Combining cone-beam computed tomography scans, intraoral jaw scans, and facial scans allow modern dentistry the ability to accurately create a virtual patient. The enormous emphasis on digital full arch implant workflow has spawned vast innovation, opening the doors for practitioners to treat the terminally dentate and edentulous patients with more efficiency, precision, and satisfaction. As every patient presents with different conditions, protocols must be developed to facilitate an accurate virtual patient. These protocols must provide a direct match of the digital datasets to the patient.
Key points
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The transition from analog to digital workflows in dentistry has revolutionized dental records, prosthetic design, and treatment planning, improving outcomes for terminally dentate and edentulous patients.
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Intraoral scanning and cone-beam computed tomography (CBCT) are now standard tools in modern dentistry, significantly reducing the need for traditional impressions and improving diagnostic accuracy.
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3D facial scanning technology allows for the precise alignment of digital records, creating a virtual patient that enhances treatment predictability and efficiency.
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Digital workflows in full arch restorations improve patient outcomes by integrating facial scans, CBCT, and intraoral scans, leading to more accurate and aesthetically driven prosthetic designs.
Full arch dentistry challenges
Patients with terminal dentition or complete edentulism often seek dental solutions not merely for implants, but for prosthetic teeth that closely mimic the appearance, function, and comfort of natural teeth. , An oral health report in 2000 found that a well-functioning chewing system is crucial for allowing patients to consume nutritious foods, smile confidently, engage in social interactions without embarrassment, and enjoy an improved quality-of-life. According to the Centres for Disease Control and Prevention, over 36 million Americans are entirely edentulous, while 120 million are missing at least 1 tooth. Tooth loss can result from various causes including decay, gum disease, trauma, cancer, or wear. Approximately 90% of edentulous individuals experience problems with denture stability and retention, adversely affecting their quality-of-life. With an anticipated 200 million people requiring full arch fixed implant prosthetics within the next 15 y, the dental profession faces the challenge of delivering these solutions affordably, efficiently, and predictably. Addressing these needs necessitates the implementation of advanced, cost-effective, and streamlined digital workflows. The integration of 3-dimensional (3D) facially generated digital workflows represents a promising solution, which improves the predictability and efficiency of full arch dental surgery and prosthetics.
Analog versus digital prosthetic workflows
Analog Workflow: The primary role of the dental facebow is to assist the laboratory technician in accurately positioning denture teeth within the wax rim, ensuring that when the restoration is tried in the patient’s mouth, the teeth are correctly aligned with the patient’s facial features. However, this technique poses several challenges for laboratory technicians. Since the teeth are set in wax without direct facial orientation, a 2D photograph can be used as a reference, but it has limitations related to image quality and orientation. Additionally, translating data from the photo to the actual dental wax up can be unpredictable. The process requires meticulous execution by both the dentist and the laboratory technician, including proper facebow placement, registration records, impressions of the maxillary and mandibular arches, pouring and mounting of casts, capturing and mounting bite records, and setting the teeth according to the correct occlusal plane, curve of Spee, and buccal corridor spacing. Success in the wax try-in appointment depends heavily on precise coordination and skilled craftsmanship, making the workflow complex and challenging.
Digital Workflow: Digital technology transformation is significantly impacting various fields, including dentistry. Advanced digital tools, such as intraoral and facial scanners, and low-dose cone-beam computed tomography (CBCT), combined with sophisticated computer-aided design and manufacturing (CAD/CAM) software, are revolutionizing dental practices. Innovations in aesthetic materials and manufacturing technologies, like milling machines and 3D printers, further enhance this transformation. 3D facial scanning has been shown to serve as an effective alternative to the traditional analog facebow technique. The key advantage of the 3D facial digital workflow is the precise alignment of all digital records—CBCT, intraoral scans (IOS), and facial scans. By creating a virtual patient through facial scanning, clinicians can achieve precisely align the IOS and facial scan of the maxillary teeth. A digital bite record facilitates the mounting of maxillary and mandibular teeth. This alignment, when combined with CBCT data, creates a 1:1 digital replica of the patient. The digital workflow allows for thorough assessment of digital records before restoration design and manufacturing, resulting in improved diagnostic accuracy, enhanced communication between clinicians, laboratory technicians, and patients, and a more predictable and efficient treatment process for both surgical and restorative phases.
Facial Scanning Technology A facial scanner is a noninvasive tool that captures 3D facial models with accurate skin and tooth texture and color in a brief scanning process. Recent advancements have shown that 3D facial scanners offer significant benefits in dental clinics, where the detailed 3D models are used for precise diagnostics, treatment planning and manufacturing of full arch restorations. By integrating volumetric data from CBCT, facial scans and IOS, a comprehensive 3D virtual patient can be created ( Fig. 1 ). This virtual model enhances preoperative diagnosis, treatment planning, and overall patient outcomes. Compared to traditional 2D methods, 3D scanning provides superior accuracy and predictability, allowing for more detailed facial landmark identification and better visualization of treatment effects. The increased precision not only accelerates the treatment process but also improves facial aesthetics, profile accuracy, and the creation of a digital smile design, ultimately leading to more favorable and predictable results in fewer visits to the dental office. As a result, implementing a facially scanner into a complete digital workflow can help make these complex full arch cases more affordable to patients.
All facial scanners are not created equal and having all of the digital records align accurately within CAD software is determined by the level of accuracy the facial scanner provides. Hassan and colleagues published a pilot study where they combined IOS with 3 different facial scans. They found that there were inaccuracies both capturing the detail of the reference dentures, as well as aligning the 3 scans due to movement in the forehead. So, an accurate facial scanner is necessary to create a true virtual patient. Xabier Amezua’s study found the accuracy with which a maxillary digital scan is located with respect to a 3D face scan in a virtual facebow technique is strongly influenced by the facial scanning method used. The InstaRisa facial scan has the accuracy necessary to create a true virtual patient with the maxillary jaw mounted a virtual articulator. It was used in a study by Dr Revilla-Leon who used it as a reference scan to compare accuracy of maxillary cast transfer into a virtual semi-adjustable articulator between an analog facebow record and a digital photography technique. Accurate maxillary cast mounting is important for full arch aesthetic and functional restorations, especially when occlusal vertical dimension (OVD) will be changed ( Fig. 2 ). OVD plays a crucial role in shaping facial proportions and aesthetics by influencing the lower third of the face. A properly adjusted OVD is essential for achieving a balanced and harmonious facial appearance, as it affects features like lip support, chin projection, and overall facial height. Alterations in OVD can result in noticeable changes to facial aesthetics, which can impact a patient’s appearance and self-esteem. The correct OVD provides necessary support to the facial soft tissues, including the lips and cheeks, helping to maintain the natural contour and fullness of the face. This, in turn, prevents the sunken or aged appearance that often accompanies a reduced vertical dimension. In addition, the use of accurate facial scanners for bite records is useful for full arch implant cases, since many cases involve partially edentulous patients who have a collapsed OVD, which requires to be increased for an improved aesthetic and functional outcome. The field of view for a facial scanner is larger (30×12 cm) than that of an IOS (2×2 cm), which allows for the upper and lower jaws to be scanned within one frame, which minimizes stitching errors that may occur with a smaller IOS field of view. The IOS smaller field of requires more frames to be stitched to capture a bite record, which can be challenging when multiple teeth are missing in the quadrant since there is not anything to stitch the upper and lower jaw relationship.
Once the virtual patient is established, the planning for bone reduction required for an FP3 fixed restoration can be precisely tailored based on the maxillary and mandibular lip positions. To determine the necessary maxillary bone reduction, the patient is instructed to perform a Duchenne smile, which reveals maximum gingival display. For mandibular bone reduction, the patient is asked to say, “shhhh,” which similarly shows the extent of gingival exposure. Scanning the face during these specific lip positions aids in assessing the bone reduction needed to conceal the transition line—defined as the junction between the prosthesis and the soft tissue over the residual ridge. Identifying the transition line is crucial for planning the final prosthesis, as it allows for leveling of the alveolar crest, thus creating an optimal bone architecture that ensures sufficient bone width and adequate inter-arch space for the restoration and implant placement. Determining the amount of bone reduction in direct relationship to the lip position can now be determined by evaluating and measuring on the virtual patient can now be visualized ( Fig. 3 ). Bone reduction can be accomplished through both free-handed and digitally-designed surgical guide methods, to achieve the desired bone levels and align with the intended implant positioning and restorative outcomes. Maximizing the diagnostic and treatment planning value of 3D facial scanning technology can help improve clinical outcomes predictably.
Introduction to the InstaRisa digital full arch workflow The InstaRisa workflow facilitates the creation of a facially driven smile design that seamlessly combines ideal aesthetics with functional requirements. This innovative approach enhances patient engagement by providing a realistic preview of the final restoration outcome design in 3 facial expressions (Duchenne smile, natural smile, and repose), eliminating uncertainties commonly associated with traditional analog and 2D photography simulation methods. For the first time, clinicians can confidently commit to having the final restoration outcome match the smile design preview. This allows patients to offer feedback and request modifications before treatment begins. With the InstaRisa 3D facial digi,tal workflow, patients experience a more predictable, efficient, and satisfactory result where the final restorations align precisely with the initial digital smile design preview. The InstaRisa digital full arch workflow represents a cutting-edge approach in dental prosthetics by harnessing the full potential of connecting advanced technologies, including CBCT, IOS, CAD, 3D printers and milling, and 3D facial scanners. Central to this workflow is the use of an accurate 3D facial scanner, which integrates CBCT and IOS data to create a precise 1:1 digital representation of the patient. This comprehensive digital model allows clinicians to employ an outside-in treatment planning approach based on the facial features such as jaw positions, lip contours, teeth orientation, and gum levels. Facial features are thoroughly evaluated in order to generate a customized digital smile. Once the smile design is approved, implant placement is planned accordingly for optimal implant placement in relationship to the final restoration design. Once implants are placed and multiunit abutments (MUA) are torqued, precise implant placement is captured digitally with an IOS utilizing the InstaRisa ScanDAR technique. This technique is an alternative method to photogrammetry for capturing implant position for passive fitting full arch implant restorations. The InstaRisa component assembly stack includes: intaglio attachment (MUA analog), FP3/FP1 healing abutment, and short/tall scan body. Scan bodies are designed are with a retentive feature to stabilize ScanDAR. ScanDAR is a registration material that is placed around each scan body and attached to the neighboring scan body to facilitate IOS tracking and stitching ( Fig. 4 ). It has optimal properties for clinical usage that include: shore hardness of 90 which prevents movement while scanning, blue matte color to ease scanning, creates stable topography in between each scan body that facilitates stitching while scanning and fully sets within 45 sec to expedite the technique. Capturing the soft tissue record of the healing abutments during surgery can be done by either a blue putty impression or an IOS scan. The soft tissue and implant position records are aligned to the 3D facially generated smile design and a full arch restoration is manufactured by 3D printing or milling. In summary, the InstaRisa digital workflow is a complete system for full arch, which starts with a 3D facially generated smile design that is surgically planned then executed with a full arch passive fitting restoration.
Phase 0 intake records
The goal for Phase 0 intake records is to acquire and accurately align data from intraoral scanner, CBCT machines, facial scans, and if desired 2D photography. The data must be recorded with the patient in centric relation (CR) and the desired vertical dimension of occlusion (VDO) for rehabilitation. As pre-extraction and post-extraction measurements of VDO can be difficult to pinpoint, digitizing the records allows for the practitioner to establish a median of the anticipated range. At a later step, the practitioner may opt to increase or decrease the VDO in CAD software. For a properly digitized patient, the facial scans, IOS, and CBCT must all be recorded at this same VDO. The InstaRisa workflow categorizes patients into the following groups based on the state of the dentition:
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Fully dentate
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Partially dentate with fewer than 2 missing posterior teeth in each quadrant
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Partially dentate with more than 2 missing posterior teeth in each quadrant
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Well-fitting partial denture
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Ill-fitting partial denture
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No partial denture
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Fully edentulous
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Well-fitting denture
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Ill-fitting denture
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No denture
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Group 1 and 2 intake records appointment
The fully dentate patient pre-operative records appointment begins with scanning the maxillary and mandibular arches following the ideal scan path. The clinician then uses ScanDAR to make a bite registration at the determined VDO and at CR. Methods to achieve this include leaf gages, lucia jigs, manual and bimanual manipulation techniques, and so forth. Once the bite registration is completed, the ScanDAR record is trimmed such that the buccal cusp tips are all visible on the maxillary and mandibular teeth. Next the record is reinserted into the mouth and the bite scan is completed with the intraoral scanner. This method ensures that the patient’s jaws were in the same place while scanning the right and left sides. From here the InstaRisa facial scans are completed. The bite registration remains in the mouth for the retracted and Duchenne smile scans. It may be removed for the natural and repose facial scans. After the facial scans are complete, the patient’s CBCT is taken with the bite registration in place. This additional step allows the clinician to visualize the condyles and offers the opportunity to use the CBCT workflow for postsurgical alignment.
Group 3 and 4 intake records appointment
When patients are missing more than 2 posterior teeth, relying on the intraoral bite scans without reference objects becomes inaccurate. Reference objects may be dentures, partial dentures, or bite registration material. The appliances are scanned independently and serve as the common alignment mesh in the CAD software. For a patient with a well-fitting partial denture or denture, the prosthetic is relined with a medium and light body wash to pick up detail of the soft tissue. For a complete denture patient, the relined denture is scanned using the 360° scan technique with an intraoral scanner or a desktop scanner. This scan serves as both a tooth reference, as well as a jaw scan, assuming all the proper landmarks were accurately recorded. For the partial denture, it is recommended to scan the relined prosthetic separately, the jaw without the prosthetic in place, and the jaw with the prosthetic in place. Completing these scans allows the CAD technician multiple opportunities to properly align the mesh files. In the case of ill-fitting dentures and partial dentures, the prostheses may either be modified with border molding techniques or the clinician may decide to use the putty technique. Once the prostheses are correctly modified and relined, the clinician follows the same steps for jaw relation as in Groups 1 and 2.
The putty technique is reserved for patients without dentures or partial dentures. Fast set putty is mixed together and adapted to the upper and lower jaws at the prescribed VDO and at CR. For this technique, the clinician must help guide the patient into this position. The VDO gage is a helpful tool to accomplish this record. The putty is molded to simulate lip support in the fully edentulous patient or for Kennedy Class IV patients. As the putty registration is also used in the facial scan as a reference object, it is helpful to make some dimples in the buccal surface before the putty sets fully. These dimples serve as alignment geometries. Once the putty record is completed, it is scanned using the 360 scan technique with an intraoral scanner or a desktop scanner. The putty is left in the mouth for all facial scans, since removing it will alter the lip support and contribute to a less accurate predesign. If desired, the putty may also serve as a scan appliance for dual scan techniques if a surgical guide is desired. It is recommended to insert fiducial beads if the clinician wishes to use a dual scan workflow. For this technique, taking the CBCT with the putty in place is even more critical as the clinician is relying on manual manipulation of the patient into the putty bite. To repeat, the clinician is able to visualize the condylar positions on the CBCT only if the patient is in the same jaw position as the other digital records.
Prosthetic presurgical design
The CAD technician’s role in full arch implant rehabilitations must not be undervalued. The first task is to accurately align all the data acquired at the preoperative records appointment. The IOS, facial scans, and CBCT image are all aligned to create the virtual patient. From this point, the CAD technician may begin the facially driven prosthetic design. Designers are able to choose from a wide selection of tooth libraries to make a truly custom smile design.
Surgical planning
Successful outcomes require meticulous surgical planning. From a prosthetic standpoint, one of the most critical components is proper bone reduction. Carl Misch classified fixed implant prosthetics into 3 groups: FP-1, FP-2, and FP-3. As FP-1 and FP-2 cases allow for a visible prosthetic interface, bone reduction must correctly follow the desired ovate pontic position. FP3 cases require the lip to completely cover the prosthetic transition line at all times. In all 3 prosthetic designs, proper preoperative records are critical in determining proper bone reduction. Traditionally, clinicians would use 2D photography to communicate the high lip position to the laboratory technicians. While this is helpful, the alignment of a 2D photograph to a 3D digital model leaves room for error as the photograph must be resized and perspective is adjusted.
Using a 3D facial scanner allows a technician to design the prosthesis before surgery with extreme accuracy as the prosthesis relates to the patients face. With the facial scan, the alignment of 3D facial scan to 3D intraoral scan is a 1:1 alignment. The patient is scanned while holding 4 different poses: lip retracted, Duchenne smile, natural smile, and repose. Using this series of facial scans, the technician may toggle between each facial expression while designing the prosthesis. In this technique, the maxillary and mandibular prostheses are able to be designed in their entirety to the desired midline, occlusal plane, tooth length, and transition line using the facial scans as though the patient is present. When the prosthetic design is completed, the surgeon may then plan the implant position in a truly facially and prosthetically driven protocol.
Presurgical records
Before surgery begins it is critical to obtain IOS that accurately capture the jaws and a reference object that will be present throughout surgery. This object may be a tooth, a screw, soft tissue, and so forth. Hard reference objects are best as they do not move throughout surgery. The Artificial Reference Screw (ARS) is a novel design that allows a rigid bone screw that allows for a scan body. The ARS is placed in the palate of the maxilla or the mental symphysis of the mandible. It is recommended that only the area of the ARS is anesthetized prior to taking the presurgical scan. Once the ARS is in place, the jaw is scanned. This reference jaw scan will be used to link the intake record jaw scan to the post-surgical jaw scan. There is an alternative workflow using CBCT alignment that uses the segmented jaw as the reference marker. This technique will be discussed later.
Phase 1 surgical records
Intrasurgical Records
The next records acquisition is after implants have been placed and multiunit abutments seated. If using photogrammetry scan bodies, the time to place them is with the flap open so that complete seating may be visualized. The photogrammetry record is completed and an FP1 or FP3 cap replaces the photogrammetry scan body. If the IOS technique is employed, FP1 or FP3 caps are placed on the MUA. These caps are components that engage the MUAs to move the platform above the tissue. These caps are also attached with an open flap to enable visual seating. With the IOS technique, the flap may be closed when attaching the scan bodies in the postsurgical records acquisition.
Postsurgical Records
Following surgery, each jaw will still have the ARS in place along with the FP1 or FP3 caps. It is at this time that a final digital record of the gingiva and MUA caps are taken. The ARS scan body will align the gingiva to the presurgical IOS. If using InstaRisa’s workflow of scanning implant positions, it is at this time that the short scan bodies are placed and secured with ScanDAR. The presurgical IOS will align to the intake record scan. The final jaw record can be taken with an intraoral scanner; however, this scan may be difficult if there is a lot of mobile tissue and/or blood present. It is best to create a dry field in which to scan the postsurgical jaw scan. If the scan is still difficult, the clinician may opt to take a scannable impression.
Case Presentation #1
A patient with terminal dentition presented to the office needing full mouth rehabilitation. Patient elected for full arch maxillary FP1 and FP3 mandibular fixed restorations. The patient was missing all but 3 teeth on the lower arch; teeth numbers 21, 22, and 27 were present. The patient did not have a lower removable partial denture (RPD) to use as reference. The maxillary arch was mostly dentate with super-erupted posterior segments along with hypermobile anterior teeth opposing the mandibular dentition ( Figs. 5–9 ). Intake records were taken using an intraoral scanner, facial scanner, desktop scanner, and a CBCT. In order to record the bite, the patient was guided into CR using chin point manipulation technique until lips gently contacted. This position was determined to be the physiologic rest position. A VDO gage was used to measure rest position. The gage was shortened 2 mm then used for the position of restablished VDO. Blue putty was mixed and adapted to the maxillary dentition. The patient was then manipulated using chin point technique until the jaws came into contact. The patient was carefully guided until the VDO gage reached the desired position. The patient was held at this position until the putty fully set. A facial scan with mouth retractors in place was taken of the blue putty in place ( Figs. 10 and 11 ). A full field of view CBCT was taken with the blue putty bite in place. Following the CBCT, IOS of upper and lower jaws were completed. The blue putty bite was scanned on a desktop scanner. To review, the putty bite was used to relate both the IOS and the CBCT allowing for overlap of data. A virtual patient was created from these digital records ( Figs. 12 and 13 ). With this digital information, the prosthetic design was completed along with the surgical plan ( Fig. 14 ). A pontic guide was designed and printed to guide pontic site bone and root bank scalloping ( Figs. 15–17 ). On the day of surgery, the patient was numbed in the mental symphysis and palatal midline areas prior to securing the ARSs ( Fig. 18 ). The maxillary surgery involved vital and nonvital root banking along with placing 6 axial implants that terminated in dense basal bone. The pontic guide was utilized to guide the preparation of the root banks, as well as the bone reduction. The bone and root was reduced to 3 mm from the pontic guide. Implant position was recorded using photogrammetry (iCAM). The mandibular arch was treated with traditional All-On-X (AOX) protocol with posterior implants in addition to the typical 4 implants between the foramen. For both jaws, the FP3 caps were utilized so that the case could be delivered next day ( Figs. 19 and 20 ).
