scholarly journals Accuracy and dimensional reproducibility by model scanning, intraoral scanning, and CBCT imaging for digital implant dentistry

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Akira Komuro ◽  
Yoichi Yamada ◽  
Satoshi Uesugi ◽  
Hiroaki Terashima ◽  
Masashi Kimura ◽  
...  

Abstract Background Recently, it has become possible to analyze implant placement position using the digital matching data of optical impression data of the oral cavity or plaster models with cone beam computed tomography (CBCT) data, and create a highly accurate surgical guide. It has been reported that CBCT measurements were smaller than the actual values, termed shrinkage. Matching of digital data is reliable when the plaster model or intraoral impression values show shrinkage at the same rate as the CBCT data. However, if the shrinkage rate is significantly different, the obtained digital data become unreliable. To clarify digital matching reliability, we examined dimensional reproducibility and shrinkage in measurements obtained with a model scanner, intra-oral scanner (iOS), and CBCT. Materials and methods Three implants that were arranged in a triangle were fixed in an acrylic plate. The distance between each implants were measured using model scanner, iOS, and CBCT. The actual size measured by electronic caliper was regarded as control. Results All values measured with CBCT were significantly smaller than that of model scanner, iOS, and control (p<0.001). The model scanner shrinkage was 0.37-0.39%, iOS shrinkage was 0.9-1.4%, and CBCT shrinkage was 1.8-6.9%. There were statistically significant differences among the shrinkage with iOS, CBCT, and model scanner (p<0.001). Conclusion Our findings showed that all measurements obtained with those modalities showed shrinkage as compared to the actual values. In addition, CBCT shrinkage was largest among three different measuring methods. They indicated that data matching between CBCT and scanner measurements requires attention in regard to the reliability of values obtained with those devices.

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1236
Author(s):  
Jung-Hwa Lim ◽  
Enkhjargal Bayarsaikhan ◽  
Seung-Ho Shin ◽  
Na-Eun Nam ◽  
June-Sung Shim ◽  
...  

This study evaluated the internal fit and the accuracy of the implant placement position in order to determine how the surface shape of the tooth and the offset influence the accuracy of the surgical guide. The acquired digital data were analyzed in three dimensions using 3D inspection software. The obtained results confirmed that the internal fit was better in the groove sealing (GS) group (164.45 ± 28.34 μm) than the original shape (OS) group (204.07 ± 44.60 μm) (p < 0.001), and for an offset of 100 μm (157.50 ± 17.26 μm) than for offsets of 30 μm (206.48 ± 39.12 μm) and 60 μm (188.82 ± 48.77 μm) (p < 0.001). The accuracy of implant placement was better in the GS than OS group in terms of the entry (OS, 0.229 ± 0.092 mm; GS, 0.169 ± 0.061 mm; p < 0.001), apex (OS, 0.324 ± 0.149 mm; GS, 0.230 ± 0.124 mm; p < 0.001), and depth (OS, 0.041 ± 0.027 mm; GS, 0.025 ± 0.022 mm; p < 0.001). In addition, the entries (30 μm, 0.215 ± 0.044 mm; 60 μm, 0.172 ± 0.049 mm; 100 μm, 0.119 ± 0.050 mm; p < 0.001) were only affected by the amount of offset. These findings indicate that the accuracy of a surgical guide can be improved by directly sealing the groove of the tooth before manufacturing the surgical guide or setting the offset during the design process.


Systems ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 33
Author(s):  
Olena Klymenko ◽  
Lise Lillebrygfjeld Halse ◽  
Bjørn Jæger

Sustainability accounting is an emerging research area receiving growing awareness. This study examines the role of digital technology in manufacturing companies’ sustainability accounting. To guide the research, we use a triple layered business model canvas, which supports the accounting of a manufacturer’s performance for the economic, environmental, and social aspects of sustainability. We present an explorative case study of four Norwegian manufacturing companies representing different industries. The findings from the study indicate that while accounting for economic values is well taken care of, companies do not perform comprehensive environmental and social accounting. Furthermore, we observed a shift from a focus on sustainability issues related to the internal manufacturing process to a focus on sustainability issues for the life cycle of the product. Even though the manufacturers are at the forefront with regard to automation and control of production, with extensive use of robots giving a large amount of data, these data are not utilized towards sustainability accounting, showing that sustainability and digitalization are seen as two separate phenomena. This study sheds light on how digital data available from applied Industry 4.0 technologies could enhance sustainability accounting with limited efforts, linking sustainability and digitalization. The results provide insights for manufacturers and researchers in moving towards more sustainable operations and products.


2007 ◽  
Vol 44 (3) ◽  
pp. 278-285 ◽  
Author(s):  
Virgilio F. Ferrario ◽  
Fabrizio Mian ◽  
Redento Peretta ◽  
Riccardo Rosati ◽  
Chiarella Sforza

Objective: To compare three-dimensional nasal measurements directly made on subjects to those made on plaster casts, and nasal dimensions obtained with a surface-based approach to values obtained with a landmark representation. Methods: Soft-tissue nasal landmarks were directly digitized on 20 healthy adults. Stone casts of their noses were digitized and mathematically reconstructed using nonuniform rational B-splines (NURBS) curves. Linear distances, angles, volumes and surface areas were computed using facial landmarks and NURBS-reconstructed models (surface-based approach). Results: Measurements on the stone casts were somewhat smaller than values obtained directly from subjects (differences between −0.05 and −1.58 mm). Dahlberg's statistic ranged between 0.73 and 1.47 mm. Significant (p < .05) t values were found for 4 of 15 measurements. The surface-based approach gave values 3.5 (volumes) and 2.1 (surface area) times larger than those computed with the landmark-based method. The two values were significantly related (volume, r = 0.881; surface, r = 0.924; p < .001), the resulting equations estimated actual values well (mean difference, volume −0.01 mm3, SD 1.47, area 0.05 cm2, SD 1.44); limits of agreement between −2.89 and 2.87 mm3 (volume); −2.88 and 2.78 cm2 (area). Conclusions: Considering the characteristics of the two methods, and for practical purposes, nasal distances and angles obtained on plaster models were comparable to digital data obtained directly from subjects. Surface areas and volumes were best obtained using a surface-based approach, but could be estimated using data provided by the landmark representation.


Author(s):  
Giovanni de Almeida Prado Di Giacomo ◽  
Patrícia Cury ◽  
Airton Moreira da Silva ◽  
Jorge Vicente Lopes da Silva ◽  
Carlos Eduardo Pompeo Souto ◽  
...  

This study was designed to evaluate the accuracy of a novel computer-designed and selectively laser sintered surgical guide for flapless dental implant placement in the edentulous jaw. Fifty dental implants were placed in 11 patients with at least one totally edentulous jaw. Initially, cone-beam computed tomography (CBCT) was performed in each patient to define the virtual position of the dental implants based on the assessment of bone availability and the proposed dental prosthesis. After virtual planning, 3D surgical guides were printed using selective laser sintering. CBCT was repeated after the surgery, and the pre-and postoperative images were overlapped in the CAD software to compare the planned and actual positions of the dental implants using a one-sample t-test. The mean ± angular standard deviation between the long axes of the planned and final dental implant positions was 4.58 ±2.85 degrees; The linear deviation in the coronal position was  0.87 ± 0.49 mm and  in the apical region of the dental implants was 1.37 ± 0.69 mm. These differences were statistically significant (p &lt;0.001). The proposed modifications reduced the deviations, resulting in an improvement in the technique. We were able to place implants and temporary prostheses using the present protocol, taking into account the differences between the planned and final positions of the dental implants.


2017 ◽  
Vol 43 (5) ◽  
pp. 351-359 ◽  
Author(s):  
Panagiotis Dragonas ◽  
Charles Palin ◽  
Saba Khan ◽  
Praveen K. Gajendrareddy ◽  
Whitney D. Weiner

This case report aims to describe in detail a complication associated with resorption of regenerated bone following implant placement and ridge augmentation using recombinant human bone morphogenic protein–2 (rhBMP-2) in combination with allograft and xenograft. Bilateral maxillary sinus and ridge augmentation procedures were completed using rhBMP-2 combined with allograft and xenograft. Five months later, significant bone augmentation was achieved, which allowed for the placement of 4 implants. Upon stage 2 surgery, significant dehiscence was noted in all implants. Treatment steps to address this complication included implant removal, guided bone regeneration with xenograft only, and placement of new implants followed by soft-tissue grafting. At the time of publication, this patient is status 1½ years post case completion with maintenance of therapy outcomes. Off-label use of rhBMP-2 has gained significant acceptance in implant dentistry. However, there is limited evidence regarding the bone maturation process when rhBMP-2 is combined with other biomaterials. More research may be needed regarding the timing and process of bone healing in the presence of rhBMP-2, in an effort to avoid surgical complications.


Author(s):  
Larissa Braga dos Santos ◽  
Adriano Relvas Barreira de Oliveira ◽  
Mauro Lefrançois ◽  
Marcos Venício Azevedo ◽  
Pablo Sotelo ◽  
...  

Digital planning of the prosthesis associated with surgical planning increased predictability, since surgical guides indicate the best place for implant installation, thus reducing the number of complications, and the CAD/CAM system provides predictability in the preparation of final restorations, according to the procedure previously planned. Our study reported a digital workflow used for the guided installation of two dental implants in regions 14 and 16, extraction of tooth 15 and installation of a fixed prothesis over implants. After anamnesis and clinical evaluation, intra- and extra-oral photographs of the patient were performed, molding the upper arch with polyvinylsiloxane (2-step putty/light-body technique) and requesting computed tomography. The plaster model obtained was sent to the laboratory and scanned. The generated file (STL) was used to create a diagnostic wax-up that was aligned to the tomography (in DICOM format), enabling the three-dimensional planning of the implants, which generated a partial printed surgical guide after approval of the dentist. After six months, the patient received the provisional fixed prosthesis printed in PMMA (polymethylmethacrylate) on an intermediate in PEEK (polyetheretherketone) aiming to condition an emergency profile to receive a definitive prosthesis two months later, with zirconia-milled infrastructure on a ti-base. The correct understanding of the operator about the steps of the digital workflow (diagnosis, prosthetic planning, surgical planning, guide preparation, temporary and final restorations) gives the operator improved predictability at the time of surgery as well as satisfactory aesthetic and functional result of definitive restorations.


2017 ◽  
Vol 63 (3) ◽  
pp. 2225-2233
Author(s):  
Inass AbuElmagd ◽  
Alshaimaa Shabaan ◽  
Amr Salah eldin

2018 ◽  
Vol 21 (2) ◽  
pp. 419-437 ◽  
Author(s):  
Luci Pangrazio ◽  
Neil Selwyn

The capacity to understand and control one’s personal data is now a crucial part of living in contemporary society. In this sense, traditional concerns over supporting the development of ‘digital literacy’ are now being usurped by concerns over citizens’ ‘data literacies’. In contrast to recent data safety and data science approaches, this article argues for a more critical form of ‘personal data literacies’ where digital data are understood as socially situated and context dependent. Drawing on the critical literacies tradition, the article outlines a range of salient socio-technical understandings of personal data generation and processing. Specifically, the article proposes a framework of ‘Personal Data Literacies’ that distinguishes five significant domains: (1) Data Identification, (2) Data Understandings, (3) Data Reflexivity, (4) Data Uses, and (5) Data Tactics. The article concludes by outlining the implications of this framework for future education and research around the area of individuals’ understandings of personal data.


Author(s):  
Vasilios Alevizakos ◽  
Gergo Mitov ◽  
Constantin von See

The aim of this case report is to describe the combining of a surgical guide with a temporary restoration to streamline the implant process. A 54-year-old male patient presenting partial edentulism underwent computer-aided template-guided implant placement for the replacement of the missing upper second right incisor. The presented technique was used during the surgical procedures; it introduced the integration of a surgical guide into the temporary fixed partial denture. Using computer-aided design, computer-aided manufacturing technology and virtual implant planning, a temporary-implantation fixed partial denture was constructed, and a guidance sleeve was implemented into it. The implant bed preparation was then performed using the bridge as a surgical guide. After osteotomy, the guidance sleeve within the bridge was sealed, and the bridge was temporarily incorporated for submerged healing of the implant. The usage of a temporary restoration as a surgical guide seems to make the digital workflow of guided implant placement more efficient, by achieving a representative clinical outcome.


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