Abstract
<title>Abstract</title> <p> Objectives To evaluate the effect of incorporating Garden Cress (Lepidium sativum), fixed oil at three concentrations via Gum Arabic on the compressive strength, surface microhardness, surface roughness, and colour stability of conventional glass ionomer cement (GIC). Materials and Methods Five groups (n = 10): G1 (unmodified control), G2 (GIC + 0.5 wt.% Gum Arabic), G3–G5 (GIC + Gum Arabic + 0.5, 1.0, 1.5 vol.% oil). Compressive strength, Vickers microhardness, surface roughness, and color difference (ΔE) against the control were measured alongside FTIR and SEM characterisation. One-way ANOVA with Tukey HSD was applied (α = 0.05). Results All outcomes showed significant group differences (p < 0.0001). G3 achieved the highest compressive strength (97.10 ± 3.75 MPa), exceeding the control (89.39 ± 3.13 MPa). G2 recorded the highest microhardness (73.33 ± 2.56 VHN) and smoothest surface (Ra = 0.488 ± 0.053 µm); G3 performed comparably at the surface level. Both properties declined progressively at 1.0 and 1.5 vol.%. Colour deviation increased dose-dependently; G2–G4 remained within the clinically acceptable range (ΔE < 3.3), while G5 exceeded this threshold (4.01 ± 0.37). FTIR, SEM, and EDX findings provided chemical, morphological, and elemental corroboration of the mechanical and surface outcomes. Conclusions Lepidium sativum fixed oil at 0.5 vol.% via Gum Arabic significantly enhanced compressive strength without compromising surface microhardness, surface smoothness, or colour acceptability. Higher concentrations produced progressive deterioration across all tested properties. 0.5 vol.% Lepidium sativum oil-modified formulation represents the optimal design <italic>in-vitro</italic> . Clinical Significance: This 0.5 vol.% Lepidium sativum oil-modified formulation demonstrated superior mechanical performance and clinically acceptable aesthetic color deviation, suggesting potential as a bioactive-enhanced restorative cement for both esthetic and potential load-bearing applications. </p>