A commercial DVD is pressed, so it is a very thin sheet of metal which is punched and then sandwiched in plastic.
A home-made DVD is burnt - there is a special dye which reacts to the laser of a writer.
Because of the difference in the ways they are produced, there is no way the laser on a DVD reader could write to the data on a commercial DVD. I would he HIGHLY surprised if a DVD reader could write to a home-made disc either.
