Reply by Grandpa

Like GFADVM said use an air tool. They self cool and run forever. No motor to burn up. I am not sure what type work you are trying to do and I have never used a dental drill but I do have a friend that was carving in egg shells with the cheaper electric tools. He bought a dental drill and said it was like going from night to day. He had to pay more, a lot more, but he got a LOT more. Just what he told me.