Stabilization of a Computer‐Aided Implant Surgical Guide Using Existing Dental Implants with Conversion of an Overdenture to a Fixed Prosthesis

This clinical report describes a technique to stabilize a computer‐aided dental implant surgical guide to existing implants. A patient requested conversion of her existing mandibular implant‐assisted overdenture into a fixed complete denture. The surgical procedure was planned virtually, and the two existing dental implants were integrated into the surgical plan as a means to fixate the surgical guide. The implants were placed, and the patient's prosthesis was converted into an interim fixed complete denture.     

Zygomatic implants--protocol for immediate occlusal loading: a preliminary report.

PURPOSE: To investigate the modified protocol for immediate occlusal loading of the zygomatic implants and to report the preliminary results of this modified protocol. MATERIALS AND METHODS: Four male patients and 1 female patient with edentulous maxillae were consecutively treated with the zygomatic implants under general anesthesia. All 5 patients were examined by computed tomography and investigated by the SimPlant software (Materialise NV, Leuven, Belgium). Based on the virtual surgical plans, mucosa-supported surgical guides were manufactured by rapid prototyping technique before implant operation. Instead of making a Le Fort I Osteotomy incision or a crestal incision, buccal vestibular incision was used to expose the surgical site for the zygomatic implant osteotomy and placement. Three patients had their remaining upper teeth removed on the same day as implant placement. One patient had undergone simultaneous placement of upper and lower implants followed by immediate loading. The immediate loading protocol was a 2-stage method using a customized provisional fixed prosthesis. RESULTS: Ten zygomatic implants and 20 normal implants were installed in these 5 patients. These 5 patients were reviewed regularly for 6 to 10 months after immediate loading. The zygomatic implants were considered to be successful when they were asymptomatic with no clinical mobility and no sign of infection. All the zygomatic implants and normal implants were investigated individually after removing the provisional prosthesis and were found to be clinically stable and asymptomatic. CONCLUSION: According to our observation, immediate occlusal loading of the zygomatic implants has a very good potential for success, as much as immediate occlusal loading of normal dental implants. The surgical placement of the zygomatic implant is simplified and facilitated by making use of the computer-assisted planning and the rapid-prototyping surgical guides.     

Intraoperative computerized navigation for flapless implant surgery and immediate loading in the edentulous mandible

Computerized navigation surgery has evolved to facilitate minimally invasive procedures, the gold standard of surgery today. While flapless implant surgery may be clinically beneficial, it has generally been perceived as a blind procedure limited to straightforward cases that do not pose a risk of cortical plate perforation. The objective of this report is to describe a protocol for flapless implant placement in a completely edentulous mandible using computerized navigation surgery. The Image Guided Implantology system (IGI, DenX Advanced Dental Systems) is described. The IGI system provides real-time imaging of the dental drill and transforms flapless implant surgery into a fully monitored procedure. The highly accurate intraoperative navigation enables precise transfer of the detailed presurgical implant plan to the patient. This is particularly valuable in edentulous jaws lacking any indication of the dental arch. The accurate positioning of the implants, based on the presurgical digital plan, allows fabrication of a provisional fixed prosthesis before the implant surgery for immediate postoperative loading. This innovative protocol can enhance prosthodontic-driven placement of implants in a fully monitored flapless surgery.     

Image-guided navigation system for placing dental implants

Navigation-guided surgery has recently been introduced into various surgical disciplines, including oral and maxillofacial surgery. Since the advent of dental implants, dental computed tomography (CT) scans have been used as a diagnostic tool for preoperative planning, but not as part of the surgical phase. This article explains the principles of computer-assisted surgery and describes the use of a computer-guided navigation system in dental implantology. The system uses preoperative dental CT scans for planning and as an integral part of the surgical procedure. This system allows continuous intraoperative coordination of the implantation phase with the preoperative plan, optimizing the accuracy of implant surgery. Deviations from the planned location of the implants are minimal. Several cases are discussed.     

An implant versus a conventional fixed prosthesis: a case report

The success of endosseous implant dentistry is widely acknowledged. Clinical research and subsequent innovations with both surgical and restorative techniques--as well as improved surface features and restorative components--have made endosseous dental implants a routinely accepted dental treatment modality. Patients and referring clinicians often specifically request dental implant therapy. This article presents an example of such a patient; however, in this case, a surgical ridge augmentation and fabrication of a conventional fixed prosthesis was selected as the treatment modality. The authors believe that all therapeutic modalities should be considered when adapting appropriate treatment plans for individual patients.     

Surgical planning and prosthesis construction using computer technology and medical imaging for immediate loading of implants in the pterygomaxillary region

This report describes a protocol that uses computerized tomography (CT), computer-aided design/computer-assisted manufacture (CAD/CAM) technology, and the Internet to plan placement of anterior and posterior dental implants and construct a precise surgical template and definitive prosthesis, which is connected at the time of implant placement. This procedure drastically reduces surgical treatment time and the recovery period. Patients with an edentulous arch had a denture with radiopaque markers constructed for CT scans of the appropriate jaw. The CT images, with acquisition slices of 0.5 mm, were transferred into a three-dimensional image-based program for planning and strategic placement of dental implants. After implants were virtually placed on the computer, the surgical treatment plan was sent to a manufacturing facility for construction of a surgical template and the prosthesis, Special surgical guide components were also manufactured for placement of implants in the pterygomaxillary region. The manufactured surgical components, surgical template, and definitive prosthesis were then delivered to the clinical site. Implant placement surgery was performed using the surgical template, without a flap, and the prosthesis was delivered, achieving immediate functional loading. Minor occlusal adjustments were made. The total surgical treatment time required was less than 60 minutes. Postoperative symptoms, such as pain, swelling, and inflammation, were minimal. Identification of the bone in relationship to the tooth position via three-dimensional CT prior to surgery allows precise placement of implants. CAD/CAM technology using the three-dimensional images allows for fabrication of the surgical guide and final prosthesis. This is a significant advancement in implant dentistry and prosthodontics.     

Surgical planning and prosthesis construction using computed tomography, CAD/CAM technology, and the Internet for immediate loading of dental implants

This report describes a protocol that uses computer technology and medical imaging to virtually place anterior and posterior dental implants and to construct a precise surgical template and prosthesis, which is connected at the time of implant placement. This procedure drastically reduces patient office time, surgical treatment time, and the degree of post-treatment recovery. Patients with an edentulous arch or a partially edentulous area had a denture with radiopaque markers constructed for computed tomography (CT) scans of the appropriate jaw. The CT images, having acquisition slices of 0.4 mm, are transposed in a three-dimensional image-based program for planning and strategic placement of dental implants. After virtual implant placement on the computer, the surgical treatment plan is sent to a manufacturing facility for construction of the surgical template. The manufactured surgical components and surgical template arrive on the clinical site. From the surgical template, the dental laboratory retro-engineers the master cast, articulates it with the opposing dentition based on a duplicate of the scanning denture, and creates the prosthesis. Using the surgical template, minimally invasive surgery is performed without a flap, and the prosthesis is delivered, achieving immediate functional loading to the implants. Minor occlusal adjustments are made. The total surgical treatment time required is typically between 30 and 60 minutes. Postoperative symptoms such as pain, swelling, and inflammation are dramatically reduced. CLINICAL SIGNIFICANCE: Identification of the bone in relationship to the tooth position via three-dimensional CT prior to surgery allows the clinician to precisely place implants. Computer-aided design/computer-assisted manufacture technology using the three-dimensional images allows for fabrication of the surgical template. This is a significant advancement in implant dentistry and promotes interdisciplinary approaches to patient treatment. The implant surgeon and restorative dentist can agree upon implant locations and screw access locations prior to the surgical episode.     

Implant Supported Prosthesis After Ridge Augmentation Procedure by Distraction Osteogenesis for Atrophic Mandible

Rehabilitation of deficient alveolar ridges has long been a challenge. The distraction osteogenesis procedure before placement of dental implants has solved the puzzle and its advantages over block grafting includes simultaneous expansion of soft tissue, high degree of dimensional stability, abbreviated overall treatment time, and no graft required. In this case report distraction osteogenesis of deficient anterior mandibular ridge was performed and then an implant supported fixed prosthesis was fabricated.     

Removable partial denture design involving teeth and implants as an alternative to unsuccessful fixed implant therapy: a case report

Various dental implants have been used, and high success rates have been reported. However, as their uses increase, implant failures have been reported. There are partially edentulous patients with an initial treatment plan of an implant-supported fixed partial denture. At times, one or more strategic implants fail to osseointegrate. In situations where financial, systemic, or local conditions preclude the use of a fixed partial denture, a well constructed removable partial denture can be an excellent treatment alternative. It has been reported that prosthesis support can be improved with the use of osseointegrated dental implants, with improved preservation and maintenance of existing hard and soft tissues around dental implants. This article describes the prosthodontic rehabilitation of a partially edentulous patient by the use of a removable partial denture design involving teeth and implants as an alternative to unsuccessful fixed implant therapy. This treatment option solved a difficult clinical problem derived from the failure of two strategic implants and provided the patient with an esthetic and functional prosthesis.     

Evaluation of accuracy of computer-aided intraoperative positioning of endosseous oral implants in the edentulous mandible

The overall accuracy of a novel surgical computer-aided navigation system for placement of endosseous implants was evaluated. Five dry cadaver mandibles were scanned using high resolution computed tomography (HRCT). The position of four interforaminal dental implants was planned on the computer screen and transferred to the cadaver mandibles using VISIT, a surgical navigation software developed at the Vienna General Hospital. The specimens were HRCT-scanned again to compare the position of the implants with the preoperative plan on reformatted slices after matching of the pre- and postoperative data sets using the mutual information technique. The overall accuracy was 0.96 +/- 0.72 mm (range 0.0-3.5 mm). No perforation of the mandibular cortex or damage to the mandibular canal occurred. We conclude that computer-aided implant surgery can reach a level of accuracy where further clinical developments are feasible.     

Implant stability and peri-implant parameters in free vascularized iliac graft transplantation patients: report of three ameloblastoma cases

Background: Ameloblastoma, a benign but locally aggressive tumor, accounts for 9% to 11% of all odontogenic tumors. Radical procedures, including resection, are performed. To restore functions after resection, free vascularized iliac grafts followed by a dental implant–supported prosthesis are used as a successful treatment option. The aim of this case report is to evaluate the peri‐implant clinical status and stability of dental implants placed in patients with advanced‐stage mandibular ameloblastomas. Methods: Examinations of three patients revealed extensive ameloblastomas, and hemimandibulectomies were performed. Six months after surgeries, two to four dental implants were placed. After 6 months of healing, one fixed prosthesis and two removable prostheses were delivered. The stability of implants was evaluated at the surgical baseline and 1, 3, 6, 9, and 12 months after surgery by resonance‐frequency (RF) analysis. Peri‐implant clinical parameters (i.e., plaque index [PI], gingival index [GI], gingival bleeding time index [GBTI], and peri‐implant probing depth [PD]) were recorded at the delivery of the prosthesis and at follow‐ups at 1, 3, and 6 months. Results: Nine implants that supported one removable prosthesis and two fixed prostheses were placed. RF analysis revealed no significant changes in implant stability during 12 months of follow‐up. Peri‐implant clinical parameters (PI, GI, and GBTI) showed slight improvements during follow‐up. Although advancements were observed in 6 months, PDs were found to be deeper than optimal measurements for the whole observation time. Conclusion: The implant‐supported prosthetic rehabilitation of patients with ameloblastomas reconstructed with free vascularized iliac crest grafts can be a predictive alternative for improving the quality of life of patients in which a high implant stability and acceptable peri‐implant health may be achieved.     

Computer-guided implant planning using a preexisting removable partial dental prosthesis

Converting a conventional removable partial dental prosthesis (RPDP) into an implant-assisted removable partial dental prosthesis (IARPDP) may be facilitated by using data from the intaglio surface of the RPDP for proper implant placement. This procedure can be done by connecting the data from the intaglio surface of the RPDP to the residual ridge data of the cone beam computed tomography scan with implant planning software. However, although a misplaced implant under an RPDP can cause various complications, as yet, no technique has connected the information on a patient’s existing RPDP to the implant planning software. This article presents computer-guided implant planning, using a patient’s existing RPDP.     

Clinical and histologic analysis of calcium sulfate in treatment of a post-extraction defect: a case report

We report a case of a postextraction maxillary buccal dehiscence grafted with calcium sulfate to insert a dental implant. The clinical results were supported by histologic analysis of two specimens collected in the healed socket to better understand the biologic effects of calcium sulfate. A 42-year-old white female presented with an almost totally edentulous maxillary right arch with a wide postextraction defect in the canine region. Calcium sulfate mixed with sterile saline solution to a putty-like consistency was packed into the defect, and four dental implants were placed in the edentulous ridge. On re-entry, a dental implant and small amounts of calcium sulfate were placed in the grafted site. After 5 months, a specimen of the region implanted with calcium sulfate was retrieved for histologic evaluation. On surgical re-entry, a complete filling of the defect with mature, dense, newly formed bone occurred. Complete resorption of the grafted material and its substitution with newly formed bone tissue were confirmed by histologic analysis. All of the implants appeared to be osseointegrated successfully, and the patient was provided with a fixed implant-supported prosthesis. Calcium sulfate represents an aid in bone regeneration procedures.     

Computer-aided placement of endosseous oral implants in patients after ablative tumour surgery: assessment of accuracy

The objective of this study was to evaluate the feasibility and accuracy of a novel surgical computer-aided navigation system for the placement of endosseous implants in patients after ablative tumour surgery. Pre-operative planning was performed by developing a prosthetic concept and modifying the implant position according to surgical requirements after high-resolution computed tomography (HRCT) scans with VISIT, a surgical planning and navigation software developed at the Vienna General Hospital. The pre-operative plan was transferred to the patients intraoperatively using surgical navigation software and optical tracking technology. The patients were HRCT-scanned again to compare the position of the implants with the pre-operative plan on reformatted CT-slices after matching of the pre- and post-operative data sets using the mutual information-technique. A total of 32 implants was evaluated. The mean deviation was 1.1 mm (range: 0-3.5 mm). The mean angular deviation of the implants was 6.4 degrees (range: 0.4 degrees - 17.4 degrees, variance: 13.3 degrees ). The results demonstrate, that adequate accuracy in placing endosseous oral implants can be delivered to patients with most difficult implantologic situations.     

Brånemark Novum: prosthodontic and dental laboratory procedures for fabrication of a fixed prosthesis on the day of surgery

PURPOSE: The purpose of this report is to describe a new technique to fabricate and deliver an implant-supported fixed prosthesis to the patient on the day of surgery, and to propose a protocol for the prosthodontic and dental laboratory procedures. MATERIALS AND METHODS: The development of the Br?nemark Novum prosthodontic protocol is reviewed, and clinical and dental laboratory assessments and methods are described. RESULTS: The total treatment time to fabricate a permanent implant-supported fixed prosthesis in the mandible can be reduced to 1 day with the Br?nemark Novum technique. The new method includes a precise surgical technique using drilling templates for predetermined implant positions, a rigid splinting of the implants immediately after placement, the use of a prefabricated titanium framework, and elimination of implant impression procedures. CONCLUSION: With the technique described in this report, it is possible to provide patients with a permanent implant-supported fixed prosthesis in the mandible on the day of implant surgery. Patient benefits are obvious, with drastically reduced total treatment time, lower cost, and fewer clinical visits.     

Clinical application of spiral tomography in anterior implant placement: case report

BACKGROUND: Placement of endosseous dental implants in edentulous areas of the anterior maxilla poses a unique challenge due to variations in the amount of residual alveolar bone. Implant position becomes crucial in cases demanding high esthetic results but possessing minimal ridge width or in cases requiring augmentation. Recent advances in spiral tomography have allowed for more precise planning and placement of endosseous implants in these challenging areas. METHODS: The purpose of this report is to describe a series of clinical cases in which spiral tomography was utilized in the planning and placement of endosseous dental implants. Two cases will be described utilizing initial spiral tomographic radiographs for implant planning and surgical guide fabrication, followed by post-insertion tomography to evaluate the results of implant position and inclination. RESULTS: Preimplant spiral tomograms revealed that the initial prosthetic trajectory through the proposed incisal edge of each tooth replacement would result in a final osteotomy site that would compromise the overall thickness of the facial cortical plate. After adjusting for magnification and distortion factors, new prosthetic/surgical trajectories were fabricated into the surgical guide, and this information was utilized to prepare the final implant osteotomy site. This adjustment resulted in 2 mm of residual crestal facial bone postimplant insertion, which became wider at more apical measurements. These findings were verified in the postimplant serial tomograms. CONCLUSIONS: Spiral tomography was a valuable adjunct in the treatment planning phases of endosseous dental implant placement especially in cases with minimal crestal width, high esthetic demands, or where exact implant placement is critical for successful treatment outcomes.     

Predictable implant placement with a diagnostic/surgical template and advanced radiographic imaging

The technique described facilitates precise dental implant placement. A barium-coated template with external guide wires used in conjunction with a computed tomography scan and interactive software may provide superior presurgical diagnostics, treatment planning, and prosthetically directed implant placement. Measurements predetermined on the computed tomography scan can be transferred accurately to the diagnostic/surgical template by use of a precision milled cylinder placed into the template at the proper angulation and linear dimensions. The diagnostic/surgical template shows the surgeon the optimal position for implant placement, thus establishing greater clinical confidence when placing implants.     

A complete digital approach for facially generated full arch diagnostic wax up,guided surgery,and implant-supported interim prosthesis by integrating 3D facial scanning,intraoral scan and CBCT

Continuous innovation in digital dental technology offers new prospects for creating a complete virtual environment. The technique described adds a facial approach to the conventional digital workflow by incorporating 3D face scans to cone beam computed tomography and intraoral scans. Using this workflow, clinicians can obtain a complete virtual patient for facially generated diagnostic wax up and plan and implement a predictable implant placement and interim prosthesis. This technique provides a full digital workflow for restoratively-driven computer-aided implant planning, guided surgery, and 3D printing of an interim complete-arch fixed implant-supported prosthesis.     

The implant-supported milled-bar mandibular overdenture

Osseointegrated dental implants have been proven successful in the treatment of edentulism. The predictability of the implant‐supported prosthesis has also been established. Several techniques have been described for the successful restoration of the edentulous mandible: fixed‐detachable prostheses with either the original Brånemark hybrid prosthesis design or conventional implant‐supported fixed partial dentures, implant‐retained overdentures, and implant‐supported overdentures. However, in cases of advanced ridge resorption in which facial tissue support is needed from the flanges of the prosthesis or when a removable type of prosthesis is preferred by the patient, an implant‐supported prosthesis is indicated. Electric discharge machining is often used in the fabrication of the bar for an implant‐supported overdenture. This procedure is very costly and technique sensitive. An alternative procedure to fabricate a milled‐bar implant‐supported overdenture is described. This procedure is simple and uses inexpensive equipment and materials. The milled‐bar minimizes lateral and rotational displacement. The overdenture incorporates attachments that provide retention, minimizing possible movement along the path of insertion. This type of prosthesis is available to a broad patient population, especially those with advanced ridge resorption, providing an excellent result at a reduced cost.     

Zygomatic implant placement using a robot-assisted flapless protocol: proof of concept

Robotic assistance can help in physically guiding the drilling trajectory during zygomatic implant positioning. A new robot-assisted strategy for a flapless zygomatic implant placement protocol is reported here. In this protocol, a preoperative computed tomography scan is used to plan the surgical path. After surface registration, the ROSA robot (Zimmer Biomet Robotics) guides several steps, which are performed with shared control. The surgeon performs the drilling and tapping, guided by the robotic arm, which is positioned according to the planned trajectory. Placement of the zygomatic implant is done manually. Immediate intraoperative 3D verification is performed by cone beam computed tomography (flat-panel detector, Medtronic O-arm II). Four zygomatic implants were placed in the case patient according to the flapless protocol, with a mean vector error of 1.78 mm (range 0.52–4.70 mm). A screw-retained temporary prosthesis was placed on the same day. No significant complications were observed. The application of this robot-assisted surgical protocol, which guarantees a very high degree of precision, may reduce inaccuracies in the positioning of zygomatic implants that could deviate from the surgeon’s plan. This appears to be a potentially safe flapless surgery technique. Drill slipping on the crest or on the maxillary wall is the main source of error in this procedure, emphasizing the usefulness of the assisted surgical guidance with haptic feedback.