How can i make a bowl shape object solid

[system]

I have a scanned object (a helmet)
which has hole where face and neck are.
is there an easy way i can mask the skin i want and
make the helm solid. In other words fill the face and neck

Maybe another way to describe it. I have a bowl that i want to turn into a half sphere while retaining the outside details
thanks

[Zeddie]

if it is an actual, true hole then either “close holes” or dynamesh should close it.

if by hole you actually mean a sort of indented mesh then you have to do that by hand.

[Gordon_Robb]

An image would help.