Fuente: Polymers Polymers, Vol. 17, Pages 3127: Effects of Cement Shade, Cementation, and Thermocycling on the Color Parameters and the Final Color of the SLA-Printed Photopolymer Resins
Polymers doi: 10.3390/polym17233127
Authors:
Esra Kaynak Öztürk
Elif Yılmaz Biçer
Beyza Güney
Sina Saygılı
Nagehan Aktaş
Merve Bankoğlu Güngör

This study investigated the effects of resin cement shade and thermocycling on the color parameters and final appearance of SLA-printed photopolymer resins. Specimens with a thickness of 1 mm were fabricated and categorized into eight groups based on four different cement shades (universal-A2, clear, white, and opaque) and two applications (cementation and thermal aging). Differences in color parameters (ΔL*, Δa*, and Δb*) were measured after cement polymerization and thermocycling, and overall color differences (ΔE00-1 and ΔE00-2) were calculated. Two-way ANOVA revealed significant interactions between cement shade and thermocycling for ΔL*, Δa*, and Δb* (p < 0.05). After cementation, L* decreased for universal-A2, clear, and white cements, but increased for opaque cement. Furthermore, thermocycling altered L*, a*, and b* values differently among the experimental groups. Cement shade significantly influenced ΔE00, with universal-A2 and clear cements showing higher values than white and opaque cements (p < 0.05). All ΔE00 values exceeded the clinically acceptable limit (>1.8). The findings suggest that careful selection of the cement shade is therefore critical to achieving optimal esthetic outcomes with the tested 3D-printed resin. Formlabs SLA-printed permanent resin, although labeled as an A2 shade, behaves more like white or opaque shades, highlighting inconsistencies between labeled and actual color.