Silver nano particles have antimicrobial property which makes them appropriate for disinfection. Due to their antimicrobial feature, these particles are applicable for root canal irrigation. Fluid flow inside root canal and its appropriate circulation results in more efficient removal of microorganisms. Due to the very small dimensions of a root canal, performing experimental research is very difficult to identify the phenomena occurring in the root canal; therefore, numerical investigation will be very helpful to gain appropriate insight into the flow features of a root canal during irrigation for disinfection. Computation Fluid Dynamic (CFD) can be employed to numerically simulate the flow of irrigants inside the root canal. In the present study, the flow of Ag/water nanofluid in the root canal is numerically modeled. In order to evaluate the impact of height of injection and nanofluid concentration, two heights and concentrations are considered and compared. According to the results, lower injection height is more favorable due to better circulation of an irrigant in the root canal. Moreover, increase in the concentration of the nanofluid leads to reduction in maximum velocity of the fluid; which is attributed to higher increase in dynamic viscosity in comparison with the density. Velocity and wall shear stress contours in various cases are represented to gain better insight into the irrigant motion inside the canal. According to the results of simulation, wall shear stress of the root canal increases by increment in the concentration of the nanofluid and volumetric flow rate of the irrigants.