Effect of Hydroxyapatite From Nile Tilapia (Oreochromisniloticus) Scale on Surface Hardness of Conventional and Resin Modified Glass Ionomer Cement (In Vitro Study)

Surface hardness of restoration materials affected its wear resistance and longevity. The addition of hydroxyapatite could improve mechanical properties of restoration material. Hydroxyapatite can be synthesized from fish scales for it contain calcium carbonate. The aim of this study was to evaluate the surface hardness of conventional and resin modified glass ionomers cement by incorporation of different wt% of hydroxyapatite from Black tilapia (Oreochromisniloticus) scales. Hydroxyapatite was synthesized from black tilapia scales by calcination method. Samples with a diameter of 5 mm and a height of 2 mm were made from conventional and resin modified glass ionomer cement, then divided into 7 groups (n=10), namely control, 2wt% GIC, 5wt% GIC, 8wt% GIC, 2wt% RMGIC, 5wt% RMGIC, and 8wt% RMGIC. Surface hardness test was measured with Vickers Hardness Tester. Result showed hardness value from each groups respectively were 49.81 ± 3.55 VHN, 34.49 ± 1.82 VHN, 32.58 ± 1.61 VHN, 36.63 ± 3.09 VHN, 32.05 ± 3.77 VHN, 36.23 ± 4.27 VHN, and 19.27 ± 1.71 VHN. One-way ANOVA test showed a significant differences in all group (p <0.05). It can be conclude that hydroxyapatite from fish scale had an effect on surface hardness of conventional and resin modified glass ionomer cement, whereas it decreased the hardness of conventional GIC, yet it increased the RMGIC hardness.