This article introduces the basic principles of virtually guided dental implant restoration in complex clinical scenarios. An effective workflow for digital dentistry in full-arch reconstruction applications is discussed and highlights cases in which virtual surgical planning has enabled dental rehabilitation complex dentoalveolar defects. This study also explores challenges and future directions within the field on virtual surgical planning in dental implantology.
Key points
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This article introduces the basic principles of virtually guided dental implant restoration in complex clinical scenarios.
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This article reviews an effective workflow for digital dentistry in full-arch reconstruction applications.
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This article highlights cases in which virtual surgical planning has enabled dental rehabilitation in complex dentoalveolar defects.
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This article explores challenges and future directions within the field of virtual surgical planning in dental implantology.
Introduction
Computer-assisted surgical planning, or “virtual surgical planning” (VSP), is an innovative tool utilized for oral and facial reconstruction. Patients who have suffered from trauma, pathology, dentofacial deformity or severe and debilitating resorption of the facial bony skeleton can benefit from treatment planning with this precise and accurate technology. This study describes the use of computer-assisted surgical planning and a team approach for rehabilitation of form and function in complex cases. Of note, in these complex cases, a patient’s chief concern is often dental rehabilitation.
The goal of oral and facial reconstruction is to restore cosmetic skeletal balance and esthetics and proper function of the oral cavity. Using an accurate prosthetic-driven approach, endosseous dental implants can be surgically placed in the ideal position that is optimal for the final prosthetic result. The objective of the upcoming study is to provide an in-depth exploration of VSP in the context of full-arch implantology. The content will be presented in a simple, logical, and sequential format analogous to the “digital workflow,” facilitating the application of the concepts discussed.
Fundamentals of virtual surgical planning
VSP has emerged as a transformative technology in full-arch dental implantology, revolutionizing the way complex implant procedures are planned and executed. The evolution of VSP in this field can be traced back to the early 2000s when advancements in computer technology and imaging modalities paved the way for its development and widespread adoption.
Initially, VSP in dental implantology was primarily used for single implant placements and simple prosthetic restorations. However, with the increasing demand for full-arch rehabilitations and the complexity of such cases, researchers and clinicians recognized the potential of applying VSP to optimize treatment outcomes in these challenging scenarios.
One of the seminal studies that contributed to the evolution of VSP in full-arch implantology is the work by Van Assche and colleagues, which demonstrated the accuracy and clinical benefits of using computer-guided surgery for full-arch implant-supported prostheses. The study highlighted the improved predictability, precision, and efficiency of implant placement achieved through VSP, leading to enhanced esthetic and functional results for patients. Subsequent research by Arisan and colleagues further emphasized the advantages of VSP in full-arch implantology, highlighting the ability of computer-assisted planning to reduce surgical complications, decrease treatment time, and enhance patient satisfaction. The study underscored the importance of interdisciplinary collaboration and digital workflows in maximizing the benefits of VSP for comprehensive full-arch rehabilitations.
In conclusion, the historic evolution of VSP in full-arch dental implantology has been marked by a progressive shift toward personalized, data-driven, and technology-enabled approaches to treatment planning and execution. Through ongoing research, innovation, and clinical validation, VSP is poised to continue shaping the future of implant dentistry, offering novel solutions for complex cases, and raising the standard of care in full-arch rehabilitation.
Virtual surgical planning full-arch dental implant workflow
VSP is now routinely incorporated into treatment planning for full-arch rehabilitation. We will now propose a step-by-step approach to planning such cases.
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Step 1. Preoperative records. The initial digital workflow includes a cone beam computed tomographic (CBCT) scan of the patient’s facial skeleton and intraoral scans of the existing dentition. In edentulous patients, the dual scan technique in which the patient’s dentures (or acrylic stent) are modified with a minimum of 4 radiographic markers can be used. In this technique, the dentures (or stent) are first scanned independently in the CBCT. Then, they are correctly positioned in the patient’s mouth, with the patient occluding on a prefabricated bite registration, to ensure proper anatomic positioning. It is prudent to obtain clinical photos or to utilize extraoral scans during this step.
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Step 2. Data transfer. Next, diagnostic files of the patient’s dentition or predicted final restoration are superimposed on the dicom data of the patient’s existing maxillary and mandibular arches. Restorative digital planning is facilitated by programs such as Exocad.
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Step 3. Final teeth positioning and bone reduction. A comprehensive prosthetic and facial analysis are used to establish the prosthetic envelope. Once the prosthetic design is created by the technician, the provider can estimate the planned bone reduction in accordance with the type of prosthesis planned. Fixed prosthesis (FP1) type restorations require less bone reduction because they closely resemble a natural dentition. Bulkier FP2 and FP3 devices, however, will require more reduction. Accurate preoperative records allow the provider to assess bone height, quality of bone, geography of patient-specific bony defects, and location of vital anatomic structures. This enables virtual positioning and angulation of dental implants and reduces intraoperative placement errors and operating time. In addition, a precise surgical guide can be 3 dimensional (3D)-printed preoperatively and used intraoperatively to ensure placement and angulation of the implants in their virtually planned positions during the surgical procedure.
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Step 4. Placing “breadcrumbs.” Next, the intraoperative phase begins. Surgery begins with the placement of 2 positional screws in the central palate and 2 additional screws on the buccal aspects of the bilateral mandible. These screws will later serve as reference points, breadcrumbs , for digital impressions. Care must be taken not to manipulate these screws during the entirety of the procedure. After placement, an intraoral scan is obtained and sent to the laboratory technician.
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Step 5. Tooth extraction and alveolar bone reduction. Teeth are removed and the prefabricated surgical reduction guide is positioned to direct reduction in vertical bone height.
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Step 6. Implant placement. The prefabricated guide is seated on the alveolus or “stacked” on the pre-positioned reduction guide. The ideally positioned implant is not angulated too far facially as to violate the facial aspect of the prosthesis, but also not too far palatally as to avoid unnecessary palatal bulk. In some cases, prosthetically driven implants cause some degree of surgical compromise for which angulated abutments are often utilized. Of note, when placing the surgical guide, binding, rocking, or misfit usually indicates areas of insufficient reduction. After dental implant placement, planned multiunit abutments are positioned and path of withdrawal is verified.
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Step 7. Photogrammetry. Soft tissue flaps are then closed primarily. Abutments are temporarily replaced by scan bodies, or “flags” and implant positions are recorded via (handheld multi-camera unit that combines photogrammetric scanning and structured light to capture three-dimensional data [ICAM]). Next, the scan bodies are replaced by specific intraoral (IO) scan bodies, or “white caps,” and an IO scan is obtained to include both “white caps” and “breadcrumbs.” Scanned data are directly uploaded to the software and shared with the laboratory technician who will start to design the provisional prosthetics. White cap scan is aligned to breadcrumb scan, which is aligned to the step 4 preoperative scan, in which will be used to design the final provisional prosthetics.
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Step 8. Provisional prosthesis. A 3D-printed provisional is stained and cured. Options such as Optiglaze GC are widely available. This author recommends a ratio of 2:1:1, red:blue:red-brown, for reddish-pink gingiva, and 2:1:2, red:blue:red-brown for pigmented gingiva. Once satisfied, provisional prosthetics are delivered.
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Step 9. Final prosthesis. The final prosthesis delivery occurs about 4 to 6 months from the day of surgery. During this time, it is prudent to observe patient compliance with a non-chew diet and address any possible parafunctional habits prior to final delivery. It is also necessary to confirm appropriate occlusion and patient esthetic preferences during this time. In preparation for delivery, the provisional prosthetic is removed, and soft tissue healing is assessed. All the implant abutments and implants are also tested and verified to have at least 30 Ncm of torque force at this time. An IO scan of the underlying soft tissue and bite registration with the provisional is obtained. Once satisfied with the occlusion and esthetics, the final prosthesis is designed by the laboratory technician, milled, and delivered to the patient ( Fig. 1 A and B ).
Fig. 1 ( A, B ) Virtual surgical planning for complex dental rehabilitation. 44F presenting with severe generalized periodontal disease and class II, Div. 1 malocclusion, chief complaint, “I want new teeth”. ( a–d ) Preoperative clinical photos. ( e, f ) Preoperative soft tissue overlay. ( g, h ) Preoperative CBCT. ( i, j ) Preoperative intraoral photos, frontal and lateral views. ( k–n ) Virtual surgical planning of maxillary implants; quad zygomatic (#4, 6, 11, 13), bilateral pterygoid (#2, 15), and mandibular implants (#19, 21, 23, 25, 27, 30). ( o ) Immediate postoperative intraoral photo. ( p, q ) Approximately 6 week postoperative clinical photos. ( r ) Preoperative versus postoperative profile views comparing improvement in excessive overjet. ( s, t ) Postoperative CBCT and orthopantogram. ( u, v ) Overlay of postoperative imaging with the preoperative virtually planned zygomatic implants showing coincidental positioning of the guided implants.
Applications/case studies of virtual surgical planning in oral and maxillofacial surgery
VSP can be utilized in nearly any surgical context depending on the surgeon’s experience and comfort. In this section, some of the procedures in which VSP is utilized are reviewed with special emphasis on applications in the fields of head and neck trauma and pathology.
Facial Trauma Reconstruction
Maxillofacial trauma remains a major component of the practice of oral and maxillofacial surgery. In fact, the treatment of head and neck trauma during the First and Second World Wars and Korean and Vietnam wars allowed for the development of the specialty of oral and maxillofacial surgery (OMFS). VSP is especially helpful in cases of distorted patient anatomy such as though resulting from complex facial trauma. Application of VSP in combination with 3D printing in the treatment of the patient in trauma is still in its infancy but is evolving rapidly. As technology advances and becomes more widely accessible to the surgeon, the preoperative and postoperative care of these patients will continue to improve ( Fig. 2 A and B ).
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