A digital approach to the evaluation of mandibular position by using a virtual articulator

An overview of the different digital facebow methods for transferring the maxillary cast into the virtual articulator

OBJECTIVES

The purposes of this study were to classify the described digital facebow techniques for transferring the maxillary cast into the semi-adjustable virtual articulator based on the digital data acquisition technology used and to review the reported accuracy values of the different digital facebow methods described.

OVERVIEW

Digital data acquisition technologies, including digital photographs, facial scanners, cone beam computed tomography (CBCT) imaging, and jaw tracking systems, can be used to transfer the maxillary cast into the virtual articulator. The reported techniques are reviewed, as well as the reported accuracy values of the different digital facebow methods.

CONCLUSIONS

Digital photographs can be used to transfer the maxillary cast into the virtual articulator using the true horizontal reference plane, but limited studies have assessed the accuracy of this method. Facial scanning and CBCT techniques can be used to transfer the maxillary cast into the virtual articulator, in which the most frequently selected references planes are the Frankfort horizontal, axis orbital, and true horizontal planes. Studies analyzing the accuracy of the maxillary cast transfer by using facial scanning and CBCT techniques are restricted. Lastly, optical jaw trackers can be selected for transferring the maxillary cast into the virtual articulator by using the axis orbital or true horizontal planes, yet the accuracy of these systems is unknown.

CLINICAL IMPLICATIONS

Digital data acquisition technologies, including digital photographs, facial scanning methods, CBCTs, and optical jaw tracking systems, can be used to transfer the maxillary cast into the virtual articulator. Studies are needed to assess the accuracy of these digital data acquisition technologies for transferring the maxillary cast into the virtual articulator.

A digital workflow for full-mouth rehabilitation using CAD-CAM tooth reduction template

A digital workflow is presented for multiple transfers of targeted jaw relation and restorative spaces from interim to definitive restorations in patients with severe tooth wear. Following analysis of the targeted restorative space, segmented arch stereolithographic templates were digitally created and fabricated for precise control of reduction depth. Then, the jaw relation was transferred from the initially determined stabilization splint to the temporary fixed restoration and definitive restoration by using a digital articulator. This digital approach yielded a stabilized jaw relationship and restorative spaces transferring effect throughout successive stages of occlusal reconstruction resulting in satisfactory prosthetic outcomes.

A proposed novel digital condylar position adjustment technique to help restore a normal disc-condyle relationship

Objectives

To demonstrate a novel digital technique that enables real-time visualisation of occlusal transfer and adjustment of condyle position, to (1) improve the repeatability of occlusal transfer and the accuracy of condyle position adjustment and (2) be clinically effective in helping to restore the disc-condyle relationship.

Materials and methods

Three participants were included in the study and underwent facebow transfers using two different methods. The digital method used patient-related three-dimensional imaging data matched with digital dental casts for occlusal transfer. The conventional method used anatomical facebows. The condylar position was adjusted based on occlusal transfer results. The results were evaluated and compared in three dimensions. In addition, clinical application data from 36 patients were analysed before and after condylar position adjustment. Statistical significance was set at p < 0.05.

Results

Differences in the spatial positions of the three anatomical structures reproduced by both methods were statistically significant (p = 0.000). After adjusting the rotation of the condylar position, the positional deviation of the condylar point along the X- and Z-axes was significantly lower in the digital group (p < 0.05). After adjustment for translation (X and Z), the positional deviation showed no difference along the X- and Z-axes (p > 0.05) but a significant difference along the Y-axis (p < 0.001).

Conclusion

A novel digital technique for occlusal transfer and condylar position adjustment was presented. This technique simplifies clinical practice, improves the accuracy of results, and can help restore a normal disc-condyle relationship.

Digital application of three-dimensional diagnosis and treatment with a virtual articulator

OBJECTIVE

The purpose of this article was to introduce a method for the digital application of three-dimensional (3D) diagnosis and treatment with a virtual articulator and 3D data.

CLINICAL CONSIDERATION

With the use of cone-beam computed tomography (CBCT) and intraoral and facial scans, we can create a virtual articulator and evaluate the mandibular position in maximum intercuspation and centric-related occlusion for the patient with an unstable occlusion and temporomandibular disorders (TMD). Based on this, we treated a case using a digital mandibular position indicator (MPI) and fabricated a stabilization splint using a 3D printer. This approach eliminates the traditional impression or model mounting process and the analog face bow transfer. Furthermore, the design of the stabilization splint is accomplished using software.

CONCLUSIONS

The approach outlined in this article offers the potential for a digital diagnosis and treatment process by seamlessly integrating CBCT, intraoral scans, and facial scans with a high degree of accuracy. This may enhance precision in diagnosis and treatment planning, especially for patients with complicated TMD, in addition to facilitating effective communication with orthodontic patients who require thorough attention.

CLINICAL SIGNIFICANCE

Utilizing a virtual articulator and digital MPI for the occlusal evaluation of patients with TMD and unstable occlusion makes it possible to diagnose and analyze the occlusal condition accurately. This approach also allows for precision and efficiency in treatment.

Accuracy of the maxillary cast transfer into the virtual semi-adjustable articulator by using analog and digital facebow record methods

STATEMENT OF PROBLEM

Different digital methods have been described for transferring the maxillary cast into a virtual articulator; however, its accuracy remains uncertain.

PURPOSE

The purpose of this in vitro study was to compare the accuracy of the maxillary cast transfer into the virtual semi-adjustable articulator by using analog and digital methods.

MATERIAL AND METHODS

A maxillary typodont with 5 markers was positioned into a mannequin, which was digitized by using an industrial scanner (ATOS Q) and an extraoral scan of the typodont obtained (T710). Three groups were created based on the technique used to transfer the maxillary cast into the virtual articulator (Panadent PCH Articulator): conventional facebow record (CNV group), digital photograph (P group), and facial scanning (FS group) (n=10). In the CNV group, conventional facebow records (Kois Dentofacial analyzer system) were digitized (T710) and used to mount the maxillary scan into the articulator by aligning it with the reference platform (Kois adjustable platform) (DentalCAD). In the P group, photographs with the reference glasses (Kois Reference Glasses 3.0) were positioned in the mannequin. Each photograph was superimposed with the maxillary scan. Then, the maxillary scan was transferred into the virtual articulator by using the true horizontal plane information of the photograph. In the FS group, facial scans with an extraoral scan body (Kois Scan Body) were positioned in the mannequin by using a facial scanner (Instarisa). The extraoral scan body was digitized by using the same extraoral scanner. The digitized extraoral scan body provided the true horizontal plane information that was used to mount the maxillary scan into the articulator, along with the Kois disposable tray of the scan body. On the reference scan and each specimen, 15 linear measurements between the markers of the maxillary scans and the horizontal plane of the virtual articulator and 3 linear measurements between the maxillary dental midline and articulator midline were calculated. The measurements of the reference scan were used as a control to assess trueness and precision. Trueness was analyzed by using 1-way ANOVA followed by the pairwise comparison Tukey tests (α=.05). Precision was evaluated by using the Levene and pairwise comparisons Wilcoxon Rank sum tests.

RESULTS

No significant trueness (P=.996) or precision (P=.430) midline discrepancies were found. Significant posterior right (P<.001), anterior (P=.005), posterior left (P<.001), and overall (P<.001) trueness discrepancies were revealed among the groups. The P group obtained the best posterior right, posterior left, and overall trueness and precision. The P and FS groups demonstrated the best anterior trueness, but no anterior precision discrepancies were found.

CONCLUSIONS

The techniques tested affected the accuracy of the maxillary cast transfer into the virtual semi-adjustable articulator. In the majority of the parameters assessed, the photography method tested showed the best trueness and precision values. However, the maxillary cast transfer accuracy ranged from 137 ±44 µm to 453 ±176 µm among the techniques tested.

Accuracy comparison of the maxillary cast transfer into the virtual semi-adjustable articulator between an analog facebow record and a digital photography technique

STATEMENT OF PROBLEM

Digital photographs can be used for transferring the maxillary cast into the virtual semi-adjustable articulator; however, its accuracy remains unknown.

PURPOSE

The purpose of the present study was to compare the accuracy of the maxillary cast transfer into the virtual semi-adjustable articulator by using an analog and a digital standardized photography technique.

MATERIAL AND METHODS

A maxillary cast was digitized (T710) and positioned into a dental mannequin. The dental midline was not coincident with the facial midline and the maxillary occlusal plane was tilted. A reference scan of the assembled mannequin was obtained by using a facial scanner (Instarisa). Two groups were created based on the technique used to transfer the maxillary cast into the articulator (Panadent PCH): conventional facebow record (CNV group) or digital photograph (Photo group) (n=10). In the CNV group, facebow records (Kois Dentofacial analyzer system) were digitized (T710) and used to transfer the maxillary scan into the articulator by aligning it with the reference platform (Kois adjustable platform). In the Photo group, photographs with a reference glasses (Kois Reference Glasses) positioned into the mannequin were acquired. Each photograph was aligned with the maxillary scan. Then, the maxillary scan was transferred into the articulator by using the true horizontal axis information contained in the photograph. On the reference scan and each specimen, 10 linear measurements between the buccal cusps of the maxillary scan and the horizontal plane of the virtual articulator and a linear measurement between the maxillary dental midline and articulator midline were calculated. The measurements of the reference scan were used as a control to compute trueness and precision. Trueness was analyzed by using 1-way ANOVA followed by the pairwise comparison Tukey test (α=.05). Precision was evaluated by using the Levene and Wilcoxon Rank sum tests (α=.05).

RESULTS

The overall discrepancy measured in the CNV group was 0.620 ±0.396 mm, while in the Photo group it was 1.282 ±0.118 mm. Significant trueness differences were found in the midline (P=.037), anterior (P=.050), posterior right (P<.001), posterior left (P=.012), and overall discrepancy (P<.001) between the CNV and Photo groups. Significant precision discrepancies were found in the midline (P=.012), posterior right (P<.001), anterior (P<.001), posterior left (P=.002), and overall discrepancy (P<.001) between the CNV and Photo groups.

CONCLUSIONS

The facebow record method impacted the accuracy of the maxillary cast transfer. The Photo group obtained better trueness in the midline transfer than the CNV group; however, the CNV group demonstrated better trueness in the anterior, posterior right, posterior left, and overall discrepancy of the maxillary cast transfer compared with the Photo group. Overall, the Photo group obtained better precision than the CNV group.

Orthodontic treatment of an open bite after splint therapy for a patient with idiopathic condylar resorption

In the treatment of orthodontic patients with idiopathic condylar resorption, symptoms of temporomandibular joint disorders and constantly changing occlusions caused by an instability of mandibular position make it difficult for orthodontists to confirm definitive orthodontic diagnosis and treatment plans. Therefore, these patients' temporomandibular joint (TMJ) structures need to be stabilized with splint therapy before active tooth movement to identify and maintain the true mandibular position. For some idiopathic condylar resorption patients, orthognathic surgery can cause further resorption on the vulnerable condyles of the mandible; thus, effective orthodontic camouflage treatment after joint stabilization should be considered. During the orthodontic camouflage treatment, adverse loads on the TMJ structures, which could change the position of condyles, should be avoided, and TMJ-friendly mechanics must be applied.

Digital diagnostic occlusal equilibration combining an intraoral scanner, optical jaw tracking system, and dental design program: A dental technique

Patients with aberrant occlusal patterns, including constricted mastication patterns or occlusal dysfunction, may require occlusal equilibration. Conventional diagnostic procedures involve diagnostic stone casts mounted in the articulator. During diagnostic procedures, occlusal equilibration methods are simulated on mounted stone casts to analyze the amount of dental structure that may need to be removed. A technique to virtually simulate an occlusal equilibration procedure is described. Digital data acquisition procedures include diagnostic casts acquired using an intraoral scanner and the repeatable reference position of the mandible or centric relation, excursive movements, and the mastication pattern captured using an optical jaw tracking system. The jaw tracker and dental design programs are used to simulate the occlusal equilibration.

The Role of Digital Facebow for CAD/CAM Implant-Supported Crowns Workflow

Recent advancements in digital technologies have transformed clinical workflows in dentistry, ensuring precise restorations. Custom-made crowns and fixed partial dentures (FPDs) now rely on virtual articulation. The digital facebow provides individualized data for CAD settings, streamlining the fabrication via digital workflow. For the purpose of demonstrating the differences observed during fabrication, we present a case report involving a 68-year-old patient seeking a replacement for missing teeth 24, 25, 26, and 27. The treatment plan involved the fabrication of an implant-supported FPD using monolithic zirconia (ZrO2). However, technical hurdles emerged during the planning phase, primarily due to spatial limitations posing a risk of mechanical failure over time. Consequently, we pivoted approach towards a porcelain fused to metal (PFM) FPD. For the PFM FPD, individual values from the digital facebow adjusted both virtual and conventional articulators. For comparison, two ZrO2 FPDs were milled-individual settings and average settings. All restorations underwent assessment for occlusion in maximal intercuspal position and eccentric mandible movements. In conclusion, the case report showed that individualized PFM FPD required minimal adjustments compared to milled ZrO2 restorations, whether using individual or average values. Utilizing individual values from the digital facebow reduced operator working time and minimized the intraoral adjustments.

Virtual Dental Articulation Using Computed Tomography Data and Motion Tracking

Dental articulation holds crucial and fundamental importance in the design of dental restorations and analysis of prosthetic or orthodontic occlusions. However, common traditional and digital articulators are difficult and cumbersome in use to effectively translate the dental cast model to the articulator workspace when using traditional facebows. In this study, we have developed a personalized virtual dental articulator that directly utilizes computed tomography (CT) data to mathematically model the complex jaw movement, providing a more efficient and accurate way of analyzing and designing dental restorations. By utilizing CT data, Frankfurt's horizontal plane was established for the mathematical modeling of virtual articulation, eliminating tedious facebow transfers. After capturing the patients' CT images and tracking their jaw movements prior to dental treatment, the jaw-tracking information was incorporated into the articulation mathematical model. The validation and analysis of the personalized articulation approach were conducted by comparing the jaw movement between simulation data (virtual articulator) and real measurement data. As a result, the proposed virtual articulator achieves two important functions. Firstly, it replaces the traditional facebow transfer process by transferring the digital dental model to the virtual articulator through the anatomical relationship derived from the cranial CT data. Secondly, the jaw movement trajectory provided by optical tracking was incorporated into the mathematical articulation model to create a personalized virtual articulation with a small Fréchet distance of 1.7 mm. This virtual articulator provides a valuable tool that enables dentists to obtain diagnostic information about the temporomandibular joint (TMJ) and configure personalized settings of occlusal analysis for patients.

Virtual facebow techniques: A scoping review

STATEMENT OF PROBLEM

Although advances in technology continue to improve the acquisition of patient data and the manufacturing of different oral rehabilitations, the method of transferring clinical information to a virtual environment has not yet been consolidated in the literature.

PURPOSE

The purpose of this scoping review was to map the existing literature on different techniques of transferring information from virtual facebows for oral rehabilitation.

MATERIAL AND METHODS

This scoping review was structured using a 5-step methodology based on guidelines proposed by Arksey and O'Malley: (1) characterization of the research question, (2) identification of relevant studies, (3) selection of studies, (4) mapping of results, and (5) selection, summary and reporting of the data. The Joanna Briggs Manual for Evidence Synthesis was followed and the review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The guiding question for the development of this review was, "What virtual facebow techniques are being used to transfer anatomic data to the virtual environment?"

RESULTS

A total of 1745 articles were found during the search, and 20 were included in this review. Nineteen of the included articles had positive results with the described techniques of registration and transfer of anatomic references to the virtual environment; however, 1 study indicated that the technique was negative.

CONCLUSIONS

Based on the findings, facial scanning, 2-dimensional photographs, and cone beam computed tomography are feasible methods of acquiring extraoral anatomic landmarks. The use of a device that allows the convergence of intraoral and extraoral images by superimposing data was revealed to be a promising option.

Chairside virtual patient protocol. Part 3: In vitro accuracy of a digital facebow

OBJECTIVES

The present study aimed to investigate the trueness and precision of an intraoral transfer element (IOTE) designed for matching intraoral and facial scans.

METHODS

A mannequin head with a maxillary model in position was used. Cone beam computed tomography (CBCT) was used to construct the master model (MM). A digital impression of the maxillary arch was taken using an intraoral scanner, and the IOTE was used to record the maxillary arch position. Twenty facial scans with and twenty without the IOTE in place were performed with a handheld device (Ipad Pro, Apple) using a dedicated software. Digital mounting was performed to build a scan model (SM). Using software for data processing, the three-dimensional deviation between the MM and SM at the central left incisor (#9#), and the left and right first molars (#3#, #14#) was calculated as trueness and linear deviation precision. . Angular deviation was also calculated at the occlusal plane.

RESULTS

The linear deviation trueness at #9#, #3# and #14# was 0.3 ± 0.12 mm, 1.07 ± 0.28 mm, and 0.18 ± 0.34 mm, respectively, whereas the precision was 1.17 ± 0.4 mm, 0.43 ± 0.12 mm, and 0.64 ± 0.28 mm, respectively. Trueness of the angular deviation at the occlusal plane was 2.17 ± 0.46°, whereas the angular deviation precision was 0.64 ± 0.28°.

CONCLUSIONS

Based on in vitro findings the proposed IOTE design is accurate and suitable for clinical use.

CLINICAL SIGNIFICANCE

Direct virtual mounting is a reliable technique in vitro; however, in vivo tests are required.

Comparison of the performance of various virtual articulator mounting procedures: a self-controlled clinical study

OBJECTIVES

This clinical study aimed to compare the performance of various virtual articulator (VA) mounting procedures in the participants' natural head position (NHP).

MATERIALS AND METHODS

Fourteen participants with acceptable dentitions and jaw relationships were recruited in this study registered in the Clinical Trials Registry (#NCT05512455; August 2022). A virtual facebow was designed for virtual mounting and hinge axis measurement. Intraoral scans were obtained, and landmarks were placed on each participant's face to register the horizontal plane in NHP. Six virtual mounting procedures were performed for each participant. The average facebow group (AFG) used an indirect digital procedure by using the average facebow record. The average mounting group (AMG) aligned virtual arch models to VA's average occlusal plane. The smartphone facial scan group (SFG) and professional facial scan group (PFG) used facial scan images with Beyron points and horizontal landmarks, respectively. The cone-beam computed tomography (CBCT) scan group (CTG) used the condyle medial pole, and horizontal landmarks were applied. The kinematic facebow group (KFG) served as the control group, and a direct digital procedure was applied using a kinematic digital facebow and the 3D skull model. Deviations of the reference plane and the hinge axis between the KFG and other groups were calculated. The inter-observer variability in virtual mounting software operation was then evaluated using the interclass correlation coefficient (ICC) test.

RESULTS

In virtual condylar center deviations, the CTG had the lowest condylar deviations. The AFG showed larger condylar deviations than PFG, SFG, and CTG. There was no statistically significant difference between the AFG and the AMG and between the PFG and the SFG. In reference plane deviations, the AMG showed the largest angular deviation (8.23 ± 3.29°), and the AFG was 3.89 ± 2.25°. The angular deviations of PFG, SFG, and CTG were very small (means of each group < 1.00°), and there was no significant difference among them. There was no significant difference between the researchers, and the ICC test showed moderate to excellent reliability for the virtual condylar center and good to excellent reliability for the reference plane in the operation of the virtual mounting software.

CONCLUSIONS

CBCT scan provided the lowest hinge axis deviation in virtual mounting compared to average mounting, facebow record, and facial scans. The performance of the smartphone facial scanner in virtual mounting was similar to that of the professional facial scanner. Direct virtual mounting procedures using horizontal landmarks in NHP accurately recorded the horizontal plane.

CLINICAL RELEVANCE

Direct digital procedures can be reliably used for virtual articulator mounting. The use of a smartphone facial scanner provides a suitable and radiation-free option for clinicians.

Four-Dimensional Superimposition Techniques to Compose Dental Dynamic Virtual Patients: A Systematic Review

Four-dimensional virtual patient is a simulation model integrating multiple dynamic data. This study aimed to review the techniques in virtual four-dimensional dental patients. Searches up to November 2022 were performed using the PubMed, Web of Science, and Cochrane Library databases. The studies included were based on the superimposition of two or more digital information types involving at least one dynamic technique. Methodological assessment of the risk of bias was performed according to the Joanna Briggs Institute Critical Appraisal Checklist. Methods, programs, information, registration techniques, applications, outcomes, and limitations of the virtual patients were analyzed. Twenty-seven full texts were reviewed, including 17 case reports, 10 non-randomized controlled experimental studies, 75 patients, and 3 phantoms. Few studies showed a low risk of bias. Dynamic data included real-time jaw motion, simulated jaw position, and dynamic facial information. Three to five types of information were integrated to create virtual patients based on diverse superimposition methods. Thirteen studies showed acceptable dynamic techniques/models/registration accuracy, whereas 14 studies only introduced the feasibility. The superimposition of stomatognathic data from different information collection devices is feasible for creating dynamic virtual patients. Further studies should focus on analyzing the accuracy of four-dimensional virtual patients and developing a comprehensive system.

An Indirect Digital Technique to Transfer 3D Printed Casts to a Mechanical Articulator With Individual Sagittal Condylar Inclination Settings Using CBCT and Intraoral Scans

With the widespread application of digital impression techniques in prosthetic dentistry, accurate intraoral scan mounting, and virtual articulator parameters setting as per patients' anatomic structures are essential for treatment planning and restoration fabrication, especially for complex rehabilitation cases; meanwhile, marginal fit checking, occlusal adjustment, and porcelain layering of restorations are also crucial procedures in all cases in which the analog procedure to mount maxillary arches on a mechanical articulator is still required. This technique article presents an indirect digital approach that can first achieve virtual intraoral scan mounting and sagittal condylar inclination value setting of an Artex virtual articulator based on bony structures provided by a single cone beam computed tomography scan. It then facilitates the transfer of virtually mounted intraoral scans from the virtual articulator to the matched Artex mechanical articulator by relating a digitally scanned mounting plate of the Artex mechanical articulator to the virtual articulator, printing the intraoral scan and mounting plate scan assembly, and then mounting the printed casts on the mechanical articulator based on the printed mounting plate. This technique eliminates the conventional facebow transfer and protrusive bite registration procedures and offers a straightforward approach for the seamless integration of virtual environments and analog workflows into clinical practice. It aids in the design of restorations that are harmonious with the mandibular movements and reduces chairside adjustment time.

ARTICULATOR APPLICATION IN ORTHODONTIC DIAGNOSTICS

OBJECTIVE

The aim: The purpose of the study was to determine the indications for the use of articulator in orthodontics based on the results of the analysis of scientific and foreign literature.

PATIENTS AND METHODS

Materials and methods: 23 scientific sources were selected, from more than 11 countries over the past 39 years (1981 - 2020) devoted to the use of orthodontics articula¬tors. As a result of processing 23 key international scientific papers on the use of articulators in orthodontics, we can talk about three areas of opinion regarding this problem.

CONCLUSION

Conclusions: To sum up 30.34% of authors consider the articulator to be an obligatory orthodontist's tool for correct diagnosis. The idea of 34.78% of specialists is that the articulator cannot simulate the physiology of the TMJ - therefore, it is more a source of additional errors than an assistant in the orthodontic diagnostics. The rest of the scientists (34.78%) agree that it is advisable to use the articulator selectively - namely, if the doctor deals with "complex" orthodontic pathologies.

Condylar repositioning according to digital bite registration method for virtual orthognathic surgery planning: A series of 49 consecutive patients

INTRODUCTION

The accurate mandibular condylar positioning for orthognathic surgical planning is fundamental in obtaining a planned occlusal result. The differences between the position of condyles seen on computed tomography or cone-beam computed tomography (CBCT) scans and during surgery reduce the accuracy of the result. This study aimed to assess the differences between the condylar position recorded on CBCT and a numerical 3-dimensional (3D) model created after mandibular repositioning for orthognathic surgery planning.

METHODS

This study retrospectively evaluated 49 patients who underwent virtual orthognathic surgery planning. The procedure involved recording a computed tomography or CBCT of the skull and dental surface using an intraoral digital scanner. The mandible was repositioned on the numerical 3D model according to the superimposed virtual bite registration in centric relation. Linear and angular measurements of the right and left condyles were recorded before and after mandibular repositioning.

RESULTS

The positions of 98 condyles were compared. Linear measurements of the posterior and superior joint spaces revealed a significant difference. Subgroup analyses displayed statistically significant differences for patients with skeletal Class II malocclusion.

CONCLUSION

According to the digital bite registration method, the difference between the mandibular position recorded on CBCT and on the numerical 3D model after repositioning may have clinical significance. Further studies are needed to validate this theory and test the accuracy of the clinical results.

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

Background

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

Methods

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

Results

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

Conclusion

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

Supplementary Information

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

Current Status of Digital Complete Dentures Technology

Fabrication of complete dentures (CDs) utilizing computer-aided design and computer-aided manufacturing (CAD/CAM) methods has attracted a lot of attention. The purpose of this paper was to summarize current knowledge about digital CDs and the relevant technology, and to present the application of the new technology in a dental geriatrics case. Initially, some of the challenges regarding digitization of the oral mucosa as a supporting surface of the CDs’ intaglio surface are listed. Next, a brief introduction of the CAD software capabilities regarding CDs is presented. The latest CAM additive and subtractive techniques for CDs are following. Subsequently, the consecutive steps for the construction of a digital CD as part of the prosthodontic treatment of a 90-year-old ambulative female patient are presented. Finally, some considerations about the digital workflow in CD manufacturing are discussed. In conclusion, the new digital technology has clear advantages; however, implementation requires careful planning. The digital workflow is applicable and versatile.

Additively manufactured scan body for transferring a virtual 3-dimensional representation to a digital articulator for completely edentulous patients

A technique is described for obtaining a virtual 3-dimensional representation of completely edentulous patients with the virtual definitive casts mounted on the virtual articulator. An additively manufactured intraoral scan body was developed to record the definitive maxillary and mandibular casts and gothic arch interocclusal registration. The intraoral scan body guided the integration of the digital definitive casts and facial scans to obtain the virtual 3-dimensional patient's representation and facilitated the transfer of the definitive casts to the virtual articulator.