Surface discoloration of hybrid materials fabricated from 3D printing technology compared with milling procedure

This in-vitro study investigated color (ΔE00) and translucency (ΔTP) changed in 3D printing (VarseoSmile Crown plus®, VS) and milling (VITAEnamic®, EN and CeraSmart®, CS) CAD/CAM hybrid material. The 306 rectangular specimens from each material were divided randomly (n=34) to be immersed in distilled water, coffee, and cola. ΔE00 and ΔTP were computed before and afterimmersing at 10, 20 and 30 days by using a spectrophotometer, following ISO/TR 28642:2016 standards. A two-way ANOVA followed by post-hoc Tamhane multiple comparison test and a one-way repeated measures ANOVA were performed(p=0.05). The result revealed that type of material, type of staining solution and interaction effect of type of material* type of staining solution material had a statistically significant effect on the ΔE00 and ΔTP at 10 days, 20 days, and 30 days (p<0.001). VS in coffee greater ΔE00 (more color change) than EN but less than CS. Also, VS in Cola has greater ΔE00 than EN and CS at day 20 and 30 of immersion. VS in water has greater ΔE00 than EN and CS at 30 days. VS in water and coffee hasreduced translucency more than EN and CS at all times. Coffee showed the highest discoloration at all times. Time is a crucial factor affecting discoloration in both 3D printing and milling resin ceramic hybrid materials in almost immersed beverages.The results can be concluded that all materials have tendency to discolor after immersion in staining beverages and gradually increased as the period of immersion.