It is desirable to improve the mechanical strength of resin- modified glass- ionomer cement material while maintaining its favorable clinical properties such as fluoride release, tooth bonding and biocompatibility. In this study, nanoparticles of silver powder (NAg) of 0.1 and 1% by weight percent were added into the resin modified glass ionomer powder. The resin-modified glass-ionomer cement (RMGIC) was used as a control without the addition of silver nanoparticles (Nag(.The effects of silver powder nanoparticles (NAg) on shear bond strength, flexural strength, compression strength, tensile strength and fracture toughness were measured using a universal testing machine from Lloyd. Recorded values of shear bond strength, bending strength, compression strength, tensile strength in (MPa) and fracture toughness in (MPa.m1/2) were collected, tabulated and statistically analysed. For testing the significance between the means of tested properties of all tested materials, which are statistically significant when the P value ≤ 0.05, one way analysis of variance (ANOVA) and Tukey s tests were used. The addition of silver nanoparticles (NAg) to the glass ionomer modified by the resin resulted in significantly higher shear bond strength, flexural strength, compression strength, tensile strength and fracture toughness. These results show that silver nanoparticles (NAg) added to the resin-modified glass-ionomer cement can be used as a dependable restorative material with improved shear bond strength, flexural strength, compression strength, tensile strength and fracture toughness. The addition of spherical nanoparticles of silver powder( NAg) to RMGIC powder has been concluded that the shear bond strength, flexural strength, compression strength, tensile strength and fracture toughness increase.