scholarly journals The development of a 3D colour reproduction system of digital impressions with an intraoral scanner and a 3D printer: a preliminary study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yushu Liu ◽  
Rui Zhang ◽  
Hongqiang Ye ◽  
Shimin Wang ◽  
Kuan-Paul Wang ◽  
...  
Keyword(s):  
Polynomial Regression ◽  
Three Dimensional ◽  
3D Printer ◽  
Intraoral Scanner ◽  
Third Order ◽  
Reproduction System ◽  
Dental Prostheses ◽  
Digital Impressions ◽  
Preliminary Study ◽  
The Aesthetic

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.

scholarly journals Accuracy of digital dental models and three-dimensional printed dental models in linear measurements and Bolton analysis

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 180
Author(s):  
William Suryajaya ◽  
Maria Purbiati ◽  
Nada Ismah
Keyword(s):  
Treatment Planning ◽  
Interobserver Reliability ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
3D Printer ◽  
Intraoral Scanner ◽  
Linear Measurements ◽  
Dental Model ◽  
Dental Models ◽  
Digital Dental Models

Background: Due to advances in digital technology, it is possible to obtain digital dental models through intraoral scanning. The stereolithographic data collected from the scanner can subsequently be printed into a three-dimensional dental model in resinic material. However, the accuracy between digital dental models and printed dental models needs to be evaluated since it might affect diagnosis and treatment planning in orthodontic treatment. This study aimed to evaluate the accuracy of digital models scanned by a Trios intraoral scanner and three-dimensional dental models printed using a Formlabs 2 3D printer in linear measurements and Bolton analysis. Methods: A total of 35 subjects were included in this study. All subjects were scanned using a Trios intraoral scanner to obtain digital study models. Stereolithographic data from previous scanning was printed using a Formlabs 2 3D printer to obtain printed study models. Mesiodistal, intercanine, intermolar, and Bolton analysis from all types of study models were measured. The intraclass correlation coefficient was used to assess intraobserver and interobserver reliability. All data were then statistically analyzed. Results: The reliability tests were high for both intraobserver and interobserver reliability, which demonstrates high reproducibility for all measurements on all model types. Most of the data compared between study models showed no statistically significant differences, though some data differed significantly. However, the differences are considered clinically insignificant. Conclusion: Digital dental models and three-dimensional printed dental models may be used interchangeably with plaster dental models for diagnostic and treatment planning purposes. Keywords: Accuracy, 3D printing, digital dental model, printed dental model.

scholarly journals Accuracy of digital dental models and three-dimensional printed dental models in linear measurements and Bolton analysis

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 180
Author(s):  
William Suryajaya ◽  
Maria Purbiati ◽  
Nada Ismah
Keyword(s):  
Treatment Planning ◽  
Interobserver Reliability ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
3D Printer ◽  
Intraoral Scanner ◽  
Linear Measurements ◽  
Dental Model ◽  
Dental Models ◽  
Digital Dental Models

Background: Due to advances in digital technology, it is possible to obtain digital dental models through intraoral scanning. The stereolithographic data collected from the scanner can subsequently be printed into a three-dimensional dental model in resinic material. However, the accuracy between digital dental models and printed dental models needs to be evaluated since it might affect diagnosis and treatment planning in orthodontic treatment. This study aimed to evaluate the accuracy of digital models scanned by a Trios intraoral scanner and three-dimensional dental models printed using a Formlabs 2 3D printer in linear measurements and Bolton analysis. Methods: A total of 35 subjects were included in this study. All subjects were scanned using a Trios intraoral scanner to obtain digital study models. Stereolithographic data from previous scanning was printed using a Formlabs 2 3D printer to obtain printed study models. Mesiodistal, intercanine, intermolar, and Bolton analysis from all types of study models were measured. The intraclass correlation coefficient was used to assess intraobserver and interobserver reliability. All data were then statistically analyzed. Results: The reliability tests were high for both intraobserver and interobserver reliability, which demonstrates high reproducibility for all measurements on all model types. Most of the data compared between study models showed no statistically significant differences, though some data differed significantly. However, the differences are considered clinically insignificant. Conclusion: Digital dental models and three-dimensional printed dental models may be used interchangeably with plaster dental models for diagnostic and treatment planning purposes. Keywords: Accuracy, 3D printing, digital dental model, printed dental model.

Accuracy of Conventional and Digital Methods for Obtaining Dental Impressions and 3D Printed Models

2020 ◽  
Author(s):  
CAIO CÉSAR DIAS Resende ◽  
Tiago Augusto Quirino Barbosa ◽  
Guilherme Faria Moura ◽  
Lucas Nascimento Tavares ◽  
Fabio Antonio Piola Rizzante ◽  
...  
Keyword(s):  
3D Models ◽  
3D Printer ◽  
Test Results ◽  
Intraoral Scanner ◽  
Tukey Test ◽  
Digital Impressions ◽  
3D Printed ◽  
Digital Methods ◽  
Similar Accuracy ◽  
Conventional Impression

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.

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
Keyword(s):  
Digital Images ◽  
Digital Technologies ◽  
Dimensional Accuracy ◽  
High Dimensional ◽  
Rank Test ◽  
3D Printer ◽  
Intraoral Scanner ◽  
Digital Impressions ◽  
Plaster Models ◽  
Wilcoxon Rank Test

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. 

scholarly journals Preliminary Study on the Assessment of the Marginal Fit of Three-Dimensional Methacrylate Oligomer Phosphine Oxide Provisional Fixed Dental Prostheses Made by Digital Light Processing

Prosthesis ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 240-245 ◽  
Author(s):  
Pedro Molinero-Mourelle ◽  
Miguel Gómez-Polo ◽  
Cristina Gómez-Polo ◽  
Rocio Ortega ◽  
Jaime del Río Highsmith ◽  
...  
Keyword(s):  
3D Printing ◽  
Phosphine Oxide ◽  
Three Dimensional ◽  
Digital Light Processing ◽  
Marginal Fit ◽  
Dental Prostheses ◽  
Polyether Ether Ketone ◽  
Fixed Dental Prostheses ◽  
Preliminary Study ◽  
Spss Software

This article aimed to assess the marginal fit of methacrylate-oligomer-phosphine-oxide curable-resin provisional-fixed dental prostheses made by digital-light-processing (DLP) three-dimensional (3D) printing. A stainless-steel master model with two abutments was scanned, and five three-unit provisional bridges were designed and printed in VITA shade A3.5 curable resin in 50 μm-thick layers. The marginal fit of each abutment was measured at six points using a profile projector. A descriptive data analysis of the fit measurements was performed by descriptive and explorative processes with the SPSS software. The curable-resin provisional restorations made by DLP 3D printing reached values of 46.37 μm (SD: 29.58 μm), which were considered clinically acceptable, with values similar to polyethylene-methacrylate and polyether-ether-ketone provisional restorations.

scholarly journals Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

2021 ◽  
Author(s):  
Keunbada Son ◽  
Young-Tak Son ◽  
Ji-Min Lee ◽  
Kyu-Bok Lee
Keyword(s):  
Three Dimensional ◽  
3D Printer ◽  
Intraoral Scanner ◽  
Replica Technique ◽  
Finish Line ◽  
Marginal Fit ◽  
Tooth Preparation ◽  
The Right ◽  
Internal Fit ◽  
Marginal Region

Abstract This study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. A supragingival finish line is recommended for interim crown fabrication using an intraoral scanner.

scholarly journals Three-Dimensional Finite Element Analysis of Stress Distribution in a Tooth Restored with Full Coverage Machined Polymer Crown

2021 ◽  
Vol 11 (3) ◽  
pp. 1220
Author(s):  
Azeem Ul Yaqin Syed ◽  
Dinesh Rokaya ◽  
Shirin Shahrbaf ◽  
Nicolas Martin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Intraoral Scanner ◽  
Element Analysis ◽  
Dental Ceramic ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Ceramic Crown

The effect of a restored machined hybrid dental ceramic crown–tooth complex is not well understood. This study was conducted to determine the effect of the stress state of the machined hybrid dental ceramic crown using three-dimensional finite element analysis. Human premolars were prepared to receive full coverage crowns and restored with machined hybrid dental ceramic crowns using the resin cement. Then, the teeth were digitized using micro-computed tomography and the teeth were scanned with an optical intraoral scanner using an intraoral scanner. Three-dimensional digital models were generated using an interactive image processing software for the restored tooth complex. The generated models were imported into a finite element analysis software with all degrees of freedom concentrated on the outer surface of the root of the crown–tooth complex. To simulate average occlusal load subjected on a premolar a total load of 300 N was applied, 150 N at a buccal incline of the palatal cusp, and palatal incline of the buccal cusp. The von Mises stresses were calculated for the crown–tooth complex under simulated load application was determined. Three-dimensional finite element analysis showed that the stress distribution was more in the dentine and least in the cement. For the cement layer, the stresses were more concentrated on the buccal cusp tip. In dentine, stress was more on the cusp tips and coronal 1/3 of the root surface. The conventional crown preparation is a suitable option for machined polymer crowns with less stress distribution within the crown–tooth complex and can be a good aesthetic replacement in the posterior region. Enamic crowns are a good viable option in the posterior region.

scholarly journals Efficient 3D printing via photooxidation of ketocoumarin based photopolymerization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaoyu Zhao ◽  
Ye Zhao ◽  
Ming-De Li ◽  
Zhong’an Li ◽  
Haiyan Peng ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Visible Light ◽  
Light Exposure ◽  
Three Dimensional ◽  
3D Printer ◽  
Light Penetration ◽  
Viable Solution

AbstractPhotopolymerization-based three-dimensional (3D) printing can enable customized manufacturing that is difficult to achieve through other traditional means. Nevertheless, it remains challenging to achieve efficient 3D printing due to the compromise between print speed and resolution. Herein, we report an efficient 3D printing approach based on the photooxidation of ketocoumarin that functions as the photosensitizer during photopolymerization, which can simultaneously deliver high print speed (5.1 cm h−1) and high print resolution (23 μm) on a common 3D printer. Mechanistically, the initiating radical and deethylated ketocoumarin are both generated upon visible light exposure, with the former giving rise to rapid photopolymerization and high print speed while the latter ensuring high print resolution by confining the light penetration. By comparison, the printed feature is hard to identify when the ketocoumarin encounters photoreduction due to the increased lateral photopolymerization. The proposed approach here provides a viable solution towards efficient additive manufacturing by controlling the photoreaction of photosensitizers during photopolymerization.

scholarly journals A New Method to Evaluate Trueness and Precision of Digital and Conventional Impression Techniques for Complete Dental Arch

2021 ◽  
Vol 11 (10) ◽  
pp. 4612
Author(s):  
KweonSoo Seo ◽  
Sunjai Kim
Keyword(s):  
Intraclass Correlation ◽  
Three Dimensional ◽  
New Method ◽  
Digital Impression ◽  
Dental Arch ◽  
Digital Models ◽  
Digital Impressions ◽  
Measuring Machine ◽  
Master Model ◽  
Conventional Impression

Purpose: The aim of this study was to present a new method to analyze the three-dimensional accuracy of complete-arch dental impressions and verify the reliability of the method. Additionally, the accuracies of conventional and intraoral digital impressions were compared using the new method. Methods: A master model was fabricated using 14 milled polyetheretherketone cylinders and a maxillary acrylic model. Each cylinder was positioned and named according to its corresponding tooth position. Twenty-five definitive stone casts were fabricated using conventional impressions of the master model. An intraoral scanner was used to scan the master model 25 times to fabricate 25 digital models. A coordinate measuring machine was used to physically probe each cylinder in the master model and definitive casts. An inspection software was used to probe cylinders of digital models. A three-dimensional part coordinate system was defined and used to compute the centroid coordinate of each cylinder. Intraclass correlation coefficient (ICC) was evaluated to examine the reliability of the new method. Independent two sample t-test was performed to compare the trueness and precision of conventional and intraoral digital impressions (α = 0.05). Results: ICC results showed that, the new method had almost perfect reliability for the measurements of the master model, conventional and digital impression. Conventional impression showed more accurate absolute trueness and precision than intraoral digital impression for most of the tooth positions (p < 0.05). Conclusions: The new method was reliable to analyze the three-dimensional deviation of complete-arch impressions. Conventional impression was still more accurate than digital intraoral impression for complete arches.

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