Incorporation of Naturally Obtained Hydroxyapatite Nanoparticles in Resin Luting Cements and Glass Ionomer Cement to Valuate Water Sorption and Solubility: An In Vitro Study

Purpose: To evaluate the water sorption and solubility of naturally obtained nano-hydroxyapatite (nano-HAp) incorporated into type 1 glass ionomer cement (GIC) and resin luting cements. Materials and methods: Hydroxyapatite synthesized from raw unfertilized eggshells <i>via</i> the co-precipitation technique was incorporated into type 1 GIC and resin cements. The eggshells were characterized using X-ray diffraction (XRD) analysis, scanning electron microscope (SEM), energy-dispersive X-ray (EDAX), and Fourier transform infrared spectroscopy (FTIR). A total of 80 disk-shaped specimens were made from type 1 GIC (group A) and resin cements (group B). The specimens of group A (<i>n</i> = 40) were further divided into subgroups (<i>n</i> = 10 specimens each) based on the percentage of incorporation of nano-HAp: A1: Control (no nano-HAp incorporated); A2: 6% nano-HAp; A3: 8% nano-HAp; A4: 10% nano-HAp. Group B (<i>n</i> = 40) was subdivided (<i>n</i> = 10 specimens each) as follows: B1: Control (no nano-HAp incorporated); B2: 0.5% nano-HAp; B3: 1% nano-HAp; B4: 2% nano-HAp. The specimens were evaluated for water sorption and solubility. For intergroup comparisons, a one-way analysis of variance (ANOVA) was performed. Following that, Tukey’s honestly significant difference (HSD) test was used for intragroup comparisons. Results: Nano-HAp synthesized from eggshells exhibited high crystallinity (up to 96%) with a particle size of 100–200 nm and the presence of phosphate, hydroxyl, and calcium ions. One-way ANOVA showed a significant difference in water sorption (<i>p</i> = 0.001) and solubility (<i>p</i> = 0.001) among group A and group B specimens. Type 1 GIC incorporated with 10% nano-HAp had the lowest water sorption (74.501 ± 2.00%) and solubility (24.833 ± 4.185%). Resin cements incorporated with 2% nano-HAp had the lowest water sorption (32.45 ± 1.73%) and solubility (15.943 ± 0.749%). Multiple comparisons of water sorption and solubility in group A and group B showed a significant difference (<i>p</i> = 0.001) between subgroups. Conclusion: Within the limitations of this study, it can be concluded that nano-HAp exhibited high crystallinity and a suitable particle size. The incorporation of nano-HAp enhanced the water sorption and solubility properties of type 1 GIC and resin-based luting cements. The addition of 10% nano-HAp in type 1 GIC and 2% nano-HAp in resin luting cement resulted in the most significant reduction in water sorption and solubility. Nano-HAp-modified GIC and resin cements may enhance marginal longevity, improve biocompatibility, prevent secondary caries, and provide esthetic and functional benefits. How to cite this article: Mariappan A, Marballi Basavaraju R, Aradya A, <i>et al.</i> Incorporation of Naturally Obtained Hydroxyapatite Nanoparticles in Resin Luting Cements and Glass Ionomer Cement to Valuate Water Sorption and Solubility: An <i>In Vitro</i> Study. Int J Prosthodont Restor Dent 2025;15(1):27–35.