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

Abstract

This 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 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 was 6.940 ranging from 1.504 to 32.660. In terms of tooth and gum shade, the median Δ was 6.313, and half of the shade blocks were above the mismatch threshold (Δ > 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.

Visual and digital tooth shade selection methods, related effective factors and conditions, and their accuracy and precision: A literature review

“…Exploiting real‐color scanning, TRIOS 3 can perform color selection with satisfactory, low mean Δ E ab values 137,238,240 . Though some shade taking devices reduce the tooth color data to a single code (e.g., A2), scanners present detailed color information 241 …”

“…137,238,240 Though some shade taking devices reduce the tooth color data to a single code (e.g., A2), scanners present detailed color information. 241 The variation of reports might be originated from differences in light reflection/detection system, different light sources (LED and a fluorescent lamp for scanners and Xenon lamp for colorimeters), and different color analyzing software algorithms. 22,200 Other dipartites between colorimeters and scanners include the differences between the size of measuring tips or measurement area which is much smaller in colorimeters than scanners.…”

Deathdaily: A Python Package Index for predicting the number of daily COVID-19 deaths

“…In statistics, polynomial regression is a form of regression analysis that models the relationship between an independent variable x and a dependent variable y as an n th degree polynomial in x. Polynomial regression is commonly used to observe trends and tendencies in a variety of applications(Zhang and Jiang 2021 ; Lee et al 2011 ; Liu et al 2019 ; Davies et al 2021 ). In deathdaily.py as shown in Fig.…”

3D Digital Printing in Healthcare: Technologies, Applications and Health Issues

“…Much progress has been made in the field of medically oriented 3D printing technology and the technology for making instrument models and permanent implants have become more mature. Researchers have successfully used various methods to improve the mechanical behaviour of individualized biodegradable scaffolds [4].…”