Casing has chipped corner, what can I use to patch it?

Hiya fixers. Attempting to replace a screen on a Surface Pro 3 (1631) and while trying to remove a bend blocking the new screen from going in, a tiny piece of the corner sheared and chipped off! I can now fit the new screen in, but now there is a small section in the corner where the under screen is exposed. It is also quite sharp where it sheared. I plan to file it down enough to where injury will not occur from handling it, but wondered if anyone had an idea of a substance I can use to patch this tiny section. A material that would be malleable at first but then become strong. Last resort I will use a case that covers the corner