Effect of Nanodiamond Incorporation on the Surface, Mechanical, and Tribological Properties of Glass Ionomer Cement

Background/Objectives: Glass ionomer cements (GICs), high-biocompatibility dental materials that release fluoride with a cariostatic and remineralising effect on hard dental tissues, are widely used in many fields of dentistry, including conservative dentistry, pediatric dentistry, prosthodontics, and orthodontics; however, their mechanical performance and wear resistance remain limited. This study investigated the effect of nanodiamond (ND) addition (0.5–4.0 wt.%) on the surface, mechanical, and tribological properties of a conventional self-curing GIC. Methods: Surface roughness, microhardness, wear resistance, coefficient of friction, and chemical composition were evaluated using confocal microscopy, Vickers microhardness testing, tribological measurements, and EDX analysis. Results: The incorporation of NDs reduced the coefficient of friction and modified the surface morphology of the cement. The lowest friction coefficient (0.444) was observed for the sample containing 2 wt.% ND. However, ND addition also resulted in an approximately 50 per cent decrease in microhardness and wear resistance compared with the unmodified cement. EDX analysis confirmed that the chemical composition of the GIC matrix remained largely unchanged. Conclusions: The results indicate that nanodiamonds can improve the tribological behavior of glass ionomer cements, although further optimization of nanoparticle concentration and dispersion is necessary to maintain adequate mechanical properties.