digital impression
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2022 ◽  
pp. 103-120
Author(s):  
Soma Ghosh

This is an analytical review of engagement and outreach of Salar Jung Museum Library's collection (MSS, printed, and digital). The chapter aims to visualize the benefits of being located in a heritage city, viz., Hyderabad, in India. The method adopted is first to trace impressions of researchers and scholars and second to gather data of its presence in libraries across the world. Tracing such variety and distinctness will open doors for further exploring the impact factors. The original collector, viz., Salar Jung, had open doors for diversity and open mind to welcome all cultural depictions of the world. Its diversity is evident in artifacts and resources that represent samples from East and West. So also is its inclusiveness – the entire collection is without bias of gender, race, or religion. The data analysis shows the engagement in heritage building is reciprocal. A study in the post-COVID era with a larger variety of data (viz., survey, virtual visits, digital impression) will reveal the full picture of reciprocity and will also highlight the actual needs and demands.


2021 ◽  
Vol 11 (24) ◽  
pp. 12034
Author(s):  
Mohammed E. Sayed ◽  
Abdulkarim Hussain Alshehri ◽  
Bandar M. A. Al-Makramani ◽  
Fuad Al-Sanabani ◽  
Fawzia Ibraheem Shaabi ◽  
...  

Accurate impression-making is considered a vital step in the fabrication of fixed dental prostheses. There is a paucity of studies that compare the casts generated by various impression materials and techniques that are commonly used for the fabrication of provisional and definitive fixed prostheses. The aim of this study is to compare the accuracy of casts obtained using conventional impression and digital impression techniques. Thirty impressions were made for the typodont model (10 impressions each of polyvinyl siloxane, alginate, and alginate alternative materials). Ten digital models were printed from the same model using a TRIOS-3 3Shape intraoral scanner. Accuracy was assessed by measuring four dimensions (horizontal anteroposterior straight, horizontal anteroposterior curved, horizontal cross-arch, and vertical). A one-way ANOVA and Tukey’s test (α = 0.05) were used to analyze data. A statistically significant difference in the four dimensions of the stone casts and digital models was observed among the four groups (exception: between alginate alternative and 2-step putty–light body impression in the horizontal anteroposterior straight, horizontal anteroposterior curved, and horizontal cross-arch dimensions; between alginate and alginate alternative in the horizontal anteroposterior curved dimension; between alginate and 2-step putty–light body impression in the horizontal anteroposterior curved dimension; and between alginate alternative and digital in the vertical dimension). Polyvinyl siloxane had the highest accuracy compared to casts obtained from other impression materials and digital impressions.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Rena Masu ◽  
Shinpei Tanaka ◽  
Minoru Sanda ◽  
Keita Miyoshi ◽  
Kazuyoshi Baba

Abstract Purpose To examine the effect of assistive devices on the precision of digital impression for multiple implants placed in the edentulous maxilla. Methods A reference model representing an edentulous maxilla with four implants was developed. The digital impression group included three settings: Type 0, without an assistive device; Type 1, with an assistive device connecting only neighboring implants; and Type 2, with an assistive device connecting not only neighboring implants but also the two posterior implants, with perpendicular branches from this bar towards the anterior implants. Digital impressions were made five times for each type using three intraoral scanners (IOSs). For conventional method, silicone impressions and verification jigs were prepared; fabricated plaster models were scanned using a laboratory scanner/industrial 3D scanner. In analysis 1, two-way ANOVA analyzed the effect of IOSs and assistive devices on the precision of digital impressions. In analysis 2, one-way ANOVA compared the silicone impressions, the verification jigs, and the most precise group of digital impressions from analysis 1. Results In analysis 1, the IOS and assistive device type (F = 25.22, p < .0001) effects and the interaction between these two factors (F = 5.64, p = .0005) were statistically significant. In analysis 2, CON, VJ, and digital impression with Type 2 devices (most precise devices in analysis 1) were compared; better precision was obtained by digital impression with Type 2 device than by CON and VJ (F = 30.08, p < .0001). Conclusions For implants placed in an edentulous maxilla, digital impressions with assistive devices can provide better precision compared to silicone impressions and verification jigs.


2021 ◽  
Vol 11 (21) ◽  
pp. 9859
Author(s):  
Hani Tohme ◽  
Ghida Lawand ◽  
Rita Eid ◽  
Khaled E. Ahmed ◽  
Ziad Salameh ◽  
...  

(1) Background: Stereophotogrammetry has recently been investigated showing high accuracy in complete implant supported cases but has scarcely been investigated in cases of tilted implants. The aim of this in vitro study was to compare the accuracy of digital impression techniques (intraoral scanning and photogrammetry) at the level of intraoral scan bodies in terms of angular deviations and 3D discrepancies. (2) Methods: A stone master cast representing an edentulous maxilla using four implant analogs was fabricated. The two anterior implants were parallel to each other, and the two posterior implants were at an angulation of 17 degrees. Digital intraoral scanning (DIOS) impressions were taken after connecting implant level scan bodies to the master cast and STL files were exported (n = 15). Digital photogrammetry (DPG) impressions were captured using a PiC Camera after tightening implant level PiC optical markers and STL files were exported (n = 15). Superimposition was carried out by a software for determining the accuracy of both. (3) Results: Significant angular discrepancies (ΔA) and 3D deviations of scan bodies were found among the groups in trueness with lower deviations for the DPG (p value < 0.001). However, trueness within ISBs varied between angular and 3D deviations and outcomes were not specific to determine the effect of implant angulation. In precision, no significant differences were detected within ISBs and among both groups in terms of angular deviation. However, DPG had less deviations than DIOS group in terms of 3D deviations (p value < 0.001). (4) Conclusion: Digital photogrammetry technique conveyed the utmost accuracy in both trueness and precision for the intraoral scan bodies among both impression methods assessed. In addition, implant angulation did not influence the precision of the impression techniques but affected their trueness without explicit conclusions.


2021 ◽  
Vol 11 (9) ◽  
pp. 932
Author(s):  
Ignacio Faus-Matoses ◽  
Clara Guinot Barona ◽  
Álvaro Zubizarreta-Macho ◽  
Vanessa Paredes-Gallardo ◽  
Vicente Faus-Matoses

The aim of this study was to analyze the accuracy and predictability of the indirect bonding technique of fixed buccal multibracket appliances using a customized iterative closest point algorithm. Materials and Methods: A total of 340 fixed buccal multibracket appliances were virtually planned and bonded on 34 experimental anatomically based acrylic resin models by using orthodontic templates designed and manufactured to indirectly bond the fixed buccal multibracket appliances. Afterwards, the models were submitted to a three-dimensional impression technique by an intraoral scanner, and the standard tessellation language digital files from the virtual planning and the digital impression were aligned, segmented, and realigned using morphometric software. Linear positioning deviations (mm) of the fixed buccal multibracket appliances were quantified at mesio-distal, bucco-lingual/palatal, and gingival/occlusal (vertical) planes, and angular deviations (°) were also recorded by analyzing the torque, tip, and rotation using a customized iterative closest point algorithm, the script for which allowed for an accuracy measurement procedure by comparing the tessellation network positioning of both standard tessellation language digital files. Results: The mean mesio-distal deviation was −0.065 ± 0.081 mm, the mean bucco-lingual/palatal deviation was 0.129 ± 0.06 m, the mean vertical deviation was −0.094 ± 0.147 mm, the mean torque deviation was −0.826 ± 1.721°, the mean tip deviation was −0.271 ± 0.920°, and the mean rotation deviation was −0.707 ± 0.648°. Conclusion: The indirect bonding technique provides accurate and predictable positioning of fixed buccal multibracket appliances.


Author(s):  
Christina Weise ◽  
Karin Frank ◽  
Cornelia Wiechers ◽  
Hannes Weise ◽  
Siegmar Reinert ◽  
...  

Summary Objective The aim of this study was to evaluate intraoral scanning (IOS) in infants, neonates, and small children with craniofacial anomalies for its feasibility, scanning duration, and success rate. Impression taking in vulnerable patients can be potentially life-threatening, with the risk of airway obstruction and aspiration of impression material. The advantage of increasingly digitalized dentistry is demonstrated. Materials and methods IOS was captured with the Trios 3® (3Shape, Copenhagen, Denmark) intraoral scanner. The underlying disorders were divided into cleft lip and palate (CLP), Trisomy 21 (T21), Robin Sequence (RS), Treacher Collins syndrome (TC), and isolated mandibular retrognathia (MR). Scan data were analysed by scanning duration, number of images, possible correlations of these factors with the different craniofacial disorders, patient age, and relationship between first and subsequent scans. Clinical experiences with the repeated digital impressions are described. Results Patient data of 141 scans in 83 patients were analysed within an 11-month period. Patients had a median age of 137 days. Median scanning duration was 138 seconds, resulting in a median of 352 images. There was a statistically significant difference in scanning duration (P = 0.001) between infants and neonates. IOS took longest in patients with CLP (537 seconds) and shortest in T21 patients (21 seconds), although there was no statistically significant difference between aetiologies. There was no statistically significant difference between first and subsequent scans in scanning duration. In four cases the IOS had to be repeated, and one patient ultimately required conventional impression taking (all CLP patients; success rate 94%). No severe adverse events occurred. Conclusion IOS is a fast, safe, and feasible procedure for neonates, small children, and infants with craniofacial malformations. One special challenge for both technician and user was identified in patients with CLP, though implementing this new approach of digital impression taking was otherwise found to be highly successful in everyday clinical routine.


2021 ◽  
Vol 11 (18) ◽  
pp. 8280
Author(s):  
Anca Jivănescu ◽  
Adrian Bara ◽  
Andrei-Bogdan Faur ◽  
Raul Nicolae Rotar

Is the accuracy of the older generation of IOSs an impediment for obtaining a quality intraoral digital impression? The aim of this study was to evaluate the differences in accuracy between four intraoral scanners (two of the latest IOSs and two older IOSs) in the scenario of a short span fixed partial denture, and to determine if these differences have a major impact on the quality of the final digital impression. Four intraoral scanners: Cerec PrimeScan, Medit i700, Cerec Omnicam and Planmeca PlanScan and one laboratory scanner were used in this study. The scanned data were processed with the help of Geomagic Control X, a metrology software. For the statistical data analysis, the level of significance was set as 0.05 (α = 0.05). The Medit i700 group displayed the best level of trueness with the median value of 23.25 µm, PrimeScan group with a median of 25.55 µm, Omnicam group with a median of 32.3 µm and the PlanScan group which displayed the lowest level of trueness with a median value of 75.8 µm. From the precision data analysis, it was concluded that the PrimeScan group showed the best results, followed by Medit i700, Omnicam and the PlanScan group which showed the lowest precision. Even if there are some significant differences in accuracy between old and new IOSs, in the in vitro scenario of short span dental prostheses, the accuracy values were within the clinically acceptable range and may present important clinical implications.


2021 ◽  
Vol 15 (3) ◽  
pp. 562-568
Author(s):  
Luciana Paula Benicio Arcas ◽  
João Paulo Mendes Tribst ◽  
Kusai Baroudi ◽  
Marina Amaral ◽  
Lais Regiane da Silva-Concílio ◽  
...  

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