The Effects of Beverages and Surface Treatments on the Color Stability of 3D‐Printed Interim Restorations

Abstract

Purpose: To evaluate the color stability of 3D-printed interim restorations with different surface treatments while immersed in various staining solutions or beverages (artificial saliva, tea, coffee, and wine) for 6 months. Material and Methods: An acrylic tooth was prepared for an all-ceramic fullcoverage restoration. A laboratory scanner was used to digitize the prepared abutment tooth. A virtual all-ceramic full-coverage restoration was designed on the digitized abutment tooth using a laboratory CAD/CAM software. Eighty abutment teeth and interim restorations were 3D-printed with tooth-colored photopolymerizing resin. The restorations were randomly allocated into two different groups: Polish and Optiglaze. For the Polish group, interim restorations were finished and polished with aluminum oxide finishers/polishers. For the Optiglaze group, one layer of nanofilled, lightpolymerizing protective coating was then applied. The 80 printed interim crowns were divided into 4 different groups depending on where they would be immersed: Artificial saliva, coffee, wine, and tea. After the sample allocations, there were 8 experimental groups. Each group was allocated with 10 specimens. Color measurements were obtained using a digital spectrophotometer in conjunction with The CIE L*a*b* system before the immersion and 6 months after the immersion. Two-way analysis of variance (ANOVA) was used to test the effects of surface treatment, immersion liquid, and their interaction on E at 6-month post-immersion. Fisher's protected least significant differences (LSD) was used as post hoc test to compare groups differences (α = .05). Results: There were significant effects of surface treatment [F(1,72) = 13.39, p = 0.000], immersion liquid [F(3,72) = 74.18, p = 0.000], and their interaction [F(3,72) = 16.33, p = 0.000] on E at 6-month post-immersion at the α = .05 level. The polish group showed significantly higher E than the Optiglaze group when immersed in coffee (p < 0.001) and wine (p = 0.015). The Optiglaze group showed significantly higher E than the polish group that was immersed in artificial saliva (p < 0.001). The wine group showed higher E than all other immersion liquid groups for both polish and Optiglaze surface treatments (p < 0.001 for all comparisons). L* showed a reduction that was significantly higher than the 2.0 acceptability threshold in the wine-polish (p < 0.001) and wine-Optiglaze (p < 0.001) groups.E showed a color change that was significantly higher than the perceptibility and acceptability thresholds for all the groups under polish surface treatment (p < 0.001).E also showed a color change that was significantly higher than the perceptibility and acceptability thresholds for artificial saliva, tea, and wine under Optiglaze surface treatment (p = 0.004). Conclusions: 3D-printed interim restorations showed significant discoloration after 6-months immersions in the artificial saliva and common beverages (including tea, coffee, and wine). Among all the chromogenic beverages, red wine caused the most signific...

Color and optical properties of 3D printing restorative polymer‐based materials: A scoping review

“…Korean authors published four studies, 40,43,44,46 with three of them coming out of the Yonsei University (South Korea). 40,43,46 The remaining studies were conducted in the United States of America (USA), 41,45,47 Chile, 39 and Brazil. 42 Most studies were published in the Journal of Prosthetic Dentistry 41,42,47 and Materials.…”

“…40 Considering the polymer type, two articles compared 3D printing polymers to CAD/CAM-milled resin blocks and conventional polymers (acrylic resin, bis-acryl or resin-based composite); 39,44 two articles compared 3D printing polymers to CAD/CAM-milled resin blocks; 43,47 two articles compared conventional polymers to 3D printing polymers; 41,42 and three studies evaluated only 3D printing polymers. 40,45,46 dentistry are still considered temporary constructs. 5 The sample size ranged from 7 42 to 60, 41 but the most popular was n = 10.…”

“…42,44 Regarding the evaluated materials properties and parameters, five studies (55.5%) focused on evaluating only color stability, measuring L*a*b* coordinates and color differences; [43][44][45][46][47] three articles (33.3%) assessed the color stability along with other materials properties (surface roughness, flexural strength, Vickers hardness, Knoop hardness, Weibull modulus, and biocompatibility) 40,42 and color masking ability; 39 and only one study (11.1%) compared color parameters of 3D printed to conventional polymers. 41 All studies used either a clinical spectrophotometer (VITA Easy-Shade ® ) 39,41,42,45,47 or a colorimeter to measure color. 40,43,44,46 It was not found any study evaluating optical properties (scattering, absorption, and transmittance), and only two papers 39,46 evaluated translucency using the translucency parameter (TP) 46 or relative translucency parameter (RPT) 39 .…”

“…Most studies included in the present review examined color changes and color stability before and after thermocycling, 39 after storage in various discoloration media and for different time, 43,44,46,47 and using different surface treatments 42,45,47 and post-curing time. 40 The greater the storage time, the greater the discoloration of the polymers.…”

“…A CIELAB color difference (ΔE* ab ) from 1.4 to 3.8 was found after polishing procedures 47 and a significant influence of surface treatment on color differences was observed with a 6-month storage in various staining solutions and beverages. 45 The included studies show great variability of data for materials properties and parameters, which is mostly associated to the evaluation of different polymers manufactured by different stereolithography technology and printers. Regarding the post-curing procedure, some studies reported the use a UV device 39,40,43,46,47 or an association of UV and visible spectrum range device, 45 but other studies did not report 41,44 this information or stated that post-curing was not used.…”