy and reproducibility in printed Co-Cr surgical templates was not affected by 1-month storage.

Reliability and accuracy of skin-supported surgical templates for computer-planned craniofacial implant placement, a comparison between surgical templates: With and without bony fixation

INTRODUCTION

The purpose is to determine the accuracy of guided implant placement in the orbital, nasal, and auricular region using computer-aided designed stereolithographic skin-supported surgical templates with and without bone fixation pins.

MATERIALS AND METHODS

Preoperatively, cone-beam CT (CBCT) and multiple detector computed tomography (MDCT) scans were acquired from 10 cadaver heads, followed by virtual planning of implants in the orbital margin, auricular region and nasal floor. Surgical skin-supported templates were digitally designed to allow flapless implant placement. Fixation pins were used for stabilization comprising half of all templates in predetermined bone areas. The accuracy of the surgical templates was validated by comparing the achieved implant location to its virtual planned implant position by calculating the linear and angular deviations.

RESULTS

Surgical templates with the use of bone fixation pins produced statistically significant greater implant deviations as compared to the non-fixated surgical templates.

CONCLUSION

The results of this study indicate that significant deviation has to be taken into account when placing cranio-maxillofacial implants using skin-supported surgical templates. Surprisingly, the use of bone-fixated pins worsened the accuracy.

Role of three-dimensional printing in periodontal regeneration and repair: Literature review

Three-dimensional (3D) printing is the process of building 3D objects by additive manufacturing approach. It is being used in endodontics, periodontology, maxillofacial surgery, prosthodontics, orthodontics, and restorative dentistry, but our review article is focused on periodontal application. A detailed literature search was done on PubMed/Medline and Google Scholar using various key terms. A total of 45 articles were included in this study. Most of the studies were in vitro, preclinical, case reports, retrospective, and prospective studies. Few clinical trials have also been done. Periodontal applications included education models, scaffolds, socket preservation, and sinus and bone augmentation and guided implant placement. It showed better alveolar ridge preservation, better regenerative capabilities, greater reduction in pocket depth and bony fill, ease of implant placement in complex cases with greater precision and reduced time with improved outcome and an important tool for education and training using simulated models.

The accuracy of a 3D printing surgical guide determined by CBCT and model analysis

PURPOSE

The aim of this clinical study was to assess the accuracy of the implants placed using a universal digital surgical guide.

MATERIALS AND METHODS

Among 17 patients, 28 posterior implants were included in this study. The digital image of the soft tissue acquired from cast scan and hard tissue from CBCT have been superimposed and planned the location, length, diameter of the implant fixture. Then digital surgical guides were created using 3D printer. Each of angle deviations, coronal, apical, depth deviations of planned and actually placed implants were calculated using CBCT scans and casts. To compare implant positioning errors by CBCT scans and plaster casts, data were analyzed with independent samples t-test.

RESULTS

The results of the implant positioning errors calculated by CBCT and casts were as follows. The means for CBCT analyses were: angle deviation: 4.74 ± 2.06°, coronal deviation: 1.37 ± 0.80 mm, and apical deviation: 1.77 ± 0.86 mm. The means for cast analyses were: angle deviation: 2.43 ± 1.13°, coronal deviation: 0.82 ± 0.44 mm, apical deviation: 1.19 ± 0.46 mm, and depth deviation: 0.03 ± 0.65 mm. There were statistically significant differences between the deviations of CBCT scans and cast.

CONCLUSION

The model analysis showed lower deviation value comparing the CBCT analysis. The angle and length deviation value of the universal digital guide stent were accepted clinically.

An accuracy study of computer-planned implant placement in the augmented maxilla using osteosynthesis screws

Previous research on the accuracy of flapless implant placement of virtually planned implants in the augmented maxilla revealed unfavourable discrepancies between implant planning and placement. By using the osteosynthesis screws placed during the augmentation procedure, the surgical template could be optimally stabilized. The purpose of this study was to validate this method by evaluating its clinically relevant accuracy. Twelve consecutive fully edentulous patients with extreme resorption of the maxilla were treated with a bone augmentation procedure. Virtual implant planning was performed and a surgical template was manufactured. Subsequently, six implants were installed using the surgical template, which was only supported by the osteosynthesis screws. Implant deviations between planning and placement were calculated. A total of 72 implants were installed. Mean deviations found in the mesiodistal direction were 0.817mm at the implant tip and 0.528mm at the implant shoulder. The angular deviation was 2.924°. In the buccolingual direction, a deviation of 1.038mm was registered at the implant tip and 0.633mm at the implant shoulder. The angular deviation was 3.440°. This study showed that implant placement in the augmented maxilla using a surgical template supported by osteosynthesis screws is accurate.

Accuracy of a direct drill-guiding system with minimal tolerance of surgical instruments used for implant surgery: a prospective clinical study

PURPOSE

A recently introduced direct drill-guiding implant surgery system features minimal tolerance of surgical instruments in the metal sleeve by using shank-modified drills and a sleeve-incorporated stereolithographic guide template. The purpose of this study was to evaluate the accuracy of this new guided surgery system in partially edentulous patients using geometric analyses.

MATERIALS AND METHODS

For the study, 21 implants were placed in 11 consecutive patients using the direct drill-guiding implant surgery system. The stereolithographic surgical guide was fabricated using cone-beam computed tomography, digital scanning, computer-aided design and computer-assisted manufacturing, and additive manufacturing processes. After surgery, the positional and angular deviations between planned and placed implants were measured at the abutment level using implant-planning software. The Kruskal-Wallis test and Mann-Whitney U test were used to compare the deviations (α=.05).

RESULTS

The mean horizontal deviations were 0.593 mm (SD 0.238) mesiodistally and 0.691 mm (SD 0.344) buccolingually. The mean vertical deviation was 0.925 mm (SD 0.376) occlusogingivally. The vertical deviation was significantly larger than the horizontal deviation (P=.018). The mean angular deviation was 2.024 degrees (SD 0.942) mesiodistally and 2.390 degrees (SD 1.142) buccolingually.

CONCLUSION

The direct drill-guiding implant surgery system demonstrates high accuracy in placing implants. Use of the drill shank as the guiding component is an effective way for reducing tolerance.