Optical properties evaluation of rapid sintered translucent zirconia with two dental colorimeters

Abstract

Background/purpose The efficient rapid sintering technique has employed to dental zirconia ceramics for shortening the fabrication time of zirconia restorations. The purpose was to compare the optical properties of two generations of rapid sintered translucent zirconia using two dental colorimeters. Materials and methods Two generations of translucent zirconia ceramics, 3 mol% yttria-tetragonal zirconia polycrystal (3Y-TZP): Copran Zr-i Ultra-T (UT) and Cercon HT (HT), and 5 mol% yttria-tetragonal zirconia polycrystal (5Y-TZP): Cercon xt (XT), of different thicknesses (0.5, 0.8, and 1.2 mm; n = 5) underwent rapid sintering (RS) or conventional sintering (CS). The CIELAB values were measured on the white and black backgrounds, respectively, by digital colorimeters, shadepilot, DeguDent (DD) and Easyshade V, Vita (Vita). Translucency parameter (TP), color difference (ΔE), surface morphology, and surface roughness were evaluated. Results RS resulted in reduced lightness, except in the XT group. The chromaticity increased slightly after RS. Translucency decreased with increasing material thickness. ΔE values differed between both sintering processes but were clinically acceptable (ΔE < 5). Grain size of XT decreased after RS. RS did not affect the surface roughness. Conclusion RS is a feasible method for shortening the manufacturing time of zirconia restorations. A significant difference in TP value was only in the XT group between both sintering methods as measured on DD. Color differences in rapid sintered translucent zirconia materials are imperceptible and acceptable. The specimen thickness affected more in the TP values of Vita than DD. DD has higher sensitivity to translucency and color compared with Vita.

Effect of Cooling Rate during Glazing on the Mechanical and Optical Properties of Monolithic Zirconia with 3 mol% Yttria Content

“…Numerous studies have been conducted for improving the aesthetics, strength, and toughness of zirconia [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Grain boundaries, pores, the presence of secondary phases, and light scattered by rough surfaces have been reported to reduce the translucency of zirconia [ 25 ].…”

Translucency of recent zirconia materials and material-related variables affecting their translucency: a systematic review and meta-analysis

“…Translucency (TP) was not significantly influenced by the sintering method - highest TP was Kat. UTML CS (25.40 ± 0.48)/ lowest TP Zpex Smile SS (15.34 ± 0.54) Liu 2022 [ 43 ] translucency TP of different sintering using two colorimeters 3Y-PSZ : Cercon HT (HT),Copran Zr-i Ultra-T (UT) 5Y-PSZ: Cercon xt (XT), 5 Conventional and rapid sintering according to the manufacturers’ instructions 0.5, 0.8, and 1.2 mm Vita Easy-shade V, zahinfabrik,Germany (Vita) Shadepilot,DeguDent, GmbH, Germany (DD) Results were shown in figures TP values of the CS, RS group were nearly, except XT group with DD. XT was significantly highest TP Vafaei 2022 [ 44 ] translucency parameter (TP) with various sintering temperature 5Y-PSZ : -White Peaks Symphony (WPS) -e. max ZirCAD (IEZ) 10 at 1530, 1500, or 1440 °C with 17 °C/min heating rate for 2 h 1 mm digital camera (Canon EOS 6D 20.2MP) (TP) WPS 1440: 9.25 ± 0.99, 1500: 11.33 ± 0.68, at 1530: 13.34 ± 0.83 IEZ 1440: 8.12 ± 0.47, 1500: 9.32 ± 0.25, at 1530: 10.65 ± 0.48 Park 2022 [ 45 ] translucency parameter (TP) 5Y-PSZ : Rainbow High Shine, 4Y-PSZ: Rainbow Shine, 3Y-PSZ :RainbowShade, lithium disilicate 10 sintered according to the manufacturers’ instructions 0.8 mm and 1.5 mm spectrophotometer (SpectroShade Micro; MHT Optic Research AG) TP at 0.8 mm: 3Y-TZP: 13.32 ± 0.32 4Y TZP: 14.12 ± 0.18 5Y TZP: 16.47 ± 0.39 Lithium disilicate 19.17 ± 0.29 TP at 1.5 mm: 3Y-TZP: 10.55 ± 0.14 4Y TZP: 11.89 ± 0.26 5Y TZP: 14.13 ± 0.12 Lithium disilicate: 14.20 ± 0.32 Kongkiatkamon.2022 [ 46 ] Effect of speed sintering on translucency parameter (TP) 5Y-PSZ: Katana STML 15 RS: regular sintering for 2 h, at 1550 ◦C SS: speed sintering for16 min, at1560 ◦C 1.23 mm ...…”

“…Several studies suggested speed sintering procedures resulted in a reduction in translucency. that further investigations are necessary to find out the effect of different sintering methods on various YSZ [ 42 , 43 , 52 , 53 , 56 , 65 , 66 , 75 ]. Salah 2023 found that superspeed sintering for 10 min significantly reduced translucency and resulted in a greater change in color [ 39 ].…”

Do Polishing Methods and Colorant Beverages Affect the Color Stainability of 3D-printed Permanent Restorations?

“…Although Vita Easyshade V is designed for in-vivo color measurements, it has also been used for in-vitro measurements in many studies and its accuracy and reliability have been demonstrated. 8,13,15,22,23 CIELAB color difference formula (ΔE) has been used to evaluate color changes in dental restorative materials. However, in the last decade, researchers have been reporting color changes using the CIEDE2000 color change formula (ΔE 00 ), which has been proven to be more accurate in the visual perception of color change.…”