Surface Roughness and Color Stability of Conventional Glass Ionomer Cement Reinforced With a Nanofiller Synthesized by the Coprecipitation Method.

Aim: Modification of conventional glass ionomer cement (GIC) using nanofillers is a promising approach to enhance its clinical performance. This study aimed to evaluate the surface roughness and color stability of conventional GIC after modification with a synthesized 70:30 hydroxyapatite/chitosan (HA/CTS) nanocomposite.

Materials and methods: A 70:30 hydroxyapatite/chitosan nanocomposite was synthesized and incorporated into GIC powder at 1, 3, and 5 wt.%. Four groups were prepared: Group I (control), Group II (1 wt.% HA/CTS), Group III (3 wt.% HA/CTS), and Group IV (5 wt.% HA/CTS). A total of 80 specimens were fabricated (n = 10 per group for each test). Surface roughness (Ra) was measured using a profilometer, while color stability (ΔE) was assessed using a spectrophotometer. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test (α = 0.05).

Results: GIC modified with the 3 wt.% HA/CTS nanocomposite exhibited the lowest surface roughness and demonstrated clinically acceptable color change (ΔE ≤ 3.3) (p < 0.05). Higher nanocomposite loading (5 wt.%) resulted in significantly increased surface roughness and clinically perceptible color alteration.

Conclusions: Incorporation of the 3 wt.% 70:30 HA/CTS nanocomposite into conventional GIC produced a smoother surface and acceptable esthetic outcome, suggesting a promising formulation for improved clinical performance.