Normal temperatures after change thermal paste

Hi guys, I’ve recently changed the thermal paste on my old boy, a macbook pro mid 2010 15”.

I’ve used the MX-4, using the spread technique, the only bad thing is that some residues of the old paste, didn’t came out, I mean between the step near the PCB and CPU, I’ve used alchool to remove the old, and I made the surface clean like a mirror, unless those bad step ( I made my best using the spudger but the old paste was very very dry, probably I had to use a solvent).

Now the temps are from 38 - 50 if I use chrome and any other light app, but when I put at full screen a 1080p video on youtube, the temp goes up tu 80/90 ° ( It depends if I use the mac while is charging)

What do you think ? Are good temps or I’ve to redo the work using a solvent to remove these old dry rest of thermal paste?