Introduction: Any esthetic restorative material largely depends on the color match and the color stability of the material in long term use. Also the smooth surface appear to be critical for composite performance and it's aesthetic outcome. However resin composites are materials that can show color changing when exposed to staining media.
Objectives: The aim of this invitro study is to evaluate the color stability, change in opacity and change in surface roughness of an ORMOCER, and two methacrylate based composites after being immersed in different staining solutions with different time intervals.
Materials and methods: A total of one hundred twenty disc specimens (10mm in diameter and 2mm in thickness) were prepared from three composite resins, A bulk fill ORMOCER based (Admira fusion X-tra) and a bulk fill methacrylate based (X-tra fill) and an incremental fill methacrylate based (Esthet-X HD) composite resins (n = 40). Specimens of each type were divided in to four groups according to immersion solutions (n = 10). Group A= Specimens were immersed in coffee (Nescafe classic, Nestle, Egypt), Group B= Specimen were immersed in tea (Lipton yellow lable, Unilever brand, Egypt), Group C = Specimen were immersed in cola (Coca cola company, Egypt) and Group D= Specimen were immersed in distilled water as a control group. Color evaluation was done at base line before staining and then at periods of 7 days, 14 days, 28 days using spectrophotometer. Change in color (∆E*) and opacity (∆Op) were obtained using the CIE L*a*b* system. Surface roughness was evaluated using Atomic Force microscopy at baseline before staining and then at 28 days from immersion in staining solutions.
Results:All composite used showed change in color values at the end of the time intervals after 28 days of immersion in staining solutions. Group A (coffee) was the highest effecting group (ΔE >3.3) and Admira fusion X tra was the material with the highest change in color. Surface roughness also increased especially in group C (cola) for all materials after 28 days with no statistically significant difference between groups (p>0.05).
Conclusions: Coffee has a higher effect on staining composite resin than tea and cola. While cola affected the surface roughness of the composite resins used  more than the other solution used.