Do we need to use dental cement to seal the hole on the dura when we finish the adeno-associated virus injection in the hypothalamus, if the injection speed is slow enough?
Not really. The speed of injection is not critical, you do not get reflux through the skull. Althoug, it is better to keep integrity of the bone if you need long-term survival and behavioural readouts.
Is it mice or rats? and for how long do they have to survive afterwards? I would not judge cementing as critical for acute/sub-acute survival. If the skull and wound are thoroughly cleaned after surgery and you have no reflux or bleeding, then the cementing of the hole should not be critical. Of course it depends on the size of your craniotomy, but for standard ones, I'd say you could just move forward without cementing. Good luck!
The dura will heal on itself. So, no closure necessary. Depending on the size of the hole in the skull bones use bone wax as suggested above and close the skin over it with sutures and/or tissue adhesives. Ask your veterinarian if you need help. Good luck!
As a precaution, we keep the injector tip in the brain for one minute post-injection. After removing the injectors, we clean the skull and close the holes in the skull with a small amount of bone wax. This is why making a small hole is important!
Like others have said, cement is not necessary. We use silk sutures to close the incision site.