CALCIUM PHOSPHATE cements (CPCs), using B-triCALCIUM PHOSPHATE (ß-TCP, Ca3 (P04)2), diCALCIUM PHOSPHATE (DCP, CaHP04), CALCIUM carbonate (Ca CO3), and hydroxylapatite (HAp, Ca10(P04)6(OH)2) as powder cement and disodium hydrogen PHOSPHATE (Na2HP04) solution as liquid component were prepared. After mixing the powder and liquid constituents, injectable and self-setting CALCIUM PHOSPHATE cements (CPCs) were prepared with different liquid to powder ratios (UP) that formed hydroxylapatite and ß-triCALCIUM PHOSPHATE as the only end products, which were characterized by FTIR, XRD and SEM techniques. The results showed that, at certain concentration of Na2HP04 (6 wt%), the initial and final setting times decreased by decreasing the UP ratio.

Objectives: Due to the importance of using more effective varnishes to prevent dental caries, this study aimed to compare the effect of conventional casein phosphopeptide-amorphous CALCIUM PHOSPHATE (CPP-ACP) and CPP-ACP with 1 and 2 w% nanosilver particles on microhardness of enamel of primary canines. Methods: The initial surface micro-hardness of 36 intact human deciduous canines were measured by a Vickers hardness tester, then samples were immersed in demineralization solution for 24 hours, and then the microhardness of samples was re-measured. All samples were randomly divided into 4 groups (n=9): (A) control group(without therapy), (B) conventional CPP-ACP, (C) CPP-ACP with 1% nano silver, and (D) CPP-ACP with 2% nanosilver. Then samples were entered into pH cycles for 7 days. At the end of pH cycling, the surface microhardness of samples was measured, and the mean for each group was calculated. Data analysis was performed using one-way ANOVA and Tukey analysis. Results: The mean enamel micro-hardness in all groups after demineralization decreased significantly (P<0. 05), but this reduction was significantly less in all three experimental groups compared to the control group (P<0. 05). There was no significant difference in the rate of surface microhardness changes between the three experimental groups (P>0. 05). Conclusion: Conventional CPP-ACP and CPP-ACP with 1 and 2 w% Nanosilver particles were equally effective on the enamel surface microhardness of human deciduous teeth. Silver Nanoparticles have no negative effect on enamel microhardness.