Impact of red propolis addition on the color stability and surface roughness of glass ionomer cements

Objective: The present study aimed to evaluate the surface roughness (SR) and color stability of ­conventional restorative glass ionomer cements (GICs) modified with the addition of red propolis ethanolic extract (RPEE) as an antimicrobial agent. Methodology: Four GICs (Riva, Maxxion, Vidrion, and Ketac) were used with the addition of RPEE at ­concentrations of 11% and 20%. For the control groups, the GICs were manipulated according to the manufacturers’ instructions. SR was assessed using a surface profilometer. For the color variation analysis, the specimens’ colors were measured in the CIE Lab* color space using a spectrophotometer. The Kruskal–Wallis test, followed by Dunn’s test, was used to evaluate statistical significance. Results: The addition of RPEE did not negatively affect the SR of Riva, Maxxion, and Ketac GICs (p = 0.796, p = 0.111, and p = 0.858, respectively). By contrast, a significant reduction in SR was observed in Vidrion GIC with the addition of RPEE (p = 0.009). When comparing the different GIC brands, Riva and Ketac exhibited the lowest SR, with significant differences relative to Vidrion (p = 0.008) and Maxxion (p = 0.006). Both RPEE concentrations (11% and 20%) caused major color changes in all GICs tested, with no statistical differences between the two concentrations (p = 1.000), nor among the different GIC brands (p = 0.071). Conclusion: The incorporation of RPEE into conventional GIC did not increase SR, though in the case of Vidrion cement, it resulted in a significant reduction of this parameter. Conversely, the addition of red propolis at both 11% and 20% concentrations caused significant and clinically unacceptable color changes in all tested cements, regardless of brand or concentration.