I just searched through the third party driver website and there is no listing at all for Dell printers. However, Dell printers are generally the same as Lexmark (actually made for Dell by Lexmark). You may be able to find a Lexmark driver that will work. But to be honest, it may be easier to just buy a new printer that is Mac compatible.
Generally, HP, Canon, Epson, and Brother printers all come with Mac drivers. Check the box or spec sheet to make sure before you buy.