Once your 8mm film to DVD has been restored and completed, there are companies that can put that video back on film. It isn’t easy and it isn’t cheap, but video can be put back on 8mm film.
A better way to achieve good quality is to transfer the 8mm film to a format like HD-AVI files instead of transferring your 8mm film to DVD. DVD is highly compressed and is only about ½ the resolution of your 8mm film. HD-AVI has 1080 lines of resolution which is just above the 800 to 1000 lines of resolution on your 8mm film.
So, by having your film transferred to a high definition video format, you can retain the quality of the 8mm film. Then a company can take that high resolution file and create 8mm film from it.
So, yes, it is possible to transfer you 8mm film to DVD and then back to film but you will get better quality by transferring your film to a high definition format first and then take that back to 8mm film.