scholarly journals Study of the dimensional accuracy of jaw models obtained by 3d printing using stereolithography

2020 ◽  
Vol 27 (1) ◽  
pp. 40-48
Author(s):  
Evgeny N. Zhulev ◽  
Yuliya A. Vokulova

Aim. To study the dimensional accuracy of dentition models produced by digital and conventional methods using an experimental model and digital technologies.Materials and methods. This article presents an assessment of the dimensional accuracy of jaw models created using an Asiga Max UV 3D printer from digital images of dentition created by an iTero Cadent intraoral scanner and plaster jaw models obtained from one-stage two-layer A-silicone impressions. The DentalCAD software and the Meshlab computer program were used to study the dimensional accuracy of the as-obtained digital images. The nonparametric Wilcoxon rank test was used for statistical analysis of the obtained data.Results. It is established that jaw models made of DETAX Freeprint model UV photopolymer using an Asiga Max UV 3D printer, based on digital impressions obtained by an iTero Cadent intraoral scanner, have a greater dimensional accuracy in comparison with plaster jaw models obtained from single-stage double-layer A-silicone impressions by 31.6% with a signifi cance level p < 0.05.Conclusion. Jaw models created using an Asiga Max UV 3D printer are characterized by high dimensional accuracy as compared to plaster models. 

Author(s):  
Vokulova Yu.A. Vokulova ◽  
E.N. Zhulev

This article presents the results of studying the dimensional accuracy of the bases of complete removable prostheses made using a 3D printer and the traditional method. Bases of complete removable prostheses were made using an intraoral laser scanner iTero Cadent (USA) and a 3D printer Asiga Max UV (Australia). To study the dimensional accuracy of the bases of complete removable prostheses, we used the DentalCAD 2.2 Valletta software. The Nonparametric Wilcoxon W-test was used for statistical analysis of the obtained data. We found that the average value of the difference with the standard for bases made using digital technologies is 0.08744±0.0484 mm. The average value of the difference with the standard for bases made by the traditional method is 0.5654±0.1611 mm. Based on these data, we concluded that the bases of complete removable prostheses made using modern digital technologies (intraoral laser scanning and 3D printer) have a higher dimensional accuracy compared to the bases of complete removable prostheses made using the traditional method with a significance level of p<0.05 (Wilcoxon's W-test=0, p=0.031). Keywords: digital technologies in dentistry, digital impressions, intraoral scanner, 3D printing, ExoCAD, complete removable dentures.


2020 ◽  
Author(s):  
CAIO CÉSAR DIAS Resende ◽  
Tiago Augusto Quirino Barbosa ◽  
Guilherme Faria Moura ◽  
Lucas Nascimento Tavares ◽  
Fabio Antonio Piola Rizzante ◽  
...  

Abstract Background: Different sizes of arch could influence in digital methods to obtaining dental impressions and 3D models. The purpose of this study was to evaluate and compare the accuracy of two intra-oral scanners and conventional impression methods for the fabrication of working casts. Methods: Conventional impressions of a reference cast were obtained. Digital impressions were obtained with two intra-oral scanners: Cerec Omnicam (CO) and 3Shape Trios (ST). The obtained digital stereolithographic casts were printed on Zenith D 3D printer. The reference cast and fabricated casts were scanned with a bench top scanner and saved in STL format. All STL records were analyzed in specific software: complete arch (CA), partial arch (PA) and prepared teeth area (PT). One-way and two-way analyses of variance were performed to compare the accuracy, followed by the Tukey test. Results: No significant intergroup differences in trueness and precision were observed for the two intra-oral scanners. 3D printed casts had the lowest trueness when complete arch was analyzed and differed statistically from the stone cast. For complete arch precision, stone cast presented better results, however statistically different only from the CO. Conclusions: The two intraoral scanner systems had similar accuracy. Stone casts had higher trueness than 3D printed casts for CA. For CA precision, 3D printed cast presented similar results to the stone cast.


2021 ◽  
Vol 16 (4) ◽  
pp. 130-135
Author(s):  
Yuliya Vokulova ◽  
Evgenij Zhulev

Subject. Modern digital technologies make it possible to automate the process of creating bridges to a large extent. First, digital images of the patient's dentition are obtained, then the future prosthesis is virtually modeled and manufactured using a subtractive method using milling and grinding machines or an additive method using a 3D printer. For clinical evaluation of the quality of orthopedic fixed structures made using digital methods, it is necessary to evaluate their dimensional accuracy. The aim is to conduct a comparative assessment of the dimensional accuracy of bridge prosthesis frames made using modern digital technologies and traditional casting method. Methodology. The intraoral laser scanner iTero Cadent, the 3D printer Asiga Max UV, the CAD/CAM system KaVo ARCTICA, the software DentalCAD 2.2 Valletta and the computer program MeshLab were used to study the dimensional accuracy of the bridge frames. The Kruskal-Wallis H-test and the Mann-Whitney U-test were used for statistical analysis of the data obtained. Results. All digital methods of manufacturing bridge frames are distinguishable from the traditional casting method with a significance level of p<0.05 on the basis of dimensional accuracy. The frames of bridge prostheses made by the subtractive method have a higher dimensional accuracy compared to the frames obtained using additive technologies. There were no statistical differences in the dimensional accuracy of milled titanium and zirconium bridge frames. Conclusions. Based on the data obtained, we concluded that the bridge frames made using modern digital technologies have a higher dimensional accuracy (the average value of the median distance of milled zirconium frames is 0,03067 ± 0,001234 mm, milled titanium frames are 0,03032 ± 0,002698 mm, frames made using additive technologies are 0,03686 ± 0,003068 mm) compared to the bridge frames made by the traditional casting method (the average value of the median distance 0,04342 ± 0,003722 mm), with a significance level of p<0,05 (U-Mann-Whitney criterion =0, p=,002).


2017 ◽  
Vol 17 (03) ◽  
pp. 1750084 ◽  
Author(s):  
HONGFU ZHOU ◽  
QIN FAN

This research studies an integrated dental 3D reconstruction scanning method which combines impression model scanning, intraoral camera scanning and CT scanning. In the dental integrated scanning, tooth root data is acquired from CT DICOM data and 3D reconstruction is processed by Mimics®software developed from Materialise. The tooth crown and the tooth bridge 3D data are obtained by scanning the tooth impression model or scanning with an intraoral scanner. Also, it surveys that the dental prosthesis are fabricated with traditional methods and printed with Select Laser Melting (SLM) technology. In the research, it presents that SLM additive manufacturing (AM) method can fabricate customized dental prosthesis with high dimensional accuracy.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yushu Liu ◽  
Rui Zhang ◽  
Hongqiang Ye ◽  
Shimin Wang ◽  
Kuan-Paul Wang ◽  
...  

AbstractThis study aimed to develop a three-dimensional (3D) colour reproduction system to improve the aesthetic effects of dental prostheses. The system’s colour accuracy was also evaluated. Based on the concept of colour management, 96 colour patches were selected to develop colour profiles for an intraoral scanner and a 3D printer using polynomial regression. The colour differences Δ$${E}_{ab}^{\ast }$$Eab⁎ between colour patches reproduced using different colour profiles and the original colour patches were analysed to select the best combinations of colour profiles. The 3D colour reproduction system with the best-performing (i.e. third-order polynomial regression) colour profiles was finally evaluated using tooth and gum shades. The median Δ$${E}_{ab}^{\ast }$$Eab⁎ was 6.940 ranging from 1.504 to 32.660. In terms of tooth and gum shade, the median Δ$${E}_{ab}^{\ast }$$Eab⁎ was 6.313, and half of the shade blocks were above the mismatch threshold (Δ$${E}_{ab}^{\ast }$$Eab⁎ > 6.80). In conclusion, the colour management based on polynomial regression can decrease the colour difference of the 3D colour reproduction system, but not to clinically acceptable levels. Further advances are needed to improve the methods and hardware.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 580
Author(s):  
Francisco J. G. Silva

Though new manufacturing processes that revolutionize the landscape regarding the rapid manufacture of parts have recently emerged, the machining process remains alive and up-to-date in this context, always presenting itself as a manufacturing process with several variants and allowing for high dimensional accuracy and high levels of surface finish [...]


Author(s):  
Alexander Schmidt ◽  
Leona Klussmann ◽  
Maximiliane A. Schlenz ◽  
Bernd Wöstmann

Abstract Objectives Due to the partly strongly differing results in the literature, the aim of the present study was to investigate a possible deformation of the mandible during mouth opening using an intraoral scanner (IOS) and a conventional impression for comparison with a reference aid. Materials and methods Four steel spheres were reversibly luted in the mandibular (n = 50) with a metallic reference aid at maximum mouth opening (MMO). Two digital impressions (Trios3), at MMO and at slightly mouth opening SMO and a conventional impression (Impregum), were taken as the measuring accuracy of the reference structure was already known. Difference between MMO-SMO for digital impressions and deviations between digital and conventional (SMO) were calculated. Furthermore, the angle between the normal vectors of two constructed planes was measured. Statistical analysis was performed with SPSS25. Results Deviations for linear distances ranged from −1 ± 3 μm up to 17 ± 78 μm (digital impressions, MMO-SMO), from 19 ± 16 μm up to 132 ± 90 μm (digital impressions, SMO), and from 28 ± 17 μm up to 60 ± 52 μm (conventional impressions, SMO). There were no significant differences for digital impressions (MMO-SMO), and there were significant differences between the conventional and digital impressions at SMO. Conclusions Based on the results of the present study, no mandibular deformation could be detected during mouth opening with regard to the digital impressions. The results were rather within the measuring tolerance of the intraoral scanner. Clinical relevance Based on the present study, no deformation of the mandibular during mouth opening could be observed at the level previously assumed. Therewith related, dental techniques related to a possible mandibular deformation therefore should be reconsidered.


Cephalalgia ◽  
2014 ◽  
Vol 34 (11) ◽  
pp. 927-932 ◽  
Author(s):  
Antonia FH Smelt ◽  
Willem JJ Assendelft ◽  
Christel E van Dijk ◽  
Jeanet W Blom

Background Clinical trials on the prophylactic effect of propranolol and metoprolol for migraine show that starting this medication leads to a decrease in the use of attack medication of 0.9–8.9 doses per month. However, studies in daily practice are lacking. Methods We compared the number of triptans prescribed in the six months before and the six months after the start of propranolol/metoprolol in a Dutch national representative primary care cohort. Results Of the 168 triptan-using patients who started with propranolol or metoprolol, the number of triptans prescribed before starting was 4.6 doses per month. The number of triptans prescribed six months before compared with six months after starting propranolol/metoprolol decreased with 1.0 dose per month (Wilcoxon rank test; p = 0.000). Conclusion In this primary care population, although the number of triptans prescribed decreased after starting propranolol or metoprolol, the decrease is relatively small compared to data from clinical trials.


Author(s):  
Jesús Peláez Rico ◽  
Jorge Cortés-Bretón Brinkmann ◽  
María Carrión Martín ◽  
Mabel Albanchez González ◽  
Celia Tobar Arribas ◽  
...  

The aim of this clinical report is to describe a maxillary full-arch implant supported restoration with immediate loading performed by means of an entirely digital workflow with photogrammetric system and intraoral scanning. A female patient with an edentulous maxillary arch attended the dental clinic seeking a maxillary fixed restoration. After treatment planning, six implants were placed using a surgical splint fabricated digitally by intraoral scanning of her previous removable prosthesis. Multi-unit abutments were fitted and two digital impressions were taken, one with a photogrammetric system for determining implant positions, and the other with an intraoral scanner for soft tissue registration. The acrylic resin structure of the immediate prosthesis was milled and placed within 8 hours of implant surgery. This provisional structure fitted correctly and provided adequate esthetics and function. Radiographic and clinical follow-up after 24 months observed adequate implant evolution.


Author(s):  
Mahsa Abbasi ◽  
Behnaz Ebadian ◽  
Negin Aminianpour

Introduction: Digital impression tools are an alternative to old impression materials and have developed significantly in recent years. These systems generally include two types of scanners: direct and indirect scanners. This article aimed to review and compare these two types of scanners. Description: Data were collected by reviewing a total of forty articles on dimensional accuracy, a combination of scans, and internal and marginal gaps for comparison of direct and indirect scanners. These articles were retrieved from PubMed and Scopus and published between 2010 and 2020 using the following keywords: intraoral scanner, lab scanner, marginal gap, internal gap, and accuracy rate. Results: Direct scanners had a lower amount of marginal and internal gaps, while indirect scanners had a lower deviation in more prepared teeth in the half and full arch due to the ability of stitching scans. Regarding the dimensional accuracy, the results of studies were inconsistent, but clinical studies pointed to the superiority of indirect scanners. The type of scanner suggested being selected depending on conditions such as the size of area, time, convenience of procedure, etc. The clinical results of both types of scanners were clinically acceptable.


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