Digital workflow for fabricating a verification device for an all-on-4 abutment: A dental technique.

The all-on-4 implant concept has been used to overcome anatomic limitations and has been reported to have high success rates. A verification device is commonly used to transfer the position of the angled distal abutment accurately. This article describes a digital workflow for fabricating a verification device to position the angled distal abutment with a hexagon connection during computer-guided flapless surgery.

Natural Bone Healing In Compromised Sockets After Tooth Extraction: Digital Measurement Methods With Cone-Beam Computed Tomography.

This study aimed to evaluate bone regeneration within infected extraction sockets with bone defects using cone-beam computed tomography (CBCT) at a 1-year follow-up after implant placement in a prosthetically driven implant position. Forty-eight patients requiring premolar or molar tooth extraction due to bone defects caused by periodontal diseases were included. Vertical and horizontal bone volumes were assessed by overlapping the CBCT scan images with the full digital process. At 1-year post-extraction, a prosthetically-driven implant was planned using virtual implant planning software. At 1 year after extraction, CBCT revealed significant horizontal and vertical bone gains; an overall mean buccolingual bone width gain of 5.46 ± 2.87 mm, and an overall mean vertical bone gain of 0.27 ± 1.28 mm for the lingual bone plate level and 3.50 ± 1.81 mm for the buccal bone plate level were observed. Except for 4 (out of 48) sites, implants were virtually positioned in the center of the edentulous spaces. In summary, despite the dimensional changes after tooth extraction in compromised posterior sockets, there was sufficient bone for placing an implant using the prosthetically driven approach.

Digital workflow for fabricating an overdenture by using an implant surgical template and intraoral scanner.

Implant-supported overdentures can significantly increase function and satisfaction during the first year and can last for 5 to 10 years. The 2-implant-supported mandibular overdenture is recommended as a standard treatment for edentulous patients. In the recent years, studies have reported the use of digital complete dentures. However, as a modified technique for complete dentures, few studies have evaluated the use of digital techniques in the fabrication of overdentures. The purpose of this article was to introduce a digital workflow for fabricating overdentures by using information from the existing dentures.

Immediate nonfunctional loading of implants placed simultaneously using computer-guided flapless maxillary crestal sinus augmentation with bone morphogenetic protein-2/collagen matrix.

BACKGROUND: Immediate loading has shown positive results for total, partial, or single edentulism. The effects of BMP-2 addition to graft materials on bone formation and implant stability in the early stages of healing have rarely been studied, especially in patients with severely atrophic maxillae. PURPOSE: To evaluate the effects of simultaneously placed immediate non-functional loaded implants and bone morphogenetic protein-2 (BMP-2)-loaded Bio-Oss collagen, on bone formation and implant stability during the early healing stages of patients with a severely atrophic posterior maxilla using crestal approach. MATERIALS AND METHODS: Thirty-three cases presenting posterior maxillary residual alveolar bone height of 1-3 mm were evaluated. Flapless crestal sinus augmentation surgery was performed using BMP-2-loaded Bio-Oss collagen, with non-functional implants immediately loaded after surgery. The bone height was assessed using preoperative and postoperative cone beam computed tomography (CBCT). Bone density of the sinus graft sites and implant stability (after 3 months) were evaluated using postoperative CBCT scans and Periotest, respectively. The periodontal parameters and marginal bone loss around the implant were checked after 37.3 months of final prosthesis. RESULTS: The survival rate of the implants was 100% and the gingiva around the implants remained healthy. All implants remained integrated, and all sinus grafts showed radiographic bone formation. The results indicated high level of bone density and good implant stability, showing minimal marginal bone loss after 37.3 months. CONCLUSION: This technique could be used in the posterior maxillary region exhibiting poor bone quantity.

Digital Workflow for Computer-Guided Implant Surgery in Edentulous Patients with an Intraoral Scanner and Old Complete Denture.

A double-scan procedure is commonly performed in the process of fabricating an implant surgical template; however, this entails the disadvantage of recording 2 cone beam computed tomography (CBCT) scans requiring additional time, effort, and costs. The purpose of this article is to introduce a digital protocol to acquire adequate preoperative diagnostic information for a fully edentulous patient, using the existing complete denture with a metal framework, an intraoral scanner, and CBCT.

Accuracy of computer-guided implant placement in anterior regions.

STATEMENT OF PROBLEM: Implant placement in the anterior regions is often challenging because of limited space and bone volume availability. PURPOSE: The purpose of this clinical study was to investigate the accuracy of computer-guided surgery with a long drill key to place implants in the anterior regions. MATERIAL AND METHODS: Computer-guided implant surgery was performed for 32 participants requiring implants in anterior regions. The procedure involved using a 12-mm-long drill key to guide the 2.0-mm-diameter drill. Deviations between the planned and actual implant positions were evaluated by using cone beam computed tomography (CBCT) scans obtained before and after surgery. A t test was used for comparisons between the planned and placed implants and to determine the influence of the arch (maxilla/mandible) and time (immediate/delayed) on accuracy. RESULTS: A total of 40 implants (20 implants in the maxilla and 20 implants in the mandible) were placed. The mean linear deviation was 0.46 mm (range, 0 to 1.15 mm) for the implant shoulder and 0.67 mm (range, 0.14 to 1.19 mm) for the implant apex. The mean angular deviation was 1.40 degrees (range, 0.30 to 2.57 degrees). The mean depth deviation was 0.15 mm (range, 0.10 to 0.82 mm). CONCLUSIONS: This clinical study showed that the accuracy of computer-guided implant placement may be enhanced by using a long drill key and may thus enable more accurate implant placement in anterior regions.

A digital technique for fabricating an interim implant-supported fixed prosthesis immediately after implant placement in patients with complete edentulism.

The conversion of a denture into an interim implant-supported, screw-retained restoration has become the standard method for immediate interim restoration in patients with complete edentulism. The most critical steps of the denture conversion process are the creation of appropriate denture access holes to prevent displacement of the denture by the interim cylinders and removal of the denture flanges to facilitate both good esthetics and accessibility for oral hygiene after the denture is connected to the interim cylinders. This article presents a digital technique for designing and fabricating an interim implant-supported, fixed prosthesis for edentulous patients. The interim prosthesis has cylinder access holes that are digitally prefabricated and a denture flange part that is designed to be easily sectioned. This technique facilitates more straightforward and efficient immediate restoration for edentulous patients after implant placement.

Crestal Sinus Augmentation in the Presence of Severe Sinus Mucosal Thickening: A Report of 3 Cases.

PURPOSE: In the presence of severe sinus mucosal thickening, the ostium can be blocked when the sinus membrane is lifted, causing drainage disturbances and sinusitis. Here, we present 3 cases in which maxillary sinus floor elevation was performed using a crestal approach in the presence of severe sinus mucosal thickening (>10 mm). MATERIALS AND METHODS: The effects of maxillary sinus floor elevation using the crestal approach technique on sinus mucosal thickening and bone formation in the sinus were evaluated using cone beam computed tomography. RESULTS: None of the patients exhibited an increase in sinus membrane thickness. No complications were encountered during the follow-up periods, and bone formation was observed around the implants at the sinus floor. All implants were functioning successfully. CONCLUSIONS: Maxillary sinus floor elevation using the crestal approach technique in the presence of severe sinus mucosal thickening allows for minimally invasive sinus grafting and simultaneous implant placement and does not increase sinus membrane thickness.

A CAD-CAM technique for conversion of interim-to-definitive restoration in patients with complete edentulism.

An interim restoration is a prototype for the definitive prosthesis and preserves the occlusal information and the original vertical dimension of the occlusion. Several techniques have been developed to transfer the information from implant-supported fixed interim to definitive restoration. However, these conventional techniques have limitations, and they are time-consuming, require making impressions and stone casts, and mounting in an articulator. The purpose of this article was to describe a digital technique to accurately transfer the information from complete-arch implant interim restoration to definitive restorations without using definitive casts.

Digital immediate denture: A clinical report.

Fabricating an immediate complete denture in the conventional manner may be complicated and difficult. The purpose of this article was to describe a fully digital workflow used to fabricate an immediate complete denture before removing the teeth and without the use of conventional impressions or stone casts. The digital data for the workflow were acquired using an intraoral scanner and were then used to design the denture base and teeth after deleting any remaining tooth images from the virtual 3-dimensional image of the jaw. The resulting data were exported to a milling machine for denture fabrication.

Digital intraoral scanning technique for edentulous jaws.

Few studies have evaluated direct digital scans of edentulous jaws using intraoral scanners because it is difficult to scan edentulous sites that are smooth and devoid of features. A scanning technique is introduced for making direct digital scans of edentulous jaws with intraoral scanners in patients with a broad palate.

Development of complete dentures based on digital intraoral impressions-Case report.

PATIENT: A 60-year-old man presented for refabrication of his maxillary complete denture. In this case, a digital process was chosen to replace the ill-fitted complete maxillary denture. A specialized scan retractor was used to retract the mobile tissues of the lips, cheeks and vestibule while taking a digital impression. The interocclusal record obtained in the patient's mouth was scanned in order to digitally register the occlusal vertical dimension. The denture base and teeth were designed on virtual models that were mounted at the occlusal vertical dimension, and were made using CAD/CAM technology. DISCUSSION: Unlike conventional impression techniques, intraoral scanning is not able to be performed while the tissue is moving. This case report used a scan retractor that facilitated stretching and fixation of the vestibular area. It also helped to retract the lips and cheeks. This report also demonstrates that virtual models at OVD can be obtained without the use of conventional stone models, flasking or processing techniques. One of the main shortcomings in the existing CAD/CAM denture fabrication technology is that it is not able to produce customized denture teeth. The present article demonstrates that the digital denture fabrication workflow can provide customized denture teeth to optimize occlusion. CONCLUSION: This case demonstrated how digital complete dentures can be made without requiring conventional stone models or mounting the models in an articulator.

Crestal Sinus Augmentation in the Presence of an Antral Pseudocyst.

PURPOSE: Antral pseudocysts classically have a well-defined, hyperdense, unilocular, dome-shaped appearance in radiographs. The best therapeutic approach for treating these cysts in the context of sinus floor augmentation remains controversial. This article presents a new technique that allows both sinus membrane elevation and cyst removal through a crestal approach in patients with pseudocysts in the maxillary sinus. MATERIALS AND METHODS: The technique combined aspiration of the cysts during sinus floor elevation with a sinus augmentation procedure using a hydraulic sinus elevation system. Aspiration of the cyst fluid was performed through the crestal osteotomy site after sinus floor elevation. RESULTS: Two patients showed a significant amount of bone formation around the implant at the sinus floor without evidence of a recurrent cyst after the procedure. CONCLUSIONS: The technique allows the minimally invasive removal of antral pseudocysts at the time of sinus grafting and simultaneous implant placement, preserving the integrity of the sinus membrane.

Digital Workflow for Computer-Guided Implant Surgery in Edentulous Patients: A Case Report.

PURPOSE: The purpose of this article was to describe a fully digital workflow used to perform computer-guided flapless implant placement in an edentulous patient without the use of conventional impressions, models, or a radiographic guide. MATERIALS AND METHODS: Digital data for the workflow were acquired using an intraoral scanner and cone-beam computed tomography (CBCT). The image fusion of the intraoral scan data and CBCT data was performed by matching resin markers placed in the patient's mouth. RESULTS: The definitive digital data were used to design a prosthetically driven implant position, surgical template, and computer-aided design and computer-aided manufacturing fabricated fixed dental prosthesis. CONCLUSION: The authors believe this is the first published case describing such a technique in computer-guided flapless implant surgery for edentulous patients.