How does same capacitor with different dielectric affects the circuit?
My question is how does two diffrenet capacitor having same
  capacitance and footprint and voltage rating but only diffrent
  dielectric will affect my overall effect on circuit.


On some circuits it will have no affect and on some other circuits it may have a significant effect. Temperature of operation of your circuit can also play a part. On some circuits the better dielectric material of X7R still may not be good enough compared to going to C0G/NP0 dielectric.

So really, to answer this you have to look at your target circuit and ask yourself if the dielectric material is going to cause problems. Look at this picture below for an example of dielectric effects causing capacitor value changes versus temperature: -



And some dielectrics will modify the terminal capacitance depending on how much DC voltage is applied: -