Influence of Silver-Doped Hydroxyapatite Nanoparticles on the Mechanical and Functional Properties of Glass Ionomer Cement

Abstract

Background: Glass ionomer cement (GIC) is widely used in restorative dentistry because of its chemical adhesion to tooth structure, fluoride release, and biocompatibility. However, its relatively lower mechanical strength and wear resistance limit its long-term clinical performance in stress-bearing areas. Incorporation of bioactive nanoparticles has emerged as a promising strategy to improve the functional properties of GIC.

Aim: To evaluate the influence of silver-doped hydroxyapatite nanoparticles on the surface roughness, microhardness, fluoride release, and compressive strength of glass ionomer cement.

Materials and Methods: In this in vitro study, sixty specimens were prepared and randomly divided into three groups (n = 20): Group I – conventional GIC, Group II – silver-doped hydroxyapatite nanoparticle-modified GIC, and Group III – bulk-fill composite resin. Silver-doped hydroxyapatite nanoparticles were incorporated into conventional GIC powder to obtain a homogeneous modified restorative material. Standardized specimens were fabricated using stainless steel molds. Surface microhardness was assessed using a Vickers hardness tester following simulated toothbrushing of 10,000 cycles. Surface roughness was evaluated using a non-contact profilometer, and representative specimens were analyzed using atomic force microscopy. Fluoride release was measured at predetermined intervals using an ion-selective method. Compressive strength was determined using a universal testing machine. Data were analyzed using one-way ANOVA and post hoc tests with significance set at p < 0.05.

Results: The silver-doped hydroxyapatite modified GIC demonstrated improved microhardness and compressive strength compared with conventional GIC. Surface characteristics showed favorable roughness values after brushing simulation. Fluoride release was maintained/enhanced in the modified group. Statistically significant differences were observed among the groups (p < 0.05).

Conclusion: Incorporation of silver-doped hydroxyapatite nanoparticles enhanced the mechanical and functional properties of GIC while preserving its fluoride-releasing potential. This modified material may serve as a promising restorative option for improved clinical performance.