Reliability of implant placement after virtual planning of implant positions using cone beam CT data and surgical (guide) templates

Efficacy of Novel Digital-Based Surgical Guide in the Limited Interocclusal Distance

Accurate implant placement is essential for achieving successful outcomes. To aid in this, digitally designed surgical guides have been introduced. Both closed-sleeve and open-sleeve designs are commonly utilized. However, the closed-sleeve design has limitations with restricted interocclusal distance, interference with irrigation, and limited visibility, while the open-sleeve design is known to be less accurate. To address these limitations, a new slope-sleeve design was introduced. This design reduces the interocclusal distance requirement compared to the closed-sleeve design and provides improved accuracy. A constraint model with a 31 mm interocclusal distance was created, and three types of surgical guides (closed, open, and slope), printed using either a PolyJet or Digital Light Processing (DLP) 3D printer, were tested on resin bone blocks. Horizontal and angular deviations were measured for the accuracy of each guide after drilling, with data analyzed using one-way ANOVA and independent t-tests. The slope-sleeve design showed significantly lower horizontal and angular deviations in wide-sized guides. Additionally, PolyJet-printed guides showed higher accuracy compared to DLP-printed guides. The slope-sleeve guide offers enhanced stability and precision in restricted interarch spaces. When coupled with high-precision 3D printing technologies like PolyJet, the slope-sleeve design provides a reliable solution for improving implant placement accuracy in challenging clinical scenarios.

Anatomical Factors of the Anterior and Posterior Maxilla Affecting Immediate Implant Placement Based on Cone Beam Computed Tomography Analysis: A Narrative Review

BACKGROUND

The aim of this narrative review was to provide insights into the influence of the morphological characteristics of the anatomical structures of the upper jaw based on cone beam computed tomography (CBCT) analysis on the immediate implant placement in this region.

MATERIAL AND METHODS

To conduct this research, we used many electronic databases, and the resulting papers were chosen and analyzed. From the clinical point of view, the region of the anterior maxilla is specific and can be difficult for immediate implant placement.

FINDINGS

Anatomical structures in the anterior maxilla, such as the nasopalatine canal and accessory canals, may limit and influence the implant therapy outcome. In addition to the aforementioned region, immediate implant placement in the posterior maxilla may be challenging for clinicians, especially in prosthetic-driven immediate implant placement procedures. Data presented within the recently published materials summarize the investigations performed in order to achieve more reliable indicators that may make more accurate decisions for clinicians.

CONCLUSION

The possibility for immediate implant placement may be affected by the NPC shape in the anterior maxilla, while the presence of ACs may increase the incidence of immediate implant placement complications. The variations in IRS characteristics may be considered important criteria for choosing the implant properties required for successful immediate implant placement.

An in vitro analysis of the accuracy of static and robot-assisted implant surgery

OBJECTIVES

Robot-assisted implant surgery (RAIS) is purported to improve the accuracy of implant placement. The objective of this study was to compare RAIS with static computer-assisted implant surgery (sCAIS) in a controlled environment.

MATERIALS AND METHODS

A total of n = 102 implants were placed in the same modified typodont (n = 17 repeated simulated implant surgeries with each n = 3 implants per group) using robot-assisted or static computer-assisted implant surgery. The final implant positions were digitized utilizing cone-beam tomography and compared with the planned position. The angular deviation was the primary outcome parameter. 3D deviations at the implant platform level and the apex were secondary outcome parameters. Accuracy in terms of trueness and precision were assessed. Means, standard deviation, and 95%-confidence intervals were analyzed statistically.

RESULTS

The overall angular deviation was 2.66 ± 1.83° for the robotic system and 0.68 ± 0.38° for guided surgery using static guides (p < .001), the 3D-deviation of the implant platform at crest level was for sCAIS 0.79 ± 0.28 mm and RAIS 1.51 ± 0.53 mm (p < .001) and at the apex for sCAIS 0.82 ± 0.26 mm and for RAIS 1.97 ± 0.79 mm (p < .001), respectively.

CONCLUSIONS

Robotically guided implant surgery was less accurate in terms of trueness (planned vs. actual position) and precision (deviations among implants) than traditional static computer-assisted implant surgery in this in vitro study.

Impact of 3D imaging techniques and virtual patients on the accuracy of planning and surgical placement of dental implants: A systematic review

Aim

The integration of advanced technologies, including three-dimensional (3D) imaging modalities and virtual simulations, has significantly influenced contemporary approaches to preoperative planning in implant dentistry. Through a meticulous analysis of relevant studies, this review synthesizes findings related to accuracy outcomes in implant placement facilitated by 3D imaging in virtual patients.

Methods

A comprehensive literature search was conducted across relevant databases to identify relevant studies published to date. The inclusion criteria were studies utilizing 3D imaging techniques, virtual patients, and those focusing on the accuracy of dental implant planning and surgical placement. The selected studies were critically appraised for their methodological quality.

Results

After a rigorous analysis, 21 relevant articles were included out of 3021 articles. This study demonstrates the versatility and applicability of these technologies in both in vitro and in vivo settings. Integrating Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), cone bean computed tomography (CBCT), and advanced 3D reconstruction methodologies showcases a trend toward enhanced precision in implant planning and placement. Notably, the evaluation parameters varied, encompassing distances, discrepancies, and deviations in the implant placement. The ongoing integration of systems such as dynamic navigation systems, augmented reality, and sophisticated software platforms shows a promising trajectory for the continued refinement of virtual reality applications in dental implantology, providing valuable insights for future research and clinical implementation. Moreover, using stereolithographic surgical guides, virtual planning with CBCT data, and 3D-printed templates consistently demonstrates enhanced precision in dental implant placement compared to traditional methods.

Conclusion

The synthesis of the available evidence underscores the substantial positive impact of 3D imaging techniques and virtual patients on dental implant planning and surgical placement accuracy. Utilizing these technologies contributes to a more personalized and precise approach that enhances overall treatment outcomes. Future research directions and potential refinements to the application of these technologies in clinical practice should be discussed.

Guided bone regeneration in implant dentistry: Basic principle, progress over 35 years, and recent research activities

Bone augmentation procedures are frequent today in implant patients, since an implant should be circumferentially anchored in bone at completion of bone healing to have a good long-term stability. The best documented surgical technique to achieve this goal is guided bone regeneration (GBR) utilizing barrier membranes in combination with bone fillers. This clinical review paper reflects 35 years of development and progress with GBR. In the 1990s, GBR was developed by defining the indications for GBR, examining various barrier membranes, bone grafts, and bone substitutes. Complications were identified and reduced by modifications of the surgical technique. Today, the selection criteria for various surgical approaches are much better understood, in particular, in post-extraction implant placement. In the majority of patients, biodegradable collagen membranes are used, mainly for horizontal bone augmentation, whereas bioinert PTFE membranes are preferred for vertical ridge augmentation. The leading surgeons are using a composite graft with autogenous bone chips to accelerate bone formation, in combination with a low-substitution bone filer to better maintain the augmented bone volume over time. In addition, major efforts have been made since the millenium change to reduce surgical trauma and patient morbidity as much as possible. At the end, some open questions related to GBR are discussed.

Reliability of Cone Beam Computed Tomography in Predicting Implant Treatment Outcomes in Edentulous Patients

Since the development of CBCT has been utilized in dentistry, the images of the CBCT can assist the surgeon to evaluate the anatomy carefully. Despite the value of radiology evaluation, implant procedures may require additional consideration rather than only evaluating the anatomical factors. The purpose of this study is to evaluate the predictability of using CBCT alone to plan for implant placement in edentulous patients digitally. CBCT images were analyzed by clinicians, measuring the maxillary and mandibular ridge heights and widths digitally of four predetermined implant sites in the maxillary and two selected implant sites in the mandibular arches of 91 patients planning for implant-supported overdenture. A total of 47 patients out of the 91 had completed implant placement on the edentulous ridge, contributing to 55 upper and/or lower arches (136 dental implants). Both predictabilities are low, implying that CBCT planning for implant placement on the edentulous ridge is not a good index and is insufficient to predict the surgical procedures as a solo method. The findings of this study indicate that digital planning by CBCT is insufficient to serve as an individual tool to predict implant procedures. Further information and evaluation must be considered for implant placement in the edentulous ridge.

An in vivo study to assess and compare the angular, linear, and depth deviation as well as the difference in bone density of implants placed using computer-aided design/computer-aided manufacturing fabricated three-dimensional guides versus the implants placed using bone pen kit in maxillary and mandibular ridges

Aim

The aim is to assess and compare angular, linear, and depth deviation and difference in bone density of dental implants placed using computer aided design/computer aided manufacturing (CAD/CAM) fabricated surgical guides versus implants placed using Bone Pen Kit. Till now, no original research exists in the search engines such as Pubmed, Google Scholar, Science Direct, and Research Gate on this kit.

Settings and Design

In vivo- Randomised control trial.

Materials and Methods

Twenty clinical cases were selected and split into two distinct groups. Group 1 involved the placement of 10 implants using CAD/CAM fabricated three dimensional guides and Group 2 involved the placement of 10 implants using Bone Pen Kit. Four deviation parameters were evaluated, which included: (a) Angular deviation, (b) Linear deviation at implant platform, (c) Linear deviation at implant apex, and (d) Depth deviation and difference in bone density before and after implant placement was also evaluated.

Statistical Analysis Used

SPSS software version 23 was utilized for the analysis of the data. The comparison was made using the Whitney test, and Wilcoxon signed rank test.

Results

When comparing angular deviation, the results indicated a statistically significant difference with a P < 0.05. The values observed for angular and linear deviation in Group 2 were significantly greater than those in Group 1. No statistically significant difference in depth and linear deviation was found at the implant platform among the two groups. Bone density before and after implant placement was significantly higher in Group 1.

Conclusions

(1) Angular and linear deviation at the apex in Group 2 exhibited higher values in comparison to Group 1, (2) No difference in depth and linear deviation at the implant platform was found among the two groups, and (3) There was no difference in change in bone density among two groups.

Accuracy of a custom two-piece surgical guide for all-on-four dental implant placement: An in vitro study

STATEMENT OF PROBLEM

Although fully guided dental implant surgery has been reported to provide a high degree of accuracy, it has disadvantages including the lack of external irrigation during osteotomy formation and the need for special drills and equipment. Whether a custom 2-piece surgical guide has sufficient accuracy is unclear.

PURPOSE

The purpose of this in vitro study was to design and fabricate a new surgical guide concept that fully guides the placement of implants to the desired position and angulation without affecting the external irrigation during osteotomy preparation, to eliminate the need for a special armamentarium, and to determine the accuracy of the guide.

MATERIAL AND METHODS

A 2-piece surgical guide was 3-dimensionally designed and fabricated. Implants were placed according to the all-on-4 concepts in laboratory casts using the newly fabricated surgical guide. Placement accuracy was determined from a postoperative cone beam computed tomography scan that was superimposed over the preplanned implant positions to calculate the degree of angular deviation and position of placement. Adopting 5% alpha error and 80% study power in estimating sample size, a total of 88 implants were placed according to the all-on-4 concept in 22 mandibular laboratory casts. These were divided into 2 groups: with the newly fabricated surgical guide and with a traditional fully guided protocol. Deviations at the point of entry, at the apex horizontally, the vertical apical depth, and angular deviations from the proposed plan were measured from the superimposed scans. Differences in apical depth, horizontal deviation at the apex, and horizontal deviation in the hexagon measurements were compared with the independent t test, while differences in angular deviation were assessed with the Mann-Whitney U test (α=.05).

RESULTS

No statistically significant difference was found in the apical depth deviation (P>.05), but significant differences were found in the apex (P=.002), hexagon (P<.001), and angular deviation (P<.001) between the new guide and the traditional guide.

CONCLUSIONS

The new surgical guide showed potential for higher accuracy in implant placement when compared with the fully guided sleeveless surgical guide. In addition, it provided an undisturbed flow of irrigation around the drill throughout the drilling procedure, with the advantage of eliminating the special armamentarium usually required.

Integration of conventional and digital surgical guide fabrication techniques for the partially edentulous patient: Reducing the number of surgical procedures for a complete arch implant-supported prosthesis

Surgical procedures on partially edentulous patients for complete arch implant-supported prostheses involve remaining tooth extraction, alveolar bone reduction, and implant placement. Traditionally, partially edentulous patients undergo multiple surgeries, which extends the healing time and results in an extensively prolonged total treatment timeline. This technical article focuses on the fabrication of a more stable and predictive surgical guide to perform multiple surgical procedures in a single surgical appointment and planning a complete arch implant-supported prosthesis for the partially edentulous patient.

Development of artificial intelligence model for supporting implant drilling protocol decision making

PURPOSE

This study aimed to develop an artificial intelligence (AI) model to support the determination of an appropriate implant drilling protocol using cone-beam computed tomography (CBCT) images.

METHODS

Anonymized CBCT images were obtained from 60 patients. For each case, after implant placement, images of the bone regions at the implant site were extracted from 20 slices of CBCT images. Based on the actual drilling protocol, the images were classified into three categories: protocols A, B, and C. A total of 1,200 images were divided into training and validation datasets (n = 960, 80%) and a test dataset (n = 240, 20%). Another 240 images (80 images for each type) were extracted from the 60 cases as test data. An AI model based on LeNet-5 was developed using these data sets. The accuracy, sensitivity, precision, F-value, area under the curve (AUC) value, and receiver operating curve were calculated.

RESULTS

The accuracy of the trained model is 93.8%. The sensitivity results for drilling protocols A, B, and C were 97.5%, 95.0%, and 85.0%, respectively, while those for protocols A, B, and C were 86.7%, 92.7%, and 100%, respectively, and the F values for protocols A, B, and C were 91.8%, 93.8%, and 91.9%, respectively. The AUC values for protocols A, B, and C are 98.6%, 98.6%, and 99.4%, respectively.

CONCLUSION

The AI model established in this study was effective in predicting drilling protocols from CBCT images before surgery, suggesting the possibility of developing a decision-making support system to promote primary stability.

A generalized image quality improvement strategy of cone-beam CT using multiple spectral CT labels in Pix2pix GAN

Objective. The quantitative and routine imaging capabilities of cone-beam CT (CBCT) are hindered from clinical applications due to the severe shading artifacts of scatter contamination. The scatter correction methods proposed in the literature only consider the anatomy of the scanned objects while disregarding the impact of incident x-ray energy spectra. The multiple-spectral model is in urgent need for CBCT scatter estimation. Approach. In this work, we incorporate the multiple spectral diagnostic multidetector CT labels into the pixel-to-pixel (Pix2pix) GAN to estimate accurate scatter distributions from CBCT projections acquired at various imaging volume sizes and x-ray energy spectra. The Pix2pix GAN combines the residual network as the generator and the PatchGAN as the discriminator to construct the correspondence between the scatter-contaminated projection and scatter distribution. The network architectures and loss function of Pix2pix GAN are optimized to achieve the best performance on projection-to-scatter transition. Results. The CBCT data of a head phantom and abdominal patients are applied to test the performance of the proposed method. The error of the corrected CBCT image using the proposed method is reduced from over 200 HU to be around 20 HU in both phantom and patient studies. The mean structural similarity index of the CT image is improved from 0.2 to around 0.9 after scatter correction using the proposed method compared with the MC-simulation method, which indicates a high similarity of the anatomy in the images before and after the proposed correction. The proposed method achieves higher accuracy of scatter estimation than using the Pix2pix GAN with the U-net generator. Significance. The proposed scheme is an effective solution to the multiple spectral CBCT scatter correction. The scatter-correction software using the proposed model will be available at: https://github.com/YangkangJiang/Cone-beam-CT-scatter-correction-tool.

Free-Hand versus Surgical Guide Implant Placement

One of the most key areas of dentistry is dental implant surgery. The use of digital equipment and software in dentistry has developed considerably in recent years compared to other fields of medicine. Since examining the advantages and disadvantages of each approach, along with case studies, can help physicians make informed decisions, this review study aims to raise the awareness of dentists to make easier decisions about using guided or free-hand surgery. When planning for a dental implant, one of the most challenging questions that doctors face is which method to use (guided surgery or free-hand). Choosing the right method, such as other clinical considerations, will depend on the individual circumstances of each patient and the preference of the treating physician. Free-hand surgery is a cost-effective method in which the flap is reflected, and, according to the doctor's diagnostic information, an implant is placed, which in many cases is a useful method. Guided surgery has the highest level of accuracy and control, in which osteotomy is designed and printed through a digital surgery guide, and depending on the complexity of the case and the patient's anatomy, it has a higher level of value than free surgery. The surgical guide helps the surgeon make the implant surgery more accurate, safer, simpler, at a lower cost, and in less time. In fact, there are patterns that convey information about the position of the tooth to the dentist before the implant is placed.

Morphological and Morphometric Characteristics of Anterior Maxilla Accessory Canals and Relationship with Nasopalatine Canal Type-A CBCT Study

This study aimed to evaluate principal morphological and morphometric characteristics of accessory canals (ACs) of the anterior maxilla, as well as to analyze the relationship with nasopalatine canal (NPC) type. The results of our study showed that ACs were observed in almost 50% of participants. They were mostly presented bilaterally and in a curved shape, with a palatal foramen position. The morphometric characteristics of ACs were significantly influenced by NPC type. NPC type had the strongest impact on the distance between the NPC and AC, as well as on the distance between the AC and the facial aspect of buccal bone wall, in inferior parts of the alveolar ridge. On the other hand, the distance between the AC and central incisors was not significantly influenced by NPC shape in the lower region of the anterior maxilla. However, the participants with the banana-type of the NPC expressed the reduction in distance from the AC to the central incisor at the upper part in comparison with the subjects with the cylindrical-type of the NPC. On the basis of the results of this study, the simultaneous estimation of ACs and the NPC seems reasonable, as this approach may be useful in the prevention of complications which could occur during implant surgery interventions.

A Novel Digital Implant Planning Workflow in Patients with Preexisting Metal Restorations: A Technical Report

A prosthetically-driven virtual implant plan is considered a challenging procedure depending on accurate registration of the three-dimensional optical surface scan and 3D volumetric rendering reconstructed from cone-beam computed tomography (CBCT) images. However, the presence of preexisting metal restorations may significantly negatively influence the registration process. This technical report describes a novel digital workflow to optimize the implant planning outcome for the partially edentulous patient with preexisting metal restorations by accurately aligning the standard triangle language data of the intraoral scanner with the CBCT rendering using a dual-scan technique and an appliance with radiographic markers.

Alveolar Bone Ridge Augmentation Using Polymeric Membranes: A Systematic Review and Meta-Analysis

Alveolar bone ridge resorption occurred after natural teeth loss and it can restrict the possibility of dental implants placement. The use of bone regenerative procedures is frequently required. The existing evidence regarding the efficacy of horizontal bone ridge augmentation trough guided bone regeneration (GBR) using polymeric membranes was stated. A systematic review and meta-analysis were performed. Electronic and manual literature searches were conducted. Screening process was done using the National Library of Medicine (MEDLINE by PubMed), Embase, and the Cochrane Oral Health. Included articles were randomized controlled trials and observational studies. Weighted means were calculated. Heterogeneity was determined using Higgins (I2). If I2 > 50% a random-effects model was applied. It was found that the mean of horizontal bone gain was 3.95 mm, ranging from 3.19 to 4.70 mm (confidence interval 95%). Heterogeneity is I2 = 99% (confidence interval 95%) and significance of the random-effects model was p < 0.001. The complications rate was 8.4% and membrane exposure was the most frequent. Through this study, we were able to conclude that the existing scientific evidence suggests that GBR using polymeric membranes is a predictable technique for achieving horizontal bone augmentation, thus, permitting a proper further implant placement.

Assessing the frequency of deep lingual concavities in 826 posterior mandible sockets

PURPOSE

To evaluate the frequency of deep lingual concavities in the lower jaw, which can cause surgical complications while inserting dental implants.

METHODS

Cross-sections of the mandible alveolar ridge at the edentulous sockets were obtained via cone-beam computed tomography. Measurements were carried out using the freeware 'IC Measure' and based on the basic definitions of a previous study.

RESULTS

Most (767/826 = 93%) sockets had concavities of various degrees (30-90°), while 59 (7%) sockets had no concavity. However, the majority of the concavities (71%) were mild, with angles > 60°. The other 220 (26%) sockets had deeper concavities of <60°; among these, 12 (1%) had extremely deep concavities of <40°.

CONCLUSIONS

Only a few cases have deep lingual concavities that pose a high risk for lingual plate perforation during dental implantation.

Early Loading of Mandibular Molar Single Implants: 1 Year Results of a Randomized Controlled Clinical Trial

The purpose of this study was to compare the implant survival, peri-implant marginal bone level, and peri-implant soft tissue of three different types of implants. This was performed with an early loading protocol, using a complete digital workflow, for one year of follow-up. Twenty-four patients with a single missing tooth in the mandibular posterior region were randomly assigned to the control group (SLActive Bone level implant; Institut Straumann AG, Basel, Switzerland), experiment group 1 (CMI IS-III Active implant; Neobiotech Co., Seoul, Korea), and experiment group 2 (CMI IS-III HActive implant; Neobiotech Co., Seoul, Korea). For each patient, a single implant was installed using the surgical template, and all prostheses were fabricated using a computer-aided design/computer-aided manufacturing system on a 3-dimensional model. A provisional prosthesis was implanted at 4 weeks, and a definitive monolithic zirconia prosthesis was substituted 12 weeks following the implant placement. The implant stability quotient (ISQ) and peri-implant soft tissue parameters were measured, and periapical radiographs were taken at 1, 3, 4, 8, 12, 24, 36, and 48 weeks after implant placements. Seven implants in the control group, nine implants in the experiment 1 group, and eight implants in the experiment 2 group were analyzed. There were no significant differences among the three groups in terms of insertion torque, ISQ values between surgery and 8 weeks of follow-up, marginal bone loss at 48 weeks of follow-up, and peri-implant soft tissue parameters (P > 0.05). Statistically significant differences in ISQ values were observed between the control and experiment 1 groups, and the control and experiment 2 groups at the 12 to 48 weeks' follow-ups. Within the limits of this prospective study, an early loading protocol can be applied as a predictable treatment modality in posterior mandibular single missing restorations, achieving proper primary stability.

Expectation and reality of guided implant surgery protocol using computer-assisted static and dynamic navigation system at present scenario: Evidence-based literature review

In the field of modern dentistry, ideal three-dimensional positioning of dental implant with optimal prosthetic fit offers successful long-term outcomes. To achieve such accurate implant placement, presurgical evaluation of hard and soft tissue matters the most. Their efforts can be attained using various application programs such as digital imaging, implant planning software, laboratory- or computer-assisted surgical guides, and dynamic navigation approach. To overcome different opinions and choices regarding guided surgery, this article explains an evidence-based literature review to assess its various outcomes and allowing informed choices before using various guided surgical techniques based on its expectation and reality outcomes. This highlights a clinician's choice to guide his successful implant surgery without causing distress in the midway of treatment. An online search was done on PubMed/Medline database to bring in accuracy to the expertise. This review includes reference of publications from 2000 to 2019, which is related to promising outcomes using computer-assisted static or dynamic navigation system for the placement of implant. Out of these, 809 were related to the computer-guided implant placement. Relevant papers were chosen in accordance with the inclusion and exclusion criteria. This review article contemplates to reflect the fact that computer-guided approach is considered to offer more predictable, safer, and faster implant placement with the predetermined final prosthetic outfit. Thus, digital planning and placing of dental implants in the correct position keep escalating to a higher achievement levels than a classical freehand approach. Nevertheless, this guided surgical approach also holds some errors and risks, which must be identified and rectified.

Comparison Between a Computer-Aided Surgical Template and the Free-Hand Method: A Systematic Review and Meta-Analysis

BACKGROUND

During implantation planning, dentists should be able to make an informed decision regarding whether to use an implant template to assist the surgery.

PURPOSE

The aim of this meta-analysis was to assess the results of implantation with or without an implant template based on the accuracy, survival rate, and other considerations.

MATERIALS AND METHODS

In January 2018, a systematic review was undertaken for randomized controlled trials and retrospective and prospective cohort studies with relevance to implant accuracy and the survival rate between the implant template and free-hand method. The odds ratios (ORs) of the survival rate and the mean difference of accuracy deviation from the selected papers were estimated by meta-analysis.

RESULTS

Of the 362 screened articles, 6 studies were included in the meta-analysis. Comparison of the survival rate of implant surgery with or without an implant template revealed no significant result (OR = 1.71, 95% confidence interval [CI] 0.65-4.51). Significant differences in accuracy were observed in angular (mean difference = -5.45 degrees, 95% CI -0.66 to -4.24 degrees) and apical deviation (mean difference = -0.83 mm, 95% CI -1.12 to -0.54).

CONCLUSIONS

With the technology of computer-aided surgical template, implant placement can be more accurate than free-hand operation. No significant difference is observed in the survival rate between template and free-hand.

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.

Digital Evaluation of the Accuracy of Computer-Guided Dental Implant Placement: An In Vitro Study

Compared to traditional implant surgical guides, computer-assisted implant surgical guides can be considered for positioning implants in the final prosthesis. These computer-assisted implant surgical guides can be easily fabricated with personal 3D printers after being designed with implant planning CAD software. Although the accuracy of computer-assisted implant surgical guides fabricated using personal 3D printers is an important factor in their clinical use, there is still a lack of research examining their accuracy. Therefore, this study evaluated the accuracy of computer-assisted implant surgical guides, which were designed using two implant planning CAD software programs (Deltanine and R2gate software) and fabricated with personal 3D printers using a non-radiographic method. Amongst the patients who visited Kyungpook National University Dental Hospital, one patient scheduled to undergo surgery of the left mandibular second premolar was randomly selected. Twenty partially edentulous resin study models were produced using a 3D printer. Using the Deltanine and R2gate implant planning CAD software, 10 implant surgical guides per software were designed and produced using a personal 3D printer. The implants (SIII SA (Ø 4.0, L = 10 mm), Osstem, Busan, Korea) were placed by one skilled investigator using the computer-assisted implant surgical guides. To confirm the position of the actual implant fixture, the study models with the implant fixtures were scanned with a connected scan body to extract the STL files, and then overlapped with the scanned file by connecting the scan body-implant fixture complex. As a result, the mean apical deviation of the Deltanine and R2gate software was 0.603 ± 0.19 mm and 0.609 ± 0.18 mm, while the mean angular deviation was 1.97 ± 0.84° and 1.92 ± 0.52°, respectively. There was no significant difference between the two software programs (p > 0.05). Thus, the accuracy of the personal 3D printing implant surgical guides is in the average range allowed by the dental clinician.

The dimensions of the facial alveolar bone at tooth sites with local pathologies: a retrospective cone-beam CT analysis

OBJECTIVE

To assess the impact of various local pathologies on facial alveolar bone dimensions at tooth sites.

MATERIALS AND METHODS

Cone-beam computed tomography images of 60 patients were analyzed. Healthy teeth and teeth with local pathologies (i.e., endodontically treated, periodontally diseased teeth, and teeth with periapical lesions) were included. The thickness of the facial alveolar bone was measured at five locations: (1) the bone crest (W0), (2) 25% (W25), (3) 50% (W50), (4) 75% (W75) of the distance from the bone crest to the root apex (A), and (5) in the A region (W100). The results were considered statistically significant at p < 0.0008 (adjustment according to the statistical correction for multiple testing).

RESULTS

A total of 1174 teeth (707 healthy and 467 with the local pathologies) were assessed. Periodontally diseased maxillary premolars and anterior teeth in the mandible in the W0 position, as well as maxillary molars in the W25 position, tended to have a lower facial bone thickness when compared to the healthy teeth (0.68 mm vs. 0.84 mm, p = 0.008; 0.47 mm vs. 0.55 mm, p = 0.004; and 1.27 mm vs. 1.72 mm; p = 0.009, respectively). In contrast, the observed tendency pointed towards thicker facial bone wall for the periodontally diseased mandibular anterior teeth in the W50 position (0.74 vs. 0.52, p = 0.001). Healthy maxillary molars tended to display a thicker facial alveolar bone compared to the teeth with local pathologies in the W25, W50, and W75 positions (p = 0.001, p = 0.005, and p = 0.004, respectively).

CONCLUSIONS

The present analysis has indicated that local pathologies are commonly associated with a compromised socket morphology.

CLINICAL RELEVANCE

The facial bone thickness was particularly reduced at periodontally diseased teeth, which may challenge implant therapy.

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.

Cone Beam Computed Tomography in Oral and Maxillofacial Surgery: An Evidence-Based Review

Cone Beam Computed Tomography (CBCT) is a valuable imaging technique in oral and maxillofacial surgery (OMS) that can help direct a surgeon’s approach to a variety of conditions. A 3-dimensional analysis of head and neck anatomy allows practitioners to plan appropriately, operate with confidence, and assess results post-operatively. CBCT imaging has clear indications and limitations. CBCT offers the clinician 3-dimensional and multi-planar views for a more accurate diagnosis and treatment without the financial burden and radiation exposure of conventional computed tomography (CT) scans. Furthermore, CBCT overcomes certain limitations of 2-dimensional imaging, such as distortion, magnification, and superimposition. However, CBCT lacks the detailed depiction of soft tissue conditions for evaluation of pathologic conditions, head and neck infections, and temporomandibular joint (TMJ) disc evaluation. This review evaluates the evidence-based research supporting the application of CBCT in the various fields of oral and maxillofacial surgery, including dentoalveolar surgery, dental implants, TMJ, orthognathic surgery, trauma, and pathology, and will assess the value of CBCT in pre-operative assessment, surgical planning, and post-operative analysis when applicable. Additionally, the significant limitations of CBCT and potential areas for future research will be discussed.

Accuracy of linear measurements on CBCT images related to presurgical implant treatment planning: A systematic review

OBJECTIVE

The aim of this systematic review was to identify, review, analyze, and summarize available evidence on the accuracy of linear measurements when using maxillofacial cone beam computed tomography (CBCT) specifically in the field of implant dentistry.

MATERIAL AND METHODS

The search was undertaken in April 2017 in the National Library of Medicine database (Medline) through its online site (PubMed), followed by searches in the Cochrane, EMBASE, ScienceDirect, and ProQuest Dissertation and Thesis databases. The main inclusion criterion for studies was that linear CBCT measurements were performed for quantitative assessment (e.g., height, width) of the alveolar bone at edentulous sites or measuring distances from anatomical structures related to implant dentistry. The studies should compare these values to clinical data (humans) or ex vivo and/or experimental (animal) findings from a "gold standard."

RESULTS

The initial search yielded 2,516 titles. In total, 22 studies were included in the final analysis. Of those, two were clinical and 20 ex vivo investigations. The major findings of the review indicate that CBCT provides cross-sectional images that demonstrate high accuracy and reliability for bony linear measurements on cross-sectional images related to implant treatment. A wide range of error has been reported when performing linear measurements on CBCT images, with both over- and underestimation of dimensions in comparison with a gold standard. A voxel size of 0.3 to 0.4 mm is adequate to provide CBCT images of acceptable diagnostic quality for implant treatment planning.

CONCLUSIONS

CBCT can be considered as an appropriate diagnostic tool for 3D preoperative planning. Nevertheless, a 2 mm safety margin to adjacent anatomic structures should be considered when using CBCT. In clinical practice, the measurement accuracy and reliability of linear measurements on CBCT images are most likely reduced through factors such as patient motion, metallic artefacts, device-specific exposure parameters, the software used, and manual vs. automated procedures.

Gauging electrical properties of bone with a bioimpedance-sensing drill

OBJECTIVE

Multiple surgical procedures require drilling through bone to access underlying anatomy or for device placement. In dental applications, iatrogenic injury caused by accidental perforation of cortical bone into critical anatomy occurs in a significant number of dental implant procedures. Limited real-time sensing methods are available to guide clinicians while drilling through cancellous bone towards cortical interfaces. Early interface detection could prevent accidental damage to underlying anatomic structures. This study aims to demonstrate that electrical impedance spectroscopy can be integrated within a standard surgical drill to distinguish between bone types.

APPROACH

A custom bearing and insulated drill bit were designed to collect 10 cortical and cancellous impedance measurements from ex vivo femurs (2 pigs) and 80 bone measurements from in situ femurs (4 pigs). In the in situ study, two return electrodes (simulating a lip-clip and shoulder pad) were used to assess impedance differences associated with return electrode geometry.

MAIN RESULTS

Significant ex vivo differences (p  <  0.05) between cortical and cancellous bone occurred in the real resistivity from 0.1 to 100 kHz and in the imaginary resistivity from 0.3 to 10 kHz, with a maximum cortical-to-cancellous impedance ratio of 1.48. Significant in situ differences (p  <  0.01) were observed in both real and imaginary resistivities from 0.1 to 100 kHz, with a maximum impedance ratio of 2.94. AUCs for classifying bone type based on the real resistivity ranged from 0.84 to 0.96 for ex vivo bone and 0.98 to 1.0 for in situ bone. Mean differences between return electrode geometries were less than 5%.

SIGNIFICANCE

The significant cortical-to-cancellous contrast observed indicates this system's potential to provide real-time tissue differentiation during bone drilling procedures.

A retrospective study of the accuracy of template-guided versus freehand implant placement: A nonradiologic method

OBJECTIVE

The aim of this retrospective case study was to evaluate implant placement accuracy in inexperienced clinicians with use of a surgical guide template vs the freehand method for preoperatively planned implant position.

STUDY DESIGN

Oral implant therapy was performed by inexperienced dental practitioners (<20 implants placed) on eligible patients after cone beam computer tomography (CBCT)-based software planning. Two patients' groups were formed according to the surgical technique: guided and freehand implant placement. The casts used for the fabrication of reconstructions were scanned by using a 3-dimensional (3D) laser scanner, the implant positions were superimposed with preoperative planning data, and the 3D deviations were calculated.

RESULTS

Twenty adult patients were included in this retrospective study (20 guided and 21 freehand implant placements). Mean calculated deviations with use of a surgical guide template were significantly lower compared with those of the freehand method with regard to angulation (P = .002), apical position (P = .002), and basal position (P = .012). No significant differences in implant placement accuracy were detected between the groups according to the implant position (premolars/molars; upper jaw/lower jaw) (P > .05).

CONCLUSIONS

Computer-aided planning and the use of surgical guides in accordance with CBCT images may help inexperienced clinicians to place implants with high accuracy.

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.

Clinical outcomes and cost effectiveness of computer-guided versus conventional implant-retained hybrid prostheses: A long-term retrospective analysis of treatment protocols

BACKGROUND

Computer-guided systems were developed to facilitate implant placement at optimal positions in relation to the future prosthesis. However, the time, cost and, technique sensitivity involved with computer-guided surgery impedes its routine practice. The aim of this study is to evaluate survival rates and complications associated with computer-guided versus conventional implant placement in implant-retained hybrid prostheses. Furthermore, long-term economic efficiency of this approach was assessed.

METHODS

Patients were stratified according to implant placement protocol into a test group, using computer-guided placement, and a control group, using traditional placement. Calibrated radiographs were used to measure bone loss around implants. Furthermore, the costs of the initial treatment and prosthetic complications, if any, were standardized and analyzed.

RESULTS

Forty-five patients (149 implants in the test group and 111 implants in the control group) with a minimum follow-up of 5 years, and a mean follow-up of 9.6 years, were included in the study. While no significant difference was found between both groups in terms of biologic and technical complications, lower incidence of implant loss was observed in the test group (P < 0.001). A statistically significant difference in favor of the non-guided implant placement group was found for the initial cost (P < 0.05) but not for the prosthetic complications and total cost (P > 0.05).

CONCLUSIONS

Computer-guided implant placement for an implant-supported hybrid prosthesis is a valid, reliable alternative to the traditional approach for implant placement and immediate loading. Computer-guided implant placement showed higher implant survival rates and comparable long-term cost to non-guided implant placement.

Freehand Versus Guided Surgery: Factors Influencing Accuracy of Dental Implant Placement

INTRODUCTION

Patient anatomy, practitioner experience, and surgical approach are all factors that influence implant accuracy. However, the relative importance of each factor is poorly understood. The present study aimed to identify which factors most critically determine implant accuracy to aid the practitioner in case selection for guided versus freehand surgery.

METHODS

One practitioner's ideal implant angulation and position was compared with his achieved position radiographically for 450 implants placed using a conventional freehand method. The relative contribution of 11 demographic, anatomical, and surgical factors to the accuracy of implant placement was systematically quantified.

DISCUSSION

The most important predictors of angulation and position accuracy were the number of adjacent implants placed and the tooth-borne status of the site. Immediate placement also significantly increased position accuracy, whereas cases with narrow sites were significantly more accurate in angulation. Accuracy also improved with the practitioner's experience.

CONCLUSION

These results suggest tooth-borne, single-implant cases performed later in the practitioner's experience are most appropriate for freehand placement, whereas guided surgery should be considered to improve accuracy for multiple-implant cases in edentulous or partially edentulous sites.

Accuracy evaluation of computer-designed surgical guide template in oral implantology

OBJECTIVE

The purpose of this study was to assess the accuracy of implant placement using surgical guide templates, and to compare the results with implant placement based on computer-aided design (CAD) planning merely.

MATERIAL AND METHODS

A total of 60 patients with dentition defects were included in our study, who were equally divided into group I and group II. Preoperative cone beam computed tomography (CBCT) was performed and preoperative planning was designed with Simplant software for all 60 patients. A total of 52 implants were placed in group I patients based on the preoperative planning without surgical guide templates. Implant surgical guide templates for group II patients were designed and produced by a rapid prototyping (RP) technique. A total of 57 implants were inserted in group II patients with the assistance of surgical templates. Postoperative CBCT was performed for all 60 patients. Image registration was carried out between postoperative CBCT data and that of preoperative planning data. Deviations of the implant between the actual and planned positions were measured and compared.

RESULTS

There was no significant structure damage during the surgery. Osseointegration was achieved in all implants, and both soft and hard tissues around implants were stable. Variation at the implant shoulder in group II was 1.18 ± 0.72 mm, apex 1.43 ± 0.74 mm, angulation 4.21 ± 1.91 mm, and depth 0.54 ± 0.29 mm, whereas the variation in group I was 2.07 ± 0.51 mm (P < 0.01), 2.89 ± 1.02 mm (P < 0.01), 8.84 ± 4.64 mm (P < 0.05), and 0.78 ± 0.33 mm (P > 0.05).

CONCLUSION

The use of surgical guide templates can achieve higher precision and accuracy in implant shoulder, apex, and angulation, which is much more suitable for complicated procedures and conditions such as the flapless method, immediate loading, aesthetic restoration, and insufficient bone height.

Cone beam computed tomography: basics and applications in dentistry

The introduction of cone beam computed tomography (CBCT) devices, changed the way oral and maxillofacial radiology is practiced. CBCT was embraced into the dental settings very rapidly due to its compact size, low cost, low ionizing radiation exposure when compared to medical computed tomography. Alike medical CT, 3 dimensional evaluation of the maxillofacial region with minimal distortion is offered by the CBCT. This article provides an overview of basics of CBCT technology and reviews the specific application of CBCT technology to oral and maxillofacial region with few illustrations.

Analyses of anatomical relationship between mandibular third molar roots and variations in lingual undercut of mandible using cone-beam computed tomography

Background/purpose

Anatomical features of the lingual undercut region is a potential factor that might increase the risk of displacement of a tooth or fragment. The aim of this study was to report the normal anatomical relationship of impacted lower third molar roots to the lingual cortex and soft tissues of mandible and anatomical variations of lingual balcony in the impacted third molar region.

Materials and methods

One hundred impacted third molars (54 males, 46 females) from 65 (31 men, 34 women) patients were evaluated for this study using cone-beam computed tomography. Three measurements [bone thickness, angle (Ang) 1 and Ang 2] were recorded on the coronal section slices of cone-beam computed tomography images; in these images, the impacted third molar root was closest to the lingual soft tissues.

Results

The average distance between the tooth root and the lingual outer cortical bone layer (bone thickness) was 1.03 mm. The averages of Ang 1 and Ang 2 were 140.61° and 153.44°. Ang 1 and Ang 2 of female patients were larger than those of male patients.

Conclusion

The narrow angulation of the lingual balcony region and the relationship between roots and lingual soft tissues should be noted to avoid undesirable complication of displacement of a tooth or fragment into sublingual, submandibular, and pterygomandibular spaces. There was no relation in the floor of the mouth between the position of the impacted third molar roots and different lingual undercut angulation variations.

Topographic analysis of the maxillary premolars relative to the maxillary sinus and the alveolar bone using cone beam computed tomography

OBJECTIVE

The purpose of the present study was to elucidate the anatomic characteristics of the maxillary premolars for the planning of dental treatment using cone beam computed tomography (CBCT).

STUDY DESIGN

CBCT images were obtained for 150 maxillary premolars in 68 patients. The internal angle formed by the long axis of the maxillary premolars and the long axis of the alveolar bone was evaluated on the cross-sectional images. The vertical relationships between the maxillary premolars and the maxillary sinus were classified into 5 categories. The bone width and internal angle were compared among the images classified into the 5 categories.

RESULTS

The internal angle was 25.5 ± 6.9° at the maxillary first premolars. The incidence of Type I in the maxillary first premolars was 46.7%. In the maxillary second premolars, the incidence of Type I (14.7%) was significantly lower than the total incidence of Types II, III, IV, and V (85.3%). Type I had the significantly largest internal angle (28.0 ± 7.7°) among all types for the maxillary first premolars.

CONCLUSION

When considering dental treatment in the maxillary premolars, one should observe the inclination of the maxillary premolars to the alveolar bone as well as the position of the inferior wall of the maxillary sinus.

Three-dimensional bio-printing equipment technologies for tissue engineering and regenerative medicine

Three-Dimensional (3D) printing technologies have been widely used in the medical sector for the production of medical assistance equipment and surgical guides, particularly 3D bio-printing that combines 3D printing technology with biocompatible materials and cells in field of tissue engineering and regenerative medicine. These additive manufacturing technologies can make patient-made production from medical image data. Thus, the application of 3D bio-printers with biocompatible materials has been increasing. Currently, 3D bio-printing technology is in the early stages of research and development but it has great potential in the fields of tissue and organ regeneration. The present paper discusses the history and types of 3D printers, the classification of 3D bio-printers, and the technology used to manufacture artificial tissues and organs.

Applications of Cone Beam Computed Tomography in Orthodontics: A Review

Cone Beam Computed Tomography (CBCT) is being extensively used in orthodontics for diagnostic and treatment planning, especially in complex clinical conditions. The objective of this study was to review the English language literature for current applications and trends of CBCT in orthodontic diagnosis and treatment. Several electronic databases were searched with the primary words: "orthodontics and radiography" and "cone beam computed tomography" or "CBCT." Abstracts that appeared to fulfill our inclusion criteria were selected, and the complete articles were obtained. Twenty-eight abstracts initially met our search criteria, and 12 were selected for the review. Ten articles were later added to the list after hand searching the references. It was concluded that there is a need for prospective randomized clinical trials to evaluate the risk/benefit ratio of CBCT, such as higher cost, greater risk for radiation dose (compared to digital panoramic and cephalograms) versus superior diagnosis and treatment outcomes.

Accuracy of computer-assisted implant placement with insertion templates

Objectives: The purpose of this study was to assess the accuracy of computer-assisted implant insertion based on computed tomography and template-guided implant placement.

Material and methods: A total of 246 implants were placed with the aid of 3D-based transfer templates in 181 consecutive partially edentulous patients. Five groups were formed on the basis of different implant systems, surgical protocols and guide sleeves. After virtual implant planning with the CoDiagnostiX Software, surgical guides were fabricated in a dental laboratory. After implant insertion, the actual implant position was registered intraoperatively and transferred to a model cast. Deviations between the preoperative plan and postoperative implant position were measured in a follow-up computed tomography of the patient’s model casts and image fusion with the preoperative computed tomography.

Results: The median deviation between preoperative plan and postoperative implant position was 1.0 mm at the implant shoulder and 1.4 mm at the implant apex. The median angular deviation was 3.6º. There were significantly smaller angular deviations (P=0.000) and significantly lower deviations at the apex (P=0.008) in implants placed for a single-tooth restoration than in those placed at a free-end dental arch. The location of the implant, whether in the upper or lower jaw, did not significantly affect deviations. Increasing implant length had a significant negative influence on deviations from the planned implant position. There was only one significant difference between two out of the five implant systems used.

Conclusion: The data of this clinical study demonstrate the accuracy and predictable implant placement when using laboratory-fabricated surgical guides based on computed tomography.

Clinical problems of computer-guided implant surgery

Background

The utilization of a cone-beam computed tomography (CT)-assisted surgical template allows for predictable results because implant placement plans can be performed in the actual surgery. In order to assess the accuracy of the CT-guided surgery, angular errors and shoulder/apex distance errors were evaluated by data fusion from before and after the placement.

Methods

Computer-guided implant surgery was performed in five patients with 19 implants. In order to analyze differences of the implant fixture body between preoperative planned implant and postoperative placed implant, angular error and distance errors were evaluated.

Results

The mean angular errors between the preoperative planned and postoperative placed implant was 3.84° ± 1.49°; the mean distance errors between the planned and placed implants were 0.45 ± 0.48 mm horizontally and 0.63 ± 0.51 mm vertically at the implant neck and 0.70 ± 0.63 mm horizontally and 0.64 ± 0.57 mm vertically at the implant apex for all 19 implants.

Conclusions

It is important to be able to utilize these methods in actual clinical settings by improving the various problems, including the considerations of patient mouth opening limitations, surgical guide preparation, and fixation.

Three-dimensional imaging and guided surgery for dental implants

Clinicians worldwide are increasingly adopting guided surgical applications for dental implants. Clinicians are becoming more aware of the benefits of proper planning through advanced imaging modalities and interactive treatment planning applications. All aspects of the planning phase are based on sound surgical and restorative fundamentals. As an integral part of the implant team, dental laboratories have now moved from analog to the digital world, providing the necessary support to the new digital workflow.

Computerized implant-dentistry: Advances toward automation

Advancements in the field of implantology such as three-dimensional imaging, implant-planning software, computer-aided-design/computer-aided-manufacturing (CAD/CAM) technology, computer-guided, and navigated implant surgery have led to the computerization of implant-dentistry. This three-dimensional computer-generated implant-planning and surgery has not only enabled accurate preoperative evaluation of the anatomic limitations but has also facilitated preoperative planning of implant positions along with virtual implant placement and subsequently transferring the virtual treatment plans onto the surgical phase via static (guided) or dynamic (navigated) systems aided by CAD/CAM technology. Computerized-implant-dentistry being highly predictable and minimally invasive in nature has also allowed implant placement in patients with medical comorbidities (e.g. radiation therapy, blood dyscrasias), in patients with complex problems following a significant alteration of the bony anatomy as a result of benign or malignant pathology of the jaws or trauma and in patients with other physical and emotional problems. With significant achievements accomplished in the field of computerized implant-dentistry, attempts are now been made toward complete automation of implant-dentistry.

Verification of the usability of a navigation method in dental implant surgery: in vitro comparison with the stereolithographic surgical guide template method

OBJECTIVE

This study investigates the usefulness of a navigation method using a reference frame directly fixed to the mandible compared to the stereolithographic (STL) surgical guide template method in dental implant surgery.

MATERIALS AND METHODS

Twenty rapid prototyping (RP) mandibular models were divided into two groups. Simulation surgery was performed using SimPlant software for both groups. The actual dental implants were placed in the RP models using a real-time navigation system or the surgical guide template, which was fabricated based on STL data by a 3-dimensional printer. Positional implantation errors were measured by comparing the simulation surgery implant positions to the actual postoperative implant positions.

RESULTS

The vertical distance error of the top surface area in the first molar region was not significantly different between groups. Otherwise, the implantation method using real-time navigation showed greater errors except for the horizontal and vertical errors in the apical area of the canine region.

CONCLUSION

The STL surgical guide template was associated with fewer errors than the real-time navigation method in dental implant surgery.